CSZ Programme-FINAL

May 10-21, 2021

PROGRAMME

VIRTUAL ORGANIZING COMMITTEE

Graham Scott (Co-Chair) Grant McClelland (Co-Chair)

Gary Anderson Oana Birceanu John Brubacher Dillon Chung Paul Craig Kyle Elliot Paul Faure Catie Ivy Barb Katzenback Sally Leys Gigi Lau Keegan Lutek Katie Marshall Matt Pamenter Matt Regan Cayleih Robertson Mike Sackville Jonathan Stone Andy Turko Mike Wilkie Joanna Wilson

2 ACKNOWLEDGEMENTS

The virtual organizing committee would like to thank the sponsors below for their generous financial contributions and for supporting our conference in what has been a year like no other. We would also like to thank Mark Belan (www.artscistudios.com) and Amy Zhu for creating the wonderful conference and conference website images, and Nicolas Pichaud for assistance with French translations.

3 TABLE OF CONTENTS

Welcome from the Virtual Organizing Committee 5

Welcome from the CSZ President and Past President 7

General Information 8

Conference Code of Conduct 12

Live Program 13

Monday May 17 14

Tuesday May 18 18

Wednesday May 19 21

Thursday May 20 30

Friday May 21 36

Education Workshop (pre-recorded) 39

NSERC Workshops (pre-recorded and live discussions) 40

List of Attendees 41

Abstracts 47

Symposium Presentations 47

Contributed Talks 53

Contributed Posters 133

4 WELCOME FROM THE VIRTUAL ORGANIZING COMMITTEE

We would like to welcome you to the 60th Annual (and first virtual) Meeting of the Canadian Society of Zoologists! It has been a year like no other. Up until last September, we were filled with naive optimism that the end of the COVID-19 pandemic was near, and we were still hopeful that we could host an in-person meeting at McMaster University. It soon became clear that large in-person events would be impossible in May 2021, and we have since been busily preparing what we think will be an excellent programme full of great research in zoology. We are extremely excited about this year’s virtual meeting, and we hope it is just as informative, interactive, and inspiring as any other CSZ meeting. Thank you for joining us!

Along with the challenges of the COVID-19 pandemic, the past year has brought into sharp focus the challenges to equity, diversity, and inclusion (EDI) that many scientists and aspiring scientists still face. As a society, the CSZ strives to be a diverse and inclusive community that welcomes everyone, and has made a commitment to equity, diversity, and inclusion and to removing barriers to participation for all Canadian zoologists. In keeping with this commitment, this year’s meeting will feature two excellent EDI events. The EDI Workshop will provide an opportunity for panel presentations and discussions about “Combating racism in the lab and field: building an inclusive community with BIPOC colleagues”. The ZET Lecture will be presented by Dr. Andrea Reid, a citizen of the Nisga’a Nation and an Assistant Professor at the University of British Columbia, who will speak about Indigenous knowledge and science in a presentation entitled “Learning from the land as a pathway to pluralism”. These promise to be fantastic events that will be highlights of the programme.

This year’s meeting will also feature the excellent programming you have come to expect of a CSZ annual meeting. The live program will include society award lectures from both 2020 and 2021 awardees, student and postdoc award competitions, five symposia, section meetings, and networking events, and will conclude with the annual general meeting and awards ceremony. Contributed oral and poster presentations will be pre-recorded and viewable on-demand, starting the week before the live program begins. Presenters of contributed talks will also have opportunities for live interactions and Q&A in live discussion sessions. We took this approach to maximize flexibility, helping accommodate busy schedules and the demands of having attendees spread across Canada’s six time zones.

Although a virtual meeting makes it difficult to experience the usual social interactions of a normal in-person conference, we have attempted to replicate some of the social interactions that might occur during networking events, coffee breaks, and evening socials. The popular Trainee Networking Mixer will provide trainees with an opportunity to chat informally with faculty members and to discuss strategies for professional development. Coffee breaks and evening ‘Quarantinis’ will provide opportunities for casual interactions over a drink in a laid-back setting, using a fantastic online socialising platform (Wonder; https://www.wonder.me/r?id=29b70fea-0dcb-4056-a143- 06f093fc21e8). We encourage all attendees to make the most of these opportunities!

Organizing this year’s virtual meeting has been an immense team effort, and many members of the virtual organizing committee (VOC) put in a huge amount of work. Local organizing committees can usually rely heavily on resources and advice from past organizers to help guide their way, but this year was different. Few on the VOC had ever attended a virtual conference, let alone organized one. Virtual event management is a relatively new and growing industry, and platform providers are still learning about the various needs of academic conferences. It has been a fun and educational process to figure things out, but the uncertainty of hosting CSZ’s first ever virtual meeting will inevitably lead to a few bumps in the road. For that, we hope you will forgive us J

We hope you enjoy this year’s CSZ conference, and we look forward to seeing you all in person in 2022.

Graham R. Scott and Grant B. McClelland Co-Chairs, Virtual Organizing Committee of CSZ 2021

6 WELCOME FROM THE CSZ PRESIDENT AND PAST PRESIDENT

It has been a difficult year in many ways, and we were unable to hold the 2020 CSZ meeting in Saskatoon (stay tuned for that one in 2023!). In 2020 there was neither a meeting programme nor a welcome address from last year’s President. Thus, this year’s welcome comes from both the Past President, Grant McClelland and the current President, Sally Leys.

We both welcome you to this, our first ever virtual meeting of the Canadian Society of Zoologists. This has been a remarkable year leading up to this remarkable event that includes all the usual aspects of our in-person meeting, through a combination of many exciting live and on-demand components. A particular highlight for us is that both the 2020 and 2021 winners of major society awards will be honoured. This event would not have been possible without the immense efforts of co-Chairs Graham Scott & Grant McClelland and the Virtual Organizing Committee (VOC) team. Thank you to Graham and all the members of the VOC who have worked hard for months to make this conference happen.

It is an unusual honour for Sally Leys to be the first CSZ President to oversee the Society during a completely ‘Online’ year – almost a virtual president – but after you see what the society has accomplished this year in research while in lockdown (through the many excellent presentations), and in engagement in society business, you will see that the society’s activities have been very real this year.

A short list of things accomplished, some of which will come to you for discussion at the Annual General Meeting on Friday May 21 include:

• The CSZ has established a vigorous committee engaged in ensuring we function with equity, we are diverse, and inclusive, and to this end they have been formulating a code of conduct for our society. • The CSZ has an active Communications Committee, which is keeping CSZ in the forefront on a range of social media platforms. • Council has begun a process of seeking feedback from members on a Science Communication Policy, which we hope to bring to you for discussion at the Annual General Meeting. • Our Society has joined with other sister Canadian Societies in giving feedback on the Federal Budget aimed towards science.

We look forward to seeing you at the meeting, and celebrating with you at the awards ceremony after the Annual General Meeting.

Enjoy CSZ-SCZ 2021!

Sally Leys Grant McClelland President 2020-2021 President 2019-2020 Current Past-President

7 GENERAL INFORMATION

The virtual conference will take place at https://csz-scz2021.showcare.io/, hosted by the virtual event platform Showcare. The conference begins for all attendees on May 10, when pre-recorded talks and posters from contributed abstracts will be available for viewing on demand, and attendees can start using the networking functionality of the website. The live program will take place from May 17-21, and will include society award lectures, student and postdoc award competitions, five symposia, section meetings, several networking events, and the Annual General Meeting and awards ceremony. Discussion Sessions in the live program (Wednesday May 19 and Thursday May 20) will provide presenters of contributed oral presentations a chance for live interactions and for fielding questions from other attendees. The event platform uses Zoom, setup as webinars (for lectures and symposia) or meetings (for workshops, discussions, and mixers), and should hopefully operate in a manner that is familiar to many attendees.

For the best experience and to avoid connection issues, it is best to use a hardwired or a strong reliable internet connection to view the live and pre-recorded content. Please note that the virtual conference platform only supports Chrome, Firefox, or Safari. It is also recommended that you install the Zoom app; the conference platform can be viewed within a web browser but there may be some limited functionality during some sessions.

In the sections below, we have included some general information for all attendees, for invited speakers and other live presenters, and for presenters of pre-recorded talks and posters from contributed abstracts.

Attendees

Once you receive your welcome email, the first step is to login and setup your profile. A complete profile is essential to begin interacting with other participants and is how you present yourself at the conference. Complete your profile in the event platform fully, including a profile picture. The image below shows a profile page in a generic Showcare website.

Next, check out the ‘Sessions’ area where events in the live program and some additional on-demand content are located. From here, you can map out your schedule in advance, you can enter sessions as they begin by clicking the session tiles, and you can navigate between concurrent live sessions. Check out the ‘Contributed Presentations’ area where pre-recorded talks and posters from contributed abstracts will be available for viewing on demand. Each presentation has its own page in this area, where the Theme Group in which each presenter has been assigned in the live Discussion Sessions is also shown. It is ideal to view the pre-recorded presentations ahead of time, before the live Discussion Sessions on Wednesday May 19 and Thursday May 20. The titles and abstracts for all presentations along with the titles and composition of each Theme Group are included in this programme to help you plan which presentations to view and which live discussion sessions to attend.

Check out other areas of the virtual event platform to see the various features for Networking, for viewing content from Exhibitors, and for viewing conference news. In the ‘Networking’ area, you can build profile connections and initiate conversations with your peers. You can also begin discussions that are visible to all conference attendees, or you can initiate or join roundtable discussions with small groups of up to 6 attendees. In the Exhibit Hall, you can engage with exhibitors through chat and direct messaging. In the Community Q&A section, you can post general questions.

In case you miss something, live sessions will be recorded and made available on the conference website until June 13. All pre-recorded talks and posters will also remain on the conference website until June 13.

Invited Speakers and Other Live Presenters

The conference event platform uses Zoom, setup as webinars (in the case of lectures and symposia) or meetings (in the case of workshops, discussions, and mixers). Invited speakers and other live presenters will receive a special Zoom link by email from Showcare to access the session in which they will present. Please use this link to connect to the “green room” for your session, 20 minutes prior to the scheduled start of your session (i.e., 20 minutes before the start of the symposium, not your individual talk if you are in a session with multiple presenters). This advance period in the green room is essential for checking connections and audio, so please do not arrive late. When presenting, share only the screen that contains your presentation. Turn off all notifications such as email, texts, etc. on your desktop to avoid pop-up interruptions.

This email containing the special Zoom link should be received several days before your presentation, so please contact the conference organizers if it is not received by the day before your presentation (Graham Scott [email protected] or Grant McClelland [email protected]). Also, have a backup way of reaching the session chairs or conference organizers in the event of a technical failure.

Presenters of Pre-Recorded Talks and Posters from Contributed Abstracts

Once you have logged in and completed your profile, access your presentation page by clicking on Groups from your profile page…

… and then click your presentation title

Next, select the Documents tab on that page to upload your materials.

The Documents list (shown below) provides areas to upload each type of material – abstract PDF, poster PDF, and presentation video. If you are presenting a poster, upload your poster PDF, and if desired, upload a short (optional) 2-3 minute poster presentation video as an MP4 file. If you are presenting a pre-recorded oral presentation, upload your 10 minute presentation video as an MP4 file. In both cases, please also upload a PDF file of your abstract.

Please note that all conference attendees will have access to the platform to start viewing presentations on Monday May 10, when judging of section awards will also begin, so please upload your poster or oral presentation by this date.

All presenters of pre-recorded oral presentations are expected to take part in live Discussion Sessions on Wednesday May 19 and Thursday May 20. The ‘theme group’ to which each presenter has been assigned can be found in the Live Programme below, along with the date and time of the session, and is also shown on each respective presentation page on the virtual platform. Join the live discussion for your theme group 5-10 minutes in advance to check connections and audio. It is recommended that you watch all of the presentations by others in your theme group, to think of questions and help stimulate lively discussion.

11 CONFERENCE CODE OF CONDUCT

It is expected that all conference attendees will communicate openly with respect and consideration for others, valuing a diversity of views and opinions. By attending this CSZ conference, all attendees must agree voluntarily to abide by the following code of conduct.

All authors associated with a presentation must agree on all information contained in the presentation. Attendees are expected to not fabricate, falsify, or suppress results, deliberately misrepresent research findings, or otherwise commit scientific fraud.

Presenters and attendees cannot screenshot, capture, or otherwise share images or presentation data without a presenter’s expressed written permission. Presentations should be considered privileged and should not be shared outside the virtual platform.

CSZ is dedicated to providing a safe, hospitable, and productive environment for everyone attending the annual conference, regardless of age, gender identity or expression, race, ethnicity, colour, cultural background, religion, place of origin, pregnancy or parental role, sexual orientation, ability, or socio-economic situation. It is important to remember that a community where people feel uncomfortable or threatened is neither healthy nor productive. Intimidating, threatening, or harassing conduct during the conference is prohibited. Conference attendees in violation of these rules may be sanctioned or expelled from the conference, at the discretion of CSZ leadership and/or conference organizers.

Harassment of conference participants will not be tolerated in any form. Harassment includes offensive gestures or verbal comments related to ethnicity, religion, disability, physical appearance, gender, or sexual orientation; deliberate intimidation; sustained disruption of talks or other events; unwelcome attention; and spamming online discussion boards, chats, question section, or social media by saying or reposting the same word/content repeatedly in order to disrupt the conversation. Participants asked to stop any harassing behavior are expected to comply immediately.

If a participant engages in harassing behavior, CSZ leadership and/or conference organizers may take appropriate action, which could range from a simple warning to expulsion from this and future conferences. If you are being harassed, notice that someone else is being harassed, or have any other concerns, please contact a member of the CSZ Executive (https://csz-scz.ca/wp/about-the-society/team/) or the conference organizers (Graham Scott [email protected] or Grant McClelland [email protected]), who will work to resolve the situation. Confidentiality will be maintained to the extent that it does not compromise the rights of others.

CSZ leadership or conference organizers may revoke meeting credentials to anyone engaged in online harassment and may seek the assistance of law enforcement if necessary. We value your attendance and want to make your experience as productive and professionally stimulating as possible.

12 LIVE PROGRAM

Live Program at a Glance (May 17-21; times in EDT)

EDT Monday Tuesday Wednesday Thursday Friday 1130 Cameron Lecture Boutilier Lecture 1145 Welcome remarks (2020 Awardee) (2020 Awardee) 1200 Fry Lecture Fry Lecture ZET Symposium 1215 (2020 Fry Medallist) (2021 Fry Medallist) Cameron Lecture Boutilier Lecture 1230 (2021 Awardee) (2021 Awardee) 100 Break Break Break Break Break 130 Hoar Award Symposium Presidents’ Award CMD IEE EDI Workshop CPB PIE 200 Symposium Symposium Symposium Symposium Symposium 230 300 Break Break Live Discussion Sessions Live Discussion Sessions Break 330 VOC Symposium CPB PIE Section (Q&A with contributed oral (Q&A with contributed oral Annual General Meeting 400 Section Meeting presenters and section presenters and section and Awards Ceremony Meeting award competitors) award competitors) 430 CMD IEE Section 500 Section Meeting Meeting 530 Break Break Break Break 545 Quarantini social Trainee Networking Mixer Quarantini social 600 Student/PDF NSERC 630 Session

13 Monday May 17

11:45-12:00 Welcome Remarks 12:00-1:00 Fry Lecture 1:00-1:30 Coffee Break 1:30-3:00 Hoar Award Symposium 3:00-3:30 Coffee Break 3:30-5:30 VOC Symposium 5:30-6:00 Coffee Break 6:00-7:00 Student/PDF NSERC Session

11:45-1:00

Fry Lecture - 2020 F.E.J. Fry Medallist The F.E.J. Fry Medal is given to a Canadian Zoologist who has made an outstanding contribution to knowledge and understanding of an area in zoology, and who is expected to deliver a plenary lecture at the next annual conference. Both the 2020 and 2021 Fry Medallists will be presenting at this year’s conference, and this lecture will be given by the 2020 Medallist.

Welcome Remarks: Graham Scott, Co-Chair (McMaster University) Grant McClelland, Co-Chair (McMaster University)

Introduction: Grant McClelland, CSZ Past-President (McMaster University)

Anthony P. Russell Department of Biological Sciences, University of Calgary

The sticky fingers of geckos: from esoteric backwater to mainstream interdisciplinary science

The remarkable locomotor abilities of geckos have intrigued scientists and the lay public for centuries. Attempts to understand their adhesive capabilities have been the subject of scientific publications for over 200 years. Earlier studies were mostly based upon external components of the adhesive apparatus and chiefly focused on single species, especially those commensal with humans and their habitations. My research was initially devoted to investigating the integrative hierarchical structure of the gekkotan adhesive apparatus as a unified system, using a broadly comparative, stepwise approach. The resultant synthesis became markedly more influential following an observational breakthrough in 2000. At the turn of the millennium gecko adhesion metamorphosed from fascinating, curiosity-driven science to being the impetus for a broad array of biomimetic and application-driven investigations reliant upon interdisciplinary study. Major advances were made rapidly, but it was soon realized that a lack of understanding of how geckos operate in their natural environment was hindering further advances. This provided the impetus for the second phase of my research adventure, wherein I undertook field studies dedicated to better understand both the circumstances in which the system is used in nature and how, and under what

14 ecological circumstances, it may have originated. My research journey has shown me that a deep understanding grounded in comparative biology and natural history are of fundamental importance not only for how we can understand evolution and ecology but also how we can provide foundational information necessary for the successful development of bioinspired applications.

Les doigts collants des geckos: du marigot ésotérique à la science interdisciplinaire dominante

La capacité locomotrice remarquable des geckos a toujours fasciné les chercheurs et le public depuis des siècles. Les recherches visant notamment à comprendre leurs capacités d’adhérences font partie des sujets de publications scientifiques des 200 dernières années. Les premières études sur ce sujet étaient principalement basées sur des composantes externes de l'appareil adhésif et se concentraient sur des espèces uniques, en particulier sur les espèces commensales de l’Homme et de leurs habitations. Mes recherches se sont initialement concentrées sur l'étude de la structure hiérarchique intégrative de l'appareil d’adhérence des geckos en tant que système unifié, en utilisant une approche par étapes largement comparative. Au tournant du millénaire, à la suite d’une percée scientifique la compréhension du système d'adhérence du gecko s'est métamorphosée, passant d'un sujet fascinant et axé sur la curiosité scientifique à être l’apanage d'un large éventail de recherches biomimétiques et axées sur des applications reposant sur des études interdisciplinaires. Des progrès majeurs ont été réalisés rapidement, mais le manque de connaissances sur l’étude du mode de vie des geckos dans leur environnement naturel entravait les progrès futurs. Cela a donné l'élan à la deuxième phase de mon aventure de recherche, dans laquelle j’effectuais des études de terrain visant à mieux comprendre les circonstances dans lesquelles le système est utilisé dans la nature et comment et dans quelles circonstances écologiques ce système a trouvé son origine. Mon parcours de recherche m'a montré qu'une compréhension approfondie de la biologie comparative et de l'histoire naturelle est d'une importance fondamentale non seulement pour comprendre l'évolution et l'écologie, mais aussi pour apporter des informations fondamentales nécessaires au développement réussi d'applications bio-inspirées.

1:30-3:00

Hoar Award Symposium The William S. Hoar Award is given for the best student talk at the Annual Conference of the Society. The award finalists in this symposium were selected by a committee of judges based on a written summary of their oral presentation.

Chair: Gary Anderson, CSZ 1st Vice-President (University of Manitoba)

1:30-1:42 Naomi Pleizier (University of British Columbia) Too much of a good thing; factors affecting the relationship between total dissolved gas supersaturation and gas bubble trauma in fish

1:42-1:54 Kristen Lalla (McGill University)

15 Purple martins as central-place foragers: foraging range and habitat selection of chick-rearing and non-breeding individuals

1:54-2:06 Susan Procopio (University of Guelph) Change of season, change of heart: adaptive divergence of seasonal heart plasticity in Pumkinseed sunfish (Lepomis gibbosus)

2:06-2:18 Keegan Lutek (Ottawa University) Neuromuscular plasticity and terrestrial locomotion in an amphibious fish

2:18-2:30 Jess Kennedy (University of British Columbia) Drivers of plasticity in freeze tolerance in the intertidal mussel, Mytilus trossulus

2:30-2:42 Carlie Muir (Western University) Kickstart my heart: elevated rearing temperature alters heart morphology and thermal performance in juvenile Atlantic salmon

2:42-2:54 Megan Ridgway (University of Guelph) Novel spikey ionocytes in an amphibious fish are regulated by cortisol

3:30-5:30

Virtual Organizing Committee (VOC) Symposium

Integrating Organismal Function and Behaviour to Understand How Animals Cope in a Changing World

Chair: Andy Turko (McMaster University)

3:30-4:00 Martha M. Muñoz (Yale University) Behavior is a motor and brake for evolution

4:00-4:30 Shaun S. Killen (University of Glasgow) Who leads and who follows? The interplay between metabolic phenotype and social behaviour in fish

4:30-5:00 Jeremy A. Goldbogen (Hopkins Marine Station, Stanford University) Integrative organismal biology at the largest scale

5:00-5:30 Giulia S. Rossi (University of Guelph) Animals seek hypoxic microhabitats that accentuate metabolic depression during dormancy

6:00-7:00

Student/PDF NSERC Discussion Session This discussion session will provide students and postdocs an opportunity to ask questions about NSERC scholarship and postdoctoral fellowship programs. Attendees are strongly encouraged to view the pre-recorded presentation associated with this discussion session, which can be found in the on-demand session NSERC PGS and

16 PDF Presentation, before attending this event. NSERC has also made available on YouTube a number of additional videos about various aspects of each scholarship and fellowship competition. A link to these YouTube videos is provided below, and should also be considered before attending this live event.

Chair: Alyssa Weinrauch, CSZ Postdoc Councillor (University of Manitoba)

Panelist: Jennifer Houghton, Program Officer in Scholarships and Fellowships, NSERC

The YouTube playlist of tutorial videos for scholarships and fellowships program applications can be found at the following link: https://www.youtube.com/watch?v=9OwteeJIWdg&list=PL6ox0GB7vXYlhaAY7mE qwmMqYK9TGCp1E

17 Tuesday May 18

12:00-1:00 Fry Lecture 1:00-1:30 Coffee Break 1:30-3:00 Presidents’ Award Symposium 3:00-3:30 Coffee Break 3:30-4:20 Comparative Physiology and Biochemistry (CPB) Section Meeting Parasitism, Immunity & Environment (PIE) Section Meeting 4:30-5:20 Comparative Morphology, Development, and Biomechanics (CMDB) Section Meeting Integrative Ecology and Evolution (IEE) Section Meeting 5:30-7:00 Quarantini Social

12:00-1:00

Fry Lecture - 2021 F.E.J. Fry Medallist The F.E.J. Fry Medal is given to a Canadian Zoologist who has made an outstanding contribution to knowledge and understanding of an area in zoology, and who is expected to deliver a plenary lecture at the next annual conference. Both the 2020 and 2021 Fry Medallists will be presenting at this year’s conference, and this lecture will be given by the 2021 Medallist.

Introduction: Sally Leys, CSZ President (University of Alberta)

Helga Guderley Département de Biologie, Université Laval

Muscle metabolic plasticity: environment and evolution

Muscle holds an image of an animal’s recent and evolutionary past; its capacities are influenced, not only by evolutionary strategies of locomotion, but also by environmental conditions and physiological requirements. As a student, I vaguely understood these relationships, but they came into much sharper focus during my research career. My research in Peter Hochachka’s lab examined gluconeogenic adaptations during the crustacean molt cycle. At Laval, my focus landed on muscle and its responses to the biotic and abiotic environment. While my lab worked with animals as diverse as crabs, alligators, alcids, stickleback and mice, today I will talk about our research on cod, trout and scallops. I started to work with cod because I thought muscle enzyme levels could indicate the status of wild cod. Effectively, nutritional stress markedly affects muscle metabolic capacities and swimming performance as red and white muscle both contribute to sustained and burst swimming. Trout were our workhorse for mitochondrial studies. Cold acclimation leads trout mitochondria to increase oxidative capacities while changing their phospholipid composition. Feeding trout diets differing in lipid composition markedly changes mitochondrial phospholipid composition, but leaves mitochondrial oxidative capacities unchanged. Clearly, membrane phospholipid composition is under homeostatic regulation. Venezuela took me from fish to scallops. We showed that scallop muscle mitochondria change with reproductive investment as

18 does escape response physiology. Next we found marked interspecific differences in adductor muscle use, structure and metabolic capacities. The interspecific trends are paralleled by differences in shell characteristics. Thus, cod, trout and scallops provide clear evidence of the malleability of muscle properties in response to environmental and evolutionary pressures. All this would not have been possible without the brilliance, energy and enthusiasm of my wonderful students, post-docs and technicians!

La plasticité métabolique musculaire: l’environnement et l’évolution

Le muscle d’un animal montre à la fois ses passés récent et évolutif; les capacités musculaires sont influencées par les stratégies de locomotion et par les conditions environnementales et les besoins physiologiques. Comme étudiante, j’avais une idée générale de ces relations mais elles sont devenues plus claires durant ma carrière de recherche. Durant mon doctorat chez Hochachka, j’ai étudié les adaptations gluconéogeniques du cycle de mue des crustacés. A Laval, j’ai mis mon regard sur le muscle et ses réponses à l’environnement biotique et abiotique. Mon groupe a travaillé avec les crabes, alligators, alcidés, épinoches et souris, mais aujourd’hui je vais me limiter aux morues, truites et pétoncles. J’ai commencé à étudier les morues car je croyais que les activités enzymatiques musculaires pourraient indiquer l’état des morues sauvages. En effet, le stress alimentaire influence de façon marquée les capacités métaboliques musculaires et la performance de nage car les muscles blanc et rouge participent durant la nage soutenue et la nage à vitesse de pointe. Les truites étaient notre cheval de bataille pour les études mitochondriales. L’acclimatation au froid stimule les mitochondries à augmenter leur capacité oxydative et à modifier leur composition phospholipidique. En revanche, l’alimentation des truites avec des compositions lipidiques distinctes change la composition phospholipidique des mitochondries, mais ne change pas leurs capacités oxydatives. Nous avons ainsi démontré la régulation homéostatique de la composition phospholipidique mitochondriale. Venezuela m’a amené aux pétoncles. Nous avons trouvé que les pétoncles changent leurs propriétés mitochondriales et leurs réponses de fuite avec l’investissement reproducteur. Ensuite nous avons montré des différences interspécifiques prononcées dans l’emploi, la structure et les capacités métaboliques du muscle adducteur. Ces différences interspécifiques suivent l’écologie et les caractéristiques des coquilles. Ainsi, les morues, les truites et les pétoncles montrent clairement que les propriétés musculaires sont malléables en réponse aux pressions environnementale et évolutives. Je dois remercier mes étudiants, post-docs et techniciens sans qui le tout n’aurait jamais pris forme!

1:30-3:00

Presidents’ Award Symposium The Presidents’ Award is given for the best talk by a postdoctoral fellow at the Annual Conference of the Society. The award finalists in this symposium were selected by a committee of judges based on a written summary of their oral presentation.

Chair: Gary Anderson, CSZ 1st Vice-President (University of Manitoba)

19 1:30-1:45 Lauren A. Todd (University of Waterloo) Are microRNAs involved in amphibian innate antiviral responses?

1:45-2:00 Dillon J. Chung (National Heart, Lung and Blood Institute, NIH) Mitochondrial network formation as a tissue-specific phenomenon in a mammalian model of extreme metabolism

2:00-2:15 Erin Faught (Leiden University, Netherlands) A stress symphony: the coordinated efforts of corticotropin-releasing hormone and cortisol in mediating stress behaviour

2:15-2:30 Gail Schwieterman (University of California, Santa Barbara) A change of heart: Jensen’s inequality in a eurythermal marine teleost

2:30-2:45 Andy J. Turko (McMaster University) Thermal preference and aerobic performance of the endangered redside dace

2:45-3:00 Brittney G. Borowiec (Wilfrid Laurier University) Effects of the lampricides TFM, niclosamide, and their mixture on mitochondria function in adult sea lamprey (Petromyzon marinus) at three environmentally-relevant temperatures

20 Wednesday May 19

11:30-1:00 Cameron Lecture Symposium 1:00-1:30 Coffee Break 1:30-3:00 Comparative Morphology, Development, and Biomechanics (CMDB) Symposium Integrative Ecology and Evolution (IEE) Symposium 3:10-5:30 Live Discussion Sessions with Presenters of Contributed Talks 5:30-5:45 Break 5:45-7:00 Trainee Networking Mixer

11:30-1:00

Cameron Lecture Symposium The T.W.M. Cameron Award recognizes the author of an outstanding Ph.D. thesis in zoology at a Canadian University. Both the 2020 and 2021 Cameron Award winners will be presenting at this year’s conference in this symposium.

Chair: Sally Leys, CSZ President (University of Alberta) Grant McClelland, CSZ Past President (McMaster University)

Till Harter Department of Zoology, The University of British Columbia, Vancouver, Canada Scripps Institution of Oceanography, University of California San Diego

The functional significance of plasma-accessible carbonic anhydrase for cardiovascular oxygen transport in teleosts

August Krogh showed that the transfer of oxygen (O2) from the environment into the blood and from the blood to the tissues is driven by passive diffusion alone. Teleost (bony) fish are no exception in this regard, however, my PhD work generated evidence for an active mechanism at the level of the red blood cell (RBC) that enhances the diffusion of O2 at their tissues. The RBCs of most teleosts can actively regulate their intracellular pH (pHi) with adrenergically-stimulated sodium-proton-exchangers (β-NHE). These transporters create a H+ gradient across the RBC membrane that is “short- circuited” by plasma-accessible carbonic anhydrase (paCA) at the tissue capillaries, which acidifies the RBC and promotes the unloading of O2 from pH-sensitive haemoglobins. My dissertation tested the hypothesis that teleosts use β-NHE short- circuiting to enhance cardiovascular O2 transport in vivo. Results indicate that, in rainbow trout, the kinetics of β-NHE short-circuiting were fast enough to increase O2 unloading within the tissue capillaries and that β-NHE activity in the venous system was fast enough to recover RBC pHi to promote renewed O2 loading at the gills; consistent with a mechanism that can enhance O2 unloading with every pass of the RBCs through the circulation. In Atlantic salmon swimming at a slow speed or at rest, the inhibition of paCA required a compensatory increase in cardiac output by ~30%, corroborating a role of paCA in enhancing O2 transport over a broad range of in vivo conditions. And, in coho salmon, paCA was present in the heart lumen, indicating that also cardiac O2

21 supply may rely on β-NHE short-circuiting. Thus, by actively controlling their pHi, teleost RBCs may enhance the passive diffusion of O2 that Krogh discovered a century ago, with important implications for the physiology, the conservation and the evolutionary history, of nearly half of all vertebrates.

L'importance fonctionnelle de l'anhydrase carbonique accessible au plasma pour le transport cardiovasculaire de l'oxygène chez les téléostéens

August Krogh a montré que le transfert de l'oxygène (O2) de l'environnement vers le sang et du sang vers les tissus s’effectue uniquement par diffusion passive. Bien que les poissons téléostéens (osseux) ne sont pas des exceptions à cet égard, mon travail de doctorat a mis en évidence un mécanisme actif au niveau des globules rouges (RBC) qui améliore la diffusion de l'O2 dans leurs tissus. Les globules rouges de la plupart des téléostéens peuvent réguler activement leur pH intracellulaire (pHi) avec des échangeurs sodium/proton (β-NHE) stimulés par voie adrénergique. Ces transporteurs créent un gradient de H+ à travers la membrane des globules rouges, qui est «court-circuité» par l'anhydrase carbonique accessible au plasma (paCA) au niveau des capillaires tissulaires, ce qui acidifie les globules rouges et favorise le déchargement d'O2 des hémoglobines sensibles au pH. Ma thèse a testé l'hypothèse que les téléostéens utilisent le court-circuitage du β-NHE in vivo pour améliorer le transport cardiovasculaire de l'O2. Les résultats indiquent que, chez la truite arc-en-ciel, la cinétique de ce court-circuit du β-NHE est suffisamment rapide pour augmenter le déchargement d'O2 dans les capillaires tissulaires et que l'activité du β-NHE dans le système veineux est suffisamment rapide pour rétablir le pHi des globules rouges afin de favoriser une nouvelle charge d'O2 aux branchies; concordant avec un mécanisme pouvant améliorer le déchargement d'O2 à chaque passage des globules rouges en circulation. Chez le saumon de l'Atlantique nageant à vitesse lente ou au repos, l'inhibition de la paCA a nécessité une augmentation compensatoire du débit cardiaque d'environ 30%, corroborant le rôle de la paCA dans l'amélioration du transport d'O2 sur une large gamme de conditions in vivo. Enfin, chez le saumon coho, la paCA était présente dans la cavité cardiaque, indiquant que l'apport cardiaque en O2 peut également reposer sur un court-circuit des β-NHE par la paCA. Ainsi, en contrôlant activement leur pHi, les globules rouges des téléostéens peuvent améliorer la diffusion passive d'O2 que Krogh a découverte au denier siècle, avec des implications importantes pour la physiologie, la conservation et l'histoire évolutive de près de la moitié de tous les vertébrés.

Cayleih Robertson Department of Biology, McMaster University

A tale of mice and mountains: developmental thermoregulatory adaptations in high-altitude North American deer mice

Altricial mammals develop the ability to independently thermoregulate during the first few weeks of postnatal development. This shift from poikilothermy to endothermy is driven by the maturation of the two primary thermo-effector organs, brown adipose tissue (BAT) and skeletal muscle which are both non-functional at birth. In wild rodent populations this is also a time of high mortality (50-95%), making the physiological

22 systems that develop during this period potential targets for natural selection. High altitude is a particularly challenging environments for small endotherms due to unremitting low O2 availability and consistently low ambient temperatures. As a result, some high-altitude taxa have evolved a superior adult thermogenic capacity. However, it is unclear if selection has occurred to survive these unique challenges early in development. The goal of my dissertation was to address this gap in knowledge and assess developmental thermoregulatory adaptations in an altricial high altitude endotherm. I used 3 populations of Peromyscus mice; deer mice (P. maniculatus) native to high and low elevations, and the strictly low altitude white-footed mouse (P. leucopus), all raised under common garden conditions to assess how high-altitude adaptation has altered the onset of endothermy, developmental plasticity of thermogenic capacity and maternal care. I showed that selection has fundamentally delayed the maturation of the BAT and skeletal muscle in high altitude natives and has altered their capacity for developmental and adult plasticity. Additionally, high altitude mothers spend less time nursing and incubating their offspring compared to lowlanders. High altitude pups can maintain growth rates and body composition under cold hypoxic conditions despite receiving less maternal care than their low altitude counterparts. These data suggest that high altitude adapted mice have evolved to suppress energetically costly thermogenesis during development. Additionally, maternal-offspring co-adaptation was likely an important factor in the successful colonization of alpine ecosystems.

Une histoire de souris et de montagnes: adaptations thermorégulatrices du développement chez les souris sylvestres d'Amérique du Nord en haute altitude

Les mammifères altriculaires développent la capacité de thermoréguler indépendamment au cours des premières semaines du développement postnatal. Ce passage de la poïkilothermie à l'endothermie est dû à la maturation des deux principaux organes thermo-effecteurs, le tissu adipeux brun (BAT) et le muscle squelettique, tous les deux étant non fonctionnels à la naissance. Dans les populations de rongeurs sauvages, c'est aussi une période de mortalité élevée (50-95%), faisant des systèmes physiologiques qui se développent pendant cette période des cibles potentielles pour la sélection naturelle. La haute altitude est un environnement particulièrement difficile pour les petits endothermes en raison de la faible disponibilité constante d'oxygène et des températures ambiantes constamment plus basses. En conséquence, certains taxons de haute altitude ont développé une capacité thermogénique adulte supérieure. Cependant, on ne sait pas si la sélection agit au début du développement afin de promouvoir la survie à ces défis uniques. L'objectif principal de ma thèse de doctorat était de combler cette lacune dans notre compréhension et d'évaluer les adaptations thermorégulatrices développementales dans un endotherme altriculaire de haute altitude. J'ai utilisé 3 populations de souris du genre Peromyscus; deux populations de souris cerfs (P. maniculatus) originaires de hautes et basses altitudes, et une population de souris à pattes blanches strictement de basse altitude (P. leucopus), toutes élevées dans des conditions expérimentales communes pour évaluer comment l'adaptation à haute altitude a modifié l’apparition de l'endothermie, la plasticité développementale de la capacité thermogénique ainsi que les soins maternels. J'ai démontré que la sélection naturelle a fondamentalement retardé la maturation du BAT et du muscle squelettique

23 chez les natifs de haute altitude et a altéré leur capacité de plasticité développementale et adulte. De plus, les mères de haute altitude passent moins de temps à allaiter et à couver leur progéniture que les mères des plaines. Les rejetons de haute altitude peuvent maintenir leur taux de croissance et leur composition corporelle dans des conditions froides et hypoxiques, même s'ils reçoivent moins de soins maternels que leurs homologues de basse altitude. Ces données suggèrent que les souris adaptées à la haute altitude ont évolué pour supprimer la thermogenèse énergétiquement coûteuse pendant le développement. De plus, la co-adaptation mère-progéniture a probablement été un facteur important dans la réussite de la colonisation des écosystèmes alpins.

1:30-3:00

Comparative Morphology, Development, and Biomechanics (CMDB) Symposium

Teachers, Muses, and Fellow Travelers: a Celebration of Animals

Chair: John Brubacher, CMDB Section Chair (Canadian Mennonite University)

1:30-2:00 Sandy M. Kawano (George Washington University) Modeling the biomechanics of fins and limbs during the evolutionary invasion of land by vertebrates

2:00-2:30 Matthew K. Vickaryous (University of Guelph) The regenerative repertoire of geckos: hearts, minds, and other tales of replacing tissues

2:30-3:00 Ehab Abouheif (McGill University) The ants: model (super)organisms for eco-evo-devo

Integrative Ecology and Evolution (IEE) Symposium

Life at the Largest Scales

Chair: Ian Hatton, IEE Section Chair (Max Planck Institute for Mathematics in the Sciences)

1:30-1:50 Gillian Chow-Fraser (Canadian Parks and Wilderness Society) The tricky business of managing landscapes and species across scales

1:50-2:10 Richard E. Feldman (Centro de Investigación Científica de Yucatán, Mexico) Species-energy relationships during bird migration

2:10-2:30 Daniel M. Perkins (University of Roehampton, UK) Across ecosystem comparisons of body-size and biomass structure

2:30-2:50 Eric D. Galbraith (McGill University) The flow of energy through the global marine size spectrum

2:50-3:00 Discussion

3:10-5:30

Live Discussion Sessions with Presenters of Contributed Talks Small groups of presenters in distinct theme groups will be available for Q&A and discussion. Attendees can enter, leave, and move between each theme group at their leisure to interact with presenters. The name for each presenter is listed for each theme group. Pre-recorded presentations by each speaker can be found in the ‘Contributed Presentations’ area of the conference website. To help stimulate lively discussions, watch pre-recorded presentations ahead of time and come ready to each theme group discussion with lots of questions.

3:10-3:30 Live Discussions – Session 1

Biomechanics and functional morphology 1: feeding and breathing Moderator: Kelsey Gil Francis Letendre Kelsey Gil Elisabeth Bergman Evgeni Matveev

Ecology Moderator: Dave Shutler Dave Shutler Jarrett Blair Jake Dytnerski Dominica Harrison Rielle Hoeg André L. Martel

Temperature 1- Performance/Swimming Moderator: Suzie Currie Emily Hardison Ryan Sprenger Ana Breit Lauren Rowsey Sean Andrew

Stress Biology Moderator: Erin Faught Carol Best Leena Thorat Kira (Xin Ci) Li Femilarani Antomagesh Eric Ignatz

H.I. Battle Award Competition Moderator: Heather Jamniczky Finalists TBD

3:40-4:00 Live Discussions – Session 2

Feeding and Digestion Moderator: Alyssa Weinrauch Alyssa Weinrauch Ellen Jung J. Lisa Hoogenbom Junho Eom Gracie Li-Ting-Wai

Genetic resources in novel model organisms Moderator: John Brubacher Arteen Torabi-Marashi Setu Chakraborty Shun Sogabe

Temperature 2 - Remodeling/Development/Plasticity Moderator: Todd Gillis Leonardi Nataprawira Jared Shaftoe Tessa Blanchard

G.F. Holeton Prize Competition Moderator: Anne Dalziel Finalists TBD

4:10-4:30 Live Discussions – Session 3

Biomechanics and functional morphology 2: Environmental Influences Moderator: Bob Shadwick Thomas Stroud Lisa Liang Evan McKenzie Shea McInnis

Molecular Biology of Environmental Stress Moderator: Heather Ikert Eric Ignatz Anne Beemelmanns Heather Ikert Ayush Namboothiri Zoe Klein Aline Ingelson-Filpula

Temperature 3 -Thermal Tolerance Moderator: Matthew Gilbert Alexandra Schoen Aaron Klymasz-Swartz

26 Yangfan Zhang Matthew Gilbert

4:40-5:00 Live Discussions – Session 4

Ion and Osmoregulation 1 Moderator: Alex Zimmer Liam Tigert Sophie Roth Shuang Liu Manny Kapur Alex Zimmer

Parasitology 1 Moderator: Laura Ferguson Emma Rempel Brooke McPhail Laura Ferguson Ashley Pidwerbesky Avril Wang Rikki Clark

Temperature 4 - Behaviour & Development Moderator: Andy Turko Connor Reeve Brittany Bard Chloé Melanson Jessica Desforges

5:10-5:30 Live Discussions – Session 5

Ion and Osmoregrulation 2 Moderator: Mike Wilkie Farwa Sajadi Chris M. Wood Michael Wilkie Derek Somo

Parasitology 2 Moderator: Olwyn Friesen Laura McMillan Olwyn Friesen Scott Malotka Samantha Stevens Jenna Priest Sarah Hirtle

Temperature 5 -Cold/Freeze Tolerance Moderator: Brent Sinclair

27 Jacqueline Lebenzon Isaiah Box Kurtis Turnbull Lauren Gill

Evolution and development Moderator: Heather Jamniczky Karin van der Burg Heather Jamniczky Arjuna Rajakumar Pablo Aragones-Suarez Emma Esposito Vance Trudeau

5:45-7:00

Trainee Networking Mixer Students and postdocs are invited to meet with faculty members to discuss strategies for professional development both within and outside of academia. The mixer will start with an introduction that discusses the organization of the mixer, after which trainees will be able to move from topic to topic as they wish and partake in friendly and casual discussion. Each mixer topic is listed below, and will each be opened as distinct group meetings after the mixer introduction has ended.

Mixer Introduction and Organization Lauren Rowsey Sulayman Lyons Alyssa Weinrauch

Mixer topic 1 – Careers outside academia Kamal Khidas (Canadian Museum of Nature) Stephanie Tessier (Canadian Museum of Nature) Brett Favaro (British Columbia Institute for Technology)

Mixer topic 2 – Science communication and social media Brittney Borowiec (Wilfrid Laurier University) Katie Marshall (University of British Columbia)

Mixer topic 3 – Publish or perish: writing efficiently while avoiding burnout Matt Regan (Université de Montréal) Vance Trudeau (University of Ottawa) Tetsuto Miyashita (Canadian Museum of Nature)

Mixer topic 4 – Partnering with government/industry Ken Jeffries (University of Manitoba) Tamzin Blewett (University of Alberta) Erika Eliason (University of California, Santa Barbara)

Mixer topic 5 – Building your job package Todd Gillis (University of Guelph)

28 Justin Lee (University of the Fraser Valley)

Mixer topic 6 – Establishing and managing collaborations Rachel Krause (Canadian Mennonite University) Kyle Elliott (McGill University)

Mixer topic 7 – Imposter syndrome and mental health Sigal Balshine (McMaster University) Anne Dalziel (Saint Mary's University) Allison McDonald (Wilfrid Laurier University)

Mixer topic 8 – Grant writing tips and tricks Suzie Currie (Acadia University) Richard Kinkead (Université Laval) Jim Staples (Western University)

Mixer topic 9 – Work life balance Jean-Paul Paluzzi (York University) Nicolas Pichaud (Université de Moncton) Lucy Lee (University of the Fraser Valley)

29 Thursday May 20

12:00-1:00 Zoological Education Trust (ZET) Symposium 1:00-1:30 Coffee Break 1:30-3:00 Equity, Diversity, and Inclusion (EDI) Workshop 3:10-5:30 Live Discussion Sessions with Presenters of Contributed Talks 5:30-7:00 Quarantini Social

12:00-1:00

Zoological Education Trust (ZET) Symposium The Zoological Education Trust is dedicated to developing interest in and public awareness of zoology. At every annual meeting, ZET organizes public lectures and/or workshops involving well-recognized zoologists to talk about new trends in Zoology. The target audience includes youth and others in the general public. This year’s ZET event will be a public lecture, which will be live streamed to several members of the general public, and will also be recorded and made available on YouTube after the annual meeting.

Introduction: Sally Leys, CSZ President (University of Alberta) Michael Wilkie, ZET Lecture Committee (Wilfrid Laurier University) Larry McDermott (Algonquin Elder from Shabot Obaadjiwan First Nation and Executive Director of the Indigenous NGO Plenty Canada)

Andrea Reid Centre for Indigenous Fisheries, Institute for the Oceans and Fisheries, UBC

Dr. Reid is a citizen of the Nisga’a Nation and is helping launch and lead the Centre for Indigenous Fisheries, working to build a national and international hub for the study and protection of culturally significant fish and fisheries. Her research program adopts highly interdisciplinary and applied approaches to improving our understanding of the complex interrelationships between fish, people and place. Dr. Reid’s PhD in Biology (Governor General’s Gold Medal; Carleton University, 2020) centered on multiple stressor effects on Pacific salmon, using tools and insights from Western and Indigenous sciences in tandem. Dr. Reid is a cofounder of Riparia, a Canadian charity that connects diverse young women with science on the water to grow the next generation of water protectors. She is also a National Geographic Explorer and a Fellow of The Explorers Club.

Learning from the land as a pathway to pluralism

What is encompassed by the term “land” and what does it mean to treat the land as a source of knowledge and understanding? How is land-based learning grounded in Indigenous knowledge and how does it support efforts to decolonize science? How can this form of learning transform relationships with the land and invite multiple ways of knowing to be valued and held valid in science? These questions–well discussed in the fields of Indigenous pedagogy and science–will be applied to the realm of conservation science, and specifically to the field of aquatic ecology. Here, we will look to both

30 ‘land’ and ‘water’ in pursuit of answers to these questions that we hope will motivate and inform the next generation of water educators and learners at all levels.

1:30-3:00

Equity, Diversity, and Inclusion (EDI) Workshop

Combating racism in the lab and field: building an inclusive community with BIPOC colleagues

Chairs: Joanna Wilson (McMaster University) Oana Birceanu (McMaster University)

Panelists: Arig Al Shaibah (Associate VP Equity and Inclusion, McMaster U.) Juliet Daniel (Acting Associate Dean, Faculty of Science, McMaster U.) Kalai Saravanamuttu (Associate Professor, McMaster U.) Rodrigo Narro Pérez (Ph.D. Candidate, McMaster U.) Heather Jamniczky (CSZ 2nd VP and EDI Committee Chair; U. Calgary) Julia Sunga (CSZ EDI Committee Member; U. Waterloo)

The goal of this workshop is to (1) address the roadblocks that BIPOC colleagues and students face in academia, with a focus on lab and field work, (2) reflect on how allies can provide better support and (3) address the role of institutions (department, faculty and university; research societies) in creating a supportive and inclusive research environment. The workshop will be divided into a presentation/discussion section and an activity section in break out rooms. The presentation/discussion section will be led by six panelists, who will discuss their views on the role of individuals and institutions in building an inclusive community and provide examples of success. Members of the CSZ EDI committee will discuss the advances made by the committee and will introduce a proposed guide for PIs to use when planning fieldwork with their trainees. Opportunities will be made for questions and discussion with the audience. In the activity section, participants will move into break out rooms to discuss the field guide as well as how they make their field work and lab environment more inclusive and safer for visible minorities. The goal is to provide opportunities to discuss new ways you can be involved in building a more inclusive community. Participants are encouraged to bring and share their own approaches with their colleagues.

Arig Al Shaibah is responsible for McMaster’s Equity and Inclusion Office. She has been overseeing the development and implementation of McMaster’s strategic equity, diversity and inclusion plan.

Juliet Daniel is a key faculty member on McMaster campus for EDI. She has been active in the Presidential Advisory Committee for Building and Inclusive Community, and a founding member of the African-Caribbean Faculty Association, formed in 2010 to network, promote and advance Black academics at McMaster. ACFAM has been critical in working with the university in promoting diversity within the faculty ranks and encouraging hiring members from diverse communities. Juliet is an amazing mentor for

31 Black students, supporting students directly and through their formation of various Black student groups. She has been critical for the development of Women in Science networking opportunities for faculty, the formation of the Academic Women’s Success and Mentorship Initiative, and the organization of a number of workshops targeting female students, post-doctoral researchers, and faculty. In her new role as Acting Associate Dean of Research for the Faculty of Sciences, Juliet is helping to contribute to faculty-wide EDI workshops such as 10 Simple Rules for Building an Antiracist Lab.

Kalai Saravanamuttu was a driving force for the Academic Women’s Success and Mentorship Initiative at McMaster and has been instrumental in implementing new EDI initiatives in the Department of Chemistry. Kalai’s work in her department has been to support graduate students and faculty discuss difficult EDI topics and institute workshops. As an example, Chemistry organized a faculty wide workshop on Allyship.

Rodrigo Narro Pérez has done significant international and Canadian fieldwork and has been a critical student voice on McMaster campus for the Latin American/Latinx and BIPOC community. He has been a key organizer for the Latin American Heritage Month activities and celebrations at McMaster and many other EDI initiatives. One example are the ongoing Let’s Talk About Race! events, which are facilitated discussions serving the needs of McMaster’s Black, Indigenous and racialized students, staff, and faculty. Rodrigo’s personal experience as a Peruvian-born latino student in a largely white research community will be an important voice for students at CSZ.

Heather Jamniczky and Julia Sunga (Ph.D. candidate) will represent the CSZ EDI Committee to discuss the goals and priorities of the committee and to introduce the new field guide that will set up the break-out room discussions.

3:10-5:30

3:10-3:30 Live Discussions – Session 6

Respiration 1 Moderator: Dillon Chung Anne Kim Simon Cormier Soren Coulson Brynne Duffy

Immunology 1 Moderator: Barb Katzenback

32 Setu Chakraborty Emma Monod Oliver Bullingham Hajarooba Gnanagobal

Toxicology 1- Eco-Physiological Responses Moderator: Oana Birceanu Rachel Parkinson Michael Lawrence Oana Birceanu Adrian Ionescu

NSERC Grants Q&A 1 Moderator: Kathleen Gilmour Katrina (Kate) Traikov (NSERC Program Officer) Marie-Claude Caron (NSERC Team Leader)

3:40-4:00 Live Discussions – Session 7

Respiration 2 Moderator: Brittney Borowiec Fouzia Haider Jennifer Steffen Catherine Ivy Michael Yusishen

Immunology 2 Moderator: Lauren Todd Jenna Nauss Sarah Au Melanie Smith

Toxicology 2 - Biotransformation-Cellular Responses Moderator: Joanna Wilson Shannon Bird Nicole Gauvreau Joanna Wilson

Ecology in the Anthropocene Moderator: Russell Wyeth Jeffrey Ethier Emily Black Hossein Mehdi Allanique Hunter Ilse Esparza

NSERC Grants Q&A 2 Moderator: Suzie Currie Katrina (Kate) Traikov (NSERC Program Officer) Marie-Claude Caron (NSERC Team Leader)

4:10-4:30 Live Discussions – Session 8

Scaling/ Hibernation Moderator: Danielle Levesque Danielle Levesque Krista Kraskura Jessica Li Julia Nomikos Hichem Menail Samantha Logan

Immunology 3 Moderator: Barb Katzenback Alexander Douglas Yemaya Choo-Yin Manuel Soto-Davila Emily Blacklock

Toxicology 3 -Effects on Development Moderator: Andrew Thompson Pankaj Puar Erik Folkerts Yueyang Zhang Theanuga Chandrapalan Andrew Thompson

Growth and Performance Moderator: Tyson MacCormack Tyson MacCormack Ian Bouyoucos Maria Martinez-Silva Brenna Wilson Jean-Baptiste Quéméneur

4:40-5:00 Live Discussions – Session 9

Evolutionary Physiology Moderator: Trish Schulte Marco Lee Caleb Northam William von Herff Matthew Morris Andrea Wishart

Neurophysiology 1 Moderator: Michael Jonz Arash Shahriari Sinan Zhang

34 Michael Jonz Michael Country Niepukolie Nipu

Toxicology 4 - Metals and Ions Moderator: Erin Leonard Ryan Shartau Carolyn Morris Nathalie Nash Beverly H. K. Po Erin Leonard Vlad Kodhahinchev

Postembryonic development, growth and scaling Moderator: Tamara Franz-Odendaal Cassandra Donatelli Karen Kadamani Drayke Evans Zachary Millar

5:10-5:30 Live Discussions – Session 10

Hypoxia Moderator: Matt Regan Natascha Ouillon Sarah McGeachy Mohammad Ojaghi Loïck Ducros Emma Zucker

Neurophysiology 2 Moderator: Giulia Rossi Giulia Rossi Louise Tunnah Yihang (Kevin) Pan Claire Allore Maiah Devereaux

Animal Movement Moderator: Kim Birnie-Gauvin Andrea Brown Kim Birnie-Gauvin Julia Baak Rebecca Howe

35 Friday May 21

11:30-1:00 Boutilier Lecture Symposium 1:00-1:30 Coffee Break 1:30-3:00 Comparative Physiology and Biochemistry (CPB) Symposium Parasitism, Immunity & Environment (PIE) Symposium 3:00-3:30 Coffee Break 3:30-5:00 Annual General Meeting and Awards Ceremony

11:30-1:00

Boutilier Lecture Symposium The Robert G. Boutilier New Investigator Award recognizes early career researchers that have made significant contributions to zoology and are considered to be a “rising star” in their field. Both the 2020 and 2021 Boutilier Award winners will be presenting at this year’s conference in this symposium.

Chair: Sally Leys, CSZ President (University of Alberta) Grant McClelland, CSZ Past President (McMaster University)

Kyle H. Elliott Department of Natural Resource Sciences, McGill University

Energetics as the basis for movement ecology

Movement is a fundamental feature of all organisms, and plays a key role in determining fitness. Classically studied through biomechanical, cognitive or optimality lenses, there is growing awareness of the need for a general theory of organism movement. Energetics provides a framework for unifying these themes. The integration of sensors that record both fine-scale movement and energetics provides the possibility of testing that framework on wild animals. By studying seabirds that move in all three media (air, land and water), I will provide examples of how energetics can illuminate the linkages between biomechanics (flight kinematics), cognition (personality) and optimal foraging (decision-making), and link those facets with fitness. In particular, I will examine how movement patterns can vary throughout an animal’s lifespan, and how the efficiency of those patterns can determine lifetime reproductive success. Critical to understanding the link between movement, energetics and fitness has been my ability to access long- term, longitudinal studies that record movement patterns over scales relevant to lifespans; such long-term studies are essential to ecology in the 21st Century.

L’énergie comme base pour l’écologie du mouvement.

Le mouvement est une caractéristique fondamentale de tous les organismes et joue un rôle clé dans la détermination du fitness. Étudiée de manière classique via la biomécanique, la cognition ou l'optimalité, il y a une prise de conscience croissante pour le développement d’une théorie générale du mouvement des organismes. L'énergétique fournit un cadre pour unifier ces thèmes. L’intégration de capteurs qui enregistrent les

36 mouvements à petite échelle et les dépenses énergétiques offre la possibilité de tester ces idées sur des animaux sauvages. En étudiant les oiseaux de mer qui se déplacent dans trois milieux différents (en l’air, sur terre et dans l’eau), je fournirai des exemples de la façon dont les dépenses énergétiques peuvent éclairer les liens entre la biomécanique (le vol), la cognition (personnalité) et la recherche de nourriture optimale (les décisions), ainsi que le lien que ces aspects ont avec le fitness. En particulier, j’examinerai comment le mouvement peut varier tout au long de la vie d’un animal, et comment l’efficacité des mouvements peut déterminer le succès reproductif. Ma capacité à accéder à des études longitudinales à long terme, qui enregistrent le mouvement sur des échelles pertinentes à la durée de vie, est essentielle pour comprendre le lien entre le mouvement, l'énergie et le fitness, ce qui est essentiel à l'écologie au 21e siècle.

Erika Eliason Department of Ecology, Evolution and Marine Biology, University of California, Santa Barbara

The beauty and heartbreak of studying Pacific salmon

I have had the distinct privilege and pleasure of studying Pacific salmon thermal tolerance and physiology over the last >15 years. Pacific salmon are an iconic species with immense cultural, ecological, and economic importance yet they are imperiled by anthropogenic stressors across much of their range. Research in the Eliason lab has focused on intraspecific variability in thermal tolerance. We are particularly interested in whether individual variation can enable salmon to survive and succeed in a changing world. Specifically, we have studied how thermal tolerance and performance varies across populations, over the life history, and between sexes. We take advantage of this variation to investigate the underlying mechanisms that determine thermal tolerance. By working collaboratively with managers and stakeholders (e.g., Recreational and Commercial Fishers, First Nations communities, Fisheries and Oceans Canada, Pacific Salmon Commission, Oregon Department of Fish and Wildlife, Los Padres National Forest) we aim to identify stressor thresholds to inform conservation policy.

La beauté et le crève-cœur de l'étude du saumon du Pacifique

J'ai eu le privilège et le plaisir d'étudier la tolérance thermique et la physiologie du saumon du Pacifique au cours des 15 dernières années. Le saumon du Pacifique est une espèce emblématique avec une immense importance culturelle, écologique et économique, mais il est menacé par des facteurs de stress anthropiques dans une grande partie de son aire de répartition. La recherche du laboratoire Eliason est concentrée sur la variabilité intraspécifique de la tolérance thermique. Nous cherchons particulièrement à savoir si les variations individuelles peuvent permettre au saumon de survivre et de réussir dans un monde en changement. Plus précisément, nous avons étudié comment la tolérance et les performances thermiques varient, selon les populations, au cours du cycle biologique et entre les sexes. Nous utilisons à notre avantage cette variation pour étudier les mécanismes sous-jacents qui déterminent la tolérance thermique. En travaillant en collaboration avec les gestionnaires et les intervenants (les pêcheurs récréatifs et commerciaux, les communautés des Premières

37 nations, Pêches et Océans Canada, la Commission du saumon de la Pacifique, le ministère de la Pêche et de la Faune de l'Oregon, Los Padres National Forest), nous visons à identifier les seuils de stress pour éclairer la politique de conservation du saumon du Pacifique.

1:30-3:00

Comparative Physiology and Biochemistry (CPB) Symposium

Honouring the Work of Ron O’Dor: Animal Telemetry and Bioenergetics

Chair: Anne Dalziel, CPB Section Chair (Saint Mary's University)

1:30-1:45 Fred G. Whoriskey (Ocean Tracking Network; Department of Biology, Dalhousie University) Ron O’Dor: A life of joy in science

1:45-2:00 Rui Rosa (Universidade de Lisboa) Climate change, cephalopods, and Ron O’Dor

2:00-2:15 Roger T. Hanlon (Marine Biological Laboratory, Woods Hole) Ron O’Dor the cephalopod physiologist: an agile mind and a bold pioneer

2:15-2:30 Lucy A. Hawkes (University of Exeter) Future trends in measuring physiology in free-living animals

2:30-2:45 Shelly A. Adamo (Dalhousie University) Why do squids school? A story of currents and cannibalism

2:45-3:00 Discussion

Parasitism, Immunity & Environment (PIE) Symposium

Host-Parasite Interactions and the Environment

Chair: Patrick Hanington (University of Alberta)

1:30-2:00 Daniel R. Barreda (University of Alberta) Taking advantage of your environment to defend against pathogens

2:00-2:30 Julie D. Alexander (Oregon State University) Using models to evaluate the efficacy of management actions for invertebrate hosts of salmonid parasites

2:30-3:00 K. Fraser Clark (Dalhousie University) Crustacean PIE: an Atlantic Canadian approach

38 EDUCATION WORKSHOP

Every cloud has a silver lining – lessons learned from the pandemic and teaching strategies that might carry forward

Moderator: Gary Anderson, CSZ 1st Vice-President (University of Manitoba)

The Education Workshop will be provided as a pre-recorded presentation, which can be found in the on-demand session entitled Education Workshop Presentation, available in the Session area. There is no question that the global pandemic has forced all of us to adopt new and innovative ways to teach students from virtual platforms. It has demonstrated how we share a passion for learning and working with students directly in the classroom. Hopefully we will soon be able to return to in person teaching but our landscape has changed and it is likely as we move on from the pandemic that we will adopt aspects of our experiences into how we deliver our classes in the future. This short symposium is a compilation of three such ideas that have been successfully used during and before the pandemic and likely transfer to many of the courses we deliver across the country. The first is a writing course originally offered by Dr. Brock Fenton from Western in London ON. It is a course Dr. Fenton successfully delivered prior to the pandemic and involves peer assessment. The second is a field inquiry-based approach offered by Dr. Rachel Krause from Canadian Mennonite University in Winnipeg, MB. The final is a lab-based approach that incorporates instruction in R-studio for data analysis offered by Dr. Chris Guglielmo with help from his PhD student Kevin Young. I would like to thank all contributors and the folks on the Education sub-committee, in particular Russel Wyeth for coming up with this idea. We hope you find some or all of these ideas useful in your own teaching endeavours.

39 NSERC WORKSHOPS

NSERC Grants Workshop for Faculty

Program Officers from NSERC have suppled a pre-recorded presentation, which can be found in the on-demand session NSERC Grants Presentation, to provide some general information about NSERC Discovery Grants, other grant competitions, and supports for grantees related to the COVID-19 pandemic. There will also be live Discussion Sessions to follow the pre-recorded presentation. Katrina (Kate) Traikov and Marie- Claude Caron, who are Program Officer and Team Leader respectively in the Biological Systems and Functions Evaluation Group (1502), will be present to answer questions about NSERC Grants programs. These live sessions will be held on Thursday May 20 from 3:10-3:30 pm (Live Discussion Session 6) and from 3:40-4:00pm (Live Discussion Session 7) (see page 33). Attendees are strongly encouraged to view the pre-recorded presentation before attending this live event.

NSERC Scholarships and Fellowships Workshop for Students and Postdocs

Program Officers from NSERC have suppled a pre-recorded presentation, which can be found in the on-demand session NSERC PGS and PDF Presentation, to provide advice and tips for writing a successful scholarship or fellowship application. NSERC has also made available on YouTube several additional videos about various aspects of each scholarship and fellowship competition, including information about the types of NSERC scholarships and fellowships that are currently available and the basic components of an application. A link to these YouTube videos is provided below.

There will also be a live discussion session to provide students and postdocs with an opportunity to ask questions about NSERC scholarship and postdoctoral fellowship programs. Jennifer Houghton, a Program Officer in Scholarships and Fellowships at NSERC, will be present to answer questions. This live session will be held on Monday May 17 (see pages 16-17) and will be chaired by Alyssa Weinrauch (CSZ Postdoc Councillor, University of Manitoba). Attendees are strongly encouraged to view the pre- recorded presentation and any relevant YouTube videos before attending this live event.

40 LIST OF ATTENDEES (in Alphabetical Order)

Abouheif, Ehad Boulding, Elizabeth Adamo, Shelly Bouyoucos, Ian Afifi, Salwa Box, Isaiah Agard, Marishia Brady, Laura Al Shaibah, Arig Brauner, Colin Alderman, Sarah Breit, Ana Alexander, Julie Britney, Scott Allore, Claire Brown, Sarah Altshuler, Douglas Brown, Andrea Anderson, W. Gary Brubacher, John Andrew, Sean Bucking, Carol Anthony, Susan Bugg, William Antomagesh, Femilarani Bullingham, Oliver Aragones-Suarez, Pablo Cadonic, Ivan Arnaout, Bassel Calik, Derin Au, Sarah Campbell, James Campbell, Kevin L. Audet, Céline Caron, Marie-Claude Baak, Julia Chakraborty, Setu Baker, Daniel Balshine, Sigal Chandrapalan, Theanuga Bard, Brittany Cheng, Hang Barreda, Daniel Choi, Daeun Barrera, Karemna Choo-Yin, Yemaya Beemelmanns, Anne Chow-Fraser, Gillian Ben Youssef, Mariem Chung, Dillon Benfey, Tillmann Clark, Rikki Bergman, Elisabeth Clark, Fraser Best, Carol Collins, Sydney Birceanu, Oana Cormier, Simon Bird, Shannon Coulson, Soren Birnie-Gauvin, Kim Country, Michael Black, Emily Craig, Paul Blackett, Lia Currie, Suzie Blacklock, Emily Dalziel, Anne Blair, Jarrett Daniel, Juliet Blanchard, Tessa Dave, Preeti Blewett, Tamzin Dawe, Rachel Borowiec, Brittney Dawson, Neal Bouafoura, Raed Derksen, Naomi

41 Desforges, Jessica Folkerts, Erik Deslauriers, David Foster, Kathleen Detwiler, Jillian Franz-Odendaal, Tamara Devereaux, Maiah Fraz, Shamaila DeWitte-Orr, Stephanie Friesen, Olwyn Dixon, Brian Gair, Carly Dogan, Serkan Galbraith, Eric Dolezal, Aleksandra Garrett, Emily Donatelli, Cassandra Gauvreau, Nicole Douglas, Alexander Gil, Kelsey Drake, Paige Gilbert, Matthew Driedzic, William Gill, Lauren Drummond, Jenna Gillis, Todd Du, Trina Gilmour, Kathleen M. du Plooy, Michele Gleadall, Ian Duclos, Kevin Gnanagobal, Hajarooba Ducros, Loïck Goldbogen, Jeremy Duffy, Brynne Goss, Greg Dytnerski, James Gray, Jack Easy, Russell Guderley, Helga Eaton, Liam Guglielmo, Christopher El Nabbout, Amal Gunby, Stephanie El-Saadi, Mahmoud Gunby, Stephanie Eliason, Erika Haider, Fouzia Elliott, Kyle Hanington, Patrick Eom, Junho Hanlon, Roger Esparza, Ilse Hardison, Emily Esposito, Emma Harrison, Dominica Ethier, Jeffrey Harter, Till Evans, Drayke Hatton, Ian Farrell, A.P. (Tony) Hawkes, Lucy Faught, Erin Hirtle, Sarah Faure, Paul A. Hoeg, Rielle Feldman, Richard Hoogenboom, J. Lisa Fenton, Brock Horricks, Ryan Ferguson, Laura Houghton, Jennifer Ferreira, Patricia Howe, Rebecca Flatt, Elizabeth Hunter, Allanique Fletcher, Garth Hutchinson, Amalie Huynh, Kenny Flewwelling, Luke Ignatz, Eric

42 Ikert, Heather Léger, Adèle Ingelson-Filpula, W. Aline Legros, Jade Ionescu, Adrian Leonard, Erin Ivy, Catherine Letendre, Francis Jamniczky, Heather Levesque, Danielle Jeffrey, Jennifer Lewis, Johanne Jeffries, Ken Leys, Sally Jimenez Padilla, Yanira Li, Jessica Jonz, Michael G. Li, Kira (XinCi) Jung, Ellen (Hyewon) Li-Ting-Wai, Gracie Kadamani, Karen Liang, lisa Kandil, Ali Liu, Shuang Kapur, Manny Logan, Samantha Katzenback, Barbara Lum, Samantha Kawano, Sandy Lutek, Keegan Kecheliev, Dimo Lyons, Sulayman Kennedy, Jessica MacCormack, Tyson Khidas, Kamal MacPherson, Jess Killen, Shaun Malhotra, Aayush Kim, Anne Malotka, Scott King, Katie Mandic, Milica Kinkead, Richard Manzon, Richard G. Klein, Zoe Marsh-Rollo, Susan Klymasz-Swartz, Aaron Marshall, Katie Kodzhahinchev, Vladimir Martel, André L Kraskura, Krista Martinez-Silva, Maria A. Krause, Rachel Matthews, Benjamin Kwong, Raymond Matthews, Philip Lalla, Kristen Lamarre, Simon Matveev, Evgeni Laronde, Daniel McClelland, Grant Lau, Gigi McDermott, Larry Lavoie-Rochon, Annie S. McDonald, Allison E. Lawrence, Michael McGeachy, Sarah Lazaro-Côté, Analisa McInnis, Shea Le, Gam McKenzie, Evan Le Moine, Chris McMillan, Laura Lebenzon, Jackie McPhail, Brooke Lee, Justin Mehdi, Hossein Lee, Lucy Melanson, Chloé Lee, Marco Melissis, Jacob

43 Menail, Hichem Parkinson, Rachel Middleton, Ella Perkins, Daniel Middleton, Kaela Perry, Steve F. Millar, Zachary Perugini, Gabrielle Miller, Leslie Pfeifer, Louis Miller, Linh Pichaud, Nicolas Milligan, Louise Picinic, Britney Milsom, William K. Pidwerbesky, Ashley Misutka, Melissa Pleizier, Naomi Mitrovic, Dejana Po, Hoi Ki Miyashita, Tetsuto Porteus, Cosima Moffatt, Kelsy Priest, Jenna Moir, Camden Procopio, Susan Monod, Emma Puar, Pankaj Montgomery, Daniel Purvis, Katherine Moon, Thomas W. Quéméneur, Jean- Morash, Andrea Baptiste Morris, Carolyn Rajakumar, Arjuna Morris, Matthew Rajan, Felicia Muir, Carlie Reeve, Connor Muldoon, Taryn Regan, Matthew Muñoz, Martha Reid, Kim Myrka, Alexander Reid, Kim Namboothiri, Ayush Reid, Andrea Narro Pérez, Rodrigo Rempel, Emma Naseer, Tania Rempel, Emma Nash, Nathalie Ridgway, Megan Nataprawira, Leo Rivard, Gabrielle Nauss, Jenna Robertson, Mel Nelson, Charlotte Robertson, Cayleih Nipu, Niepukolie Robichaud, Karyn Niyogi, Som Rodela, Tammy Nomikos, Julia Rosa, Rui Northam, Caleb Rossi, Giulia Nowlan, Joseph Roth, Sophie Nurse, Colin Rowsey, Lauren Ojaghi, Mohammad Russell, Anthony Ouillon, Natascha Rutledge, Charlotte Paluzzi, Jean-Paul Sajadi, Farwa Pamenter, Matthew Salazar, Vielka Pan, Yihang (Kevin)

44 Salin, Karine Todd, Lauren Sandrelli, Rebeccah Torabi-Marashi, Arteen Santa Rita, Zandra Toxopeus, Jantina Saravanamuttu, Kalai Traikov, Katrina (Kate) Saruhashi, Stefane Trudeau, Vance Schoen, Alexandra Tunnah, Louise Schoof, Valerie Turko, Andy Schulte, Patricia Turnbull, Kurtis Schwieterman, Gail Turner, Leah Scott, Graham Ucciferri, Carmen Scovil, Allie van der Burg, Karin Selvitella, Alessandro M. van Oordt, Francis Shadwick, Robert Van Wert, Jacey Shaftoe, Jared Veilleux, Heather Shahriari, Arash Vickaryous, Matt Sharpe, Diana Vijayan, Mathilakath Shartau, Ryan von Herff, William Shutler, Dave Wagler, Brieanna Sinclair, Brent Wang, Avril Smith, Todd Wang, Yuyang Smith, Melanie Wasmuth, James Sogabe, Shun Wearing, Oliver Somo, Derek Weihrauch, Dirk Soto-Davila, Manuel Weinrauch, Alyssa Speers-Roesch, Ben Welch, Kenneth Sprenger, Ryan White, Ali Standen, Emily Whoriskey, Fred Staples, James Wilkie, Michael P Steffen, Jennifer Wilson, Jonathan Stephens, Alyssa Wilson, Brenna Stevens, Samantha Wilson, Joanna Stone, Jonathan R. Wishart, Andrea Stroud, Thomas Wood, Chris M. Sultana, Asma Sunga, Julia Wright, Patricia A. Suski, Cory Wyeth, Russell Tan, Jinghan Young, Kevin Thompson, Andrew Yusishen, Michael Thoral, Elisa Zhang, Yangfan Thorat, Leena Zhang, Sinan Tigert, Liam Zhang, Yueyang

45 Zimmer, Alex Zucker, Emma

46 ABSTRACTS

Symposium Presentations

Abouheif, Ehab McGill University, Montreal, Canada The ants: model (super)organisms for eco-evo-devo Ants show a remarkable diversity in size and head-to-body scaling within and between species, so much so, that Darwin considered ants a ‘climax of the difficulty’ for his theory of natural selection. For example, in colonies of the marauder ant, the smallest worker stands on the head of the largest. The developmental mechanisms producing these extreme differences in size and head-to-body scaling within the worker caste and how this extreme variation originated and evolved between ant species, are questions that have remained enigmatic for over 150 years. Over the last 20 years, my lab has made considerable progress in understanding these developmental and epigenetic mechanisms, which I will discuss in my talk.

Adamo, Shelley A. Dalhousie University, Halifax, Canada Why do squids school? A story of currents and cannibalism. The southern Pacific squid, Sepiateuthis lessoniana, hunts by night and typically forms aggregations during the day. In some species, a small number of larger individuals take up a position one or two body lengths ahead of the rest of the group. Based on observations of the Caribbean squid, Sepiateuthis sepioidea, Moynihan and Rodaniche argued that these individuals act as sentinels, ready to alert the other squid to the presence of predators. However, the evidence suggests a less altruistic answer. The waters around Lizard Island in the Great Barrier Reef have relatively strong (0.4 m/s) and constant currents. In these waters, S. lessoniana tend to aggregate under moored boats. Moored boats create boundary layer zones that reduce tidal flow. The largest squid monopolize the area of least current, with other squid having to work harder to maintain their position. Smaller squid are marginalized. Smaller squid probably do not attempt to share a more energetically favourable position with larger squid because cannibalism is common. Larger squid pick off smaller squid within the group. Therefore, the structure of the squid aggregation in this area can be explained by energetics and a need to avoid cannibalism.

Alexander, Julie D. Oregon State University, Corvallis, U.S.A. Using Models To Evaluate The Efficacy Of Management Actions For Invertebrate Hosts Of Salmonid Parasites Infectious diseases caused by parasites that have complex lifecycles are often poorly understood. Models can be useful tools for bridging data gaps and for evaluating efficacy of proposed management actions. We used a tandem modeling approach to evaluate management actions (flow manipulation) employed to reduce invertebrate hosts of Ceratonova shasta (myxozoan parasite) in the Klamath River, USA. Ceratonova shasta alternately infects Manayunkia occidentalis (freshwater annelid) and salmonids, and has been associated with salmon population declines. Our aims were to predict annelid host distribution in three sections of the Klamath River’s infectious zone, a river section characterized by elevated C. shasta densities. Two-dimensional hydraulic models (2DHMs) were developed for each river section and used to describe hydraulic variation and stratify annelid host sampling locations across gradients of depth and velocity within substrate classes. Benthic samples were used to build predictive distribution models; distribution was associated with substrate, as well as depths and velocities predicted from the 2DHMs during the previous water year’s peak discharge. We evaluated model performance against independent datasets collected in multiple water years. Our results demonstrate that hydraulic conditions during peak discharge (natural or managed) drives annelid host distribution the following season. This in turn may influence C. shasta prevalence in and risk of infection for salmonids. Our study provides a tool that allows us to predict how annelid distribution responds to flow manipulation at the study sites and evaluate the potential efficacy of proposed management scenarios to affect annelid hosts, and in turn, salmon disease risk.

47 Barreda, Daniel R. University of Alberta, Edmonton, Canada Taking advantage of your environment to defend against pathogens Recent findings from our lab suggest that, contrary to the long-standing paradigm, fish do not have an under-developed immune system compared to mammals. However, because fish lack endogenous metabolic-driven endothermy, they require movement to/from warmer temperatures at different stages of disease to activate protective antimicrobial mechanisms. These dynamic temperature changes are at the core of the crosstalk between fish, pathogens and the environment. Thermal promotion of immune competence is achieved through a combination of earlier, tailored defenses that are quickly followed by efficient inflammation control. This allows for both enhanced antimicrobial protection as well as efficient use of energy resources. Behavioural thermoregulation (BTR) also opens the door to enhance long-term immune memory. Together, this represents an important shift in our understanding of fish immunity and has major applied implications for Canada's aquaculture sector. This presentation will describe the basic mechanisms contributing to the regulation of fish immunity through BTR.

Chow-Fraser, Gillian Boreal Program Manager, CPAWS Northern Alberta The tricky business of managing landscapes and species across scales In the Canadian Rocky Mountains, multiple competing land uses have rapidly changed the landscapes upon which a diverse mammalian community depends. Terrestrial community dynamics and species distributions are impacted by various human land uses, and conservation of the ecological integrity of these landscapes requires broad understanding of how species use these spaces to persist and coexist. But, were it only so simple! In many ways, conservation of biodiversity is best achieved through land management to conserve, protect, or increase necessary habitat types. But land management can be challenged by the issue of scale and a lack of consideration for cumulative impacts. For instance, many land management processes approve industrial activities on a project-by-project basis, though ecological processes occur at much broader scales. I unpack the interface between wildlife research and land management in Alberta to illuminate the ways wildlife, land and resource management successfully or unsuccessfully incorporates wildlife research outcomes, and how researchers use their science to inform conservation.

Clark, K. Fraser Dalhousie University, Halifax, Canada Crustacean PIE: An Atlantic Canadian Approach Crustaceans are part of a diverse arthropod taxon consisting of predators, prey and important components of aquaculture and commercial fisheries globally. They also represent interesting models for exploring host- pathogen-environment interactions as crustaceans have evolved unique innate immune systems with different susceptibilities and resistances to microorganisms in their shared aquatic environments. Our lab is using genomic tools to explore these differences to highlight unique differences within their related immune systems. We are also examining the impact of protist and helminth parasites on the behaviour and immune responses of their crustacean hosts. Are they benign parasites, or do they fundamentally change biological pathways in crabs and lobsters? I will also highlight some recent microbiome research that we have been conducting on how both the environment and species influences the surface microbiome of crabs inhabiting the same environment. This presentation will finish will a quick acknowledgment of two research tools that have fundamentally changed the way that I think about experimental design and analysis: Galaxy bioinformatic servers (if you can do a statistical test, then you can perform bioinformatic analysis) and Arduino/ Raspberry Pi-based approaches for accurate and affordable laboratory instrument design.

Feldman, Richard E. Centro de Investigación Científica de Yucatán, Merida, Mexico Species-energy relationships during bird migration The species-energy relationship is one of the most ubiquitous scaling relationships in ecology. However, the relationship is predicated on species being in equilibrium with their environment, a condition not applicable to all systems. For example, birds during migration need to rest and recuperate after crossing geographic barriers, which may constrain their movement and prevent them from exploiting energy-rich

48 habitats. Across the Yucatan Peninsula of Mexico, my students and I found that spatiotemporal variation in species richness was only weakly associated with primary productivity and instead, more strongly associated with distance to the coast. In individual coastal stopover sites, daily variation in species richness was weakly associated with resource availability, possibly because bird abundance and stopover duration varied independently of resources. On the other hand, in winter, species richness was higher inland and, we found that, in the city of Merida, Yucatan, species richness tracked productivity across space and time. Thus, as birds migrate into and out of the tropics, habitat selection may be decoupled from local energy and resources, but, as winter approaches, species redistribute themselves to match energy availability.

Galbraith, Eric D. McGill University, Montreal, Canada The flow of energy through the global marine size spectrum Stored energy is primarily provided to the marine ecosystem in the form of biomass, produced by phytoplanton. This energy is then extracted by organisms when that biomass is respired. Biomass is also transferred between organisms without being respired, providing the mass that supports growth. Because of the strong size structuring of the marine ecosystem, size offers an excellent framework in which to understand how these processes determine the fate of energy in the system. I will show new results from a global compilation of marine biomass, which has implications for how the consumption of energy is distributed across sizes, as well as for general patterns of trophic efficiency. In addition, the disruption of energy flow due to global fishing and climate change will be estimated.

Goldbogen, Jeremy A. Stanford University, Pacific Grove, California Integrative Organismal Biology at the Largest Scale Some of the largest baleen whales—such as blue whales, fin whales and humpbacks—fall into a family called rorquals that use an unusual feeding method. These whales feed on zooplankton aggregations and fish by lunging with their mouths open wide to tremendous gape angles to force vast volumes of water and prey into their expandable oral cavities. This extreme lunge feeding strategy is facilitated by some of the most bizarre anatomical adaptations, many of which are unique among mammals. This talk will present new insights using tag technology and remote sensing into how the largest vertebrates survive on the smallest food.

Hanlon, Roger T. Woods Hole, Massachusetts, U.S.A. Ron O’Dor the cephalopod physiologist: an agile mind and a bold pioneer Ron thought differently about the how and why of cephalopod energetics. He was never constrained by current methods or favored ideas, but rather he was a visionary of big questions that seemed untouchable. Ron had the special talent of convincing others to help address these bigger issues, and he was especially good at ad-libbing in the field when things went awry. He got the goods in most cases. I will give a few examples from field expeditions to South Africa and Australia.

Hawkes, Lucy A. Exeter University, Exeter, United Kingdom Future trends in measuring physiology in free-living animals Although ecophysiology research is often conducted in controlled lab-based environments, it is possible to record some physiological variables in free-living animals using animal-attached logging devices, including inertial-measurement, heart-rate and temperature loggers. In no small part thanks to innovation and development from the O’Dor lab, modern animal biotelemetry can track animals in aquatic and terrestrial environments in fine, three-dimensional scale, and record parameters relating to energetics. In this talk, we argue that non-invasive, multi-sensor miniature devices, ubiquitous in the world of human health and fitness monitoring, create invaluable opportunities for animal and human physio-logging to drive synergistic advances. By capitalising on the research efforts and advancements made in the development of human wearables, it will be possible to design the noninvasive loggers needed by ecophysiologists to collect accurate physiological data from free-ranging animals ethically and with an absolute minimum of impact. In turn, findings have the capacity to foster transformative advances in animal biology, conservation and human health monitoring. We call for biomedical engineers and

49 researchers to collaborate with the animal-tagging community to drive forward the advancements necessary to realise the full potential of both fields.

Kawano, Sandy M. George Washington University, District of Columbia, USA Modeling the biomechanics of fins and limbs during the evolutionary invasion of land by vertebrates The invasion of land by stem tetrapods was a key evolutionary event that introduced a new suite of selective pressures, leading to functional innovations of the musculoskeletal system. An intriguing transformation in this context was the evolution from fins to digit-bearing limbs. Although terrestrial locomotion is often thought to have resulted from the evolution of limbs, paleontological examinations indicate that the earliest tetrapods were aquatic. Increased gravitational loads on land can make bones more prone to injury, but how stressful was terrestrial locomotion for early tetrapods? I will review the work we have conducted on semi-aquatic salamanders and fishes to model the locomotor capabilities of early tetrapods and tetrapod- like fishes spanning the water-to-land transition. Our studies show that a semi-aquatic salamander (Pleurodeles waltl) had a hyper-sprawled limb posture compared to a terrestrial tiger salamander (Ambystoma tigrinum), with ground reaction forces intermediate between semi-aquatic mudskipper fish and terrestrial A. tigrinum. We applied these data to our computational model of a crownward early tetrapod (Greererpeton burkemorani) using a salamander-like gait and found that femoral stresses decreased as the limbs became more sprawled but never exceeded the ultimate bending strength for amphibian limb bones, suggesting limbs bones may have been well suited for terrestrial locomotion relatively early in their evolution. Further work on how ecology shapes bone mechanics is ongoing and will provide insights into the locomotor behaviours that were likely unrealistic as incipient stages for terrestrial locomotion.

Killen, Shaun S. University of Glasgow, Glasgow, United Kingdom Who leads and who follows? The interplay between metabolic phenotype and social behaviour in fish Social behaviours come with a variety of costs and benefits for individual animals. For this reason, individuals tend to vary in their degree of sociability. Recent evidence suggests that this behavioural variation is linked to various traits associated with bioenergetics, including metabolic rates and locomotor ability. On the one hand, underlying variation in metabolic traits (e.g. maintenance metabolism, maximum metabolism) seems to affect sociability by affecting predator avoidance, foraging needs, and competitive ability. Specifically, an animal’s energetic status influences not only whether an individual will join a group of conspecifics, but also the behaviour of individuals that have already joined groups. Conversely, an animal’s social environment can feedback to affect its physiological traits and performance. This can occur via the effects of aggression and competition but also through stress reduction and the energy- saving benefits of moving in groups. Here I review this interplay between social behaviour and individual physiology, including the modulating role of additional factors such as temperature and oxygen availability. I also discuss ways in which these links may be relevant in the context of human predation on fish populations and fisheries-induced evolution.

Muñoz, Martha M. Yale University, New Haven, U.S.A. Behaviour is a motor and brake for evolution One of the most striking patterns of evolution is its uneven tempo across the tree of life. Whereas some traits and lineages diversify rapidly, others appear to remain inert over millions of years. But why is this so? What allows some features to achieve evolutionary overdrive, and why do some traits appear to straddle evolution's slow lane? I explore this question by focusing on one of evolution's key architects: behavior. I illustrate how organisms are not the passive targets of selection; rather, through behavior, they can be the agents of selection. Using Caribbean Anolis lizards as a model system, I reveal the signatures of behavior at both micro- and macroevolutionary scales and illustrate the constraints on this phenomenon. Behavior has the power to slow and hasten evolution and, on occasion, it does both simultaneously.

50 Perkins, Daniel M. University of Roehampton, London, UK Across ecosystem comparisons of body-size and biomass structure Body-size and biomass structure provide a powerful means for understanding energy flow through food webs. However, it is uncertain whether common mechanisms underpin the emergent structure of food webs across ecosystem types. Here I will discuss results from large-scale analyses addressing this question in terrestrial, marine and freshwater ecosystems. This work identifies key constraints on the distribution of body sizes and biomass within and across ecosystems, paving the way for improved assessment of energy flow through food webs.

Rosa, Rui Faculdade de Ciências da Universidade de Lisboa, Cascais, Portugal Climate change, cephalopods, and Ron O’Dor The global ocean has been shielding our planet from abrupt climate change, by absorbing a large portion of the anthropogenically emitted carbon dioxide and the excess heat trapped in the atmosphere, leading to ocean acidification and warming. Additionally, oxygen loss in the ocean (also known as deoxygenation) is being exacerbated by the global rising temperatures. This complex 3-way interaction (“deadly trio”) will definitely shape populations’ fitness and ecosystems’ health in the ocean of tomorrow. Here I will discuss the differential impacts of the “deadly trio” on the marine biota, with a special emphasis on cephalopods and Ron O’Dor’s related work.

Rossi, Giulia S. University of Guelph, Guelph, Canada Animals seek hypoxic microhabitats that accentuate metabolic depression during dormancy Several animals enter a state of dormancy to survive harsh environmental conditions. During dormancy, metabolic depression can be critical for economizing on limited endogenous energy reserves. We used the amphibious fish, Kryptolebias marmoratus, to test the hypothesis that animals seek hypoxic microhabitats that accentuate metabolic depression during dormancy. Using custom-built tunnels that maintained a longitudinal O2 gradient (hypoxic to normoxic), we assessed the O2 preference of K. marmoratus during prolonged air exposure. In support of our hypothesis, we found that fish preferred to spend more time in aerial hypoxia compared with aerial normoxia after 21 days in air, likely because aerial hypoxia exposure accentuated metabolic depression. We then tested the hypothesis that chronic aerial hypoxia acclimation would protect endogenous energy reserves and skeletal muscle integrity, thereby maintaining locomotor performance in K. marmoratus. Indeed, we found aerial hypoxia acclimation minimized glycogen usage, lipid catabolism, and white muscle atrophy, as well as preserved terrestrial locomotor performance. Following this study, I was curious to know whether other dormant taxa exhibited similar microhabitat selection strategies. I travelled to Australia to test whether green-striped burrowing frogs (Cyclorana alboguttata) also seek hypoxic microhabitats at the onset of aestivation. Interestingly, we found that frogs also preferentially occupied hypoxic microhabitats in response to habitat drying, and had significantly lower metabolic rates at the onset of aestivation when maintained under hypoxic conditions. Taken together, these studies suggest that microhabitat selection strategies are at least as important as the physiological mechanisms used by dormant animals to tolerate environmental extremes.

Vickaryous, Matthew K. University of Guelph, Guelph, Canada The regenerative repertoire of geckos: hearts, minds, and other tales of replacing tissues Comparative studies are the benchmark for reparative investigations and provide unique opportunities to probe naturally evolved mechanism of tissue regeneration. Among amniotes, some of the most dramatic examples of regeneration are observed in gekkotan lizards (geckos). Although best known for tail regeneration, geckos demonstrate a surprisingly diverse repertoire of regenerative abilities. Drawing on examples from the heart and brain, we show how geckos can expand and enhance our understanding of regenerative biology. Injuries to the heart ventricle via a puncture or an ischemic lesion result in an immediate loss of cardiac muscle cells. Within two weeks, there is a surge in cell proliferation by cardiac muscle cells bordering the injury as well as aggregation of mesenchymal-like cells within the wound site. These populations eventually give rise to mature cardiac muscle cells and near-perfectly restore the original tissue architecture. Neurochemical lesions to the gecko forebrain are also spontaneously resolved. Neuron

51 degeneration and loss is followed by new neuron formation and migration to the site of injury. Within a month, damage to the forebrain is structurally repaired and repopulated by new neurons. Taken together, these findings provide important steps towards understanding the evolution and phylogenetic variation of regeneration.

Whoriskey, Fred G. Dalhousie University, Halifax, Canada Ron O’Dor: A life of joy in science Ron O’Dor passed away May 11, 2020, a victim of the COVID epidemic that has shaken the world to its foundation. Ron was a midwestern boy, born in Kansas City, Missouri (20 Sept 1944) and raised in Liberty, Missouri. The ocean got into his blood when he moved to California for his undergraduate degree (U. Cal Berkeley, BSc Biochemistry with honors, 1967). There he met Janet Spiller who became his partner of 52 years. From California Ron travelled to UBC where he earned his doctorate in medical physiology in 1971, working on salmon calcitonin. Showing signs of his wanderlust, the next step was a 2 years of postdoctoral fellowship at Cambridge University in the UK and the Stazione Zoologica in Naples, Italy. Here he discovered squid and octopus, and never looked back. Ron’s research from then on focused primarily on cephalopods and their endocrinology, bioenergetics, life-histories and movements in the ocean. Dalhousie University became home for most of the rest of his career. There he carved out a distinguished career as a researcher, teacher and administrator. He was renowned for his sense of fun and his quirkiness, focusing masses of time on trying to study flying squid and getting experiments onto the space shuttle. Ron spent 10 Y at the end of his career on leave from Dalhousie University to act as the Chief Scientist of the Sloan Foundation’s Census of Marine Life, and in initiating Canada’s Ocean Tracking Network. Cruelly, he was struck with early onset Alzheimer’s which precipitated his retirement, and yet he continued to faithfully attend OTN gatherings for as long as he could remember how to get home. Ron left behind Janet, two children, and four grandchildren, and a world that was dimmer and less fun than when he was here with us.

52 Contributed Talks

Allore, C. A.1, Rossi, G. S.,1, Wright, P. A.1 Department of Integrative Biology, University of Guelph, Guelph, Canada Hydrogen sulphide impacts visual acuity in an amphibious fish (Kryptolebias marmoratus) Hydrogen sulphide (H2S) is highly toxic to most living organisms. Exposure to H2S causes inhibition of cytochrome c oxidase (COX) and a reduction in aerobic ATP production. Unlike most fishes, the amphibious mangrove rivulus (Kryptolebias marmoratus) are highly H2S tolerant. However, sensory systems such as vison may be impaired by H2S exposure, since eyes are highly aerobic organs, and the tissue is in direct contact with water. We hypothesised that the visual acuity of fishes is altered by H2S exposure due to changes in COX activity in the eye. We tested visual acuity and COX activity at low (~100 µM), medium (~200 µM), and high (~400 µM) H2S concentrations. We tested each fish in control water (10 min), then H2S-rich water (10 min), followed by recovery in 0 µM H2S (10 min). Visual acuity significantly decreased when fish were exposed to ≥ 200µM of H2S and did not show recovery after exposure to 400 µM H2S but did recover if left for 1 hour. COX activity in the eye was also significantly reduced in fish exposed to ≥ 200µM, with no recovery after 10 min, but again COX activity recovered after 1 hr. Overall, our results support the hypothesis that H2S impairs vision in K.marmoratus probably due to an inhibition of COX activity. Our study suggests that in their natural habitats, K.marmoratus may experience visual impairment ( ≥ 200µM H2S), which in turn may impact predator avoidance, navigation, and foraging behaviour.

Andrew, S.1, Currie, S.2, Morash, A.J.1, 1Department of Biology, Mount Allison University, Sackville, Canada 2Department of Biology, Acadia University, Wolfville, Canada Efficiency and Limits of Sustainable Swimming in Atlantic salmon (Salmo salar) under Warm Summer Environments with Diel Thermal Variability Warm temperatures and greater thermal variability have been implicated in the recent decline of Atlantic salmon in Eastern Canada. Diel thermal variations in key salmon habitats such as the Miramichi river in New Brunswick, can be as wide as 5-9oC in the summer. To date, we know little about how these diel thermal variations affect swimming performance in fishes. For Atlantic salmon which migrate as smolts and adults through the Miramichi, swimming sustainably and efficiently is key. The goal of this study is to understand the effects of diel thermal variability on swimming efficiency and the speed limit for sustainable swimming (Usus). To this end, we acclimated Atlantic salmon smolts from the Miramichi to two ecologically realistic diel thermal profiles (16-21oC and 19-24 oC), and then tested individuals over a common thermal cycle (16-24oC). We measured standard metabolic rate, metabolic rate at a range of swimming speeds, and tail thrust at each speed to assess energetic- and kinematic- swimming efficiency o at five temperatures (16, 18, 20, 22, and 24 C). We also determined and defined Usus as the fastest speed before salmon start swimming unsustainably (burst and coast), then calculated the sustainable aerobic scope (ASsus). ASsus and Usus varied significantly with test-temperature for salmon acclimated to 16-21 and 19-24oC but remained optimal (>90% of maximum) at 24oC. Temperature did not appear to affect energetic- and kinematic- swimming efficiency. It appears that Atlantic salmon can swim just as efficiently and sustainably at cool and warm parts of the day, and after acclimation to either 16-21oC and 19-24oC.

Antomagesh, F.1*, Vijayan, M. M.1 1Department of Biological sciences, University of Calgary, Calgary, Canada *Presenting Author Cortisol modulates glucose uptake and storage during stress in zebrafish skeletal muscle The circulating glucocorticoid (GC) levels elevate in response to stress, and this response is conserved in vertebrates. GCs play an important role in mobilizing glucose, a key fuel to cope with the increased energy demand, which allows in the metabolic adjustments to stress. GCs have also been shown to restrict skeletal muscle glucose uptake during stress, but the mechanisms are far from clear. We hypothesized that the glucocorticoid receptor (GR) activation by GCs restricts insulin-stimulated skeletal muscle glucose uptake during stress using zebrafish (ZF) as a model. Cortisol is the principal GC in this species, and we treated ZF with cortisol to mimic the stressed levels. The cortisol-treated ZF showed impaired plasma glucose clearance when subjected to an intraperitoneal glucose tolerance test. This

53 impaired glucose clearance was not rescued by insulin treatment. To assess glucose uptake by target tissues, we used a fluorescent glucose analog 2-NBDG, and cortisol-treated ZF showed a significant reduction in skeletal muscle glucose uptake. To test if GR is directly involved in this response, we used a ubiquitous GR knockout ZF (GRKO) developed in our laboratory. This GRKO fish is hypercortisolemic, yet they had significantly higher skeletal muscle glucose uptake than the wildtype (WT). To determine the possible mechanism involved in this glucose restriction, we measured the transcript abundance of glucose transporters (GLUTs), and markers of insulin sensitivity, including phospho-protein kinase B (AKT) expression and glycogen content in the skeletal muscle. Overall, the results suggest that during stress GC restricts skeletal muscle glucose uptake and storage by GR activation, and this response may be independent of skeletal muscle responsiveness to insulin.

Aragonés-Suarez, P. G.¹*, Leys S.P.¹ 1Department of biological Sciences, University of Alberta *Presenting Author Extant sponge morphology provides a metric for identifying sponge-grade fossils The tempo and mode of early animal evolution remains one of the biggest conundrums in biology. Molecular data suggest Porifera diverged from the metazoan lineage some 800 Ma to 650 Ma, which contrasts with the earliest irrefutable fossils of sponges at 535 Ma, and leaves a gap of at least ~100 Myr. Stratigraphy shows that this gap is not due to poor preservation or lack of search effort; nevertheless, the lack of criteria by which to recognize the earliest animals in the fossil record presents a challenge. Although the organization of the ancestor that gave rise to Metazoa remains unknown, the sponge body plan has not changed since the first verifiable fossils from the early Cambrian, which makes a sponge- type animal a good candidate for a search pattern for the earliest fossils. Here we propose a method for identifying an organism as sponge-grade: by translating the sponge pump character into a quantifiable morphological trait. We show that the ratio between the two major components of the aquiferous system, surface area (SA) and the cross sectional area of the osculum (OSA), correlates with the pump characteristic of extant sponges, and the slope of this ratio is distinct for three classes of Porifera, Demospongiae, Calcarea and Hexactinellida. Furthermore, this metric (SA/OSA) is the same for extant taxa and fossils from two extremes of the Phanerozoic, the Cambrian and Eocene, demonstrating its utility in distinguishing fossil fauna as sponges. We also tested this metric on the putative Ediacaran sponge Thectardis avalonensis from specimens found at Mistaken Point, Newfoundland, and found Thectardis had a ratio consistent with Cambrian sponges and a slope consistent with demosponges. These analyses show the SA/OSA ratio is a reliable characteristic by which to identify fossils as sponge- grade, opening up exciting possibilities for classifying new fossils as sponges, or not.

Au, S. K. W.*, Semple, S. L., DeWitte-Orr, S. J. Department of Biology, Wilfrid Laurier University, Waterloo, Ontario, Canada *Presenting Author Investigation of Long dsRNA Mediated RNA Interference (RNAi) in Vertebrates RNA interference (RNAi) was first characterized in plants and invertebrates as an antiviral innate immune response. It is a natural antiviral defence mechanism to degrade viral RNA by virus-induced gene silencing. Studies showed synthetic long double-stranded RNA (dsRNA; >30bp) degraded Caenorhabditis elegans messenger RNA (mRNA) transcripts, resulting in sequence-dependent gene silencing. Currently, there is only limited research on RNAi in vertebrates, particularly with the use of long dsRNA to trigger sequence-specific gene silencing and prevent viral infection. This is because long dsRNAs trigger interferon responses and upregulate interferon stimulated gene (ISG) expression that masks gene- specific RNAi effects in vertebrates. This study explores long dsRNA-mediated RNAi pathways in rainbow trout cells and human cells from two aspects. Firstly, the optimal dsRNA concentration that would funnel into RNAi without triggering type 1 interferon responses was determined. Secondly, the potential of sequence-specific dsRNA to mediate gene silencing and protect against viral infection was identified. Luciferase sequence specific, long dsRNA (dsRNA-Luc) was able to silence induced RTG-P1 luciferase gene expression in the transgenic rainbow trout gonadal cell line, RTG-P1, while a mis-match dsRNA sequence did not. Additionally, a dsRNA-CSV sequence was able to protect the rainbow trout gonadal cell line, RTG-2, against chum salmon reovirus (CSV) infection. Similar methods were proven to be applicable on telomerase-immortalized human fibroblasts cells, THF, by using a dsRNA-VSV sequence for the prevention of vesicular stomatitis virus (VSV) infection. Long thought non-functional in

54 vertebrates, long RNAi-based strategies could be used to study vertebrate gene functions, develop new drugs and vaccines to control infectious diseases in the future.

Baak, J. E.¹*, Patterson, A.¹, Elliott, K. H.¹ 1Department of Natural Resource Sciences, McGill University, Sainte-Anne-de-Bellevue, Canada *Presenting Author Nonbreeding distribution and landfill use of glaucous gulls (Larus hyperboreus) from the Canadian Arctic As climate change impacts and anthropogenic activities increase in the Arctic, understanding seabird distribution will be essential to inform conservation measures and assess risks to seabird populations. Glaucous gulls (Larus hyperboreus) are generalist predators with flexible foraging and migratory behaviour and they may alter these behaviours in response to climate change and anthropogenic activities, such as access to landfills. Importantly, little is known about glaucous gull distribution and landfill use during the nonbreeding period in the Arctic. We deployed Global Positioning System (GPS) and Global Location Sensor (GLS) tags on glaucous gulls from Coats Island, Nunavut, Canada in 2017 and 2018 to examine variability in migration routes and overwintering distributions among and within individuals. Additionally, we investigated the relationship between GPS locations and landfill sites during migration. Differences in migration routes, stopover sites and overwintering areas may expose seabirds to different risks, thus should be used to inform conservation measures for migratory seabirds in the Arctic.

Bard, B.1*, Dodge, A.1, Joyce, W.1,2, Lawrence, M. J.3, Cooke, S. J.3, Gilmour, K. M.1 1Department of Biology, University of Ottawa, Ottawa, Canada 2Department of Biology-Zoophysiology, Aarhus University, Aarhus C, Denmark 3Department of Biology and Institute of Environmental and Interdisciplinary Science, Carleton University, Ottawa, Canada *Presenting Author Chronic social stress impairs the thermal tolerance of rainbow trout (Oncorhynchus mykiss) Juvenile rainbow trout (Oncorhynchus mykiss) held in pairs form dominance hierarchies, with subordinate individuals experiencing chronic social stress, as evidenced by prolonged elevation of the stress hormone cortisol. Prior work reported that the thermal tolerance (measured as critical thermal maximum, CTmax) of subordinate fish was reduced, but the cause of this impairment was unknown. Here we tested the hypothesis that reduced thermal tolerance in subordinate trout is caused by prolonged elevation of circulating cortisol levels, through cortisol-dependent effects on cardiac structure and function. In support of this hypothesis, subordinate trout that were allowed to recover from social stress for 48 h, a period sufficient to return cortisol to normal baseline levels, no longer showed a reduced CTmax. Furthermore, treatment of subordinates with cortisol to maintain elevated cortisol levels during the period of recovery from social stress prevented thermal tolerance from recovering. Additionally, treatment of non-stressed fish with cortisol mimicked the effects of subordinate status on thermal tolerance, and normal thermal tolerance was maintained when cortisol was co-administered with a glucocorticoid receptor blocker. To investigate the possible downstream effects of prolonged elevation of cortisol levels, cardiac remodelling in subordinate trout was explored by assessing heart histology and molecular markers, and monitoring heart rate (fH). Differences in fH responses of subordinate versus dominant fish were detected during acute warming. Specifically, peak heart rates tended to be observed at lower temperatures in subordinate fish relative to dominant. However, no other differences in cardiac morphology and physiology were detected. Thus, chronic social stress had only minor effects on cardiac structure and function, but high baseline cortisol levels in subordinate trout result in lowered thermal tolerance.

Beemelmanns, A.1,2*, Zanuzzo, F. S.1, Xue, X.1, Sandrelli, R. M.1, Anastasiadi, D.3, Ribas, L.4, Rise, M. L.1, Gamperl, A. K.1 1 Department of Ocean Sciences, Memorial University, St. John’s, Canada 2 Institut de Biologie Intégrative et des Systèmes, Université Laval, Québec City, Canada 3 The New Zealand Institute for Plant and Food Research, Nelson, New Zealand 4 Institut de Ciències del Mar, Barcelona, Spain *Presenting Author Warm and Hypoxic: Transcriptional and DNA Methylation Responses in Atlantic Salmon (Salmo salar) Challenged with High Temperature and Moderate Hypoxia

55 The marine environment is predicted to become warmer and more hypoxic, and these conditions may become a challenge for marine fish species. Phenotypically plastic acclimatization responses can be mediated by DNA methylation through the modulation of gene expression. Thus, we examined transcriptome expression and DNA methylation changes in the liver of post-smolt Atlantic salmon exposed to i) an incremental temperature increase (12 → 20°C, 1°C week-1) and then 20°C for 4 weeks under normoxia; or ii) combined with moderate hypoxia (~ 70% air saturation) as compared to control conditions (12°C, normoxia). When considering both scenarios, we found 2,894 differentially expression genes, with up-regulated transcripts connected to the heat-shock response, apoptosis, and immune defence, while genes associated with metabolic processes, proteolysis and oxidation-reduction were highly suppressed. We uncovered dynamic DNA methylation changes at CpG sites around the transcription start of six treatment-responsive genes (cribp, jund, pkd3, prdx6, serpinh1, ucp2), which resulted in distinct CpG methylation profiles for fish exposed to each environmental condition (‘epigenetic footprint’). CpG methylation changes correlated with transcriptional changes and can be considered as regulatory epigenetic marks (‘epimarkers’). These dynamic associations between transcript expression and CpG methylation in Atlantic salmon suggest that epigenetic mechanisms may mediate physiological acclimation to changing environments.

Bergman, E. A.¹*, Green, E. L.¹, Matthews, P. G. D.1 1Department of Zoology, University of British Columbia, Vancouver, Canada *Presenting Author The Biomechanics and Energetics of Xylem Feeding in the Common Meadow Spittlebug (Philaenus spumarius) Xylem sap in vascular plants can exist under tremendous tension (negative pressure), routinely exceeding 1 MPa. Despite this, some bugs feed exclusively on this liquid, using a muscular cibarial pump to extract 100 to 1000 times their body mass in xylem per day. However, both the magnitude of the forces generated by these xylem-feeding specialists, and the energetic cost associated with this activity, are unknown. Adult Philaenus spumarius froghoppers were studied to address these gaps in our knowledge. Using the dimensions of their cibarium and associated musculature obtained from micro-CT scans, combined with measurements of sarcomere length from the cibarial dilator muscle, we calculated that P. spumarius generate a mean maximum tension of 1.3 MPa within their cibarial chamber. The energetic cost of this activity was then determined using flow-through respirometry to measure the bug’s metabolic rate as they fed on various legume species. By growing the plants hydroponically, it was possible to expose the plant’s roots to polyethylene glycol, thereby increasing the xylem tension of the plant up to 1.1 MPa while the insect was feeding. Simultaneously recorded video allowed both the volume of the excreted xylem sap droplets, and the cibarial pumping frequency, to be measured. We show that increases in xylem tension do not reduce xylem excretion rate, but do significantly increase metabolic rate and pumping frequency. From estimates of xylem’s energy content, it is concluded that P. spumarius can gain energy feeding on xylem sap with tensions close to their calculated morphological limit.

Best, C.*, Gilmour, K. M. Department of Biology, University of Ottawa, Ottawa, Canada *Presenting Author Regulation of cortisol production in the head kidney of rainbow trout (Oncorhynchus mykiss) during chronic social stress Rainbow trout held in pairs form social hierarchies, with dominant and subordinate fish differing both behaviourally and physiologically. Key among these differences is that subordinate fish sustain elevated levels of the stress hormone cortisol. In addition, when subordinates are challenged with an acute stressor, their cortisol response is blunted relative to that of dominant fish. We hypothesized that chronic social stress alters regulation of the pathway for cortisol synthesis in the interrenal cells of the head kidney, leading to the altered cortisol dynamics observed in the whole animal. To test this hypothesis, juvenile rainbow trout were held in pairs to form social hierarchies, with subordinates exhibiting elevated circulating cortisol after 4 days of interaction. Cortisol production in response to adrenocorticotropic hormone (ACTH) injection was reduced in these subordinates, suggesting that blunting of the cortisol response to acute stress arises downstream of ACTH. Cortisol production from isolated head kidney tissue in vitro was assessed in dominant and subordinate trout, with and without stimulation by ACTH or the cAMP analogue dibutyryl-cAMP. Tissue from subordinate fish had higher unstimulated cortisol

56 production, but an attenuated response to ACTH and db-cAMP, suggesting that blunting of the acute cortisol response arises downstream of cAMP signaling. Several key components of the steroidogenic pathway were elevated in subordinates, including the melanocortin (ACTH) receptor accessory protein (mrap), a paralog of steroidogenic factor 1 (ff1d), p450 side chain cleavage enzyme (p450scc), steroidogenic acute regulatory protein (star), and phosphorylated PKA substrates. Collectively, these results demonstrate that chronic social stress increases the capacity for cortisol production in interrenal cells while reducing the production of cortisol in response to acute stress at a point downstream of cAMP production.

Birceanu, O.1, Wilson, J.Y.1, Nielsen, K.2, McMaster, M.2, Parrott, J.2, Palace, V.4, Kidd, K.1,3, Ussery, E.2 1Department of Biology, McMaster University, Hamilton, ON, Canada 2Environment and Climate Change Canada, Burlington, ON, Canada 3School of Earth, Environment and Society, McMaster University, Hamilton, ON, Canada 4International Institute for Sustainable Development, Experimental Lakes Area, Winnipeg, MN, Canada Mesocosm investigations of the ecotoxicological effects of metformin on fish health The occurrence and fate of pharmaceuticals in the aquatic environment is an emerging issue in aquatic toxicology. Currently, one of the most prevalent contaminants is the type-2 diabetic drug, metformin, which is released in freshwaters via wastewater effluent. Although this chemical is continuously released in the environment, little is known about its fate and effects in freshwater organisms. In the laboratory, metformin reduces larval fish growth and alters whole-body metabolome, but little is known about its impact in wild fish. To this end, we conducted an 8-week in-lake mesocosm study at the IISD- Experimental Lakes Area, to investigate the fate and effects of metformin in adult, wild-caught fathead minnows. Fish were randomly assigned to mesocosms containing 1, 4, or 40 µg/L metformin (n = 4 mesocosms per treatment). At the end of the 8-week exposure, fish condition factor and carcass water content, along with brain and liver glucose, remained unaffected. Although not significant, hepatosomatic index decreased, while the gonadosomatic index increased in a dose-responsive manner in the metformin-exposed fish. Exposure to 4 µg/L metformin significantly decreased carcass lipid levels, while in fish exposed to 40 µg/L metformin, liver lactate dehydrogenase activity was increased, suggesting that these animals were metabolically stressed. To date, our study shows that exposure of wild fish to environmentally relevant levels of metformin leads to disturbances in energy allocation, liver metabolism and gonadal investment.

Bird, S. E. 1*, Birceanu, O. 1, Fraz, S. 1, Wilson, J. Y. 1 1Department of Biology, McMaster University, Hamilton, Canada *Presenting Author A new lens for toxicokinetics in fishes: The influence of temperature on toxicant metabolism Anthropogenic climate change threatens aquatic life as global ocean temperatures are predicted to increase 1-4°C by 2100. The rising temperature could be especially threatening to poikilotherms such as fishes, as they directly depend on the environmental temperature to regulate biological processes. Optimal functioning of toxicokinetic processes constituting absorption, distribution, metabolism, and elimination (ADME) in fishes are susceptible not only to thermal changes but also to excessive toxicant concentrations. Significant advances in the 20th century progressed understanding of toxicokinetics in fishes, but fewer studies have explored the influence of temperature on these processes. In this review, we integrate studies to provide evidence of the effects of temperature on whole organism responses to toxicants and the underlying processes that control toxicokinetics. Selecting a metal and a piscicide as case studies, we report that temperature impacts how fishes respond to these toxicants. Cadmium exposure at increased temperature generally shows increased tissue accumulation and elevated metallothioneins, which are proteins responsible for metal sequestration and detoxification, with no change to lethal concentrations. For TFM, a piscicide used to control sea lamprey populations in the Great Lakes, in summer there is an increase in lethal concentrations and mRNA abundance for UGT in liver; UGT is the critical conjugation enzyme responsible for TFM metabolism. In response to the predicted global temperature changes and this evidence of thermal influence on toxicant metabolism, we suggest that future research incorporate temperature as a central component when modeling toxicokinetics, to better predict the effects of toxicants on fishes.

57 Birnie-Gauvin, K.1*, Larsen, M. H.1, Peiman, K. S. 2, Midwood, J. D. 3, Wilson, A. D. M. 4, Cooke, S. J. 2, Aarestrup, K1. 1 DTU Aqua, Section for Freshwater Fisheries and Ecology, Technical University of Denmark, Silkeborg, Denmark 2 Fish Ecology and Conservation Physiology Laboratory, Carleton University, Ottawa, Canada 3 Great Lakes Laboratory for Fisheries and Aquatic Science, Fisheries and Oceans Canada, Burlington, Canada 4 School of Biological & Marine Sciences, Marine Biology and Ecology Research Centre, University of Plymouth, Devon, United Kingdom *Presenting Author Early-life stressors have short-term but not long-term carryover effects in a wild salmonid fish Early-life experiences can shape life histories and population dynamics of wild animals. To examine whether stressful stimuli experienced in early life resulted in carryover effects in later life stages, we conducted several experimental manipulations and then monitored wild fish with passive integrated transponder tags during juvenile outmigration and adult return migration. In total, 3217 juvenile brown trout (Salmo trutta) were subjected to one of six manipulations: chase to exhaustion, thermal challenge, food deprivation, low concentration cortisol injection, high concentration cortisol injection, and sham injection, plus a control group. Cortisol and food deprivation treatments were previously shown to have short-term effects on juveniles such as lower survival to outmigration and changes in migration timing. However, it remained unknown whether any of the six manipulations had effects that carried over into the adult phase. We therefore investigated whether these extrinsic manipulations, as well as intrinsic factors (size and condition), affected probability of return as adults and time spent at sea. Of the 1273 fish that outmigrated, 146 returned as adults. We failed to detect any effect of treatments on return rates, while high concentration cortisol weakly affected time spent at sea in one tagging event. We also found that juvenile condition was positively correlated to likelihood of adult return only in one tagging event. Overall, our findings suggest that neither intrinsic factors nor extrinsic stressful early-life experiences have a strong effect on fish that survive to adulthood. This suggests that some species may be more resilient than others to stressful stimuli encountered early in life.

Black, E. N., Marshall, K. E. Department of Zoology, University of British Columbia, Vancouver, Canada Using community science to uncover phenological drivers of speciation Hyphantria cunea (the fall webworm) is a Lepidopteran defoliator with two distinct colour morphs: red and black. The two morphs have different host plant preference, behaviour, nest structure, and genetics, and their taxonomic relationship is not clear. An incipient allochronic speciation event has been proposed as a mechanism for the differences observed between morphs, but a large-scale investigation into their phenology has not yet been performed. Community science records of the fall webworm offer an extensive and reliable dataset for broad-scale analysis of phenology. We annotated over 9000 fall webworm observations from iNaturalist and used these to model fall webworm geographic range and generational timing. The morphs were found to be unequally distributed across their range, and the number and timing of generations each year was statistically different between the morphs, with greater differences being observed in southern populations. This supports previous hypotheses of allochronic speciation being responsible for the differences between morphs. This also led us to hypothesize that there is a speciation gradient across the fall webworm range, with populations in the south being more divergent than populations in the north due to increased length of the breeding season. We are currently investigating this using analysis of genetic differences between morphs at various latitudes and determining whether larval body colour is more divergent in southern populations. Our results have implications for the classification and taxonomy of this species, furthering our understanding of the process of speciation, and the usefulness of community science data in peer-reviewed research.

Blacklock, E. K.1*, Alkie, T. N.2, Monod, E.2, DeWitte-Orr, S.2, Clark, K. F.1 1Department of Animal Science and Aquaculture, Faculty of Agriculture, Dalhousie University, Bible Hill, NS 2Department of Biology, Wilfrid Laurier University, Waterloo, ON *Presenting Author The Impact of a Viral Mimetic on the Northern Clearwater Crayfish (Faxinius propinquus)

58 Crustaceans are a highly valuable species; in 2017, Canada landed approximately 300,000 metric tons valued at $2.8 billion. Along with the current crustacean fisheries, crustacean aquaculture is starting to become more common in Canada, with shrimp farms appearing in British Columbia and Ontario. With shrimp aquaculture on the rise, developing a better understanding of how crustaceans respond to viruses will be beneficial for the industry. The goal of this study was to examine changes in gene expression that occur in crayfish hepatopancreas when exposed to a viral memetic. Faxinius propinquus were caught in Waterloo, Ontario and were injected with PBS or polyIC before being euthanized and tissues collected. The study used RNA-seq to measure global changes in transcript expressions following the injections. A de novo transcriptome of F. propinquus was created through Galaxy Europe which contained 579,496 sequences ranging in length from 117 to 42,250 nucleotides. Using the edgeR and DESeq2 pipelines of Galaxy Europe, 503 and 15 differentially expressed genes were found, respectively, when comparing the crayfish injected with PBS compared to polyIC. In comparing the results of the two pipelines, 5 of the differentially expressed genes were found in both. From this study, a greater understanding the effect in viral mimetics will result which can have implications for the management of viruses in the crustacean aquaculture industry.

Blair, J.1, Weiser, M. D.2, Kaspari, M.2, Siler, C.2,3, Marshall K. E.1 1 Department of Zoology, University of British Columbia, Vancouver, Canada 2Department of Biology, University of Oklahoma, Norman, United States of America 3Sam Noble Oklahoma Museum of Natural History, University of Oklahoma, Norman, United States of America Automated identification of pitfall-trap-collected ground beetles using machine learning Insect populations are rapidly changing, and monitoring these changes is essential for understanding the causes and consequences of these shifts. However, large scale monitoring of insect populations often involves sorting and counting many thousands of specimens, which can be labour intensive, time consuming and costly. A potential solution to this problem is automated specimen photo identification using computer vision (a subset of machine learning), which previous studies have demonstrated can quickly and accurately identify insects from photos. In this study, we trained and tested five types of machine learning models on image data taken from 25 species of ground-beetles (3270 individuals, family: Carabidae). All beetles were collected in pitfall traps by the National Ecological Observatory Network at 17 locations all across the contiguous United States. Image data was extracted as feature vectors using ImageJ. Species-level accuracy of our best performing model was 84.6%, with accuracy increasing as taxonomic resolution decreased. Additionally, we look towards ways in which automated specimen identification can be improved using other ecological data. We show that supplementing machine learning models with information such as contextual metadata and phylogenetic relationships can increase the model’s usefulness compared to using image data alone. Overall, we present a methodological framework for identifying bulk insect specimens collected from pitfall traps using machine learning that is neither data nor compute intensive. We recommend that machine learning identification methods such as ours are used as a tool to assist taxonomists with routine identifications rather than a complete replacement for human identification.

Blanchard, T. S.¹*, Schulte, P. M.¹ 1Department of Zoology, University of British Columbia, Vancouver, Canada *Presenting Author Persistent effects of early developmental temperatures on thermal phenotypes in F. heteroclitus Temperature is an important environmental factor governing development in fishes. The degree, timing, and length of temperature exposures during early development plays a large role in shaping phenotypic responses and can result in significant phenotypic variation in subsequent life-stages. The objective of this study was to examine how exposure to different temperatures during early developmental shape adult thermal phenotypes. We hypothesized that developmental temperatures alter the thermal performance of adult fishes as a result of beneficial developmental plasticity. We used Fundulus heteroclitus, a species of topminnow that inhabit intertidal saltmarshes along the Atlantic coast of North America. Embryos from 8 different families were incubated at either 20°C or 26°C until hatch. Once hatched, fish were raised at a common temperature of 20°C until juvenile stage (6-8 months). We found that a higher rearing temperature during development had no significant effect on thermal tolerance (CTmax). However, we found that hypoxia tolerance (time to LOE) was significantly higher in fish reared at

59 warmer temperatures during development. In both phenotypic traits, we found that family effects played a significant role in shaping thermal and hypoxia tolerance in juveniles. These data demonstrate that early developmental temperatures can have long lasting effects on juvenile phenotypes.

Borowiec, B. G.¹*, Birceanu, O.2, Wilson, J. M.1, Wilkie, M. P.1, McDonald, A. E.¹ 1Department of Biology, Wilfrid Laurier University, Waterloo, Canada 2 Department of Biology, McMaster University, Hamilton, Canada *Presenting Author Effects of the lampricides TFM, niclosamide, and their mixture on mitochondria function in adult sea lamprey (Petromyzon marinus) at three environmentally-relevant temperatures TFM (3-trifluoromethyl-4-nitrophenol), niclosamide (Bayluscide, 5-chloro-N-[2-chloro-4-nitrophenyl]-2- hydroxybenzamide), and mixtures of TFM with trace amounts of niclosamide are used to control invasive sea lamprey populations in the Laurentian Great Lakes. TFM is selective for larval lamprey and appears to be an uncoupler of oxidative phosphorylation in the mitochondria. Recent work shows that TFM toxicity varies considerably across the treatment season, with the lampricides being less toxic to lamprey during warmer months. Much less is known about the mode of action and seasonality of niclosamide toxicity, though niclosamide is consistently far less specific and more potent than TFM. We tested the hypothesis that niclosamide, like TFM, acts by uncoupling oxidative phosphorylation, leading to increased maintenance costs (state 4 or LEAK respiration) and reduced membrane integrity and coupling (as reflected by the respiratory control ratio, RCR). Mitochondria isolated from the livers of adult sea lamprey were exposed to a range of physiologically-relevant concentrations of lampricides (TFM, niclosamide, or a mixture of TFM and 1% niclosamide) and temperatures (7oC, 13oC, and 25oC). Low to moderate levels of lampricides (up to ~ 40 µM TFM or ~0.4 µM niclosamide) caused a substantial increase in LEAK respiration and a corresponding decrease in RCR, indicating that the lampricides, alone and in mixtures, are uncoupling agents. Additionally, we observed that high levels of lampricides decreased state 3 (OXPHOS) respiration. This effect was not entirely explained by our vehicle control, implying that lampricides may have secondary toxic effects that have yet to be characterized. Excluding the expected effects of temperature on respiration rate, we found that mitochondrial responses to lampricides were similar across the range of temperatures tested, suggesting that increased tolerance to lampricides at warmer temperatures is not related to effects of temperature on the mitochondria, but other metabolic processes such as detoxification. Supported by the GLFC.

Boulding, E.G.¹* 1Department of Integrative Biology, University of Guelph, Guelph, Canada *Presenting Author Effect of mode of larval development on the demographic responses of four intertidal gastropod species to two major El Niño events Life history traits that simultaneously affect dispersal ability could have large effects on the responses of species to global climate change. However long-term population studies of ecologically-similar species that differ in life-history traits are rare. We compared the recruitment of two poorly-dispersing species with ‘direct development’ with that of two highly-dispersing species with a planktotrophic larval stage by monitoring their abundance and size-distribution between 1993-2020. The two major El Niño-Southern Oscillation (ENSO) events that occurred during this period (1997/1998 and 2015/2016), were followed by large anomalous increases in two planktotrophic intertidal gastropods, Littorina scutulata and L. plena, that were synchronous at two study sites. These abundance anomalies were positive correlated with higher sea surface temperature (SST) anomalies and with increased poleward transport of warm water in winter by the El Niño-augmented Davidson current. In contrast, the abundance anomalies of the usually common direct-developing species, L. subrotundata, was less synchronous between sites and were negatively correlated with SST anomalies. Further the second 2015/16 El Niño coincided with a large decrease in all size-classes of L. subrotundata and no change in the rarer direct-developing species, L. sitkana. Single factor hypotheses for the decline of L. subrotundata that could be rejected included: 1) increased predation from temporary range extensions of two shore crab species, 2) increased competition for biotic refuges, and 3) heat stress from positive rock temperature anomalies. Instead the decline is postulated to result from El Niño-driven positive air and rock temperature anomalies that increased thermal stress and from negative windspeed anomalies which, reduced average wave-height,

60 thereby increasing desiccation stress. Our long timeseries shows that the mechanisms behind population responses to climate change can differ for species that vary in dispersal potential.

Bouyoucos, I. A.¹*, Yoon, G. R.¹, Anderson, W. G.¹ 1Department of Biological Science, University of Manitoba, Winnipeg, Canada *Presenting Author Preliminary insight into post-prandial metabolic rates in age-0 lake sturgeon Acipenser fulvescens In conservation aquaculture, knowledge of the energetic efficiency of digestion has implications for improving rearing protocols. Lake sturgeon (Acipenser fulvescens) are reared in conservation aquaculture throughout North America to replenish populations across their range. The present study sought to provide preliminary insight into the post-prandial metabolism of age-0 A. fulvsecens. A first series of experiments sought to stimulate the appetite of A. fulvescens so that fish would feed within respirometry chambers. This approach would allow for measurement of post-prandial oxygen uptake rates (ṀO2; a proxy for metabolic rate). Food odours (L-alanine or homogenised bloodworm) or a freshwater vehicle control were injected into respirometry chambers to measure responses in ṀO2 relative to standard (SMR, maintenance metabolic costs) and routine metabolic rate (RMR, any metabolic cost above SMR). Then, food was introduced, and their response was monitored. Only L-alanine was associated with elevated ṀO2 relative to SMR and RMR, but A. fulvescens would not feed in situ. In a second series of experiments, A. fulvescens were fed ad libitum in rearing tanks for 30 minutes and were then transferred to respirometry chambers. Another group of A. fulvescens were subjected to three minutes of forced exercise and one minute of air exposure to elicit their maximum metabolic rate (MMR) for comparison with peak post-prandial ṀO2. Surprisingly, peak post-prandial ṀO2 did not significantly differ from MMR following exercise. Finally, cross-study comparison of MMR measured in sturgeon suggests that the methods used in the present study may underestimate A. fulvescens’ maximal aerobic capacity. Together, these data suggest that age-0 A. fulvescens exhibit tremendous increases in post-prandial ṀO2 that may utilise these fish’s full aerobic capacity during digestion of meals. Further understanding of the energetic efficiency of digestion in sturgeon will contribute to improved rearing protocols for conservation aquaculture programs for imperilled taxa, like A. fulvescens.

Box, I. C. H.*, Matthews, B. J., Marshall, K. E. Department of Zoology, University of British Columbia. Vancouver, Canada *Presenting Author The role of ice-binding proteins in the freeze tolerance of intertidal invertebrates Many intertidal invertebrates in temperate regions, including the bay mussel (Mytilus trossulus) experience freezing temperatures during low tide in the winter. While M. trossulus can tolerate freezing of body fluids throughout the year, individuals collected in the winter and higher in the intertidal zone can survive lower temperature exposures. While the mechanisms of freeze tolerance in intertidal species are poorly understood, many other freeze tolerant organisms use ice-binding proteins (IBPs) to modulate internal ice formation. IBP functions can include preventing ice formation, controlling ice crystal growth, and encouraging ice formation. We hypothesized that ice-binding proteins exist in intertidal species and play a role in the variation in freeze tolerance seen both seasonally and between intertidal regions. We used both in silico and in vitro techniques to investigate 1) whether there was evidence for IBP presence in the genomes of intertidal species, and 2) whether there was evidence for IBP activity in M. trossulus. We first assembled a query database of all IBP sequences with lab-confirmed IBP activity, then assembled a database of habitat information for all genome-sequenced invertebrates within Mollusca, Crustacea and Cnidaria. We then looked for evidence of homology with IBP sequences within these genomes and tested whether hits were clustered in habitats or phyla. We found many Type II and AFGP IBPs had strong homologous matches in invertebrate genomes, and the majority of these were found in intertidal species. On the second arm of our study, we collected M. trossuulus monthly from both the high and the low intertidal zone. We then assayed these mussels for IBP activity. Ice nucleating activity was successfully characterized in the mussels and was verified to be mediated by proteins. This research provides further understanding of intertidal invertebrate freeze tolerance and adds to our knowledge of the evolution of IBPs.

Breit, A. B.1*, Treat, M.2, Smith, G. R.2, Lighton, J. R. B.3, McCue, M. D.3, van Breukelen, F.2, Levesque, D., L.1

61 1School of Biology and Ecology, University of Maine, Orono, U.S.A. 2School of Life Sciences, University of Nevada-Las Vegas, Las Vegas, U.S.A. 3Sable Systems International, Las Vegas, U.S.A. *Presenting Author The limit does not exist; Absent critical limits of the thermoneutral zone in the basoendothermic Tenrec ecaudatus The basoendothermic tailless tenrec (Tenrec ecaudatus), an oddity by mammal thermoregulatory standards, has one of the lowest eutherian mammalian body temperatures and can hibernate for months without interbout arousals. With their normothermic body temperature tracking ambient temperature, tenrecs exemplify the extreme end of thermolability, resulting in a hard-to-discern, if present, thermoneutral zone. To test thermoregulatory capabilities and the associated metabolic costs, we used flow-through respirometry to measure O2 consumption and H2O and CO2 production of 16 individual tenrecs. We conducted 8-hour long trials over a range of ambient temperatures (12-34°C) plus a separate test of acute exposure to ramping temperatures starting at 30°C and increasing by 1°C/hr until they showed visible signs of distress. In a separate experiment, we photographed tenrecs using a thermal camera to identify and quantify their thermal windows. We expected tenrecs to have higher metabolic rates at the lower and higher ranges of temperatures, but instead found high variation among individual’s thermoregulatory responses. At low temperatures (12-15°C), individual tenrecs fluctuated between relatively high and relatively low metabolic rates, but these changes in metabolic rates were not correlated to changes in body temperatures. At these cooler temperatures, metabolism appeared to be uncoupled from body temperature. Tenrecs retain many of the ancestral mammal characteristics (nocturnality, insectivory, relatively unspecialized limbs, cloaca, lack of zygomatic arches) and inhabit environments similar to those present during the evolution of endothermy in mammals. A further understanding of thermoregulation in this unique mammal may therefore give us insight into the evolution of endothermy and the role of metabolism in thermoregulation.

Brown, A.1, McCabe, R.1, Therrien, JF.2, Wiebe, K.3, Weidensaul, S.4, Brinker, D.5, Gauthier, G.6, Elliott, K. H1. 1Department of Natural Resource Sciences, McGill University, Ste-Anne-de-Bellevue, Canada 2Acopian Center for Conservation Learning, Hawk Mountain Sanctuary, Pennsylvania, US 3Department of Biology, University of Saskatchewan, Saskatoon, Canada 4Ned Smith Center for Nature and Art, Pennsylvania, US 5Maryland Department of Natural Resources, Maryland, US 6Department of Biology, Université Laval, Quebec City, Canada Nomadic breeders, snowy owls (Bubo scandiacus), do not use stopovers to sample the breeding environment during settling Nomadic breeders are assumed to select a summer settlement region (e.g. breeding site) based on annual variation in the abundance of prey to sustain them throughout the summer. Selection of habitat would presumably require extensive sampling via stopovers during the pre-breeding period, but behavior during site selection remains poorly known. In addition, habitat selection and migration movement might vary due to differential migration among age- and sex- classes. Snowy Owls (Bubo scandiacus) are known for both differential and nomadic migration strategies, where summer and winter locations can vary year-to-year. Additionally, Snowy Owls display irruptive migration causing further variation in wintering locations. Large irruptions are associated with high lemming years leading to high population density and intra-specific competition. We examined the spring migration behavior of Snowy Owls (n = 24) to determine if there are differences in migration timing among age- and sex- classes, as well as to describe their migratory route to identify stopover sites. Each owl was tagged and equipped with a GPS- GSM transmitter during the overwintering period in the US and Canada from 2013 to 2018. Initiation timing of spring migration, number of stopovers and time spent at each stopover did not vary among age- and sex- classes. Completion time of spring migration in adults was found to be significantly earlier then immatures, however no differences were found between sex classes. However, Snowy Owls had a higher probability of having a stopover at the beginning of their migration compared to the end of their spring migration. We conclude that Snowy Owls use stopovers primarily to build up reserves at the start of migration and can select appropriate summer settlement regions without extensive sampling via stopovers.

62 Bullingham, O. M. N.¹*, Firkus, T. J.² , Goetz, F.3, Murphy, C. A.², Alderman, S. L.¹ 1Department of Integrative Biology, University of Guelph, Guelph, Canada 2 Department of Fisheries and Wildlife, Michigan State University, Michigan, United States 3 NOAA Northwest Fisheries Science Center, Manchester Research Station, Port Orchard, United States *Presenting Author Lake trout clotting response acts as a plasma biomarker of sea lamprey parasitism: implications for management and wound assessment Sea lamprey (Petromyzan marinus) have been decimating the Great Lakes fisheries over the past century, and their control has become the key to protecting fish populations. Decisions of where to apply lamprey control methods are made, in part, by collecting wounding data on host fish. On its own, wounding data offers a qualitative and error-prone perspective on lamprey parasite numbers, but a reliable quantitative measure of parasitism events would increase the value of these assessment efforts. Therefore, we asked whether protein biomarkers of lamprey parasitism could be quantified in host fish plasma. Male siscowet lake trout (Salvelinus namaycush) were parasitized in a lab setting for four days, after which the lamprey was removed, a blood sample was collected, and the wound was classified as A- type (severe) or B-type (mild). Host fish were recovered for six months, and then a second blood sample was collected. The plasma proteome was quantified using iTRAQ, and the relative abundances of 170 proteins were compared between parasitized and non-parasitized control fish at each time point. A major finding of this study was a marked decrease in the abundance of six clotting-related proteins, including two fibrinogen alpha chain and two beta chain proteins, in fish with A-type wounds. Four of these proteins showed recovery, while two did not. Here, we propose that the use of a clotting assay alongside wound assessment efforts may help improve the accuracy and efficacy of sea lamprey control measures.

Chakraborty, S.1*, Surendra Kumar, S.1,2, Hossain, A.1, Cao, T.1, Gnanagobal, H.1, Boyce, D.3, Hall, J.4, Segovia, C.1, Santander, J.1 1Marine Microbial Pathogenesis and Vaccinology Laboratory, Department of Ocean Sciences, Memorial University of Newfoundland, St. John’s, Canada; 2Ocean Frontier Institute, Memorial University of Newfoundland, St. John’s, Canada; 3Dr. Joe Brown Aquatic Research Building, Department of Ocean Sciences, Memorial University of Newfoundland, St. John’s, Canada; 4Aquatic Research Cluster, CREAIT Network, Department of Ocean Sciences, Memorial University of Newfoundland, St. John’s, Canada Transcriptional response of lumpfish (Cyclopterus lumpus) to Aeromonas salmonicida infection. Lumpfish (Cyclopterus lumpus), a native fish of the North Atlantic Ocean, has been utilized as cleaner fish to biocontrol sea-lice (Lepeophtheirus salmonis) infestations in Atlantic salmon (Salmo salar) farms in the North Atlantic. Aeromonas salmonicida subspecies salmonicida is a Gram-negative facultative intracellular pathogen that causes lethal furunculosis in several fish species, including lumpfish. The molecular immune response of lumpfish to A. salmonicida infection is unknown. In this study, we established an A. salmonicida infection model in lumpfish, and examined the transcriptome profile of central lymphoid tissues after infection. Groups of lumpfish (50 g; n=60 per group) were intraperitoneally (ip) injected with different doses of A. salmonicida to calculate the median lethal dose (LD50). Samples of blood, head kidney, spleen, and liver were collected at different time points to determine the infection 2 kinetics. We determined that A. salmonicida lethal dose 50 (LD50) is 10 bacterial cells per dose. A Transcriptome sequencing of triplicated head kidney, spleen and liver was performed in Nova-Seq Illumina platform, which generates 1,034 million pair-end reads. The de novo assembly resulted in 403,204 transcripts with an average read length of 497 bp, representing 270,150 Trinity genes. In total, 11,795 significantly differentially expressed genes (DEGs) were identified by the de novo assembly. On the other hand, A reference-based downstream analysis was performed in the CLC Genomics Workbench 20 simultaneously. In total, this reference-based RNA-seq analysis generated 2,121,782,925 clean reads and identified 7651 DEGs. The differentially expressed genes related to the immune system process, cellular process and metabolism, and apoptosis occupied the dominant position involved in the infection. These results are in concordance with the fish behaviour prior disease onset and mortality and provide with a valuable resource and novel insight of the interaction fish-pathogens.

Chakraborty, S.a*, Woldemariam, N. T.b, Visnovska, T.c, Rise, M. L.d, Boyce, D.e, Santander, J.a,, Andreassen, R.b

63 a Marine Microbial Pathogenesis and Vaccinology Laboratory, Department of Ocean Sciences, Memorial University of Newfoundland, 0 Marine Lab Rd, St. John's, NL A1C 5S7, St. John’s, Canada. b Department of Life Sciences and Health, Faculty of Health Sciences, OsloMet–Oslo Metropolitan University, Pilestredet 50, N-0130 Oslo, Norway. c Bioinformatics core facility, Oslo University Hospital, Oslo, Norway. d Department of Ocean Sciences, Faculty of Sciences, Memorial University of Newfoundland, 0 Marine Lab Rd, St. John's, NL A1C 5S7, St. John’s, Canada. e Dr. Joe Brown Aquatic Research Building (JBARB), Department of Ocean Sciences, Memorial University of Newfoundland, St. John’s, Canada. Reference miRNAome of lumpfish (Cyclopterus lumpus) MicroRNAs (miRNAs) are endogenous small RNA molecules involved in the post-transcriptional regulation of protein expression by binding to the mRNA of target genes. They are key regulators in teleost development, maintenance of tissue-specific functions, and immune responses. Lumpfish (Cyclopterus lumpus) is becoming an emergent aquaculture industry to biocontrol sea lice (e.g., Lepeophtheirus salmonis) infestation in the Atlantic Salmon (Salmo salar) aquaculture industry. As no study has previously characterized lumpfish miRNAs this study aimed to identify and characterize miRNA genes in adult lumpfish, embryos, and larvae. Sixteen samples from six different adult lumpfish organs (spleen, liver, head kidney, brain, muscle, and gill), embryo, and larvae were individually small RNA sequenced. The miRDeep2 software package was applied to identify miRNA precursors and their mature 5p and 3p read using the draft lumpfish genome sequence. Additional Basic Local Alignment Search Tool (BLAST) searches against miRNAs in miRbase version 22 were finally carried out to characterize and annotate all miRNAs according to the miRBase guidelines and nomenclature. The study identified 391 conserved miRNAs genes, eight novel miRNAs genes, and 443 unique mature miRNAs in lumpfish. DESeq2 analysis identified differentially expressed mature miRNA across different organ and developmental stages. Utilizing mature sequences from the newly characterized miRNA repertoire in lumpfish, we carried out additional RT-qPCR of selected miRNAs that revealed conserved organ-specific miRNA expression (e.g., miR-122-1-5p in the liver). In conclusion, our study provides the first reference miRNAome for high-throughput sequencing (HTS)-based expression studies in lumpfish. Furthermore, the enriched organ-specific expression of some miRNAs suggests they may regulate essential organ speciﬁc functions.

Chandrapalan, T.¹*, Kwong, R. W. M.¹ 1Department of Biology, York University, Toronto, Canada *Presenting Author Evaluating the importance of dietary iron in swimming performance and reproductive capacity in adult zebrafish Iron is an essential micronutrient for fish and iron content in the body can affect many parameters of health and wellbeing. The deficiency of iron can negatively impact development and survival while iron also has the potential to be toxic at high concentrations due to its involvement in oxidative stress. The diet is considered an important source of iron but the implication of varying dietary iron levels and their impact on major determinants of survival and fitness like swimming and reproduction, are not well examined in fish. In this study, adult zebrafish (Danio rerio) were exposed to 10, 400, and 2000 mg iron/kg via the diet, for a duration of 20 or 40 days. Swimming performance (e.g., critical swimming speed) and oxygen consumption rates (MO2) along with other metabolic parameters were measured. Our study showed that fish fed an iron-enriched diet performed better during the swim trials. Further, fish exposed to a high iron diet exhibited an increased number of embryo production, suggesting that dietary iron has the potential to alter reproductive capacity. Elevation in iron accumulation in the intestine and brain was also observed following iron exposure. Moreover, in the 20-day exposure, iron content in the ovaries was significantly reduced in the low iron treatment. Nevertheless, no significant changes in iron content were found in the embryos. The results of this study highlight the important role of iron in physiological performance and also the capacity of fish to regulate iron balance during times of low and high dietary availability.

Choo-Yin, Y. Y.1*, Lillico, D. M. E.1, Stafford, J. L.1 1 Biological Sciences, University of Alberta, Edmonton, Canada *Presenting Author

64 Bioactivity profiling of oil sands process affected waters using an immune cell-based bioassay system Northern Alberta is an economically important region due to its large volume of bitumen; a viscous form of oil that exists as a surface mixture of sand and water known as the oil sands. Industrial scale bitumen extraction processes generate large volumes of contaminated water commonly referred to as oil sands process-affected water (OSPW), which are permanently stored in large tailings ponds. Due to the expanding presence of tailings ponds containing contaminated and potentially toxic waters, OSPW must be remediated before it can be safely released into the environment. However, this represents a formidable challenge since all of the potentially toxic components within OSPW have yet to be identified. My research aims to develop an immune cell-based bioindicator system using mouse macrophages to monitor changes in their gene expression after exposure to different OSPW samples. To date, my results reveal that genes associated with inflammation and antimicrobial functions are basally upregulated by macrophages acutely exposed to sub-lethal doses of OSPW. This suggests that OSPW contains bioactive constituents capable of activating macrophages to produce antimicrobial and proinflammatory molecules; a response that is only normally observed during infections and/or inflammation. These observations confirm that OSPW has bioactive properties which can be rapidly and sensitively monitored via distinct changes in immune cell antimicrobial gene expression profiles. Based on these results, I established bioactive profiles for two different OSPW sources and their organic and inorganic fractions. Overall, my data shows that whole OSPW waters and their fractions induced unique bioactive signatures.

Chung, D. J.1*, Madison, G. P.1, Bleck, C. K. E.1, Darmani, N.2, Balaban, R. S.1 1National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, USA 2Department of Basic Medical Sciences, College of Osteopathic Medicine of the Pacific, Western University of Health Sciences, Pomona, USA *Presenting Author Mitochondrial network formation as a tissue-specific phenomenon in a mammalian model of extreme metabolism Most eukaryotes rely on mitochondria to maintain energetic homeostasis, but the functional relevance of mitochondrial structure and connectivity on tissue and whole-organism performance remains poorly understood. Here, we investigated mitochondrial structure/networking, content, protein programming, and we also sequenced and annotated the genome of the North American least shrew (Cryptotis parva) – a diminutive mammal (4-6 g) with a high mass-specific basal metabolic rate. We compared mitochondrial structure/composition among the heart, skeletal muscle, liver and kidney as these tissues are among the largest contributors to maximum and basal metabolism. An extensive mitochondrial reticulum occurs in striated muscle that is organized similarly to those in larger organisms. But these networks exhibit a greater incidence of nanotunneling and unique intermitochondrial junctions (mitosynapses) that may support the high metabolic demand of C. parva. Mitochondrial content and protein composition of the liver and kidney approaches that of the heart, suggesting a major contribution of these organs to the extreme metabolism of C. parva. However, despite a similar concentration of mitochondria, no mitochondrial reticulum was detected in the liver and kidney. This demonstrates that mitochondrial density, and associated maximum metabolic rate, is not a determinant in the formation of the reticulum. Instead, the liver and kidney adjust mitochondrial content and localization according to cellular requirements (e.g., extensive mitochondria-ER interactions in the liver). These results reveal conditions that necessitate the formation of mitochondrial networks and provide insight into mechanisms that underpin the extreme metabolism of small mammals.

Clark, R.1*, King, K.1*, Muldoon, T.1*, Hillier, N.K.1, Savage, J.2, Chuard, P. J. C.2, Shutler, D.1 1Department of Biology, Acadia University, Wolfville, Nova Scotia, Canada 2Department of Biology, Bishop’s University, Sherbrooke, Québec, Canada *Presenting authors eTick as a Model for Effective Surveillance Using Citizen Science Researchers are regularly constrained by limited resources in obtaining broad geographic coverage for important biological questions. For example, surveillance of disease vectors such as ticks is crucial to creating a functional epidemiological picture of zoonoses and their associated risks to populations of domestic animals and humans; however, surveillance that obtains data representative of tick populations in areas of high human-tick interaction is difficult to conduct for reasons including costs and shortages in

65 person-power. Passive surveillance through citizen science initiatives has been an effective tool that allows researchers to monitor much larger areas and gather data that are more representative of tick populations. Previously, the greatest barrier to studying ticks using citizen science initiatives was public willingness to participate, especially if such projects involved more intensive participation from citizens, such as collecting and mailing ticks to the appropriate university or agency. eTick has reduced this barrier by having citizens use the mobile app or website to upload digital photographs directly to the project database where trained personnel identify the ticks and relay information of relevance to public health. The ability of eTick to easily and rapidly address public concerns appears to encourage a high level of participation, leading to more comprehensive passive surveillance of tick populations in Nova Scotia and other participating provinces.

Collins, S. M.¹*, Hedd, A. H.2, Fifield, D.², Wilson, D. R.1, Montevecchi, W. A.¹ 1 Cognitive and Behavioural Ecology, Departments of Biology and Psychology, Memorial University of Newfoundland, St. John’s, Canada 2 Environment and Climate Change Canada, Mount Pearl, Canada *Presenting Author Small birds by-pass big risks on the Grand Bank of Newfoundland The global population of Leach’s Storm-Petrels, the smallest and most abundant breeding seabird species in Eastern Canada, has halved over 30 years. As a result, the International Union for the Conservation of Nature (IUCN) and the Committee for the Status of Endangered Wildlife in Canada (COSEWIC) list the species as Threatened. Fatal attraction to anthropogenic light is a known risk for seabirds globally. The largest colonies of Leach’s Storm-Petrels, located off the eastern coast of Newfoundland, Canada, are experiencing the most dramatic declines. The foraging paths of storm-petrels from these colonies intersect with oil production platforms on the Grand Banks, and light attraction is considered to be a major contributing factor to the species’ population decline. Using a dataset spanning from 2016 to 2020, we show high consistency in the distance, location, and behaviour exhibited during foraging trips within and between years. Although oil platforms were within their core foraging area, parental storm-petrels tended to transit quickly past the oil platforms during the day when light attraction is minimized. Based on these findings, we emphasize the need for future research to focus on risks to juveniles and immature birds and to threats outside the breeding season to facilitate the creation of mitigation tactics that can be employed strategically when and where human-induced risk poses the greatest threat to these seabirds.

Cormier, S. B., Boudreau, L. H., Pichaud, N. Department of Chemistry and Biochemistry, Université de Moncton, Moncton, Canada Mitochondrial adjustments in overwintering honeybees In recent years, beekeepers are reporting unsustainably high honeybee colony losses during winter, which have been notably linked to cold temperature, parasitization and virus infection. The honeybee is one of the few insect species that is adapted to survive winter conditions by modulating their physiology and behavior. Notably, winter bees that emerged at the beginning of October have increased longevity and form thermoregulating clusters. These clustering bees vibrate their flight muscles to generate heat during winter, maintaining a temperature of ~15°C and ~35°C on the outer edge and in the core of the cluster, respectively. Thus, overwintering provides a unique challenge for honeybees to overcome, and more specifically at the level of their metabolism. In this study, we evaluated mitochondrial respiration of thorax muscle in honeybees sampled from August 2020 to March 2021 to investigate the metabolic transition between summer and winter bees. Our results show that complex I mitochondrial respiration is highly correlated with external temperature (Pearson’s r = 0.839, P = 0.009). Specifically, we observed the highest mitochondrial oxygen consumption during August and September (296.15 ± 21.19 and 240.21 -1 -1 ± 22.04 pmol O2.s .mg tissue, respectively) and the lowest during December and January (111.43 ± -1 -1 16.37 and 107.24 ± 17.36 pmol O2.s .mg tissue, respectively). Moreover, the contribution of complex II and glycerol-3-phosphate dehydrogenase were significantly increased during the coldest months. Specifically, after succinate addition, mitochondrial respiration increased by approximately 150% and after glycerol-3-phosphate addition, it was increased by around 120% more. This suggests that these oxidative substrates play a key role in honeybee thermogenesis during winter. To the best of our knowledge, this is the first study linking the oxidative capacities of mitochondria to thermogenesis in

66 overwintering honeybees. Moreover, it identifies possible targets that could explain the massive mortalities detected during winter in Canada and Worldwide.

Coulson, S. Z.1,2 *, Staples, J. F.1, Guglielmo, C. G.1,2 1Department of Biology, Western University, London, Canada 2Advanced Facility for Avian Research, Western University, London, Canada *Presenting Author Seasonal plasticity in mitochondrial function of a migratory songbird Birds metabolically remodel their flight muscle prior to migration to better support the energetic challenges of migratory flight. The activities of mitochondrial enzymes linked to energy provisioning are elevated during the migratory season, but functional changes of intact mitochondria have yet to be investigated. We hypothesize that mitochondrial function varies with season and predict higher substrate oxidative capacity and reduced reactive oxygen species formation during migration. We captured yellow-rumped warblers (Setophaga coronata) during their fall migration at Long Point, ON. Half of the birds were sampled within two to four weeks of capture (migratory phenotype) and the remaining birds were transferred to a short day photoperiod (9L:15D) for ten to twelve weeks to induce a wintering (non- migratory) phenotype. We investigated differences in mitochondrial function by conducting high-resolution fluororespirometry on mitochondria isolated from the pectoralis major flight muscle. Oxygen consumption and hydrogen peroxide (H2O2) formation rates were measured during phosphorylating and non- phosphorylating respiration of lipid and carbohydrate substrates. Oxygen consumption specific to electron transport system protein complexes was also measured using complex-specific substrates and inhibitors. We found no effect of season in any metric of oxygen consumption, except that respiration was marginally more uncoupled in wintering birds (p = 0.09). H2O2 formation rates were similar between seasons during phosphorylating respiration (p = 0.43) but were higher in wintering birds during non- phosphorylating respiration (p = 0.02). When standardized to oxygen consumption, H2O2 formation rates were significantly higher during non-phosphorylating respiration (p = 0.02) and marginally higher during phosphorylating respiration (p = 0.06) in the winter season. Our findings partially support our hypothesis and indicate that seasonal plasticity in mitochondrial function is limited to redox balance in migratory songbirds. This plasticity is significant to migratory birds, as oxidative damage caused by H2O2 may hinder flight performance during migration.

Country, M. W.¹*, Jonz, M. G.¹,² 1Department of Biology, University of Ottawa, Ottawa, Canada 2Brain and Mind Research Institute, University of Ottawa, Ottawa, Canada *Presenting Author Mitochondrial KATP channels depolarize mitochondria early in hypoxia to trigger hypoxia tolerance in retinal horizontal cells of goldfish (Carassius auratus) Neurons of the retina require oxygen to survive and to provide vision. In hypoxia, neuronal ATP production is impaired, ATP-dependent ion pumping is reduced, transmembrane ion gradients are 2+ dysregulated, and [Ca ]i increases enough to trigger excitotoxic cell death. However, central neurons of the common goldfish (Carassius auratus) are hypoxia-tolerant. The Carassius retina can survive hypoxic insult, but the cellular mechanisms of this hypoxia tolerance have not yet been explored in the retina. To investigate, we isolated retinal interneurons (horizontal cells; HCs), and measured intracellular Ca2+ 2+ 2+ concentration ([Ca ]i) with Fura-2. Goldfish HCs maintained [Ca ]i throughout 1 h of hypoxia. In contrast, 2+ [Ca ]i increased irreversibly in HCs of the hypoxia-sensitive rainbow trout (Oncorhynchus mykiss) within + just 20 min of hypoxia. Our results suggest mitochondrial ATP-dependent K channels (mKATP) are 2+ 2+ necessary and sufficient to stabilize [Ca ]i throughout hypoxia. In goldfish HCs, [Ca ]i increased when 2+ mKATP was blocked with glibenclamide or 5-HD, whereas an mKATP agonist (diazoxide) prevented [Ca ]i from increasing in hypoxia in trout HCs. We showed that hypoxia protects goldfish HCs via mKATP 2+ channels. Glycolytic inhibition with 2-deoxyglucose increased [Ca ]i, and this increase was rescued by hypoxia in an mKATP-dependent manner. We found no evidence of plasmalemmal KATP channels in patch- clamp experiments. Instead, we confirmed the involvement of KATP in mitochondria with TMRE imaging, as hypoxia rapidly (<5 min) depolarized mitochondria in an mKATP-sensitive manner. We conclude that mKATP channels open early in response to hypoxia, to initiate a neuroprotective pathway in goldfish HCs 2+ to maintain [Ca ]i and avoid excitotoxicity in hypoxia. This model provides novel insight into the cellular mechanisms of hypoxia tolerance in the retina. This work may inform new strategies to prevent hypoxic

67 damage to the eye which occurs in diabetic retinopathy, glaucoma, and age-related macular degeneration.

Devereaux, M. 1*, Brennan, K. 1, Chiasson, S. 1, Pamenter, M. E. 1,2 1Department of Biology, University of Ottawa, Ottawa, Canada 2 University of Ottawa Brain and Mind Research Institute, University of Ottawa, Ottawa, Canada *Presenting Author Central nervous system mechanisms mediating the hypoxic ventilatory and metabolic responses of adult Damaraland mole-rats Most adult mammals hyperventilate when exposed to acute environmental hypoxia (i.e., the hypoxic ventilatory response), and exhibit little to no change in metabolism. Damaraland mole rats (DMRs) are a eusocial and fossorial mammal, whose impressive tolerance and physiological responses to hypoxia are well documented. DMRs exhibit physiological adaptations seen in other mammals that inhabit similar hypoxic niches such as marked metabolic depression (i.e., the hypoxic metabolic response) and a blunted hypoxic ventilatory response; however, the underlying central nervous system mechanisms controlling these responses are not yet understood. Using whole-body plethysmography and respirometry, I exposed DMRs to 7% and 5% O2 after intraperitoneal injection with saline (control) or antagonists of adenosine, g-aminobutyric acid (GABA), and glutamate receptors to investigate the role of these key neurotransmitters in the DMR metabolic and ventilatory responses to hypoxic. I found that (i) adenosinergic signaling is a crucial part of their hypoxic metabolic response such that adenosine receptor inhibition truncates their tolerance to hypoxia, rendering 7% O2 the lethal limit despite DMRs otherwise being able to tolerate 3% O2, (ii) unlike most adult mammals, GABAergic signaling may play an excitatory role in the hypoxic ventilatory response, and (iii) blocking glutamatergic signaling revealed an excitatory effect on both their hypoxic ventilatory response, primarily through respiratory frequency, and the hypoxic metabolic response. Taken together, the adenosine-dependent metabolic depression and excitatory role of GABA suggest much of DMRs’ hypoxia tolerance comes from the retention of neotenic signaling mechanisms.

Donatelli, C. M.1*; Han, L. 2, Standen, E. M.1 1 Department of Biology, University of Ottawa, Ottawa, Canada 2 Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, Canada *Presenting Author Sink or Swim: How Polypterus senegalus’ Changing Armor Leads to Gait changes over Ontogeny. Adult Polypterus senegalus, a species of amphibious fish native to the freshwater systems of Africa, are covered in dense, spiny, armor-like scales. However, as juveniles, their scales are thin, smooth, and flexible. We were curious to know if this change in morphology lead to a change in kinematics. Adult Polypterus swim primarily using their pectoral fins and are generally characterized as rowers. A rowing gait only produces thrust during the downstroke and is feathered during the recovery stroke to reduce drag and produce lift. Pectoral fin swimmers can also be flappers, producing thrust during both the upstroke and downstroke. For our study, we measured the 3D kinematics and hydrodynamics of the pectoral fin over ontogeny using high speed video and PIV. Our data show that there is a thrust producing phase, and a lift producing phase in larger adult fish as well as a gait transition as fish grow. The lift producing phase during swimming in adult fish characterizes them as rowers. Conversely, smaller fish tend to use a flapping gait, producing thrust during both the upstroke and downstroke. To investigate the reason for this transition, we also measured armor density, volume, and morphology over ontogeny using staining and µCT scans. Smaller fish have lighter and more flexible scales and therefore have less need for a lift producing phase to remain in the water column. Larger fish have heavier interlocking armor and must change their gait as they grow to include a longer lift production phase to prevent their bodies from dragging along the bottom. Polypterus has long been used as a model for adaptive kinematics because of its ability to transition from swimming to walking. Our study shows that they are also able to adapt to a changing body morphology over ontogeny.

Douglas, A. J.¹*, Hug, L. A.¹, Katzenback, B. A.1 1Department of Biology, University of Waterloo, Waterloo, Canada *Presenting Author The wood frog skin microbiome: Seasonal variation in bacterial communities

68 Research on emerging amphibian pathogens has highlighted the importance of the skin microbiome in innate immune defence, but it remains unclear how these microbial communities might vary in response to environment factors or shifts in amphibian habitat and behavior. The North American wood frog (Rana sylvatica) is a freeze-tolerant species native to Canada and the Northern United States that breeds in vernal pools following the spring thaw and spends the remainder of the year inhabiting the forest floor. To determine whether the composition of the R. sylvatica bacterial skin microbiome differs by sex, vernal pond site, or temporally across season (spring, summer, fall) we sampled the skin microbiota of wood frogs from two breeding ponds in the spring and from the nearby forest floor in the summer and fall. Taxon abundance data revealed a profile of bacterial phyla similar to those previously described on anuran skin, with Proteobacteria, Bacteroidetes, and Actinobacteria dominating the wood frog skin bacterial microbiome. Our results indicated that sex of the host did not have a significant effect on skin bacterial microbiota diversity. Vernal pool site had a significant effect on microbial community composition, although skin-associated communities from both ponds were more similar to each other than to the communities observed in the frogs’ respective pond water. When compared based on season of capture, diversity analyses suggested there were significant differences between the skin bacterial microbiome of frogs from spring and summer/fall groups while the average diversity within each skin- associated community remained consistent. Our results illustrate seasonal variation in the structure of the wood frog skin bacterial microbiome and highlight the importance of considering temporal trends in an amphibian microbiome, particularly for species whose life history includes recurrent shifts in habitat and behavior. [Funded by NSERC]

Ducros, L.¹ ²*, Bourloutski, E.¹, Lavoie-Rochon, A. S.¹, Pichaud, N.², Lamarre, S. G.¹ 1Département de Biologie, Université de Moncton, Moncton, Canada 2Département de Chimie et Biochimie, Université de Moncton, Moncton, Canada *Presenting Author Do fish even care? The effects of cyclic hypoxia on growth, metabolism, and physiological condition in Arctic charr The intensification of anthropic activities is currently amplifying eutrophication in aquatic environments, resulting in an increase in algae populations. As a result of photosynthesis and respiration, the concentration of dissolved oxygen increases during the day and then drops drastically at night, creating a daily cycle of alternating normoxic and hypoxic conditions. Lack of oxygen and then reoxygenation can have serious repercussions on aquatic organisms such as fish. To cope with these oxygen fluctuations, fish must adjust their phenotype. Although hypoxia is now a major issue for ecosystems and fisheries worldwide, our knowledge remains limited regarding the impact of cyclic hypoxia. Our objective was to characterize the effects of cyclic hypoxia on growth, metabolism, and physiological condition in fish. We monitored the growth of Arctic charr (Salvelinus alpinus) exposed to thirty days of cyclic hypoxia. We measured the metabolic rate, the rate of protein synthesis as well as energy reserves of fish exposed to up to one month of cycling hypoxia. Contrary to our initial hypothesis, cyclic hypoxia did not seem to have any detectable effects on Arctic charr. Growth was not affected, nor were the hepatic energy stores such as triglycerides. Furthermore, no overcompensation in protein synthesis rate and metabolic rate were observed during reoxygenation. Arctic charr appears to acclimate well to cyclic hypoxia. These results raise many questions about the ability of fish to deal with their changing environment.

Duffy, B. M.¹*, Staples, J. F.¹ 1Department of Biology, Western University, London, Canada *Presenting Author Hibernating R&R: Mitochondrial Respiration and ROS Production in the 13-lined ground squirrel During hibernation, Thirteen lined ground squirrels (Ictidomys tridecemlineatus; TLGS) cycle between torpor and interbout euthermia (IBE). Arousal from torpor to IBE creates drastic changes in oxygen demand, as mitochondrial metabolism increases as much as 95%. Oxygen supply will also increase rapidly during arousals and is often considered similar to ischemia-reperfusion, where tissues (including liver—our tissue of study) experience drastic changes in oxygenated blood flow. Non-hibernators mitochondrial maximal respiration rates are often reduced following anoxia reoxygenation, likely due to increased reactive oxygen species (ROS) production. Reverse electron transport (RET) is a primary source of ROS production following anoxia-reoxygenation. I hypothesize that RET primarily produces arousal-associated ROS production and predict that ROS production following anoxia-reoxygenation will

69 be lower with inhibition of RET. TLGS survive dozens of arousals per hibernation season, suggesting resistance to anoxia-reoxygenation. I hypothesize that suppression of mitochondrial metabolism during hibernation protects against functional oxidative damage, and I predict that torpid liver mitochondria maximal respiration will reduce less than IBE following anoxia-reoxygenation. Further, I predict that ROS production levels will differ between torpor and IBE mitochondria, as metabolism is reduced in torpor and may therefore blunt response to oxygen fluctuations. My objective was to synchronously measure mitochondrial respiration and ROS production following five minutes of anoxia, then reoxygenation, and compare functional effects on maximal respiration rate (ST3) and ROS production in torpor and IBE isolated liver mitochondria. Results show reduced maximal respiration rates following anoxia- reoxygenation in IBE but no reduction in torpor. Conversely, levels of ROS production following anoxia- reoxygenation increased in torpor mitochondria but did not increase in IBE. Additionally, inhibition of complex I (and therefore RET) prevents reduction of maximal respiration following anoxia-reoxygenation. Overall, these results support my hypotheses that metabolic suppression protects against oxidative damage and suggests that functional damage is due to ROS production by RET.

Dytnerski, J. K.1*, Marshall, K. E.2, Baker, D. M.1, Russell, B. D.1 1 The Swire Institute of Marine Science and School of Biological Sciences, The University of Hong Kong, Hong Kong SAR, China. 2Department of Zoology, University of British Columbia, Vancouver, V6T 1Z4, Canada. *Presenting author Facilitation or degradation: do the benefits of herbivory for coral communities outweigh the costs of bioerosion? Herbivores play an integral part in maintaining the health of coral reefs by suppressing the growth of algae, build-up of sediment, and facilitating coral growth. When densities of herbivores are unnaturally high, however, grazing can have detrimental effects on corals through excessive bioerosion. Yet these benefits and costs are rarely investigated concurrently. To elucidate the effect of natural densities of the dominant herbivore in coral communities in Hong Kong (the sea urchin Diadema setosum), we tested the effect of grazing using a year-long exclusion experiment. To assess benthic community response to grazing, we monitored the algae and sediment accumulation, survival, and growth of three coral species (Pavona decussata, Platygyra carnosus and Porites lutea) and bioerosion of coral skeletons across seasons. We found that urchins maintained our simple coral assemblages and when excluded, algal- sediment matrix accumulation increased 25 to 75-fold. When urchins were present, P. lutea had 100% survival and P. desussata were unaffected. Urchins neither helped nor hindered growth rates for these corals. Surprisingly, P. carnosus experienced high mortality irrespective of the presence of urchins and higher bioerosion when urchins were present. We conclude that under natural densities, sea urchins clear substrate of algae and sediment while facilitating growth of encrusting algae, increase survival of some corals, maintain growth rates and health of coral assemblages, yet can bioerode and have deleterious effects on corals with more porous skeletons. Therefore, maintenance of herbivore populations will help preserve for the overall function of coral ecosystems.

Eom, J.1,2*, Lauridsen, H.2, Wood, C. M.1,2 1Department of Zoology, University of British Columbia, Vancouver, Canada 2Bamfield Marine Sciences Centre, Bamfield, Canada 3Department of Clinical Medicine, Aarhus University, Denmark *Presenting Author Feeding behaviour, anatomy, and physiology in Pacific hagfish, Eptatretus stoutii The overall feeding physiology of hagfish is barely known, though it is generally believed that they feed on dead carcasses submerged in the deep-sea environment, penetrating into the body of an animal and scratching the soft tissues and organs using their dental plates. However, in the lab we observed Pacific hagfish (Eptatretus stoutii) feeding by engulfment on chunks of anchovies. We also observed their digestion processes while measuring their ventilation changes in the nostril duct and oxygen consumption rates in 12 gill pouches including the pharyngo-cutaneous duct (PCD). The hagfish engulfed chunks of anchovies up to ~20% of their body weight, excreted the bony structures and scales within 1.7 day and an intestine membrane together with bile acids through the anus within 5 days. We also imaged the anatomical structure of the anterior end of the fish body with µMRI in order to better understand the feeding mechanisms in hagfish (NSERC Discovery).

Esparza, I.1*, Fernie, K.2, Choy, E. S.1, Elliott, K.1 1Department of Natural Resource Science, McGill, Ste Anne-de-Bellevue, Canada 2National Wildlife Research Center, Environment Canada, Ottawa, Canada *Presenting Author Climate change, contaminants, ecotoxicology: interactions in Arctic seabird at their southern range limit Pagophilic (ice-associated) Arctic species are facing multiple stressors from climate change and contaminants, especially mercury which occurs at high levels in Arctic wildlife. We investigated whether mercury increases the impact of climate change on the thick-billed murre (Uria lomvia) by limiting its ability to respond to extreme changes in ice availability. We studied the tick-billed murres near their southern range limit during tree breeding seasons under early-ice (2017), moderate-ice (2016) and late- ice (2018) conditions. We tracked 163 breeding adults using GPS-accelerometers to classify their behaviours (i.e. total time at the colony, diving, swimming and flying) and measured concentrations of hormones (T3, T4 and corticosterone) and mercury. Under poorer ice conditions (2016 & 2017), mercury was negatively (early-ice) and positively (moderate-ice) related to T3, and T3 was negatively associated with diving (2016 & 2017). Mercury may influence the ability of thick-billed murres to adjust their foraging behaviours to variation in ice cover, especially during years where ice-break up occurs earlier, demonstrating how climate change and contaminants can interact.

Esposito, E. K. J.1*, Grombacher, L.1, Sanchez del Rio, I. A. C.1, Varry, D.1, Matveev, E.1, Riesgo, A.1, Leys, S. P.1 1Department of Biology, University of Alberta, Edmonton, Canada *Presenting Author Sensitivity and formation of the sponge aquiferous system Animal bodies are structured around epithelial-lined tubes, such as guts, kidney tubules, lungs, trachea, and blood vascular systems. These form in a variety of ways, some branching at the tips, like insect trachea, and others fusing lacunae together like blood vessels. Sensory feedback by cells that detect flow is known to play a role in both systems. We study sponges, non-bilaterian animals whose bodies are entirely organized around epithelial lined canals that bring water through the body for respiration and feeding. We asked whether, as in other animals, sensory feedback plays a role in forming the sponge aquiferous system. The freshwater sponge Ephydatia muelleri develops through 5 distinct stages: hatching (Stg1), small lacunae (Stg2), large lacunae (Stg3), canals and incipient osculum (Stg4), and fully developed canals and osculum (Stg5). The osculum or vent forms last, yet cell birth dating with pulsed EdU indicated cells that form the osculum are born in Stg1-3. Flagellated cells that drive the water flow, choanocytes, differentiate in Stg1, and form spherical chambers by Stg2. Fluorescent latex microspheres placed on the surface of Stg2 sponges were drawn into the chambers, indicating the sponge was pumping before osculum formation. Water was only seen exiting the osculum of a sponge at Stg4. Moreover, lacunae in Stg2 and 3 sponges had single, 6 µm long primary cilia. Blocking of calcium channels in primary cilia using FM 1-43, neomycin sulfate, and Gd3+, prevented canal formation, suggesting primary cilia on lacunae are necessary for canal formation. Genes involved in vascularization in other animals are upregulated during development in the sponge. These results suggests that the sponge canal system may develop via feedback from flow as lacunae expand and merge and that the mechanism of canal formation may be analogous blood vessel formation from blood islands in bilaterian animals.

Ethier, J. P.1*, Fayard, A.2, Soroye, P.1, Mazerolle, M. J.2, Trudeau, V. L.1 1Department of Biology, University of Ottawa, Ottawa, Canada 2 Centre d’étude de la forêt, Département des Sciences du Bois et de la Forêt, Université Laval, Laval, Canada *Presenting Author Life history traits of North American chorus frogs (genus Pseudacris: Hylidae) are remarkably similar: is this a risk or a benefit to conservation efforts? Amphibian biodiversity is declining globally, with over 40% of species threatened with extinction. Chorus frogs are an example of a genus that is relatively abundant but with several populations experiencing significant declines throughout North America. In Canada, the Great Lakes/St. Lawrence – Canadian

71 Shield population of Pseudacris maculata is listed under the Species at Risk Act. In the USA, P. illinoensis is restricted to a single county in Arkansas and is listed threatened in Illinois. In Mexico, P. hypochondriaca and P. cadaverina, among other amphibians are exposed to numerous environmental contaminants, leading to increased malformations that are linked to population declines. One approach to species conservation may be to develop assisted reproduction technologies and reintroduction strategies before wild populations critically decline. Both assisted reproduction technologies and reintroduction strategies rely on a thorough understanding of the ecology of candidate species. A comprehensive review of these data indicates remarkable consistency in behaviour, reproduction, development and longevity of the 18 Pseudacris spp. Consider, for example, P. maculata, in central USA and Canada, and P. hypochondriaca in western USA and Baja California. Despite being in separate taxonomic clades within the genus, these two species produce similar-sized clutches of eggs (400–750) that hatch in < 2 weeks and have larvae that metamorphose in ~2 months. Our review also revealed that the most threatened populations of the Pseudacris genus are located in eastern North America and that they may be particularly susceptible to anthropogenic disturbance and changing climate patterns. The increased susceptibility may be linked to their characteristic cold-weather breeding strategy and reliance on temporary wetlands. The strong similarities in life histories and reproductive ecology of Pseudacris spp. suggests that the assisted reproduction technologies and reintroduction strategies developed for one species could be more broadly applicable to others in this genus.

Evans, D.1*, Millar, Z.1, Wolvin, S.2, Pham, P.1, LePage, V.2, Lumsden, J. S.1 1Department of Pathobiology, University of Guelph, Guelph, Canada 2 Ripley’s Aquarium of Canada, Toronto, Canada *Presenting Author Magnesium concentration influences size and pulse rate in the upside-down jellyfish, Cassiopea andromeda Magnesium is involved in a variety of physiological processes in animals. It is known to be deleterious in both excess and deficiency and there is a need to monitor magnesium in aquatic ecosystems, including captive display systems. The purpose of the present study was to examine the effects of varying magnesium concentration on upside-down jellyfish (Cassiopea andromeda). Medusae were exposed to various artificial salt mixes (supplied by Ripley’s Aquarium of Canada), in which magnesium was the only element altered between treatments. Pulse rate and size were measured every three days in jellyfish exposed to magnesium concentrations ranging from 700 mg/L (low), 1344 mg/L (control) and 2000 mg/L (high) in two, 28-day trials. Pulse rate was determined by counting bell pulsations for 30 seconds per individual, bell diameter was measured using photos and ImageJ and morphological changes were observed. Exposure to low magnesium resulted in significantly (p<0.05) higher pulse rates, decreased bell diameter and produced oral arm degradation in all exposed animals. Exposure to high magnesium resulted in significantly (p<0.05) lower pulse rates and decreased bell diameter, as well as oral arm cupping in all exposed animals. In both low and high magnesium, almost all specimens changed colour from pale blue on Day 1, to brown by Day 28, suggesting a loss of zooxanthellae. The decrease in bell diameter and colour change was more pronounced and occurred more rapidly in low magnesium; these results were consistent between both trials. While many aspects of magnesium are well-studied, its effects in both deficiency and toxicity on many marine animals remains unknown. Magnesium concentrations are commonly monitored in systems containing coral, however the present study highlights the importance of monitoring magnesium in all aquatic environments, as well as marine display systems.

Faught, E.¹*, Vijayan, M. M.¹ 1Department of Biological Sciences, University of Calgary, Calgary, Canada *Presenting Author A stress symphony: the coordinated efforts of corticotropin-releasing hormone and cortisol in mediating stress behaviour The stress response, mediated by the hypothalamus-pituitary-adrenal (HPA) axis results in the release of glucocorticoids (GCs), causing metabolic, endocrine, and behavioural adaptations that allow an organism to cope with stress. Hyperactivity is an established behavioural response to acute stress; however, it is unknown whether it is GCs alone, or the interaction between HPA axis intermediates, which will facilitate this response. Indeed, corticotropin-releasing hormone (CRH), the primary step in HPA activation, is

72 known to play a role in stressor-mediated behaviour. We tested the hypothesis that the CRH induced rise in GCs post-stress is necessary for the initiation and maintenance of acute stress-related behaviour. In this study, we used zebrafish larvae, which have well-characterized changes in locomotion in response to acute light exposures. Given the distinct temporal release and signalling of CRH versus GCs, we assessed the changes to larvae locomotion over the short term (15 min) and long term (1 and 4 h) post- stress. We first generated and validated zebrafish containing a functional CRHR1 knockout (CRHR1-KO). Larvae lacking crhr1 did not increase cortisol post-stress and they also lacked stress-induced hyperactivity. To determine whether this was due to a lack of CRH or cortisol, the primary GC in fish, wildtype larvae were treated with metyrapone (MET). MET effectively blocked the attendant rise in cortisol post-stress; however, only abolished long-term hyperactivity. To further determine the temporal role for cortisol signalling we assessed behaviour in larvae lacking either the glucocorticoid receptor (GRKO) or the mineralocorticoid receptor (MRKO). Overall, the results suggest that the stress-induced hyperactivity is induced by the CRH/CRHR1 system, and cortisol production and the associated GR/MR signalling is essential for prolonging the stressor-induced hyperactivity. This study underscores the importance of systems-level analysis to assess stress responsivity.

Ferguson, L. V.*, Nabbout, A. E., Adamo, S. A. 1Department of Psychology and Neuroscience, Dalhousie University, Halifax, NS, Canada *Presenting Author Every season is tick season: Winter activity of black-legged tick, Ixodes scapularis, infected with Borrelia burgdorferi Black-legged ticks, Ixodes scapularis have expanded their range northward and become abundant in provinces such as Nova Scotia, where winter conditions are now insufficient to disrupt their life cycles. Ticks are often anecdotally cited to become active above 4 ºC; however, we have little empirical understanding of the physiological and environmental conditions that promote winter activity. Further, pathogens such as Borrelia burgdorferi impact the physiology of ticks and have the potential to also influence their behaviour. To determine the thermal conditions that trigger and suppress winter activity, as well as the potential influence of B. burgdorferi on winter behaviour, we monitored two years of winter activity of wild-collected, adult, female ticks under simulated winter conditions using automated activity monitors. Ticks were readily active above 0 ºC throughout the winter, but individual ticks displayed unique behavioural patterns and permissive temperatures did not guarantee activity in all ticks. Fluctuating temperatures promoted more winter activity compared to constant low, but permissive, temperatures, indicating that re-warming is an important trigger of activity. Infection with B. burgdorferi may promote increased activity near the end of the winter, although this effect was not prominent in all years. Overall, sustained winter activity is a phenomenon in at least a portion of the population of ticks; however, activity is likely driven by the physiology of the individual, and the drivers of this activity are currently unclear. It will be important to further elucidate the physiology underlying these behavioural phenotypes to predict how changing winters will shape disease incidence related to ticks in Canada.

Folkerts, E. J.1*, Alessi, D. S.2, Goss, G. G.1 1Department of Biological Sciences, University of Alberta, Edmonton, Canada 2Department of Earth and Atmospheric Sciences, University of Alberta, Edmonton, Canada *Presenting Author Immediate and latent effects of hydraulic fracturing flowback and produced water on embryonic rainbow trout (Oncorhynchus mykiss) cardio-respirometry development and physiology. During hydraulic fracturing, wastewaters - termed flowback and produced water (FPW) - are created as a by-product when wells shift operationally to extracting reserves. Given the vast volumes of FPW a single well can produce and the history of FPW release to surface water bodies, it is imperative to understand what hazards hydraulic fracturing and FPW pose to the environment and aquatic biota. Using rainbow trout embryos as model organisms, we investigated impacts to cardio-respiratory system development and function following acute (48 hr) and chronic (28-day) FPW exposure by examining occurrences of developmental deformity, rates of embryonic respiration (MO2), and changes to critical cardiac-specific genes. FPW-exposed embryos had significantly increased rates of pericardial edema, yolk-sac edema, and tail/trunk curvatures at hatch. Furthermore, when exposed at three days, post-fertilization (dpf), acute 5% FPW exposure significantly increased embryonic MO2 through development until 15 dpf, wherein a switch occurred, and significantly reduced MO2 rates were subsequently recorded. A similar trend was

73 observed during chronic 1% FPW exposures. It was also observed that embryonic genes for cardiac development and function were significantly altered following acute exposure. However, by the end of chronic exposures, significant changes to these same genes were not found. To determine if the above embryonic changes induced chronic, long-lasting impacts in FPW exposed fish, swimming performance and respirometry were investigated 8-months post-embryonic exposure to characterize cardio-respiratory alterations further. Regardless of concentration and method (acute versus chronic), embryonic FPW exposure significantly reduced maximum metabolic rates and aerobic scope in swimming fish. This reduced aerobic capacity correspondingly translated into significantly lowered critical swimming speeds in exposed fish. Together, our evidence of altered embryonic cardio-respiratory system development and function following FPW exposure may be helpful to regulatory bodies when developing hazard identification and risk management protocols concerning hydraulic fracturing activities.

Fontaine A.1*, Simard A.2, Larocque G.3, Elliott K. H.1 1Department of Natural Resource Sciences, McGill University, Montreal, Canada 2Ministère des Forêts, de la Faune et des Parcs, Quebec, Canada 3Quebec Centre for Biodiversity Science, Montreal, Canada *Presenting Author Using citizen science to monitor a wildlife decline: Estimation of spatiotemporal trends in maternity colonies from the Quebec Neighbourhood Bat Watch project Long-term and large-scale monitoring of wildlife populations is fundamental to answer questions relevant to conservation. Bats represent one-fifth of all mammal species, yet because of their cryptic habits, monitoring is difficult and population dynamics of many species is scarcely known. In the context of a disease spreading throughout North American bat populations, a citizen science project was initiated in 2012, asking the public (“citizen scientists”) to help monitor bat maternity colonies in Québec. We examined the variation in the distribution and abundance of bat populations in Quebec using the Neighbourhood Bat Watch database on location and emergence counts (n = 373) at maternity colonies from 1997-2020. We were particularly interested in trends relative to white-nose syndrome (WNS) progression and maternity colony exclusions from buildings. Myotis species declined during the first three years after WNS onset (60 % - 98 %), while mixed and big brown bat colonies slightly increased or decreased after WNS onset. Out of the 287 colonies with known fate recorded from 1997-2020, 102 (36 %) have subsequently been excluded from buildings. The probability of exclusion was higher in the north compared to the south, and in houses compared to barns, garages, and sheds, but did not vary with habitat type. Although research on bat responses to WNS must continue, to understand the population- level impacts of this disease, renewed management attention to other threats may hold more immediate promise for reducing further declines and improve bats resilience to WNS. The Neighbourhood Bat Watch citizen science project provided useful trends for declining species and likely reduce the exclusions rate and increase the rate of roost compensation measure when exclusion is unavoidable through education of participants.

Friesen, O. C.1, Aukema, H. M.2, and Detwiler, J. T.1 1 Department of Biological Sciences, University of Manitoba, Winnipeg, Canada 2 Department of Food and Human Nutritional Sciences, University of Manitoba, Winnipeg, Canada Snail chemical communication affected by host-parasite interactions Host behaviour may be modified by their parasites to increase the likelihood of transmission, but the mechanisms underlying these interactions are not well understood. Some hosts and parasites release chemical signaling molecules, like oxylipins, that may affect transmission. Oxylipins are oxygenated metabolites of fatty acids that function as signaling molecules and have essential roles in the normal physiology and function of a variety of species. Yet, the limited taxonomic and contextual scope of these studies limits our ability to understand the role of signaling molecules in parasite-modified behaviour. We characterized oxylipins in field-collected Ram’s horn snails, Planorbella pilsbryi, that are commonly infected with trematode parasites. We tested for differences in the diversity and amounts of oxylipins based on infection status and parasite activity (larval parasite emergence). Snail-conditioned water samples were produced by placing five snails into artificial spring water for four hours. We created 28 snail-conditioned water samples (n=140 snails), with 13 created from infected snails, with 7 of these exposed to light to increase parasite activity, and 15 with uninfected snails. Oxylipins were extracted from snail-conditioned water samples and quantified using high performance liquid chromatography-tandem

74 mass spectrometry. Overall, infected snails emitted 48 oxylipins in higher amounts, with 19 of these oxylipins only detected in water from infected snails. Uninfected snails emitted higher amounts of 2 oxylipins. Within infected snails, 15 oxylipins were emitted in higher amounts in snails with increased parasite activity. As infected snails emit different oxylipins and often at higher amounts than uninfected snails, the production of these oxylipins may play a role in altering transmission success. Understanding the importance and role of chemical signaling is crucial for greater understanding of community interactions.

Gauvreau, N. L.¹* and Craig, P. M.¹ 1Department of Biology, University of Waterloo, Waterloo, Canada *Presenting Author Reactive oxygen species as a marker of neurodegeneration: the impacts of wastewater effluent pharmaceuticals in darters (Etheostoma sp.) in the Grand River. The Grand River (GR) watershed extends throughout the majority of Southern Ontario with its final outlet at Lake Erie. Along the GR, several wastewater treatment plants (WWTP) with varying filtering processes are found. Many of these WWTPs are currently unable to effectively eliminate pharmaceutical by- products, such as anti-depressants and anti-convulsant’ from their final release effluent. This leads to measurable amounts (ng/L – μg/L) of pharmaceuticals within the GR, ultimately leaving aquatic species chronically exposed to these pharmaceuticals. These chronic exposures have been reported to impact oxidative stress which is measurable through reactive oxygen species (ROS) production and the antioxidant defense response which helps reduce the toxicity of ROS produced molecules. This research focuses on the effects of known pharmaceuticals of concerns on Etheostoma (Darter) species which are endemic to the GR. Darters are model species as they are abundantly found in the GR with varying tolerances to anthropogenic activity and have known impacts from wastewater effluent such as changes to gill morphology and metabolic rates. Specifically, this study determines whether any neurodegenerative effects are present in darter species downstream from the effluent release point compared to darters from a clean site upstream from the WWTP in Waterloo, ON. Evidence for such neurodegeneration can be indicated by increased ROS enzymatic activity, damage, or changes in specific transcript markers in the downstream darter species. This was assessed using transcriptional and enzyme analysis of antioxidant enzymes (SOD, GPX, CAT) and an enzyme involved in serotonin synthesis (TPH). Significantly increased expression of transcript markers was found in downstream species compared to upstream species analyzed using T-tests (p < 0.05). Enzyme activity additionally displayed significant differences; however, activity was not consistently higher downstream. Continued investigation on the impacts of pharmaceutical exposures in non-target organisms such as darters, is crucial to further the knowledge of how WWTP effluent is affecting aquatic communities.

Gil, K. N.1 1 Department of Zoology, University of British Columbia, Vancouver, Canada How do Fin Whales Protect Their Respiratory Tract While Swallowing Massive Quantities of Food Underwater? Digestive and respiratory pathways are entwined evolutionarily, developmentally, and spatially. The pharynx is the crossroads of these tracts, residing behind the nasal and oral cavities and containing the larynx. The pharynx balances breathing and swallowing, allowing food transfer while maintaining airway protection. Cetaceans have terrestrial ancestry, thus, a terrestrial framework that required modifications for life underwater. Toothed whales have a permanently intranarial tubular larynx, completely separating respiratory and digestive tracts to facilitate echolocation. Rorqual baleen whales do not echolocate, but have many adaptations related to feeding, which involves engulfing a volume of prey-laden water that can be larger than their own body. Laryngeal morphology in rorquals differs vastly from odontocetes, with a splayed open laryngeal inlet and no tubular structure. Considering the immense amounts of tiny living prey collected during each lunge, I asked: how are the pharynx and larynx adapted to maintain protection during swallowing? I explored this question with dissections of adult and fetal fin whales to reveal pharyngeal and laryngeal structures. I dissected a dolphin fetus as a representative odontocete. The pharyngeal and laryngeal positions in fin whales during deglutition are surprisingly similar to a terrestrial carnivore, with the exception of a novel structure discovered in rorquals, the oral plug, that passively protects the pharynx from water incursion during lunging. The lower airways are protected by completely sealing the larynx and trachea through passive and active mechanisms. The upper airways are

75 completely sealed by the soft palate and oral plug. Rorquals have maximized feeding ability by dedicating the entire pharynx to the digestive tract during swallowing, an adaptation that has contributed to rorquals becoming the largest animals ever to have lived.

Gilbert, M. J. H.1,2*, Harris, L. N.3, Moore, J. S.4, Farrell, A. P.2,5 1Biological Sciences, University of New Brunswick, Saint John, Canada 2Department of Zoology, University of British Columbia, Vancouver, Canada 3Freshwater Institute, Fisheries and Oceans Canada, Winnipeg, Canada 4Institute of Integrative Biology and Systems, Université Laval, Québec, Canada 5Faculty of Land and Food Systems, University of British Columbia, Vancouver, Canada *Presenting Author Population-specific thermal tolerance and cardiorespiratory performance of wild Arctic char in a rapidly warming north The Canadian Arctic is warming at nearly three times the average global rate. High water temperatures are known to constrain the exercise physiology and migration of temperate salmonids in a population- specific manner. However, we know alarmingly little about Arctic char migratory and thermal physiology, especially at the population level. Thus, predicting the impacts of environmental challenges associated with climate change is difficult. Consequently, we investigated the cardiac thermal tolerance and aerobic capacity of adult Arctic char (~3.5 kg) from four populations in the Kitikmeot Region of Nunavut. Two of these populations undertake short migrations (<5 km) and two undertake longer (>30 km), more challenging migrations, and likely encounter greater thermal variation. In general, during acute warming heart rate typically reached a peak at 17-21°C, before declining and becoming arrhythmic at 21-24°C. The temperatures at which these heart rate limitations occurred as well as maximum oxygen uptake and aerobic capacity at 10°C were lowest in Arctic char from a population with mild migratory conditions and were greatest in char with the longest, most difficult migration. Furthermore, relative heart mass tended to be greater in Arctic char from populations with more strenuous migrations. This pattern of differences suggests that Kitikmeot Arctic char may be physiologically adapted to their local migratory environments. Such physiological differences together with local environmental differences will likely make some populations more vulnerable to climate change than others, necessitating population-specific management actions.

Gill, L. T. J.*, Kennedy, J. R., Marshall, K. E. Department of Zoology, University of British Columbia, Vancouver, Canada *Presenting author Proteostasis in ice: The role of protein aggregation and stress proteins in freeze tolerance in the intertidal mussel species, Mytilus trossulus The bay mussel, Mytilus trossulus, is one of the few animals that can survive internal ice formation. Mussels are important human food sources and provide habitat for intertidal species. With the increasing frequency of cold snaps due to climate change, investigating mussel freeze tolerance will be necessary in predicting the future of our coastlines. There has been little work done on freeze tolerance of intertidal species, limiting our understanding of this survival strategy. This limited research has focused solely on the effects of sustained freezing periods. In nature, however, freeze tolerant intertidal animals freeze and thaw many times during the winter depending on air and ocean temperatures. The act of crossing the freezing threshold may present physiological or biochemical stressors that have yet to be discovered. Freezing also can present challenges such as protein denaturation which leads to aggregates, and induction of the heat shock response with expression of proteins like hsp70. This study aims to evaluate the effects of repeated freezing on mussel physiology, and we predicted that repeated freeze-thaw cycles will increase protein aggregation and hsp70 expression. Mytilus trossulus were collected from Vancouver, Canada and repeatedly frozen at -8°C for a combination of: 1x8hour, 2x4 hours or 4x2 hours. Mortality, tissue protein aggregation, and hsp70 expression was then compared across the animals. It was found that mussels exposed to freeze-thaw cycles showed increased survival compared to a single, sustained freeze. Despite the differences in survival, mussels exposed to freezing events of any duration did not produce higher quantities of protein aggregates than control. In response to repeated freezing, increased hsp70 expression was observed in low intertidal mussels and 20 hours after their final freeze. These findings provide novel insight into how intertidal invertebrates respond to repeated freezing, and the specific mechanisms of freeze tolerance in M. trossulus.

Gnanagobal, H.1*, Cao, T.1, Hossain, A.1, Dang, M.1, Hall, J. R.2, Kumar, S.1,3, Cuong, D. V.4, Boyce, D5, Santander, J.1 1 Marine Microbial Pathogenesis and Vaccinology Laboratory, Department of Ocean Sciences, Memorial University of Newfoundland, St. John’s, NL, Canada 2 Aquatic Research Cluster, CREAIT Network, Ocean Sciences Centre, Memorial University of Newfoundland, St. John’s, NL, Canada 3 Ocean Frontier Institute, Ocean Sciences Centre, Memorial University of Newfoundland, St. John’s, NL, Canada 4 Research Institute for Aquaculture No.2, Ho Chi Minh City, Vietnam 5 The Dr. Joe Brown Aquatic Research Building (JBARB), Ocean Sciences Centre, Memorial University of Newfoundland, St. John’s, NL, Canada *Presenting Author Host-pathogen Interactions between Lumpfish (Cyclopterus lumpus) and Renibacterium salmoninarum Renibacterium salmoninarum is a Gram-positive, intracellular pathogen that causes Bacterial Kidney Disease (BKD) in several fish species in fresh water and seawater. Lumpfish (Cyclopterus lumpus) is utilized as a cleaner fish to biocontrol sea lice infestation in Atlantic salmon (Salmo salar) sea farms. Although BKD outbreaks have yet to be reported in lumpfish, this fish has a potential BKD risk due to the broad host range of R. salmoninarum and horizontal transmission. In this study, we evaluated the susceptibility and immune response of lumpfish to R. salmoninarum infection. Groups of lumpfish were intraperitoneally (i.p) injected with either R. salmoninarum (1×107, 1×108, or 1×109 cells/dose) or PBS (control). The infection kinetics and mortality were followed for 98 days post-infection (dpi). Transcript expression levels of 33 immune-relevant genes were measured in head kidney (n = 6) of fish infected with 1×109 cells/dose and compared to the control at 28 and 98 dpi. Infected lumpfish displayed characteristic clinical signs of BKD. Lumpfish infected with the highest, medium, and lowest doses had survival rates of 65%, 93%, and 95%, respectively. Mortality in the high-dose infected group stabilized after 50 dpi, but R. salmoninarum persisted in the fish tissues until 98 dpi. Cytokines (il1β, il8a, il8b), pattern recognition receptors (tlr5a), interferon-induced effectors (rsad2, mxa, mxb, mxc), and iron regulation (hamp) and acute phase reactant (saa5) related transcripts were up regulated at 28 dpi. In contrast, cell-mediated adaptive immunity-related transcripts (cd4a, cd4b, ly6g6f, cd8a, cd74) were down-regulated at 28 dpi, revealing the immune suppressive nature of R. salmoninarum. However, significant upregulation of cd74 at 98 dpi suggests induction of a cell-mediated immune response. This study reveals that lumpfish is susceptible to R. salmoninarum ATCC 33209 and showed a chronic infection with an enhanced cell- mediated adaptive immune response.

Haider, F.1*, Sokolova, I. M.1 1Department of Marine Biology. Universität Rostock, Rostock, Germany * Presenting Author Can efficient mitochondria increase endurance towards stressful environmental conditions? Benthic marine invertebrates play key ecological roles as bioturbators facilitating the sediment mixing and are often exposed to salinity fluctuations in shallow coastal habitats. The soft-shell clam Mya arenaria is a common bioturbator in the shallow coast of the Baltic Sea, where salinity fluctuates due to water exchange with North Sea, precipitation, and submarine groundwater discharge. Furthermore, wave action often exposes clams on the sediment surface, compelling them to re-burrow to escape predation and washing ashore. Intracellular osmotic regulation and burrowing are considered energetically expensive; therefore, combined energetic stress from salinity fluctuation and re-burial can negatively affect survival and ecological performance of these organisms. We exposed M. arenaria to three salinity regimes (normal/NS: 15, low/LS: 5 and fluctuating/FS: 5-15) and two disturbance levels (undisturbed, and repeatedly disturbed until exhaustion). For Mya, a single burrowing cycle costed ~7% of total body-energy reserves and clams from LS and FS took longer time to bury. Burrowing was mostly (~70%) fueled by protein in clams acclimated to NS and LS, whereas 20-30% drop in protein content was observed in clams acclimated to FS. Aerobic capacity of the foot muscle dropped 60-70% in clams from LS compared to NS. The plasticity of their mitochondrial performance as well as their muscle aerobic capacity was disrupted upon acclimation to LS. Overall, salinity stress and sediment reworking negatively affected the burrowing activity and energy status of Mya population. However, our results show that individuals with

77 efficient mitochondria could sustain burrowing performance longer compared to their counterparts with less efficient mitochondria.

Hardison, E. A.¹*, Kraskura K.¹, Van Wert J. C.1, Nguyen T., Eliason E. J.¹ 1Department of Ecology Evolution and Marine Biology, University of California Santa Barbara, Santa Barbara, CA, USA *Presenting Author Diet alters thermal performance traits in a marine omnivorous fish (Girella nigricans) Thermal acclimation is a key process enabling ectotherms to cope with temperature change. To undergo a successful acclimation response, ectotherms require energy and nutritional building blocks obtained from their diet. However, diet is often overlooked as a factor that may alter acclimation responses. Using a temperate omnivorous fish, opaleye (Girella nigricans), as a model species, we tested the hypotheses that 1) diet can impact the magnitude of thermal acclimation responses and 2) traits vary in their sensitivity to temperature acclimation and diet. We fed opaleye a simple choice-omnivorous diet (ad libitum Artemia sp. and Ulva sp.) or a fixed-carnivorous diet (ad libitum Artemia sp.) at two ecologically relevant temperatures (12 and 20°C) for three weeks and then measured multiple biological rates (growth, sprint speed, metabolism, lactate dehydrogenase activity), and thermal limits (Critical and cardiac). We found evidence that diet influences thermal acclimation responses in opaleye. However, there was no consistent pattern in how traits responded to the temperature and diet treatments, with Q10 values ranging from 1-25 and some showing no diet effect (e.g., sprint, growth, thermal limits). Further, we did not find evidence that opaleye made diet choices that improved their thermal responses in the lab. When confronted with a seasonal extreme warm temperature (20°C), opaleye in the choice-omnivorous treatment had reduced cardiovascular performance and higher standard metabolic rate than those in the fixed-carnivorous treatment. Our results suggest that diet influences thermal performance differentially across traits, which could lead to performance trade-offs for temperate fishes with multiple diet options.

Harrison, D., Leys, S., De Leo Cabreara, F., Marini, S., Gallin, W., Mir, F. University of Alberta Using machine learning to recognize and map sponge behavior associated with multivariate climate parameters Demosponge behavior and responses to stimuli are not fully understood. Studies have found responses to changes in environmental variables such as temperature, salinity, pressure, light, and oxygen. Due to opportunistic circumstances, a large baseball-sized demosponge (Suberites concinnus) established itself directly under an eight-camera observatory node maintained by Ocean Networks Canad. The node, called the Folger Pinnacle, is located off the southwest side of Vancouver Island at the mouth of Barkley Sound. Images along with environmental variables were collected hourly between 2012 and 2015. Using machine learning applications such as Convolutional Neural Networks (CNN) and multivariate analysis, we developed an algorithm to map the changes in this sponge's behavior in a large set of temporal imagery. We expect to see behavioral changes associated with climatic variations. Preliminary time series analysis showed some observable behaviors that were classified into three categories: ripple, cringe, and twitch. One particular event suggests that the sponge responded to the onset of a storm. The sponge dramatically decreased in size before the start of the storm and may have responded to pressure changes associated with changing weather patterns. The next challenge in this investigation will be applying the machine learning algorithm to classify different behaviors based on changes in size, the direction of movement, and duration.

Hirtle, S.V.1, Goater, C.P.1 1Department of Biological Sciences, University of Lethbridge, Lethbridge, Canada Patterns of multiparasitism and consequences of co-infection in fathead minnows (Pimephales promelas) Parasites are ubiquitous in nature and consequently, individual hosts are regularly infected with multiple parasite species or strains simultaneously. Co-occurring parasites can profoundly impact each other and their hosts, since the effects of multiparasitism are the product of parasite interspecific interactions that may be facilitative or competitive. To further our understanding of co-infection in wild hosts, we documented the extent of multiparasitism in fathead minnows (Pimephales promelas) in lakes/ponds in southern Alberta. Sexually mature, male minnows (n=755) were collected from six sites between 2018-

78 2020. Overall, minnows hosted a diverse parasite community with a richness of 13 species. Of these, two trematodes co-occurred in 88% of all minnows sampled and accounted for 97% of the 104,945 parasites recovered. We exposed minnows to cercariae of these two dominant species to evaluate the effects of intensity dependence and co-infection on parasite development. For both species, metacercariae development involved a two- to four-week period of rapid growth followed by a consolidation and encystment phase between four and ten weeks post-infection. Negative intensity dependent growth occurred for Ornithodiplostomum ptychocheilus metacercariae in the brains of minnows, but not for Ornithodiplostomum sp. metacercariae in the livers. Additionally, both species were significantly larger post-encystment in mono-infections than in co-infections. Taken together, our results show that the development of Ornithodiplostomum spp. metacercariae in minnows is influenced by both conspecific and heterospecific intensities. The fathead minnow and its parasites are a tractable model system for exploring the broader significance of parasite co-infections in wild hosts, such as endangered and threatened fishes and those considered for the diversification of finfish aquaculture.

Hoeg, R.1*, Shutler, D.1, Pollet I. L.1 Department of Biology, Acadia University, Wolfville, Nova Scotia, Canada *Presenting author Meadow voles (Microtus pennsylvanicus) as potential seabird nest predators Herbivores may become omnivorous to meet energy demands; this may occur more frequently on islands where population densities are typically higher than on the mainland. Many seabirds nest on the ground or in burrows on islands, making them easily accessible to terrestrial predators. Meadow voles (Microtus pennsylvanicus) are herbivorous rodents suspected of depredating Leach’s Storm-petrel (Hydrobates leucorhous, hereafter LHSP) nests on Bon Portage (BP) and Country islands (CI), Nova Scotia. It is difficult to directly observe predation of LHSP nests, so we live-trapped voles, and used δ13C and δ15N stable isotope analysis of fur and faeces to examine their diet on BP and CI. We also collected vegetation and samples of LHSP tissues. δ13C values in fur, faeces, and vegetation did not differ between islands, but δ15N values were significantly higher on CI than BP. This may indicate greater marine inputs into vole diet on CI, but it is unclear whether this pattern is due to consumption of seabird tissues, or the influence of guano on vegetation and invertebrates in vole diet. Sampling of a wider variety of food sources and mainland controls are needed to get a better picture of vole diet and determine whether they are consuming LHSP eggs or nestlings.

Hoogenboom, J. L.1*, Wong, M. K.-S. 2, Hyodo, S. 2, Anderson, W. G.1 1Biological Sciences, University of Manitoba, Winnipeg, Canada 2 Physiology, Atmosphere and Ocean Research Institute, University of Tokyo, Kashiwa, Japan * Presenting author Nitrogen transporter expression within intestinal tissues of cloudy catshark (Scyliorhinus torazame) in relation to food intake Marine elasmobranchs (sharks, skates, and rays) are nitrogen-limited due to their utilization of nitrogen for somatic processes and osmoregulation. This limitation is compounded by the loss of urea across the gills and by renal routes. Our current understanding of the transport of nitrogenous compounds (ammonia and urea) across elasmobranch tissues is based primarily on studies investigating nitrogen loss (output) across the gills and kidney; however, few studies have looked at the movement of nitrogen in terms of acquisition (input). This study focused on the intestinal spiral valve as it is the main site of nutrient absorption and retention. Using real-time polymerase chain reaction (qPCR) we examined differences in mRNA expression of two Rhesus-like ammonia transporters (Rhp2 and Rhbg) and a urea transporter (UT) along the length of the intestine (anterior, mid, posterior) of fed and fasted cloudy catsharks (Scyliorhinus torazame). No difference in mRNA expression was seen between fed and fasted catsharks across the three intestinal regions for Rhp2 and UT; Rhbg showed higher mRNA expression in the posterior regions of the intestine. Immunohistochemistry and in situ hybridization were used to examine cellular localization of Rhp2 and UT along the length of the spiral valve. Immunohistochemical labelling indicated both were apically located, with Rhp2 confined to the brush-border membrane, and UT found below the goblet (mucosal) cells. Regional labelling and expression data will be discussed in the context of nitrogen movement across the intestine of elasmobranchs.

Howe, R. 1*, Guglielmo, C. 1, Soares, L.1, Morbey, Y. 1, MacDougall-Shackleton, E. 1

79 1Department of Biology, University of Western Ontario, London, Canada *Presenting Author Effects of Experimental Malaria Infection on Migration of Yellow-rumped Warblers (Setophaga coronata) Whether and how avian malaria affects bird migration, particularly during stopover (an important step in migration where birds spend most of their migratory period), has received much attention, but little experimental study. Forty Yellow-rumped Warblers (Setophaga coronata) were captured during fall migration at the Bruce Peninsula Bird Observatory and transported 300 km south to the Advanced Facility for Avian Research in London, Ontario, Canada. Twenty-five birds were experimentally inoculated with avian malaria (Plasmodium cathemerium) while fifteen birds were inoculated with uninfected blood as a control. All birds were fitted with radio-transmitters and kept in conditions similar to a migratory stopover before being released an additional 100 km south at Long Point, Ontario to continue their migration. Activity was measured in captivity using radio signal strength variability and birds were radio-tracked after release using handheld radio-telemetry and the Motus Wildlife Tracking System. Six of the treatment birds (24%) developed P. cathemerium infections after inoculation (‘responders’) but did not have statistically different captive activity levels from birds that were inoculated but did not develop infections (non- responders) or control birds. Stopover duration (time to departure after release) was not significantly different between groups. This research addresses the migratory implications of exposure to and infection with a common bloodborne pathogen, suggesting that birds do not alter their migratory strategies in response to infection.

Hunter, A. T.*, Purvis, K., Trevors, A., Wilson, E., Wyeth, R. C. Department of Biology, St. Francis Xavier University, Antigonish, Canada *Presenting Author Efficacy of graphene coatings at reducing marine biofouling in Nova Scotian waters Marine biofouling is a substantial economic and environmental issue impacting marine industries. Biofouling communities can damage fishing equipment, increase fuel consumption of boats, and also have negative environmental effects. Various preventative measures and solutions have been created in efforts to reduce biofouling on different surfaces, but there is still a need for environmentally sustainable antifouling products. This has resulted in the development of fouling-release coatings that reduce attachment strength for biofouling organisms without biocides. Graphene-based coatings present an intriguing possibility, based on their fouling-release characteristics combined with high durability. However, few experiments have tested graphene -based products for marine antifouling performance. Our experiments tested three graphene-based coating treatments (proprietary formulations provided by Graphene Innovation & Technologies, Inc.) at four testing sites in Northern Nova Scotia and Cape Breton (encompassing a number of biofouling species: Ciona intestinalis, Botryllus schlosseri, Botrylloides violaceous, Membranipora membranacea, Mytilus edulis, and Bugula sp.). The three coating treatments, which are dark grey/black, were compared against black acrylic plates as a color control and grey polyvinyl chloride (PVC) plates for comparison to past studies at these sites. A set of plates coated with commercial performance standard (Intersleek) were also deployed at one of the sites. Graphene treatments performed better than the control treatments at three out of the four sites. The relative performance of the three different graphene treatment formulations showed evidence of species specificity and site specificity. The graphene treatments did not perform as well as Intersleek. Based on our findings, we suggest that graphene-based coatings can be effective in reducing biofouling. Future efforts should consider comparing both measures of antifouling performance and durability to evaluate long term effectiveness of graphene-based coatings.

Hutchinson, A. J.¹*, Duffy, B.¹, Staples, J. F..1 1Department of Biology, Western University, London, Canada *Presenting Author Hibernation is Super Complex: Dynamics of Electron Transportation Supercomplexes Thirteen-lined ground squirrels (TLGS, Ictidomys tridecemlineatus) hibernate during winter months. Hibernation consists of two distinct steady states: torpor (low metabolic rate (MR)) and interbout euthermia (IBE, high MR), with transition states of entrance and arousal between. Previous findings in the lab suggest that changes to the electron transport system (ETS) contribute to suppressing metabolism during hibernation. Each ETS complex consists of 4-45 individual protein subunits. These

80 complexes can also combine to form different supercomplexes (SCs) within the inner mitochondrial membrane (IMM). SCs are thought to improve ETS efficiency by limiting diffusion of intermediates and decrease the escape of electrons which may form reactive oxygen species (ROS). I hypothesize that SCs decrease with mitochondrial metabolic suppression. My research question is as follows: If the abundance of SCs increases to fulfill a higher metabolic demand2, do SCs decrease to facilitate metabolic suppression seen during hibernation? We isolated mitochondria from liver, brown adipose tissue, and heart of hibernating and torpid TLGS, and performed high-resolution respirometry. State 3 (phosphorylating) respiration is significantly lower in torpor compared to IBE in all tissues. I then separated mitochondrial proteins by molecular mass using blue-native gels following solubilization with a gentle detergent. This allowed me to quantify SC abundance by staining intensity. I then cut each lane from the native gel and further separated proteins using SDS gels. This will separate SC bands into subunit components of the ETS complexes which I identified using western blotting. Preliminary results from brown adipose tissue demonstrate higher abundance of CIII in a CI/CIII2/CIV SC during IBE but higher abundance in a CIII2/CIV1-2 SC in torpor. These findings suggest a dynamic transition of the location of CIII within the ETS during the transition from torpor to IBE, perhaps contributing to changes in mitochondrial respiration and ROS production among phases of torpor bouts.

Ignatz, E. H.1*, Hori, T. S.2, Kumar, S.1, Braden, L. M.3,4, Benfey, T. J.5, Runighan, C. D.3, Westcott, J. D.6, Rise, M. L.1 1Department of Ocean Sciences, Memorial University of Newfoundland, St. John’s, Canada 2Atlantic Aqua Farms, Charlottetown, Canada 3AquaBounty Canada, Fortune, Canada 4Department of Pathology and Microbiology, Atlantic Veterinary College, UPEI, Charlottetown, Canada 5Department of Biology, University of New Brunswick, Fredericton, Canada 6Fisheries and Marine Institute, Memorial University of Newfoundland, St. John’s, Canada *Presenting Author RNA-seq Analysis of Growth Hormone Transgenic Female Triploid Atlantic Salmon (Salmo salar) Hepatic Transcriptomes Reveals Broad Temperature-Mediated Effects on Metabolism and Other Biological Processes This study examined the impact of rearing temperature (10.5, 13.5 or 16.5 °C) on the hepatic transcriptomes of AquAdvantage Salmon (growth hormone transgenic female triploid Atlantic salmon) at an average weight of 800 g. Six libraries were Illumina-sequenced from each temperature group, resulting in an average of over 100M raw reads per individual fish library. RNA-sequencing (RNA-seq) results showed the greatest difference in number of differentially expressed transcripts (1750 DETs), as revealed by DESeq2 and edgeR (q < 0.05), was between the 10.5 °C and 16.5 °C temperature groups. Comparing the DETs between these two treatments further revealed that 282 gene ontology (GO) terms were enriched (q < 0.05), with ‘response to stress’, ‘immune system process’, ‘lipid metabolic process’, ‘oxidation-reduction process’ and ‘cholesterol metabolic process’ identified as key enriched GO terms, suggesting elevated temperature elicits broad effects on multiple biological systems. Pathway analysis using ClueGO showed additional impacts on amino acid and lipid metabolism. There was significant positive correlation between RNA-seq and real-time quantitative polymerase chain reaction (RT-qPCR) results for 8 of 9 metabolic-related transcripts tested. This information also correlated to changes in fillet tissue composition previously reported in these salmon, such as methionine concentrations, suggesting that rearing temperature plays a significant role in mediating metabolic/biosynthetic pathways of AquAdvantage Salmon. This study relates phenotypic responses to transcript-specific findings, and therefore will aid in the determination of an optimal rearing temperature for AquAdvantage Salmon.

Ignatz, E. H.*, Zanuzzo, F. S., Sandrelli, R. M., Clow, K. A., Rise, M. L., Gamperl, A. K. Department of Ocean Sciences, Memorial University of Newfoundland, St. John’s, Canada *Presenting Author Phenotypic Stress Response Does Not Influence the Upper Thermal Tolerance of Male Atlantic Salmon (Salmo salar) Fish can be identified as either low responders (LR) or high responders (HR) based on whether they exhibit a proactive or reactive stress coping style, respectively. In this study, male Atlantic salmon (Salmo salar) of 17 genetic families reared at 9°C were repeatedly exposed to an acute handling stress over a period of four months, with plasma cortisol levels measured at 1 h post-stress. Fish were identified as

81 either LR or HR if their cortisol concentrations consistently fell into the lower or upper quartile ranges, respectively; with intermediate responders (IR) classified as the remainder. Salmon characterized as LR, IR or HR were then subjected to an incremental thermal challenge, where temperature was raised at 0.2°C day-1 from their acclimation temperature (12°C) to mimic natural sea-cage farming conditions during the summer/early fall in Newfoundland. Interestingly, feed intake remained high up to 22°C, while previous results have shown a decrease after 18°C. After the first three mortalities were recorded at elevated temperature, a subset of LR and HR salmon was exposed to another acute handling stress event at 23.6°C. Basal and post-stress measurements of plasma cortisol, glucose and lactate did not differ between stress response phenotypes at 23.6°C. In the end, the average incremental thermal maximum (ITmax) of LR and HR fish was not different (25.1°C). In comparison, the critical thermal maximum (CTmax) of remaining IR fish that had been held at 12°C was measured; this test, which was -1 conducted at 2°C h , is a measure of a fish’s acute thermal tolerance. The CTmax of these fish was 28.5°C. Collectively, these results: 1) show that this population of Atlantic salmon is quite thermally tolerant, and further question the relevance of CTmax in assessing responses to natural environmental conditions; and 2) indicate that characterization of stress phenotype at low temperatures is not predictive of their stress response or survival at high temperatures.

Ikert, H.¹*, Osokin, S.¹, Saito, J. R.1, Craig, P. M.¹ 1Department of Biology, University of Waterloo, Waterloo, Canada *Presenting Author Like two fish out of water: Comparing liver microRNA and predicted target responses between air stressed Oncorhynchus mykiss and Salvelinus fontinalis The teleost acute stress response is well-characterized, with rainbow trout (Oncorhynchus mykiss) as a model for physiological and molecular responses. Air exposure modulates liver microRNAs in rainbow trout; however, these highly conserved non-coding RNAs that bind to mRNA and repress translation, have never been measured in brook trout (Salvelinus fontinalis). It is unknown whether miRNA expression following acute stress is conserved between trout. Our objective was to characterize and compare the effects of acute stress on rainbow and brook trout liver miRNA expression, as well as the mRNA expression and enzyme activity that the miRNAs are predicted to target. Brook and rainbow trout were sampled before and 1-, 3-, and 24-hr after three-minute air exposure. Plasma cortisol, glucose, and lactate were measured. Liver expression of miR-21a-5p, miR-143-3p, let-7a-5p and expression and enzyme activities of five predicted targets (pyruvate kinase, glucokinase, citrate synthase, cytochrome c oxidase, and catalase) were measured. Rainbow and brook trout differed in the magnitude of their plasma metabolite responses. Furthermore, trout species shared increases in miR-143-3p and miR-21a-5p expression 24-hr post-stress. Four of the five enzymes measured had altered activity following stress, with species differences in cytochrome c oxidase and citrate synthase activity. Brook trout miRNAs had inverse expression with their target mRNA and enzyme activity, but no relationship was found in rainbow trout. We have further characterized the transcriptional and enzymatic response to acute stress in two salmonids, as well as expanding our understanding of the role of miRNA in potentially regulating the acute stress response.

Ingelson-Filpula, W. A.¹*, Storey, K.B.¹ 1Department of Biology, Carleton University, Ottawa, Canada *Presenting Author The Biogenesis and Bioinformatic Analysis of MicroRNA During Freezing in the Grey Tree Frog, Hyla versicolor Grey tree frogs (Hyla versicolor) have the remarkable ability to endure full-body freezing over the winter, with up to 42% of total body water converted into extracellular ice. Survival is aided by metabolic rate depression that greatly reduces tissue energy costs over the winter. Post-transcriptional controls on gene expression which include microRNA regulation of gene transcripts can aid the metabolic reorganization needed for this process. In this study, western immunoblotting was used to examine protein expression levels of members of the microRNA biogenesis pathway in H. versicolor control vs. frozen liver. Four of these proteins (Dicer, Drosha, TRBP, XPO5) were upregulated in liver of frozen frogs, suggesting enhanced capacity for microRNA biogenesis. Subsequent small RNA-sequencing and bioinformatic analysis of freeze-specific microRNAs showed that seven microRNAs were freeze-upregulated and four were freeze-downregulated. These microRNAs appear to target signaling pathways such as MAPK and

82 mTOR signaling as well as nuclear processes. Overall, the data show that microRNA biosynthesis is altered during freezing and differentially regulated across tissues, suggesting that microRNAs are central for the freeze tolerance strategy developed by H. versicolor. Specific microRNAs that appear crucial to this process include miR-206, miR-451a, miR-140-3p, miR-181a-5p, miR-34a-5p, miR-21-5p, miR-30e- 5p, miR-142-3p/-5p, and miR-19a-3p. Future research will elucidate more detailed roles for these microRNAs in freezing stress responses.

Ionescu, R. A.*, Mitrovic, D., Wilkie, M. P. 1Department of Biology, Wilfrid Laurier University, Waterloo, Ontario, Canada *Presenting Author Sub-lethal Niclosamide Exposure Leads to Reversible Energy Metabolism and Intracellular Muscle pH Disturbances in Lake Sturgeon (Acipenser fulvescens) The parasitic sea lamprey invasion of the Laurentian Great Lakes (late 1800s – 1930s), led to the devastation of many of the basin’s important fisheries. In the 1960s, the Great Lakes Fishery Commission introduced the use of 3-trifluoromethyl-4-nitrophenol (TFM) and 2’,5-dichloro-4’-nitrosalicylanilide (niclosamide, Bayluscide®), to control larval sea lamprey in natal rivers. Niclosamide, having magnitudes higher toxicity than TFM, is used in combination with TFM (1-2%), or alone to treat lentic habitats, fast- flowing rivers, and for population surveys. However, little is known about niclosamide’s mode of action or physiological effects on lake sturgeon (Acipenser fulvescens), a species of concern. Similar to TFM, niclosamide is believed to uncouple oxidative phosphorylation, impairing ATP production. Thus, we hypothesized that niclosamide exposure would result in metabolic and acid-base disturbances in young- of-the-year lake sturgeon, necessitating increased reliance on anaerobic processes to compensate -1 shortfalls in ATP. Exposure of sturgeon to their 9-h niclosamide LC50 (0.11 mg L ) resulted in significant decreases in brain ATP (38%) and glucose (50-60%), decreases in liver glycogen (60%) as well as muscle phosphocreatine (65-70%) and intracellular pH (pHi; 0.1-units). Accompanying increases of lactate were also observed in brain (2-fold) and muscle (4-fold). These results imply that lake sturgeon increasingly relied on glycolysis to meet ATP demands, in the presence of niclosamide. However, all surviving sturgeon recovered within 24 h of transfer to clean water, restoring all energy stores, metabolites and pHi, to pre-exposure levels. The ready recovery implies that lake sturgeon which survive niclosamide treatments would quickly recover with no lasting physiological effects.

Ivy, C. M.*, Coulson, S. Z., Gugliemo, C. G. Department of Biology, Western University, London, Canada *Presenting Author Seasonal flexibility in oxygen transport in migratory songbirds Migratory flight is an intensive exercise that requires birds to maintain high maximal aerobic capacities for many hours or days. Maintaining O2 supply to flight muscles is therefore important during migration, with past research showing that migratory passerines have increased capillary density in flight muscles compared to non-migratory species. However, no other comparative studies of other aspects of the O2 cascade have been conducted in songbirds. Here, we investigated changes in haematology and pectoralis phenotype of yellow-rumped warblers (Setophaga coronata) in fall migration and wintering conditions. We found that fall migration resulted in warblers having increased haemoglobin-O2 binding affinity and increased whole-blood haemoglobin concentration compared to birds in wintering conditions. Fall migrants also had smaller pectoralis muscles relative to body mass compared to wintering birds, but had a greater fiber density with similar capillary to fiber ratios as wintering birds. These findings suggest that yellow-rumped warblers exhibit seasonal flexibility in O2 transport, with enhanced O2 transport to tissues during migration. Funded by NSERC.

Bauer, W. G.¹*, Easy, R. H.¹, Quesada, R. C.², Arias, S.², Stewart, D. T.¹ 1Department of Biology, Acadia University, Wolfville, Canada 2 Estación de Biología Marina, Universidad Nacional, Puntarenas, Costa Rica *Presenting Author DNA Barcoding Reveals one Invasive, and Additional Previously Undescribed Species of Unionids Three groups of morphologically distinct freshwater mussels (Family: Unionidae) were observed in an aquaculture facility near Cañas, Guanacaste, Costa Rica. Fourteen individual DNA samples were extracted and sequenced in the Stewart lab at Acadia University, using universal cytochrome oxidase

83 subunit I primers, revealing invasive species Sinanodonta woodiana, and two unionid species that share ~93% and ~89% of similarity to native species Psorula profunda and Anodontites trigonus, respectively. Recent developments in Mesoamerican unionid phylogenetics suggest that the P. profunda relative is possibly among genus Nephronaias, which is undescribed on molecular databases such as GenBank. To confirm identification, phylogenetic trees were constructed using MEGA7.0.26 and MrBayes3.2.7. Dioecious freshwater mussels typically exhibit mitochondrial DNA inheritance apart from conventional Strict Maternal Inheritance across metazoa: Doubly Uniparental Inheritance (DUI) propagates male- inherited mitochondria in male germ cells, and female-inherited mitochondria in male/female somatic cells, and female germ cells. DUI was detected in putative Nephronaias sp. using primers that only amplify male-only mitochondrial genomes within polymerase chain reactions. This research discusses ecological and economic implications of S. woodiana establishment in Guanacaste and surrounding regions, as its success can be attributed to the unusual glochidial life stage of unionids, and how phylogenetics, DUI, and invasive species within freshwater mussels are all critical aspects to consider in ecological conservation – an understudied, underfunded, and underappreciated field in Mesoamerica.

Jamniczky, H. A.1*, Schutz, H.2, Anderson, R. J.3, Warwick, E. G.2, Barry, T. N.4 1Department of Cell Biology & Anatomy, University of Calgary, Calgary, Canada 2 Biology Department, Pacific Lutheran University, Tacoma WA, USA 3 Department of Biological Sciences, University of Notre Dame, Notre Dame IN, USA 4 Department of Biological Sciences, University of Lethbridge, Lethbridge, Canada * Presenting Author Considering Sexually-Mediated Variation as a Mosaic Continuum in Threespine Stickleback Sexually-mediated variation in organismal form is equally subject to the uniform genetic architecture that controls sexually homologous traits. This interplay may both constrain the evolution of sexually-mediated variation, and provide pathways to speciation and intraspecific diversity. We argue that analyzing sexually-mediated variation in a binary fashion overly simplifies the nature of the effects of selective pressures on organisms. Not all traits in a species display sexually-mediated variation, and when variation does exist in multiple traits, it is often non-uniform. Moreover, selection driving sexually-mediated variation influences phenotypic variation not directly associated with genotypic sex. This important component of phenotypic variation is often lost in discussions focusing solely on a statistically significant binary. We propose that considering sexually-mediated variation as a continuum provides rich opportunities to explore the complex relationships between organisms and their environments, and we present a case study using threespine stickleback fish (Gasterosteus aculeatus). G. aculeatus displays rapid adaptive responses and sexual variation in several phenotypic traits, ranging from body size to cranial shape. The presence, magnitude and direction of sexual variation in these traits varies greatly both within and across habitats. Using 3D geometric morphometrics and an index of differentiation scaled by variance we quantified shape and size of the cranial, pectoral and pelvic regions of sticklebacks in marine and freshwater habitats from southwestern B.C. We demonstrate that the expression of sexual differentiation varies between macro-environments (freshwater or marine habitat) as well as between micro-environments (sites within habitat type). Further, sex differences in the skull and girdles of stickleback does not manifest in a clear dimorphic pattern, but rather as a continuum of variation that reflects the interacting effects of genetic sex and ecology. Our results indicate the value of refocusing phenotypic study to explicitly consider variation as a valuable source of information about evolutionary trajectories of species.

Jonz, M. G.*, Cadiz, L., Akimenko, M. A. Department of Biology, University of Ottawa, Ottawa, Canada *Presenting Author Signalling pathways involved in gill regeneration in zebrafish (Danio rerio) In zebrafish, organs involved in respiration and ionoregulation regenerate. These include the gills, skin and opercular epithelium. Regeneration of these tissues gives rise to proliferation of O2-chemoreceptive neuroepithelial cells (NECs) and/or ionocytes (mitochondrion-rich cells). In order to understand the factors affecting regeneration and cellular proliferation in respiratory and ionoregulatory tissues, we investigated signalling pathways controlling gill regeneration. Gill filaments were surgically resected and animals were subsequently exposed to drugs to inhibit bone morphogenetic protein (BMP), fibroblast growth factor (FGF) or Notch signalling pathways. After 5 days post-resection, all drugs reduced or

84 inhibited blastema formation. At 10 days post-resection, in situ hybridization analysis revealed expression of bmp2b, fgf8 and her6 in regenerating filaments related to these respective pathways. Expression was not detected in control filaments. Interestingly, hypoxia did not diminish gill regeneration or NEC proliferation. These studies will help us understand the regenerative capacity of respiratory and ionoregulatory organs in fish.

Jung, E. H., Brauner, C.J., and Wood, C. M. Department of Zoology, University of British Columbia, Vancouver Canada In and Into the Gastrointestinal Tract: Hypercapnia, Hypoxia and High Ammonia in the Lumen yet Moderate Levels in the Venous Drainage The gastrointestinal tract of teleosts is a multifunctional organ for feeding, digestion, and osmoregulation, and thus is vital for survival. Nutrients are broken down into simpler molecules that can be assimilated, many by active transport across the gastrointestinal epithelium. The digestive process involves secretion of acid into the stomach and bicarbonate into the intestine, creating unique and heterogeneous physiological conditions within the lumen. Our recent findings show the inside of lumen to be high in PCO2 (in cases exceeding 40 mmHg) and ammonia (0.4 - 3.7 mM) but extremely low in PO2 (< 0.1 mmHg), which become even more extreme following feeding. These conditions in the lumen must impose metabolic challenges on the gastrointestinal tract, however little is known about blood gas characteristics of blood supplying and leaving this organ. To address this, we implanted catheters in the dorsal aorta and the subintestinal vein in the freshwater rainbow trout (Oncorhynchus mykiss) and monitored blood over 48 h following feeding. Within 24 h of feeding, we observed a pronounced alkaline tide in concert with - increases in [HCO3 ] and PO2 in the arterial blood. In terminal samples of the chyme, we measured high - ammonia, particularly in the stomach, and high [HCO3 ] in the intestine. In the subintestinal vein draining - the intestine, however, PCO2, PO2, ammonia, and [HCO3 ] remained unchanged from those measured prior to feeding and differed markedly from those in the lumen over this 48 h duration. Overall, we found the venous blood draining the gastrointestinal tract remained relatively undisturbed despite the dynamic and relatively extreme environment inside the gastrointestinal tract (NSERC Discovery).

Kadamani, K. L.1*, Pamenter, M. E.¹ 1Department of Biology, University of Ottawa, Ottawa, Canada *Presenting Author Microglia Morphology Changes During Development in Naked Mole-Rats (Heterocephalus glaber) Microglia are the primary macrophages within the central nervous system and play a critical role in brain development. Colonization of microglia in the brain begins during gestation and they adopt a ramified morphology as they mature in the adult brain. With developmental maturity, a shift in microglia (i.e., distribution and cell shape) occurs. It is speculated that hypoxia-tolerant and long-lived naked mole-rats (NMRs) retain neotenic traits into adulthood. We therefore hypothesized that adult NMR microglia would maintain neotenic morphology. To test this, immunohistochemistry was used on fixed brains to observe microglia in 1, 6, and 36-month-old NMRs (n = 4 NMRs per age group). We found a significant increase (P<0.0001) in total microglia branch count and length between 1 (23 ± 1 branches and 132.1 ± 8.6 µm, respectively) and 6 months (49 ± 3 branches and 262.2 ± 17.4 µm, respectively). Conversely, there were no differences between 6- and 36-month-old animals. Microglia maturation in mice occurs around postnatal week 2 to 3 with full maturation after 1 month. In adult mice, microglia have around 50 branches per cell and a total length of branch tree reaching about 600 µm (J. Chem. Neuroanat., 2017, 86:59-66). Our results provide evidence of protracted microglia development in NMRs with a lack of increased ramification in 1-month-old NMR microglia. These results suggest that NMR microglia retain some neotenic morphology as processes are much shorter in NMRs compared to other rodents, however similar branch count is found in mature mice.

Kapur, M.1*, Rix, C.1, Wilson, J. M.1,2 1Department of Biology, Wilfrid Laurier University, Waterloo ON Canada. 2CIIMAR Universidade do Porto, Matosinhos, Portugal. *Presenting author. Acid-base regulation in the brown bullhead Ameiurus nebulosus: Immunohistochemical study of gill and kidney transporters

85 The brown bullhead, Ameiurus nebulosus, is a freshwater stenohaline teleost fish native to the Atlantic and Gulf slope drainages of North America. Acid-base and ion regulation in aquatic animals are linked + + - - through Na /H and Cl /HCO3 exchange mechanisms. Although there is some research on these mechanisms in Siluriform catfishes, the molecular identity of the transporters responsible are lacking. In the present study we used immunohistochemistry to characterized the distribution of Na+/K+-ATPase (NKA), vacuolar-type proton ATPase (VHA), Na+/H+-exchanger (NHE3b), Na+: K+: 2Cl- cotransporter (NKCC)/ Na+: Cl- cotransporter (NCC) and intracellular carbonic anhydrase (CA) in gill and kidney, the major acid-base and ion regulatory organs in fishes. In gill we found two populations of NKA- immunoreactive (IR) ionocytes based on isoform expression found in both the filament and lamellar epithelia. Apical NHE3b expression could be found in a sub-type, but we could find no evidence of apical NCC in A. nebulosus. VHA was expressed in a different epithelial cell population. Catfish have a large compact type-2 kidney and proximal, distal and collecting tubules could be readily distinguished on the basis of NKA staining patterns. Renal ‘chloride’ cells were detected in the collecting tubule and collecting duct and had apical NHE3b and CA staining. Apical NKCC/NCC staining was detected in the distal tubule. Our results indicate branchial and renal cell types potentially involved in acid excretion and sodium uptake. The effects of exposure fish to hypercapnia (1% CO2) for 6h on transport expression patterns was also studied and the results will be discussed.

Kennedy, J. R. K¹*, Harley, C. D. G.1,2, Marshall, K. E.1 1 Department of Zoology, University of British Columbia, Vancouver, Canada 2Institute for the Oceans and Fisheries, University of British Columbia, Vancouver, Canada *Presenting Author Drivers of plasticity in freeze tolerance in the intertidal mussel Mytilus trossulus The intertidal mussel Mytilus trossulus has the remarkable ability to survive freezing. Since freezing is such an extreme stress to living cells, freeze tolerant animals often accumulate protective molecules (termed cryoprotectants) to prevent the cellular damage caused by freezing. While much is known about the biochemical correlates of freeze tolerance in insects and vertebrates, the cryoprotectants that are used by intertidal invertebrates are not well characterized. Previous work has proposed two possible groups of low-molecular weight cryoprotectants in intertidal invertebrates: osmolytes and anaerobic byproducts. In our study, we examined which low-molecular weight metabolites correlate with plasticity in freeze tolerance in mussels using 1H NMR metabolomics to identify potential cryoprotectants. We found that M. trossulus freeze tolerance varies on a seasonal basis, along an intertidal shore level gradient, and with changing salinity. Acclimation to increased salinity (30 ppt) increased freeze tolerance, and mussels were more freeze tolerant during the winter. Mussel freeze tolerance also increased with increasing shore level. Anaerobic byproduct accumulation was not found to be associated with increased freeze tolerance. However, osmolyte accumulation was correlated with increased freeze tolerance after high salinity acclimation and in the winter. The concentration of most low-molecular weight metabolites did not vary with shore level, indicating that another mechanism is likely responsible for this driver of variation in freeze tolerance. By identifying osmolytes as a group of molecules that assist in freezing tolerance, we have expanded the biochemical repertoire of the mechanisms of freeze tolerance. Our next step is to artificially increase mussel gill intracellular osmolyte concentrations, and determine whether this decreases cryoinjury to gill tissue.

Kim, A. B*., Richards, J. G., and Milsom, W. K. Department of Zoology, University of British Columbia, Vancouver, Canada *Presenting Author Temperature, state and pH effects on mitochondrial respiration in hibernating rodents CO2 retention (due to a mismatch between ventilation and metabolic rate suppression) and resulting changes in intracellular pH have been suggested as a mechanism for the initiation of metabolic rate suppression in hibernation. Mammalian hibernation is typically associated with a drastic reduction in body temperatures to 1-2 °C above ambient winter temperatures, which is well documented as a passive mechanism for sustained metabolic rate suppression in hibernators. To quantify the interactive effects of temperature, pH and hibernation state on mitochondrial respiration, we isolated mitochondria from the liver of three rodent species. Most notably, succinate fueled state 3 respiration measured at 37 °C was not pH-dependent in the non-hibernating Sprague-Dawley rat (Rattus norvegicus), but was pH dependent in 13-lined ground squirrels (Ictidomys tridecemlineatus; obligate hibernator) and Golden-Syrian hamsters

86 (Mesocricetus auratus; facultative hibernator), where respiration increased as pH was lowered, presumably due to direct effects on membrane potential and pH gradients. This pH effect on state 3 respiration rate was observed in liver isolated from both torpid and interbout euthermic 13-lined ground squirrels, indicating hibernation state does not alter the relationship between mitochondrial respiration rate and pH in this species. The increase in state 3 respiration with reduced pH at 37 °C does not support the hypothesis that an initial acidosis resulting from CO2 retention serves as a mechanism for metabolic suppression during entrance into hibernation. This research was funded by the Natural Sciences and Engineering Research Council of Canada (NSERC).

Klein, Z. P.1*, Torson, A. S. 1, Sinclair, B. J. 1 1Department of Biology, Western University, London, Canada *Presenting Author Alternative splicing in diapausing Asian longhorned beetles, Anoplophora glabripennis The Asian longhorned beetle (Anoplophora glabripennis) overwinters in diapause, a state of developmental arrest and metabolic suppression. Using RNA-Seq data derived from diapausing and quiescent Asian longhorned beetle fat body tissue, we created an analysis pipeline based on the R package IsoformSwitchAnalyzeR to identify isoform switches between diapausing and quiescent larvae. We used web-based annotation programs to describe and compare structural and functional features of splice variants such as protein domains and coding potential. We identified 984 genes with differential isoform use between diapause and quiescence, and observed changes in transcript features including retained introns, open reading frames, and protein domains. After mapping the alternatively spliced genes to KEGG pathways, we noted that several of these genes were in the FOXO and insulin signaling pathways, which are important in diapause. Our results suggest that alternative splicing could be an important, often-overlooked factor in regulating, maintaining, and terminating diapause. This is the first transcriptome-wide study of alternative splicing in a diapausing insect.

Klymasz-Swartz, A. K.1*, Yoon, G. R.1, Treberg, J. R.1,2, and Weihrauch, D.1 1Department of Biological Sciences, University of Manitoba, Winnipeg, Manitoba, Canada. 2Department of Human Nutritional Sciences, University of Manitoba, Winnipeg, Manitoba, Canada. *Presenting Author Northern Crayfish (Faxonius virilis) demonstrate a wide range of thermal tolerance with distinct physiological and metabolic responses to acute heat stress Temperature plays a key role in the physiology of aquatic ectotherms. Northern Crayfish (Faxonius virilis) are a keystone freshwater macroinvertebrate commonly found in North America from Oklahoma to Manitoba and therefore are subjected to a wide variety of water temperatures. Here, we investigate the thermal tolerance of F. virilis at different baseline temperatures and its physiological response to an acute heat stress of +5°C for 6 hours applied to each baseline temperature. We assessed the animals’ metabolism by measuring ammonia excretion, resting MO2 (RMR), maximum MO2 (MMR) and corresponding aerobic scope as well as hemolymph acid-base parameters. Additionally, we measured MO2 and metabolically produced ammonia in isolated gill tissue. A two-week exposure to either 5°C, 10°C, 15°C, 20°C, or 25°C resulted in predictable increases in the animal’s ammonia excretion rates and MO2. Notably, the isolated gill tissue of F. virilis had 5-17 times higher rates of oxygen consumption compared to the whole animal, signifying its multifunctional importance maintaining the - animal’s homeostasis. Hemolymph measurements resulted in a significant pH drop, a drop in HCO3 and an increase in hemolymph ammonia concentrations at higher temperatures, suggesting a metabolic - acidosis that could be compensated for by the buffering capacity of HCO3 and ammonia. Acute exposure to a +5°C increase in the various baseline temperatures caused a significant increase in ammonia excretion rates and MO2 in both the whole animal and isolated gill tissue. Aerobic scope (MMR- RMR) of the animal is sustained at temperatures up to 25°C and 25°C+5°C for six hours suggesting that F. virilis is capable of adjusting its oxygen requirements needed to respond to environmentally relevant heat stress observed in Manitoba. Overall, our results suggest that adult F. virilis have high thermal tolerance, but the long-term energy demands associated with higher temperatures could impact the long- term survivability of the species.

Kodzhahinchev, V.1, Weber, L.P.2, Niyogi, S.1 1Dept. of Biology, University of Saskatchewan, Saskatoon, Canada

87 2Dept. of Veterinary Biomedical Sciences, University of Saskatchewan, Saskatoon, Canada Alterations to Cd and BaP uptake during short-term waterborne co-exposures in adult zebrafish (Danio rerio) Cadmium (Cd) is a severely toxic trace metal commonly released as a by-product of mining. The steady increase in anthropogenic activities over the last century has resulted in Cd being an ubiquitous aquatic pollutant. While not as persistent in aquatic environments, polycyclic aromatic hydrocarbons (PAHs), a family of organic pollutants released during the incomplete combustion of organic matter and fossil fuel use, are also of great concern for aquatic organisms due to their toxicity at relatively low doses. Presently the interactive effects of Cd and PAHs on the uptake, accumulation and toxicity in fish is poorly understood. Benzo-a-pyrene (BaP), often considered as a prototypical PAH, is of particular concern due to its relatively high toxicity and is often used to assess such interactions. We have previously demonstrated that acute (72hr) aqueous co-exposures of adult zebrafish (Danio rerio) to either 0.44 or 1.06 μg/L and 5.8 or 22 μg/L Cd and BaP, respectively, resulted in a greater body accumulation of both toxicants compared to that during exposures to each toxicant individually at identical concentrations. To further elucidate the mechanistic basis for this interaction, the present study used radio-labelled Cd and BaP (109Cd and 14C-BaP) to assess the uptake kinetics of both toxicants. Zebrafish previously co-exposed to 10 μg/L Cd and 1.06 μg/L BaP for 72hrs exhibited a significantly increased toxicant influx.

Kraskura, K.¹*, Jerde, C. L. ², Eliason, E. J.¹ 1 Department of Ecology, Evolution, and Marine Biology, University of California Santa Barbara, Santa Barbara, California, USA 2 Marine Science Institute, University of California Santa Barbara, Santa Barbara, California, USA *Presenting Author Variation in metabolic scaling relationships of diverse fish across temperatures Decline in individual size has been proposed to be the third universal response to climate warming. This trend has been observed in fish populations across diverse ecosystems. However, the underlying physiological mechanisms that could lead to this trend in fish body mass are unknown. Defining metabolic scaling could provide a foundational framework to identify species sensitive to environmental change. We collated >3,000 maximum metabolic rate (MMR) and >4,000 resting metabolic rate (RMR) measurements in fish We evaluated how MMR, RMR, and aerobic scope (AS=MMR-RMR) change with body mass in fishes all together and fishes grouped by different temperature exposure histories (optimal conditions, acute exposure and acclimation to warm), morphologies and ecologies (climate, salinity habitat, lifestyles). Across all fish, we found strong evidence that the slope MMR < slope RMR, thus AS is decreasing as a function of increasing body mass. Yet, we show that the intraspecific trends in RMR and MMR can result in constant, increasing, and decreasing AS depending on fish species, their morphologies and ecologies. We also show that a metabolic constraint (slope MMR < slope RMR) could develop with increasing size in marine and tropical fish, and in fish that are exposed to warm (> optimal) temperatures. Broad generalizations do not capture the complexity of metabolic scaling and fish physiological responses to environmental change. Therefore this synthesis has major implications for untangling the physiological mechanisms by which changes to body size is impacting global fisheries and ecosystem functioning.

Lalla, K.1*, Frei, B.2, Fraser, K.3, Siegrist, J.4, Fischer, J.5, Ray, J. D.6, Cohn-Haft, M.6, Elliott, K.1 1 Department of Natural Resource Sciences, McGill University, Sainte-Anne-de-Bellevue, Quebec, Canada 2 Canadian Wildlife Service, Environment and Climate Change Canada, Gatineau, Quebec, Canada 3 Department of Biological Sciences, University of Manitoba, Winnipeg, Manitoba, Canada 4 Purple Martin Conservation Association, Erie, Pennsylvania, USA 5 Disney Animals, Science, and Environment, Orlando, Florida, USA 6 Consolidated Nuclear Security, LLC, U.S. Department of Energy-National Nuclear Security Administration Pantex Plant, Amarillo, TX, USA 7 Instituto Nacional de Pesquisas da Amazonia, Manaus, Brazil *Presenting Author Purple martins as central-place foragers: foraging range and habitat selection of chick-rearing and non-breeding individuals

88 Purple martins are central place foragers, foraging around central places during different stages of their annual cycle: the breeding colony during reproduction and roosts during the non-breeding period. We examine how breeding stage (chick-rearing or non-breeding) and latitude influence foraging range size and habitat selection around a central place. We predicted that non-breeding individuals would have larger foraging ranges because they are not constrained by feeding their chicks, and that foraging range size would be correlated with latitude such that northern birds would take advantage of large resource pulses and would have the smallest foraging ranges. For habitat selection, we predicted that individuals would select water-based habitats for foraging because of their tendency to breed near water. We deployed 104 GPS units on purple martins from 2016 to 2020. Foraging ranges were calculated using the ctmm package in R and habitat selection was determined using logistic regression. Foraging range was not correlated with latitude but was larger for non-breeding individuals. Breeding birds did not show strong local habitat selection although they weakly preferred wetland; individuals are likely selecting nesting sites in quality habitat where resources are readily available. Understanding purple martins’ foraging habitat and size requirements may aid in their conservation.

Lawrence, M. J.1, Mitrovic, D.2, Foubister, D.2, Bragg, L. M.3, Sutherby, J1, Docker, M. F.1, Servos, M. R.3, Wilkie, M. P.2, and Jeffries, K. M.1 1Department of Biological Sciences, University of Manitoba, Winnipeg, Canada 2Department of Biology & Laurier Institute for Water Science, Wilfrid Laurier University, Waterloo, Canada 3Department of Biology, University of Waterloo, Waterloo, Canada Energy Metabolism and Acute Lampricide Exposure in Fishes Control of invasive sea lamprey in the Laurentian Great Lakes relies on the application of lampricides in local rivers. The two main lampricides, 3-trifluoromethyl-4-nitrophenol (TFM) and niclosamide, impair ATP synthesis. When combined, they exert an additive effect, although the specific physiological mechanisms underlying this observation are poorly understood. The purpose of this work was to address the potential physiological mechanism(s) underlying differences in lampricide toxicity between sea lamprey and non- target bluegill sunfish. Specifically, we quantified changes in metabolites indicative of anaerobic energy metabolism across several tissues. Bluegill appeared to be physiologically resilient to both toxins but did show signs of higher metabolic costs associated with detoxification. Conversely, sea lamprey showed clear indicators of anaerobic metabolism which likely resulted from a mismatch between tissue ATP production and demand. A better understanding of these mechanisms may help us identify novel vulnerabilities that could be exploited for improved sea lamprey control.

Lebenzon, J. E*. and Sinclair, B. J. 1Department of Biology, Western University, London, Ontario *Presenting Author Beetle, it’s cold outside! The metabolomic and transcriptomic changes that drive cold tolerance in the Colorado potato beetle Temperate insects spend over half their lives overwintering, during which they must endure adverse conditions such as sub-zero temperature exposure and low resource availability. To deal with these conditions, most overwintering insects will enter diapause, a pre-programmed state of developmental arrest, and become cold-tolerant, to avoid the formation of ice in their body fluids. The Colorado potato beetle overwinters in diapause as a freeze-avoidant adult. However, we still do not understand the physiological mechanisms that drive survival of these insects at low temperatures, or the extent to which diapause confers cold tolerance. We used an ‘omics approach to uncover the metabolic and transcriptomic differences between diapause and cold tolerance in the Colorado potato beetle and identified several biological processes that could drive differences in sub-zero temperature survival. We induced diapause by rearing larvae under short days, and induced cold tolerance by exposing diapausing beetles to a fluctuating thermal regime, which enhances their survival at -10 °C. Using both targeted metabolomics and RNA-seq, we identified metabolites and expressed genes in hemolymph, fat body, and flight muscle that drive the acquisition of cold tolerance in diapausing beetles. Cold-tolerant beetles accumulate more proline (a putative cryoprotectant), and tryptophan (a putative neuroprotectant) compared to just diapausing beetles, suggesting that both these metabolites play a crucial role in overwintering survival. Interestingly, genes that encode for products of proline or tryptophan metabolism were not differentially expressed between diapausing and cold-tolerant beetles. Instead, just 38 transcripts involved in the heat shock response and protein refolding were significantly upregulated in

89 cold-tolerant beetles, which suggests that cold tolerance in these beetles might be primarily driven by chaperones, and mechanisms of cytoprotection.

Lee, T. Y. M.¹*, Westbury, K. M.¹, Martyniuk, C. J.², Nelson, W. A.¹, Moyes, C. M.¹ 1Department of Biology, Queen’s University, Kingston, Canada 2Department of Physiological Sciences, University of Florida, Gainesville, U.S.A. *Presenting Author Microevolution in hypoxia-driven enzyme activity and gene expression in Daphnia pulicaria Hypoxia is a stressor that influences animal function from ecology to molecular biology. Animals cope with hypoxia through strategies that improve oxygen delivery and anaerobic energy metabolism. Daphnia can respond to hypoxia by stimulating synthesis of an extracellular hemoglobin (Hb). We explored the link between the Hb response and the metabolic phenotype of Daphnia pulicaria under hypoxia using a combination of field surveys and a common garden experiment. We found seasonal transitions in the relationship between Hb and lactate dehydrogenase (LDH) in four hypoxic lakes. Hb was upregulated early in the season, while a relationship between Hb and LDH only emerged later in the season in a temporal pattern that was lake-specific. Individual clones of D. pulicaria from each of the four lakes were then propagated to assess the potential influence of microevolutionary variation on the expression of oxygen-responsive genes. When isofemales lines were exposed to acute hypoxia in a common garden experiment, we observed variation among lakes in both the basal expression and the oxygen- responsiveness of Hb and LDH, which is consistent with microevolutionary differences. Surprisingly, expression of pyruvate kinase (PK) and enolase (ENOL) were not upregulated under hypoxia. This result stands in contrast to expectations based on vertebrate models, where hypoxia would trigger a suite of responses controlled by a master transcriptional regulator. Overall, the complex differences in Daphnia metabolic patterns among lakes could be attributed to different degrees of hypoxic stress, as well as microevolutionary variation in the expression of individual genes. In addition, various hypoxic responses in Daphnia may be regulated through independent pathways, highlighting the importance of studying animal models with distinct ecology to understand the evolution of hypoxia-driven phenotypic remodeling.

Leonard, E. M.¹2*, Baker, S. J. C.¹2, Jonz, M. G.3, McClelland, G. B.2 1Department of Integrative Biology, University of Guelph, Guelph, Canada 2Department of Biology, McMaster University, Hamilton, Canada 3Department of Biology, University of Ottawa, Ottawa, Canada *Presenting Author Effects of copper on the acute ventilatory response and O2 sensing neuroepithelial cells of the killifish, Fundulus heteroclitus Control of breathing, whether gill ventilation or air-breathing, is influenced by receptors located in the + peripheral and/or central nervous system. These receptors respond to changes in PO2 and PCO2/H , a trait which is essential for the survival of aerobic organisms. O2-sensing neuroepithelial cells (NECs), which initiate the cardiorespiratory reflexes in aquatic vertebrates, are the peripheral receptors involved in the control of breathing. Exposure to environmental contaminants, such as copper (Cu), may affect the + ability of these cells to respond appropriately to changes in PO2 and PCO2/H in the environment. We examined the effects of Cu on the acute ventilatory drive of killifish at several levels of biological organization. Cu blunts the acute ventilatory drive of killifish, reducing the fish’s ability to respond to hypoxia. Morphometric analysis of the gills demonstrated that Cu causes a reduction in NEC projection area. Using ratiometric calcium imaging, we investigated whether Cu modulates hypoxia-induced 2+ changes in intracellular calcium concentration ([Ca ]i), a response known to be important for O2 sensing. 2+ We demonstrated that Cu (100 µg/L) reduces the [Ca ]i response to hypoxia in NECs from killifish gills by blocking T-type low threshold Ca channels but not L-type (HVA) Ca channels. Overall, Cu prevents 2+ killifish from mounting an appropriate physiological responses to low oxygen by reducing the [Ca ]i response through blocking T-type low threshold Ca channels.

Letendre, F.¹*, Mehrabian, S.¹, Cameron, C.1, 1Département de sciences biologiques, Université de Montréal, Montréal, Canada *Presenting Author The fluid mechanics of oil droplet capture and loss by filter feeding animals.

90 Filter feeders select particles from the water column using an array of ramified appendages. These particles may be solid (e.g., algae, organic matter, protists) or liquid oil droplets. Oil droplets from decaying algae or animals are nutritious, whereas crude oil droplets can have negative impacts on animals and ecosystems. Crude oil droplets emerge from oil spills by sheering caused by wind and waves, or by the use of chemical surfactants. If they are sufficiently small, they are captured and ingested by a wide range of planktonic and benthic filter feeders. We use applied fluid mechanics, high-speed photography and microscopy to further understand the forces and mechanisms governing the capture and loss (through detachment) of oil droplets by filter feeding appendages. We established a curve that, based on flow velocity and droplet size, will predict if a captured droplet will remain on the appendage or detach and re-enter the water column. This predictive tool is significant to oil spill risk assessment because it precisely determines the droplet sizes that will be captured and potentially ingested. High- speed video observations of oil droplet capture by the barnacles Balanus glandula and Balanus crenatus in a flume has shown that direct interception and inertial interaction are the capture mechanisms most likely to occur when passively feeding, more so than sieving. Feeding observations of the freshwater Cladocera Daphnia magna demonstrated that oil droplets are captured in the boundary layer of the appendages, rather than by direct contact. This biological fluid mechanics research contributes to our understanding of how oil droplets, including petroleum oils, are captured and enter marine and aquatic food webs. As an extension to these studies, my next research objective is to mitigate oil droplet capture by filter feeding animals.

Levesque, D. L. School of Biology and Ecology, University of Maine, Orono, USA Thermoregulatory Phenotypes in Mammals- The Missing Link Between Basal Metabolism and Life History? Basal metabolic, equivalent to the idling speed of mammals (measured during rest in non-reproductive, mature, fasted animals) is highly variable in mammals. Based on the hypotheses put forward by the Metabolic Theory of Ecology higher basal metabolic rates are expected to correlate with higher reproductive outputs. Yet in mammals this has consistently been shown to false. I argue that the level and degree of body temperature regulation (which also varies considerably among mammal species) as well as environmental temperatures, and the difference between the two, are key to understanding the lack of relationship between metabolic rates and reproductive outputs. Tropical and subtropical small mammals, for example, routinely experience temperatures above the lower critical limit of the thermoneutral zone and often have highly variable body temperatures. Therefore, unlike temperate species that must consistently generate heat to maintain an elevated body temperature, low latitude species spend more time at thermoneutrality and therefore can spend the energy elsewhere. I present an analyses of basal metabolic rates, body temperatures, thermolability, and life history traits in mammals and propose key areas in need of future research.

Li, J., Sprenger, R., Milsom, W. K. Department of Zoology, University of British Columbia, Vancouver, Canada Metabolic Scaling in Thirteen-Lined Ground Squirrels (Ictidomys tridecemlineatus) Metabolic scaling describes the relationship between metabolic rate and body size, and can be calculated using the equation Metabolic Rate = a(Body Mass)B. This study measured and compared metabolic rate and mass in 13-lined ground squirrels (Ictidomys tridecemlineatus) through a wide range of developmental stages to address the following questions: 1) how does mass specific metabolic rate (MSV̇ O2) change during parturition (change in metabolism with no change in weight)? 2) How does MSV̇ O2 scale as pups gain weight though development (weight gain due to growing tissue)? 3) How does MSV̇ O2 scale in adults with dramatic seasonal fluctuations in weight (weight change due to accumulation and use of white adipose tissue). Metabolic rates of 6 litters were found to increase roughly 150% upon birth. Metabolic rate then scaled hypermetrically during the early stages of development but switched to hypometric scaling at 20-26 days of age, as marked by a decrease in the exponent B from 1.20 to 0.76 (adj R2=0.90, p p=2.70E-03; adj. R2=0.67, p=2.84E-02). We are expanding this project by investigating the effects of thermoregulatory development on metabolic scaling. Calculated adult B values varied throughout the annual hibernation cycle as animals gained and then lost weight and were inversely correlated to body size, ranging from 0.61 to 0.69 (adj. R2=0.98, p=1.56E-06; adj. R2=0.93, p=1.15E-04). Weight gain through development is thus seen to result in a greater B than weight gain through fat

91 deposition. Metabolic rates measured during weight loss in hibernation were found to be significantly higher than those measured during weight gain preceding hibernation, thus exhibiting a hysteresis. The significant differences calculated for the scaling of I. tridecemlineatus questions the applicability of a singular B value for both inter- and intraspecific metabolic scaling. This research was funded by the NSERC of Canada.

Li, X.¹*, Vijayan, M. M.¹ 1Department of Biology, University of Calgary, Calgary, Canada *Presenting Author Effects of early-life cortisol perturbations on growth in juvenile zebrafish Maternal stress has been observed to negatively impact the physiology, cognition, and development in animals. In zebrafish, maternal stress manifests in the embryo as increased cortisol deposition from the mother. The effects of cortisol are mediated through the glucocorticoid (GR) and mineralocorticoid (MR) receptors. Studies have shown that higher cortisol levels in zebrafish embryos, which mimics maternal stress, affect larval development, but the long-term changes in growth are far from clear. To test if early cortisol perturbations have a negative effect on juvenile growth, zebrafish embryo cortisol content was manipulated during early development via cortisol bathing for the first 5 days post-fertilization (dpf) and cortisol injection between 0-1 hour post-fertilization (hpf). Juvenile fish weight and length were measured at 100 dpf. Growth-related transcripts, including growth hormone (GH), growth hormone receptors (GHRs), insulin-like growth factors (IGFs), insulin-like growth factor receptors (IGFRs) were measured in the brain and liver of these same fish. In this study, the 100 dpf cortisol bathed fish showed no difference in weight or length compared to the control, whereas the 100 dpf cortisol injected group was significantly heavier and longer than their control. The growth trajectory from 122 to 206 dpf was impacted by the waterborne exposure to cortisol; cortisol bathed fish showed a decreased specific growth rate. The cortisol injected group showed higher levels of igf1ra and igf1rb transcripts in the liver compared to their control. The cortisol bathed group had higher levels of gh in the brain and ghrb in the liver. Overall, early- life cortisol exposure affects the developmental growth by modulating the GH-IGF axis in zebrafish.

Li-Ting-Wai, G.1*, Johnson, N.2, Wilson, J. M.1 1Department of Biology, Wilfrid Laurier University, Waterloo, Canada 2Hammond Bay Geological Survey, Michigan, USA *Presenting Author Implementation of artificial feeders and decision-making maze tasks for behavioural analyses in parasitic sea lamprey Two sea lamprey Petromyzon marinus populations are of increasing concern, the invasive land-locked sea lamprey populations are strong and have contributed to the collapse of the Great Lakes fisheries in the mid-1900s. Other anadromous populations are currently under threat and require conservation efforts for protection. Despite the increasing concern for both populations of this species, the parasitic phase of the sea lamprey’s life cycle has not been well studied. This is due in part to ethical concerns raised around holding host fish with parasitic juveniles and the lack of an alternative feeding method to maintain these parasitic juveniles in the laboratory. An artificial feeding system has yet to be developed for the parasitic phase due to challenges in creating a demand feeder that would also reduce fouling of the water, procuring enough fish blood to feed lamprey, and having lamprey volitionally feed at comparable rates to naturally feeding fish. We proposed to develop an artificial feeder that uses pig’s blood which is readily available in lieu of using host fish to study the feeding physiology and behaviour of parasitic sea lamprey. The feeding system consists of a hollow silicone fish with self-sealing perforations filled with the liquid meal. The artificial feeder makes use of the suctorial feeding mechanism of the parasitic sea lamprey and will solve the challenges previously mentioned. Further experimentation will involve the use a decision-making maze to determine behaviours in response to olfactory cues such as varying concentrations of rainbow trout bile salts and avoidance cues. Anecdotal evidence indicates the need to increase the volitional attachment rates with use the of attractants. Should an artificial feeder be successfully developed, its use in the laboratory will allow researchers to study the parasitic phase of the sea lamprey’s life cycle, effectively contributing more to our knowledge of this species.

Liang, L.*, Lutek, K., Standen E. M. Department of Biology, University of Ottawa, Ottawa, Canada

92 Motor control changes muscle function in Polypterus senegalus Previous research has shown significant differences between walking and swimming in the locomotion patterns of the amphibious fish, Polypterus senegalus. Particularly, pectoral fins increase their range of motion and change from moving in a synchronized motion to a contralateral motion when walking compared with swimming. Intermediate in complexity between fishes and tetrapods, Polypterus has a pectoral musculature consisting of four muscle groups: abductor, adductor, zonopropterygialis, and coracometapterygialis. How the pectoral muscles change their function to accommodate the change in behaviour between swimming and walking is unknown, however, fin anatomical studies of fish exposed to walking environments show short-term damage to specific fin muscle groups and longer-term musculoskeletal plasticity. The goal of this work is to understand the mechanisms driving phenotypic plasticity and changes in general muscle function seen in fins used for terrestrial locomotion. This study uses high-speed videography and electromyography to compare muscle function between walking and swimming behaviours in Polypterus senegalus. Muscle activation patterns in all four groups of fin muscles show the largest changes in function occur within the adductor muscle, where increases in timing and duration of muscle activation during walking may explain damage and muscle fiber changes seen in previous studies. This work begins to clarify how mechanical advantage changes between drastically different gaits impacting muscle performance and improving our understanding of the mechanisms driving phenotypic plasticity in an amphibious fish.

Liu, S1*, Richards, J. G.1, Taylor, E. B.1,2 1Department of Zoology, The University of British Columbia, Vancouver, Canada 2Department of Zoology, Biodiversity Research Centre and Beaty Biodiversity Museum, The University of British Columbia, Vancouver, Canada *Presenting Author Intraspecific variation in seawater ion regulation in the prickly sculpin (Cottus asper) The prickly sculpin (Cottidae: Cottus asper) is a freshwater fish found in western North America and is part of a radiation of freshwater sculpins from marine ancestors. They are broadly distributed in the freshwater rivers and lakes in British Columbia (BC) with different historic and current connectivity to the marine environment. In a previous study, we found that populations from inland lakes had a better capacity to regulate ions in fresh water than populations from coastal estuaries. In this study, we aimed to determine whether the freshwater adaptation observed in inland populations resulted in a loss of ability to effectively ion regulate in seawater. Using multiple populations of prickly sculpin from inland lakes, coastal lakes and coastal rivers, we gradually increased the salinity from 0 ppt to 30 ppt over a two-week period of time and held them in this condition for two weeks after which we assessed ion regulatory characteristics. Seawater exposure did not result in mortality or significant changes in body mass in any population, but populations from the inland region had higher plasma ions in sweater, produced less intestinal precipitate, and had lower H+-ATPase activity across the whole intestine when compared to the populations from coastal estuaries. These results suggest that long-term freshwater adaptation in prickly sculpins is associated with a trade-off of a reduced capacity to ion regulate in their ancestral seawater environment.

Logan, S. M.¹*, Storey, K. B.¹ 1Department of Biology and Institute of Biochemistry, Carleton University, Ottawa, Ontario, Canada *Presenting Author Hibernator white and brown fat differ in how they use microRNAs to survive extreme winter conditions The sequence diversity of microRNAs (miRNAs) allows these potent regulators of mRNA fate to bind multiple transcripts, giving them the power to inhibit diverse cellular processes. Therefore, miRNAs may regulate metabolic rate suppression (also termed torpor), an adaptation used by capable species to reduce energy expenditure, minimize tissue damage, and prolong life. Small RNA-sequencing of brown adipose tissue (BAT) and white adipose tissue (WAT) from control (37 °C) and torpid (5-8 °C) ground squirrels revealed a central role for miRNAs in torpor in BAT, but perhaps less so in WAT. BAT and WAT are endocrine organs with important roles in temperature regulation and triglyceride storage, respectively, meaning they both serve indispensable functions in the fat-storing hibernator, the thirteen-lined ground squirrel (Ictidomys tridecemlineatus). Similar numbers of conserved miRNAs were identified in both tissues, but unsupervised clustering analysis revealed miRNA expression patterns only correlated with

93 condition (control/torpor) in BAT. Of the 76 miRNAs that were differentially expressed in BAT, the majority increased. By contrast, only 30 miRNAs were differentially expressed in WAT, with the majority being downregulated. In both tissues, KEGG and GO analyses implicated miRNAs in the inhibition of genes involved in energy metabolism and gene expression. Interestingly, in both tissues, processes that were suggested to be less inhibited by miRNAs during torpor included innate immune, inflammation, and repair pathways. Overall, miRNA-seq analysis of white and brown fat revealed roles for miRNAs in the downregulation of central metabolic processes necessary for MRS, with key differences in their relative profiles and target pathways. This study furthers our understanding how extreme mammals regulate metabolic rate suppression in the adipose depots and prevent adipose dysfunction.

Lutek, K.¹*, Standen, E. M.¹ 1Department of Biology, University of Ottawa, Ottawa, Canada *Presenting Author Neuromuscular plasticity and terrestrial locomotion in an amphibious fish Amphibious fish provide a unique opportunity to investigate neuromuscular plasticity. They move between aquatic (buoyancy and viscosity dominated) and terrestrial (gravity and ground friction dominated) environments using a single neuromuscular system. To accomplish this, fish must either have evolved specialized neuromuscular control for terrestrial locomotion or have plastic aquatic control systems. We use Polypterus senegalus, a primarily aquatic fish with anecdotal evidence of voluntary emersion, to investigate how neuromuscular control and physical environmental constraint interact and facilitate locomotor flexibility. We focus on the terrestrial locomotion (“walking”) of P. senegalus and ask two questions: first, are distinct kinematics between swimming and walking the result of unique neuromuscular control patterns and second are plastic changes in walking after terrestrial acclimation due to changes in neuromuscular control? We exposed P. senegalus to a gradient of environments spanning aquatic to terrestrial and recorded kinematics and muscle activity, looking for a discrete change to walking. We also recorded the walking kinematics and muscle activity of aquatically-reared and terrestrially-acclimated fish to understand how neuromuscular control changes between treatments. Our results demonstrate that despite discrete changes in both body and fin kinematic magnitude and timing across intermediate environments, there is a gradual change in body neuromuscular control. In contrast, changes in pectoral fin adductor muscle activity in lower water depths suggest a shift to a unique neuromuscular control pattern for the fin. Following terrestrial acclimation, the walking behaviour of P. senegalus becomes more effective due to shorter, higher intensity pectoral fin muscle activity and a shift in pectoral fin depressor onset closer to the start of stance. These changes reduce ground friction and facilitate more effective walking. We suggest that effective terrestrial locomotion can be accomplished through relatively small changes in neuromuscular control and that motor control plasticity is key for successfully navigating novel environments.

MacCormack, T. J.1*, Otley, N. A.1, Gates, M. A.1, Rhyno, E. L.1, Parker, K. S.1, Morash, A. J.2, Lamarre, S. G.3 1Department of Chemistry and Biochemistry, Mount Allison University, Sackville, Canada 2Department of Biology, Mount Allison University, Sackville, Canada 3Departement de Biologie, Universite de Moncton, Moncton, Canada *Presenting Author Intracellular Taurine Supports Cardiac Function And Metabolism In Salmonids Taurine is a beta amino acid found in high concentrations inside vertebrate heart and brain cells where it functions primarily as an osmolyte. Mammals tightly regulate cellular taurine levels and deficiency is associated with cardiomyopathy and disruptions in energy metabolism. Taurine levels are more dynamic in freshwater fish but the impact of fluctuations in taurine concentration have not been assessed. We developed a taurine-deficient (TD) trout model using an experimental diet rich in β-alanine, a competitive inhibitor of cellular taurine uptake. We hypothesized that TD animals would exhibit impaired cardiac function and increased sensitivity to environmental stress. Taurine concentration in heart and brain decreased by 15-20% after 4 weeks in fish fed β-alanine-enriched feed. Resting dorsal aortic pulse pressure and cardiac force production were reduced in TD trout. Aerobic scope and maximum swimming speed were not affected in TD rainbow trout, but sensitivity to both hypoxia and high temperature were significantly altered in TD brook trout. In permeabilized brook trout cardiac muscle fibers, electron transport chain complex II function and the expression of the complex IV COX3 subunit were significantly

94 elevated in TD fish. High concentrations of intracellular taurine appear necessary to support cardiac function and aerobic metabolism in trout.

Malotka, S. E.1*, Friesen, O. C.1, Detwiler, J. T.1 1 Department of Biological Sciences, University of Manitoba, Winnipeg, Canada *Presenting Author Density and Signaling Molecules Affect Freshwater Snail Host Immunity Invertebrates communicate using signaling molecules in a variety of interactions including food-finding and reproduction. While these interactions can be beneficial for individuals, increased population density may also increase the risk of parasite infection. In response, some invertebrates ramp up their immune systems when in groups (density-dependent prophylaxis). Although freshwater snails can transmit trematode parasites amongst themselves, it remains unclear if they exhibit density-dependent prophylaxis and what mechanisms are responsible. We focused on oxygenated fatty acids (oxylipins) because they are known to mediate host-trematode interactions. To determine the role of oxylipin signaling molecules in density-dependent prophylaxis, we tested the immune responses of Lymnaea elodes raised in either low density (0.0014 snails/mL) or high density (0.044 snails/mL) conditions. Experimental treatments were: 1) pretrial controls, 2) snails exposed to water conditioned with either a low or high density of snails, 3) snails exposed (and sham exposed) to one oxylipin that was either found in higher amounts in trematode-infected snails (5-HETE) or only produced by uninfected snails (11-HEPE). We assessed snail immunity using hemocyte counts and phenoloxidase activity at different times post-exposure (1-2 hrs, 4-6 hrs, and 8-10 hrs). We found that hemocyte counts increased when snails raised at low density were exposed to high density and low density conditioned water. In addition, snails exposed to low and high density conditioned water and 5-HETE had higher hemocyte counts. For 11-HEPE, there were only differences in hemocyte counts in low density snails. For phenoloxidase activity, there were no differences for any of the treatment groups. Our results suggest that density-dependent prophylaxis occurs, but is most likely mediated by hemocytes and only particular oxylipins like 5-HETE. By increasing our understanding of the role of signaling molecules in density-dependent prophylaxis in freshwater snails, we can elucidate chemical cues that mediate parasite-snail interactions.

Martel, A.L.1*, Reid, J.5, Alfonso, N.1, Paquet, A.2, Hemprich, S.3, Madill, J.B.1 , Ilves, K.1, Nowell, L.4, Geist, J.3, Cooke, S.J.5 1Beaty Centre for Species Discovery and Zoology, Canadian Museum of Nature, Gatineau QC and Ottawa ON, Canada 2Ministère des Forêts, de la Faune et des Parcs, Québec, Québec QC, Canada 3Aquatic Systems Biology Units, Technical University of Munich, Freising, Germany 4Kenauk Institute, Montebello QC, Canada 5Environmental Science and Biology, Carleton University, Ottawa ON, Canada Ecology and Genetics of The Eastern Pearlshell Mussel in two Rivers of the Kenauk Forest (Ottawa River watershed, Eastern Canada), and co-existing Fish Community Including the Brook Trout (Salvelinus fontinalis) A unique population of the Eastern pearlshell mussel (Margaritifera margaritifera) was discovered in the Kinonge River of the Kenauk forest in September 2018. It represents Canada’s westernmost distribution for this species. The Kenauk forest property is one of North America’s largest and longest-established private fish and game reserves, encompassing 265 km2 of mostly pristine wildlife reserve protected in part by the Nature Conservancy of Canada. During 2019 and 2020, our teams met in the study area with the following goals: (i) document the distribution and abundance of the pearlshell in the Kinonge River and its largest tributary, the West Kinonge River, (ii) determine whether the population was functional with recent recruitment, (iii) characterize the habitat properties, (iv) study the genetic diversity, and (v) characterize the co-existing fish community and identify the host fish. Methods included mussel searches using snorkeling and aquascopes including excavation of 0.25 m2 quadrats, substrate redox profiles and granulometry along with abundance of buried small juveniles, haemolymph sampling for genetic analysis (J. Geist method), and electrofishing for fish monitoring. The main Kinonge River had low density of pearlshells (0 to ˂ 5 ind. / m2) and its population is not functional, with no evidence of juvenile recruitment. By contrast, the West Kinonge tributary, a narrow river with an extensive and highly shaded riparian forest, had high rates of juvenile recruitment, oxygenated substrate and water temperature regime most favorable to both the mussel and the salmonid present in the system, the Brook trout. The West Kinonge

95 had the highest densities of pearlshells (commonly 15-40 ind. / m2). Haemolymph samples revealed that pearlshells at Kenauk had lower genetic diversity (allelic richness) and form a distinct group from all other North American populations. Twenty fish species, including many cyprinids and three centrarchids, but no salmonid, were collected in the main stem Kinonge River. By contrast, the West Kinonge river included only six fish species and the Brook trout was commonly captured and the likely host of the pearlshell mussel.

Martínez-Silva, M. A.1*, Vagner, M.2, Senay, C.3, Audet, C.1 1 Institute de sciences de la mer à Rimouski, Université du Québec à Rimouski, Rimouski, Canada 2 Laboratoire LEMAR, CNRS, Brest, France 3Institut Maurice-Lamontagne, Fisheries and Oceans Canada, Mont-Joli, Canada *Presenting Author Does growth and metabolism indicators can help the survey of redfish Sebastes mentella in the Estuary and Gulf of St. Lawrence Redfish (Sebastes mentella) is expected to sustain most bottom commercial fisheries in the years to come in the Estuary and Gulf of St. Lawrence (EGSL). Between 2011-2013, three strong cohorts recruited to the stock and their abundance growth exponentially. The main goal of this work was to deepen our knowledge of growth regulation in redfish, and determine how they may inform about spatial differences. Gene expression levels of three reference and seven candidate genes were analyzed by real-time PCR with Taqman probes in wild redfish captured at 7 different sites in the EGSL. Fish weight and temperature at the capture site explained 11% of the variation. The relative expression of insulin-like growth factor-1 (igf-1) and lactate dehydrogenase (ldh) correlated positively with weight, whereas myosin myo, citrate synthase cs, and pyruvate kinase pk correlated negatively. The relative expression of cytochrome c oxidase (cox) and igf-1 receptor (igf-1r) presented a negative correlation with temperature. Growth of S. mentella is not uniform in the different areas of EGSL. The estuary seemed to be the least favorable area supporting growth of Sebastes mentella, in contrast to the Cabot strait where the largest individuals were captured. We did not find any evidence of dissolved oxygen, salinity or depth effects on average mass. We found that igf-1, igf-1r, pk and cox were the best candidates as growth indicators in redfish. Transcriptomics was found to be a tool of interest to investigate growth in a deep-sea fish that is difficult to study in terms of physiology. Finally, since growth potential of Sebastes mentella is strongly correlated with temperature (being even enhanced by the temperature increase), this study suggests an ecological advantage for this species in a climate warming context.

Matveev, M.¹*, Kahn, A. S.2, Yahel, G., Eerkes-Medrano4, D., Ludeman, D.1, Aragones Suarez, P.1, Leys, S. P.1, et al. 1Department of Biology, University of Alberta, Edmonton, Canada 2 Moss Landing Marine Laboratories, California, United States 3 The Faculty of Marine Science, Ruppin Academic Center, Michmoret, Israel 4 Ecology and Conservation Group, Marine Scotland, The Scottish Government, Aberdeen, Scotland, UK *Presenting Author Passive flow revisited: the glass sponge Aphrocallistes vastus may use sense-induced flow The induced flow hypothesis, proposed by S. Vogel in the 1970’s, states that a laminar current could passively induce flow through a tube by viscous entrainment or the Bernoulli effect. This hypothesis has been widely applied to diverse living systems and biogenic structures. Sponges (Porifera) have been subject to the induced flow hypothesis , based on assumption that their canals are inert; however, current understanding of sponge morphology and physiology shows that sponges have a sophisticated sensory system, and high resistance to flow through their tissues. Glass sponges (Hexactinellida) are ideal for re- examining the induced flow hypothesis because individuals have large oscula, thin body walls, and a well- studied sensory response. Here, we used flow probes and oxygen sensors to test the hypothesis that faster ambient current enhances the flow through the sponge Aphrocallistes vastus and reduces the metabolic expenditure (measured as oxygen uptake) per liter filtered. We found that more water was filtered during periods of higher ambient current in only one of six individuals studied, and all sponges arrested filtration independently of ambient currents. This shows that flow is not passively drawn through sponges, rather they control their pumping rate. We then compared oxygen removal between low and high ambient flow during periods when the sponges were pumping (high excurrent). Sponges removed on average 30% less oxygen when the ambient current was high. This suggests a mechanism by which the

96 sponge senses increased ambient flow rates and reduces the cost of filtration, possibly by reducing resistance through canals. Our experiments imply that while sponges can take advantage of current- induced flow, flow through these animals is largely controlled by their complex physiology. Therefore, we proposed that this behavior should be referred to as “sense-induced flow”.

McGeachy, S. A.¹*, Benfey, T. J.¹ 1Department of Biology, University of New Brunswick, Fredericton, Canada *Presenting Author Improving Hypoxia Tolerance of Triploid Brook Charr (Salvelinus fontinalis) Triploid salmonids are used in aquaculture and stocking programs for recreational fishing because they are reproductively sterile and therefore cannot breed in the wild. However, they appear to be more sensitive than diploids to hypoxia and high temperature stress. The objective of my MSc is to develop a better understanding of the biological requirements of triploids (specifically hypoxia tolerances), and thereby provide advice to fish farmers and recreational fishery managers on how to improve triploid performance. I will be comparing acute hypoxia tolerance in sibling diploid and triploid brook charr that have been acclimated to either moderate hypoxia (dissolved oxygen at 70% of air saturation) or normoxia (100% saturation) for 14 days. Fish will then undergo acute hypoxia trials, by injecting nitrogen gas to displace oxygen and using loss of equilibrium as the endpoint. All fish will be measured (fork length and body mass) and a blood sample will be taken. Fish will then be euthanized and dissected to remove the whole heart, the ventricle, the liver, the gills and the gonads. I will use the body measurements, blood, and tissue samples to determine condition factor, hematocrit, whole blood glucose and lactate levels, plasma ion concentrations and osmolality, interlamellar cell mass, relative ventricular mass, hepatosomatic index and gonadosomatic index. I plan to perform a second experiment to further investigate hypoxia tolerance in triploids with its design based on the results from this first experiment.

McInnis, S. JL.¹*, Franz-Odendaal, T. A.1,2 1Department of Biology, Saint Mary’s University, Halifax, Canada 2 Department of Biology, Mount Saint Vincent University, Halifax, Canada *Presenting Author Towards Understanding the Effects of Mechanical Forces on the Zebrafish Skeleton The musculoskeletal system is responsible for executing movements and is comprised of the muscles and the skeleton. The close association between these two tissue systems begins early in development, as muscles insert into, and begin to exert mechanical forces on the developing skeleton. Muscle-based mechanical forces impact both the early development and the maintenance of the skeleton. Generally, the detection of muscle-based mechanical forces primarily involves the non-dividing bone cells, the osteocytes. In teleosts, other cells, such as the bone depositing osteoblasts and the bone resorbing osteoclasts, are also known to respond to mechanical stimuli. Many studies have investigated the role of muscle load on the skeleton, but few have considered the effects of muscle-based mechanical forces on flat bones. The aim of this study was to understand the role played by muscle-based mechanical forces in the development and maintenance of the scleral ossicles of zebrafish (Danio rerio). Prior to ossification of the flat scleral ossicles, zebrafish were forced to swim in a swim tunnel for two to three weeks. Following the period of increased muscle-based mechanical forces, the overall degree of ossification in the skeleton, the size of the scleral ossicles, along with the activity of osteoclasts and osteoblasts was examined. Overall, it was found that the entire skeleton was more ossified, with increased muscle load. Interestingly, the effect on the scleral ossicles was different depending on body size suggesting that muscle-load effects are variable over time. Furthermore, the activity of osteoclasts, but not osteoblasts, significantly changed when compared to untreated controls. These findings help to understand the effects of muscle load on the development and maintenance of the skeleton on a fundamental level and may have implications in mitigation strategies of metabolic bone disorders.

McKenzie E. K. G.1*, Kwan G.2, Tresguerres M.2, Matthews P. G. D.1 1 Department of Zoology, University of British Columbia, Vancouver, Canada. 2 Scripps Institution of Oceanography, University of California San Diego, San Diego, USA. *Presenting Author cAMP drives pH dependent expansion of the hydrostatic organs of Chaoborus midge larvae

97 The aquatic larvae of the Chaoborus midge are the only insects that can achieve neutral buoyancy. They remain suspended in the water column of lakes and ponds by regulating the volume of four internal air- filled bladders (air-sacs) that are derived from the tracheal system. Here we describe the physiological and mechanical aspects of this unique buoyancy regulation system. Unlike Teleost fish, Chaoborus do not secrete gas into their air-sacs. Instead, the air-sac wall itself expands and contracts in response to changes in its pH, altering the volume of the lumen. This pH-sensitivity is due to the presence of bands of resilin, a pH sensitive protein, in the air-sac wall alternating with bands of tracheal cuticle. The architecture of alternating contractile and non-contractile bands restricts changes in volume to only one dimension, causing the air-sac to behave as a pH-muscle, converting changes in pH directly into mechanical work. The pH of the air-sacs is regulated by an enveloping endothelium containing vacuolar type H+ APTase (VHA) as shown by immunofluorescence. Bafilomycin, a VHA inhibitor, prevents proton pumping and causes air-sac expansion. In vitro application of either 8-Bromo-cAMP or forskolin + IBMX also results in expansion of the air-sac, and therefore we hypothesize that cAMP activates exchange proteins and/or ion channels which dissipate the VHA-generated pH gradient across the endothelium. The cAMP analogue 8-pCPT-2'-O-Me-Cyclic AMP, which specifically targets exchange proteins directly activated by cAMP (Epac) effectively drives air-sac expansion, while N6Bnz which activates protein kinase A does not, indicating a role for Epac in air-sac alkalinization. This system is the first known example of a pH-driven mechanochemical engine in nature.

McMillan, L. E.¹*, Adamo, S. A.¹, Urbach, S.², Biron, D. 3 1Department of Psychology and Neuroscience, Dalhousie University, Halifax, Canada 2 Functional Proteomics Platform, Institut de Génomique Fonctionnelle, Montpellier, France 3Laboratoire Microorganism, Universite Clermont Auvergne, Clermont-Ferrand, France *Presenting Author Mind Boggling: The parasitic wasp Cotesia congregata may use viral particles to manipulate the brain of its host, the caterpillar Manduca sexta Cotesia congregata is a wasp parasitoid of the pest caterpillar Manduca sexta. Parasitic wasps such as Cotesia congregata inject polydnaviruses into their hosts during oviposition. Polydnaviruses are viruses whose DNA has been incorporated into the wasp genome. This incorporation of viral genes allows the female wasp to produce viral particles containing both viral and wasp genes. By injecting a cocktail of venom, polydnavirus, larvae and teratocytes into M. sexta, this parasitoid is able to commandeer its host; rendering it a suitable environment for its larva. While the wasp larvae develop inside the host, outwardly the caterpillar’s behaviour is normal. However, during wasp emergence from the caterpillar, the caterpillar loses the ability to feed. Its reflexes remain intact and it becomes a bodyguard for the wasp cocoons from any would-be arthropod predators. The mechanism behind the dramatic change in behaviour of the host remains unknown. This work examined M. sexta in the days directly prior to, during, and after the parasitic larva have emerged. Results show that during parasitism there is a reduction in neural investment by the caterpillar, as evidenced by a reduction in total mRNA production as well as a reduction in total protein. Furthermore, proteomic analysis of the brains of parasitized M.sexta revealed that polydnavirus proteins can be found within the brain at late stages of parasitism, even as long as 3 days after the larva have emerged from the body of its host. Unfortunately the function of these proteins is not well known, but there is evidence of neuoinflammation which would produce changes in the brain and behaviour.

Mehdi, H.1*, Lau. S. L.2, Synyshyn, C.1, Salena, M. G.1, McCallum, E. S.3, Muzzatti, M. N.1, Bowman, J. E.4, Mataya, K.4, Bragg, L. M.5, Servos, M. R.5, Kidd, K. A.2,6,7, Scott, G. R.2, Balshine, S.1 1Department of Psychology, Neuroscience & Behaviour, McMaster University, Hamilton, Canada 2Department of Biology, McMaster University, Hamilton, Canada 3Department of Wildlife Fish and Environmental Studies, Swedish University of Agriculture Sciences, Umeå, Sweden 4Royal Botanical Gardens, Burlington, Canada 5Department of Biology, University of Waterloo, Waterloo, Canada 6School of Earth, Environment and Society, McMaster University, Hamilton, Canada 7Institute for Water, Environment and Health, United Nations University, Hamilton, Canada *Presenting Author Wastewater as a potential ecological trap: Effects on fish communities in summer and winter

98 Municipal wastewater treatment plant (WWTP) effluents are a ubiquitous source of contamination whose impacts on fish and other aquatic organisms span across multiple levels of biological organization. Despite this, few studies have addressed the impacts of WWTP effluents on fish communities, especially during the winter—a season seldom studied. Here, we assessed the impacts of wastewater on fish community compositions and various water quality parameters during the summer and winter along two effluent gradients in Hamilton Harbour, an International Joint Commission Area of Concern in Hamilton, Canada. We found that fish abundance, species richness, and species diversity were generally highest in sites closest to the WWTP outfalls, but only significantly so in the winter. Fish community compositions differed greatly along the effluent gradients, with sites closest and farthest from the outfalls being the most dissimilar. Furthermore, the concentrations of numerous contaminants of emerging concern (CECs) in the final treated effluent were highest during the winter. Water quality of sites closer to the outfalls was poorer than at sites farther away, especially during the winter. We also demonstrated that WWTPs can significantly alter the thermal profile of effluent-receiving environments, increasing temperature by as much as 9 °C during the winter. Our results suggest that wastewater plumes may act as ecological traps in winter, whereby fish are attracted to the favourable temperatures near WWTPs and are thus exposed to higher concentrations of CECs. This study highlights the importance of winter research as a key predictor in further understanding the impacts of wastewater contamination in aquatic ecosystems.

Melanson, C. A.1, 2*, Lamarre, S. G.1, Currie, S.2 1 Department of Biology, Université de Moncton, Moncton, Canada 2 Department of Biology, Acadia University, Wolfville, Canada *Presenting Author Stuck between a rock and a hot place: How does sociability impact adaptive responses to warm temperature? Understanding factors affecting ectothermic fishes’ capacity to cope with warming temperature is critical given predicted climate change scenarios. We now know that a fish’s social environment affects how it responds to environmental stressors such as high temperature. Using the amphibious, selfing hermaphroditic mangrove rivulus fish (Kryptolebias marmoratus) as a model, we tested the hypothesis that the presence of other fish before or during a thermal stress would negatively influence their thermal tolerance and response to rising temperature. To test this, we measured critical thermal maximum, emersion temperature and thermal safety margin in warming scenarios with socially naïve and socially experienced fish. We performed these trials with and without social stimulation provided by mirror reflection or other fish. Past or present social experience did not influence the critical thermal maximum or thermal safety margin but did influence the emersion temperature. Prior social experience alone resulted in fish emerging at a higher temperature than socially naïve fish. Similarly, when both socially experienced and socially naïve fish were stimulated with a mirror reflection during the thermal stress, the socially experienced fish emerged at warmer temperatures than the socially naïve fish. Interestingly, the influence of social experience on the emersion temperature disappeared when fish were in the presence of conspecifics during the trial, possibly as a result of social buffering during the thermal stress. Collectively, our data suggest past and present social experiences interact to impact the behavioural response of fish to high temperature.

Menail, H., Léger A., Cormier S. B., Pichaud, N. Department of Chemistry and Biochemistry, Université de Moncton, Moncton, Canada Mitochondrial thermal sensitivity in insect species: a comparative analysis of metabolic capacity Insects are the most diverse group of organisms on earth and can withstand large temperature variations allowing them to colonize multiple habitats. The insect flight muscle is one of the most metabolically active tissues found in nature and must be extremely flexible to sustain intense activities. However, a proper examination of the thermal sensitivity of this muscle in insect species is still lacking. In this study, we investigated mitochondrial oxygen consumption in permeabilized flight muscle of three different insect species (Drosophila melanogaster, Apis mellifera and Leptinotarsa decemlineata) at 8 different temperatures (from 6 to 45°C). We also measured the activity of 8 different enzymes involved in glycolysis, tricarboxylic acid cycle and mitochondrial metabolism at 6 different temperatures (from 18 to 45°C). Our results showed that Complex I mitochondrial respiration was maximized at 24 and 30°C in -1 -1 Drosophila and Honeybees (Drosophila: 222.64 ± 14.07 and 170.59 ± 13.15 pmolO2.s .mg tissue, -1 -1 respectively; Honeybee: 115.24 ± 15.02 and 142.64 ± 20.89 pmolO2.s .mg tissue, respectively).

99 However, it then significantly and steadily declined from 30 to 45°C for both species. This decline was associated with decreased pyruvate dehydrogenase and citrate synthase activities for Drosophila and Honeybees, respectively. However, in the potato beetle, complex I substrates did not trigger increased mitochondrial respiration compared to the other species. Instead, mitochondrial respiration with proline -1 -1 was important and maximized at 24 and 30°C (24.44 ± 4.37 and 32.35 ± 5.69 pmolO2.s .mg tissue, respectively) before a decline was observed from 30 to 45°C. Interestingly, from 30 to 42°C, the oxidative substrate glycerol-3-phosphate was able to compensate for the decreased mitochondrial respiration observed for all three species. Thus, this study highlights the versatility of the metabolic control in different insect species and provides new knowledge about the utilization of mitochondrial oxidative substrates to maintain flexibility according to temperature variation.

Millar, Z. D.1*, Dovaston, K.1, Kecheliev, D.1, Lumsden, J. S.1 1Department of Pathobiology, University of Guelph, Guelph, Canada *Presenting author Rate of regeneration of Corallimorpharia Corals are able to regenerate lost tissue and asexual reproduction is important to replace damaged corals. Corallimorpharia are commonly propagated or aquacultured via asexual reproduction through fragmentation and are a useful model for coral regeneration. They do not have aragonite skeletons but are close relatives of scleractinia (reef-building corals). Ricordea florida and Discosoma sp. underwent bilateral fragmentation and the regeneration process was documented, to compare to previous research on Ricordea and Rhodactis sp.. Bilateral fragmentation was conducted using a sterile scalpel blade with sectioning through the oral disc and the mouth of the coral polyp. The process of R. florida regeneration occurred first with polyp re-circulation, then tissue fusion and finally tentacle regrowth. All R. florida (n=58) had fully regenerated within 26 days, however, the fastest polyp completed regeneration on Day 4 and the majority of polyps by Day 10. Discosoma sp. was slower with the first polyp regenerating at Day 7 and by Day 28 (end of the experiment) only 60% of the polyps (n=103) had completed regeneration; with a survival rate of 85%. To determine the impact of different fragmentation methods, mimicking different types of tissue damage, transverse fragmentation was also performed on Discosoma sp. The oral disc and pedal disc were separated from one another using a sterile scalpel blade. Oral disc portions had the least tissue loss, a 100% survival rate and all polyps (n=47) regenerated within 7 days. Regeneration in this group was complete with attachment to the substrate and closure of any visible wound. The pedal disc portions had a survival rate of 83% (lowest for Discosoma sp.) and only 66% of all polyps (n=47) had regenerated by Day 28, with the first polyp regenerating at Day 14. To complete regeneration in this group the complete oral disc including the mouth had to reform.

Misutka, M.D.1*, Glover, C.N.1,2, Goss, G.G.1, Veilleux, H.D.1 1Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada 2Faculty of Science and Technology and Athabasca River Basin Research Institute, Athabasca University, Athabasca, Alberta, Canada *Presenting Author Arctic grayling (Thymallus arcticus) environmental DNA detection and decay Arctic grayling (Thymallus arcticus) is listed as a species of special concern under Alberta’s Wildlife Act due to angling pressure and habitat destruction. In 2017, of 80 streams in Alberta in which Arctic grayling were historically found, only 39 had the species identified with high accuracy. Environmental DNA (eDNA) is a promising new tool for non-invasive biomonitoring and could improve detection of this species within Albertan waters. As eDNA monitoring relies on quantifying sometimes minute quantities of DNA in large volumes of water (or other environmental sources), it is critical to optimise assays to reduce false negative or false positive detections. Thus, we designed and optimised an Arctic grayling specific eDNA assay to ensure adequate sensitivity and specificity of our protocol. Using water from laboratory tanks housing Arctic grayling and from field-collected samples, we determined the optimal filter size, the best DNA extraction protocol, ensured the assay was species-specific, and measured eDNA detection in water with different flow rates (20L/min, 10L/min, 5L/min, 1L/min, and static). In previous data, we found eDNA to be detected at 24 hours after a brief (5s) exposure to one individual. In ongoing experiments, we are now determining decay after a longer exposure (4h) and over a longer period of time (7 days). This research will be useful in monitoring the presence of Arctic grayling in Alberta as they continue to face challenges from human activities and natural events. More broadly, this research will also be instrumental

100 in understanding the best methods for studying environmental nucleic acids and to gain insights about their use for monitoring organism and ecosystem health, which could have implications across ecology and environmental biology.

Miyashita, T.1, 2; Smeeton, J.3; Baddam, P.4; Crump, J. G.5; Graf, D.4; Palmer, A. R.6; Allison, W. T.6 1 Canadian Museum of Nature, Ottawa, Canada 2 Biology, University of Ottawa, Ottawa, Canada 3 Irving Medical Center, Columbia University, New York, USA 4 Dentistry, University of Alberta, Edmonton, Canada 5 Stem Cell Biology and Regenerative Medicine, University of Southern California, Los Angeles, USA 6 Biological Sciences, University of Alberta, Edmonton, Canada Agnathan-like heads of functionally jawless zebrafish In vertebrates, a functional jaw apparatus requires a hinge joint, so jaw joint defects are often highly disruptive. To describe the consequences of jaw-joint dysfunction, we engineered two independent null alleles of a single jaw-joint marker gene, nkx3.2, in zebrafish. These mutations caused zebrafish to become functionally jawless via fusion of the upper and lower jaw cartilages. Despite their jaws being locked, nkx3.2 mutants accommodated this defect by: a) having a remodelled skull with a fixed open gape, reduced snout, and enlarged branchial region; and b) generating weak suction by depressing the basihyal (in the absence of jaw movement). The late onset and broad extent of phenotypic changes in the mutants suggest that modifications to the skull are induced by functional agnathia, secondarily to nkx3.2 loss-of-function. Interestingly, nkx3.2 mutants superficially resemble ancient jawless vertebrates (anaspids and thelodonts) in overall head shapes. Because no homology exists in skull elements between these taxa, the adult nkx3.2 phenotype is not a reversal, but convergence due to similar functional requirements of feeding without moveable jaws. This remarkable analogy makes the mutants a unique model with which to: a) investigate adaptive responses to perturbation in skeletal development; b) re-evaluate evolutionarily inspired interpretations of phenocopies generated by gene knockdowns and knockouts; and c) gain insights into feeding mechanics of the extinct agnathans.

Monod, E.1*, Alkie, T. N.2, Rodriguez-Ramos, T.1, Poynter, S. J.2, Dixon, B.1, DeWitte-Orr, S. J.2 1Department of Biology, University of Waterloo, Waterloo, Canada 2Department of Health Sciences, Wilfrid Laurier University, Waterloo, Canada *Presenting Author The application of PACAP-38 as an immunomodulator in aquatic invertebrates Microbial resistance to antibiotics is motivating the identification of alternative antimicrobial compounds. A promising alternative is emerging, with the use of cationic antimicrobial peptides (AMPs). The present study focuses on the application of a highly conserved, multifunctional neuropeptide with antimicrobial properties – pituitary adenylate cyclase activating polypeptide (PACAP) – as an immunomodulator in an invertebrate model. In vertebrates, PACAP has been shown to regulate pro- and anti-inflammatory cytokine production through cAMP signalling cascades, interfere directly with viral protein transcription and disrupt bacterial membranes. In this study, PACAP’s function as an immunomodulator was investigated using hemolymph collected from shrimp (Pandalus danae), and Ontario native wild crayfish. Immune markers used to measure its efficacy include: total hemocyte count (THC), lectin production, nitric oxide metabolite generation, and phenoloxidase. Initial findings support PACAP’s function as an immunomodulator as in vivo stimulation increased THC, lectin production as well as increased phenoloxidase in both hemocytes and hemolymph. This work provides a fundamental understanding of PACAP’s immuno-modulatory role in invertebrate species that will help develop immune treatments that can reduce the use of antibiotics worldwide.

Morris, M. R. J.1,2*, Wuitchik, S. J., S.2,3,4, Rosebush, J.1, Rogers, S. M.2 1Department of Biology, Ambrose University, Calgary, Canada 2Department of Biological Sciences, University of Calgary, Calgary, Canada 3Informatics Group, Harvard University, Cambridge, USA 4Department of Biology, Boston University, Boston, USA *Presenting Author Mitochondrial volume density and evidence for its role in adaptive divergence in response to thermal tolerance in threespine stickleback

101 Phenotypic plasticity is predicted to permit persistence in new environments, and may subsequently evolve to enhance fitness. Colonizing environments with lower winter temperatures can lead to the evolution of lower critical thermal minima; the corresponding physiological traits associated with temperature tolerance are predicted to involve mitochondrial function. Threespine stickleback (Gasterosteus aculeatus) have colonized freshwater lakes along the Pacific Northwest. These freshwater populations are known to exhibit cold-induced increases in mitochondrial volume density in pectoral muscle, but whether such plasticity evolved before or after colonization is uncertain. Here, we measure critical thermal minima (CTmin) in one marine and one freshwater population of threespine stickleback, and mitochondrial volume density in pectoral and cardiac tissue of both populations acclimated to different temperature treatments (6.2, 14.5 and 20.6 ℃). Mitochondrial volume density increased with cold acclimation in pectoral muscle; cardiac muscle was non-plastic but had elevated mitochondrial volume densities compared to pectoral muscle across all temperature treatments. There were no differences in the levels of plasticity between marine and freshwater stickleback, but neither were there differences in CTmin. Importantly, marine stickleback exhibited plasticity under low-salinity conditions, suggesting that marine stickleback had at least one necessary phenotype for persistence in freshwater environments before colonization occurred.

Morris, C. M.1,2, Brix, K. V.3, O’Donnell, M. J.2, Po, B. H. K1, Wood, C. M.1,2 1Department of Zoology, University of British Columbia, Vancouver, Canada 2Department of Biology, McMaster University, Hamilton, Canada 3Rosenstiel School of Marine and Atmospheric Science, University of Miami, Miami, USA A Comparison between Transepithelial Potential Responses of Fathead Minnow (Pimephales promelas) and the Water Flea (Daphnia magna) to Increased Ambient Major Salt Concentrations + + 2+ 2+ - 2- There has been increasing concern about elevations in major ions (Na , K , Ca , Mg , Cl , SO4 ) in freshwater ecosystems. These excess ions originate from anthropogenic activities (e.g., road de-icing salts, fracking spills, mining) and have detrimental effects on freshwater organisms, causing iono- and osmo-regulatory stress. Although the mechanisms of ionoregulation and sensitivity to toxicants varies greatly between fish and daphnids, we have noted significant unifying principles in the transepithelial potential (TEP) responses, an endpoint predictive of toxicity, to major ions. TEP was measured in response to Na, K, Ca and Mg salts in fathead minnow (FHM) (Pimephales promelas) and Daphnia magna and the two data sets were analyzed using the Michaelis-Menten Model and previously published reference toxicity data. This analysis revealed that there is a strong correlation between toxicity in FHM and toxicity in Daphnia magna across different salts. Significant positive relationships were observed between the inverse of affinity (Km) and toxicity (Lethal Concentration 50 (LC50) values) for the various salts in the two species. As such, a high affinity for ΔTEP response (low Km) correlates with high toxicity (low LC50) for the same salt, and vice versa. A potency relationship has been identified where the potency of a salt in depolarizing the TEP is related to its potency in causing lethality. This potency relationship is similar between the two very different species, even though the absolute values may be quite different. This result suggests that electrochemical modeling could be used to predict the short-term ΔTEP value at the gills, and in turn the associated toxicity in each species. These physiological responses to toxicity will be important in further developing predictive models such as the Electric Power Research Institute’s (EPRI) Multi-Ion Toxicity Model, for regulating major ions and determining toxicity thresholds for freshwater ecosystems (EPRI, NSERC Discovery).

Muir, C. A.1*, Garner, S. R.1, Damjanovski, S.1, Neff, B. D.1 1 Department of Biology, Western University, London, Canada * Presenting Author Kickstart my heart: Elevated rearing temperature alters heart morphology and thermal performance in juvenile Atlantic salmon Individuals within a species can differ greatly in their thermal performance, often based on the environmental conditions experienced during development. This developmental plasticity in thermal performance may allow species to cope with thermal stress imposed by climate change. Here, we assessed cardiorespiratory thresholds for thermal performance in juvenile Atlantic salmon reared at temperatures indicative of either current or future (+4°C) thermal conditions. At the parr stage, maximum heart rate was measured in response to acute warming. Fish reared in the +4°C treatment displayed a 4.5°C increase in the Arrhenius breakpoint temperature for maximum heart rate (where cardiac scope is

102 maximized), and a 2.5°C increase in the temperature at which heat-induced cardiac arrythmias occurred. Histological analysis of the heart revealed that, while ventricular roundness and relative ventricle size did not differ between treatments, the proportion of compact myocardium in the ventricular wall was significantly greater in fish raised in the +4°C treatment. The effect of a thicker compact myocardium on heart function is now being examined using echocardiography-derived measures of cardiac output and diastolic function. The observed differences in heart morphology and function may contribute to increased upper thermal tolerance through improved oxygen delivery to tissues. Our research contributes to the understanding of how thermal conditions experienced during development can affect performance later in life and identifies strategies which may allow fishes to cope with increased water temperatures, as climate change increases the frequency of record heat events.

Namboothiri, A. M.*, Torson, A. S., Sinclair, B. J. 1Department of Biology, University of Western Ontario, Canada *Presenting Author Effects of Cold Exposure on Alternative Splicing in Asian Longhorned Beetles The insect cold response is predominantly based on physiological changes insects express when faced with low temperature exposure. It is understood that differential gene expression plays a role in modulating some of these physiological processes, but there has been no exploration of how post- transcriptional modulation, particularly alternative splicing, may be involved. The Asian longhorned beetle (ALB), Anoplophora glabripennis, is a forest pest species that overwinters as a freeze-tolerant larva. The focus of this study was to develop hypotheses on how ALB may control modulation of their cold recovery mechanisms by using different splice variants to their advantage. I implemented RNA-seq data of ALB fat body tissue from a cold-exposed treatment relative to a warm temperature control group into an R workflow using the IsoformSwitchAnalyzeR package. I identified 20 genes with preferential use of transcripts in ALB following cold exposure. These genes were spread over a wide range of functional roles that may be associated with ALB cold recovery. These functions include DNA repair, intracellular trafficking, cell signalling, RNA processing, ion/lipid transport, and transcriptional regulation, with between two to four genes associated with each function. This research demonstrates that ALB have a highly specific response in alternative splicing during late-stage cold recovery, which may suggest that the associated genes are closely tied to this period of recovery.

Nash, N. M., Klymasz-Swartz, A. K., Quijada-Rodriguez, A. R., Yoon, G. R., Weihrauch, D. Biological Sciences, University of Manitoba, Winnipeg, Canada Physiological response of the common water flea, Daphnia magna, to environmentally relevant elevations in isolated and combined temperature and ammonia levels With the increase in human population comes a greater anthropogenic impact on the biosphere. Heat waves, exacerbated by the production of greenhouse gases (CO2, methane, etc.), are increasing in both severity and longevity, contributing to increasing water temperatures in freshwater ecosystem. Along with rising temperatures, freshwater habitats are faced with increasing nutrient loads due to agricultural fertilizer runoff, contributing to pronounced eutrophication events. Using the planktonic freshwater crustacean, Daphnia magna, as a biological model, this study assesses the impacts of environmentally relevant single and multi-stressor conditions on the physiology of zooplankton. Animals were acclimated to four naturally occurring parameters; control (22˚C, pH 8.1, 0 µM NH4Cl), high temperature (27˚C, pH 8.1, 0 µM NH4Cl), high environmental ammonia (HEA, 22˚C, pH 8.1, 300 µM NH4Cl) and the combination of both stressors (27˚C, pH 8.1, 300 µM NH4Cl), for seven-days before assessing the total ammonia and urea excretion rates, critical thermal maximum (CTMax) and metabolic rates (MO2). The acclimation of D. magna to elevated temperatures resulted in a decrease in both total ammonia excretion and metabolic rates, along with a considerable increase in CTMax. Furthermore, individuals acclimated to HEA increased their urea excretion rates, suggesting the production of urea as a mechanism of ammonia detoxication. Notably, the acclimation to both stressors simultaneously caused no changes in nitrogen excretion rates, but a substantial decrease in MO2 and an increase in CTMax. This study vividly demonstrates the staggering impact human activity has on freshwater invertebrates and furthers research into the effects of multi-dimensional stressors in natural environments.

Nataprawira, L. G.¹*, Gillis, T. E.¹

103 1Department of Integrative Biology, University of Guelph, Guelph, Canada *Presenting Author The influence of environmental and endocrine factors on collagen regulatory pathways in rainbow trout (Oncorhynchus mykiss) cardiac fibroblasts Male rainbow trout have been observed to undergo cardiac remodelling in response to thermal acclimation, a response that includes changes in collagen composition. To begin characterizing the cellular mechanisms involved, previous studies have exposed cardiac fibroblasts from male fish to relevant levels of cyclical stretch and transforming growth factor beta 1 (TGF-β1). These treatments activated cellular signalling pathways involved in collagen deposition (stretch) and increased collagen deposition (TGF-β1). In our current study, we are looking at the influences of testosterone, angiotensin II (Ang II), and biomechanical stretch on cell signalling in cardiac fibroblasts. The influence of temperature acclimation on these responses is also being examined. We hypothesized that testosterone and Ang II would promote collagen deposition, greater mechanical force and higher frequencies would upregulate signals involved in collagen production, and cold acclimation would result in greater collagen levels compared to the warmer control group. Results indicate that treatment of fibroblasts with biomechanical stretch, testosterone, or angiotensin II lead to changes in gene expression patterns that would support an increase in collagen deposition. This includes gene transcripts for matrix metalloproteinase-9 (mmp-9), collagen type 1 alpha (col1a1), and tissue inhibitor of metalloproteinases 2 (timp-2). We are currently examining the influence of temperature acclimation on this response and how it translates into collagen protein levels in the cells. This research is supported by an NSERC Discovery Grant.

Nauss, J. L.1*, Easy, R. H.1 1 Department of Biology, Acadia University, Wolfville, Canada *Presenting Author Exploring Differential Gene Expression in Striped Bass (Morone saxatilis) in Response to Mercury Mature Striped Bass, (Morone saxatilis) feed on high trophic level prey, enabling biomagnification of contaminants such as mercury. Mercury is a non-essential heavy metal existing in several forms in aquatic environments and produces various toxic effects in organisms. In this study, the expression of genes coding for antioxidants involved in the oxidative stress response and detoxification, specifically glutathione S-transferase, metallothionein, and thioredoxin reductase in Striped Bass, were examined. Total mercury levels in liver tissues, received in coordination with local fishers in Nova Scotia, were measured using thermal decomposition, amalgamation and atomic absorption spectrometry. Real time quantitative polymerase chain reaction and the ∆∆Cq method was used to calculate relative normalized expression of target genes in comparison to the reference gene elongation factor 1-alpha. Total mercury levels in liver tissues increased with total length of Striped Bass, indicative of bioaccumulation. No statistically significant relationships were observed regarding the expression of target genes and mercury concentration in Striped Bass liver. MT gene expression exhibited a statistically significant positive relationship with mercury concentration after outlier removal and may serve as a potential biomarker of mercury exposure. This study is the first to show differential expression of novel genes involved in the oxidative stress response and detoxification processes in Striped Bass in response to mercury contamination.

104 rapamycin (mTOR), but not the ratio of phosphorylated to total AMP-activated kinase (AMPK) expression in the brain of zebrafish. The transcript abundance of key brain peptides involved in appetite regulation, including NPY, POMCa, CRH, MC3R, MC4R, Lepa and lepR, were not significantly affected by cortisol. To test if elevated glucose may play a role in the cortisol-mediated cessation of feeding, we treated fish to waterborne glucose to elevate plasma glucose levels, and this reduced food consumption. However, glucose exposure decreased the ratio of phosphorylated to total AMPK, but did not affect Akt or mTOR expression in the brain. Overall, our results suggest that the reduced feeding seen with stressed levels of cortisol may not be due to altered glucose sensing in the brain.

Nomikos, J.¹*, Robertson, C. E.¹, Ivy, C. M.², Scott, G. R.1 1Department of Biology, McMaster University, Hamilton, Canada 2Department of Biology, Western University, London, Canada *Presenting author Satellite Cells and the Evolution of Muscle Development in High-Altitude Deer Mice Many mammals native to high-altitude have adapted an altered muscle phenotype to enhance shivering and endurance exercise in their cold and hypoxic environments. In high-altitude deer mice (Peromyscus maniculatus), this phenotype manifests beginning at two weeks of age in the form of increased oxidative fiber proportion, decreased fiber area, and decreased gastrocnemius muscle mass relative to low-altitude conspecifics. However, it is unclear what physiological mechanisms during postnatal development drive this divergence in muscle phenotype. In other altricial rodents, satellite cells differentiate and fuse with muscle fibers to contribute to muscle hypertrophy during the first weeks of postnatal development. To investigate the role of satellite cells in the postnatal development of the high-altitude muscle phenotype, we examined satellite cell number during the first 30 days of development in second generation lab reared, high-altitude (4350 m a.s.l.) and low altitude (430 m a.s.l.) deer mice reared under common garden conditions. We found that there was a significant effect of population on satellite cell density and satellite cell number per muscle fiber, with the high-altitude population exhibiting overall increased satellite cell presence. This was primarily driven by a greater abundance of satellite cells at postnatal day 14 in high-altitude deer mice. Furthermore, we saw a strong relationship between satellite cell density, mean fiber area and gastrocnemius mass across populations. These results suggest that postnatal satellite cell differentiation is downregulated in high-altitude deer mice, contributing to decreased muscle hypertrophy and therefore decreased fiber area and gastrocnemius mass.

Northam, C. T.1*, Berenbrink, M.2, Campbell, K. L.1 1 Biological Sciences, University of Manitoba, Winnipeg, Canada 2 Department of Evolution, Ecology & Behaviour, University of Liverpool, Liverpool, United Kingdom *Presenting Author Convergent reductions in predicted hemoglobin buffering capacity in lineages of small, high- metabolic rate birds and mammals: A novel adaptation to aid O2 delivery The mass-specific O2 requirements of the smallest (2 g) endothermic birds and mammals are a remarkable ~375 times higher than those of 10,000 kg elephants; accordingly, their tissues require much 1–6 higher rates of O2 delivery at rest than those of larger species during vigorous exercise . To help meet these demands, numerous anatomical and physiological adaptations, such as high heart and ventilatory rates, large relative lung volumes, high tissue capillary density, and blood with a high hemoglobin (Hb) 1,2,7,9 content have been observed . Molecular modifications to Hb, such as a reduced O2 affinity and a high 1,2,7–9 Bohr effect, have also been proposed to help them meet their high O2 requirements . Here we examine another potential Hb specialization that has been largely overlooked: reductions in titratable (surface) histidine content, which is known to be positively correlated with Hb buffering capacity10,11. It has been hypothesized that reduced buffering capacity causes an exaggerated reduction in red blood cell pH for a given acid (CO2) load, which then through an (elevated) Bohr effect could potentially augment O2 offloading10,12. We therefore predicted that lineages of small endothermic birds and mammals, specifically those with elevated mass-specific metabolic rates, will have convergently evolved Hb proteins with low titratable histidine contents (reduced Hb buffering capacities), in order to help them meet their high mass- specific O2 needs. To test this hypothesis, we calculated the predicted buffering capacity of Hb for 371 avian and 454 mammalian species from the primary structures of their component globin chains. Our results reveal strong depressions in predicted Hb buffering capacity in hummingbirds (46%), perching birds (38%), shrews (36%), bats (27%), and African insectivores (27%). Notably, distinct reductions of

105 titratable histidine content were also observed for several highly aerobic mammalian species (e.g., canids, pronghorn), consistent with an adaptive role in augmenting O2 delivery.

Ojaghi, M.¹, Pamenter, M. E.¹ 1Department of Biology, University of Ottawa, Ottawa, Canada Regulation of glucose signaling in naked mole-rats during hypoxia African naked mole-rats (NMRs) are among the most hypoxia-tolerant mammals. NMRs can drastically reduce their metabolic rate to tolerate acute hypoxia, and switch from lipid-fueled metabolism in normoxia to entirely carbohydrate-fueled metabolism in hypoxia. We hypothesized that NMRs would rapidly mobilize glucose in hypoxia to help maintain carbohydrate energy metabolism through anaerobic pathways. Furthermore, we predicted that glucose mobilization would be similar across developmental stages in NMRs, indicating retention of neotenic traits into adulthood. To test our hypothesis, we exposed pus, and adult subordinates and queens to 1hr of normoxia (21% O2), followed by 1hr of hypoxia (7%, 5% or 3% O2), while indirectly measuring metabolic rate via respirometry. Blood glucose and body temperature (Tb) were also measured. In other experiments, we challenged NMRs with a bolus glucose injection in normoxia or hypoxia to evaluate the impact of hypoxia on glucose tolerance. We found that: 1) all age groups similarly reduced metabolic rate (by ~ 75-85%) and Tb (by ~ 2.5-4.5oC) in all levels of hypoxia, 2) queens metabolized carbohydrates in all conditions whereas subordinates and pups switched from lipids to carbohydrates in hypoxia, 3) blood glucose increased in 3% O2 in all groups with the largest and most rapid changes in pups, 4) although glucose tolerance was similar between groups in normoxia, glucose clearance times were increased 2-3 fold in pups and subordinates, but 5) the rate of glucose uptake from blood increased rapidly upon reoxygenation. Our findings suggest that glucose-management in NMRs is divergent across ontogeny, countering the neotenic theory of hypoxia-tolerance.

Ouillon, N.1*, Forster, S. 1, Jarret, A.1, Sokolova, I.1 1Marine Biology, Institute of Biological Sciences, Faculty of Mathematical and Natural Sciences, University of Rostock, Germany *Presenting Author The influence of different oxygen regimes on the ecological function and metabolic pathways of Mya arenaria Shallow benthic organisms in coastal environments are often exposed to oxygen deficiency. Hypoxia is a threat to aerobic ATP production and can therefore influence energy-dependent functions such as bioirrigation and bioturbation. We exposed the soft-shell clam, Mya arenaria, a widely distributed bioturbator, to constant hypoxia (~20% of air saturation), cyclic hypoxia (~10-50% of air saturation) and normoxia (~100% of air saturation). To mimic conditions that occur in coastal hypoxic zones, we changed the CO2 and pH levels along with the oxygen levels. To assess the effects of constant and cyclic hypoxia on physiological and metabolic performances of the clams, we assessed whole-organism aerobic and anaerobic metabolism, digging performance, and bioirrigation capacity of M. arenaria. Oxygen regime had no effect on the whole-organism oxygen consumption. However, enzyme activities at the phosphoenolpyruvate branch point indicate that the clams acclimated to constant hypoxia relied more heavily on aerobic glycolysis whereas the metabolism of the clams kept under cyclic hypoxia was shifted to anaerobic pathways. Reliance on anaerobic glycolysis was supported by elevated accumulation of succinate during the hypoxic phase of the cyclic hypoxia followed by the succinate oxidation during the recovery phase. Clams acclimated to constant and cyclic hypoxia dug slower than their normoxic counterparts. Additionally, clams acclimated to constant hypoxia dug shallower than clams acclimated to cyclic hypoxia. Bioirrigation capacity sharply decreased in clams acclimated to constant (but not cyclic) hypoxia. Our results indicate that acclimation to constant or cyclic hypoxia impede bioturbation and bioirrigation capacity of Mya arenaria and therefore might affect their ecological function in coastal ecosystem.

Pan, Y. K.1*, Perry, S. F.1 1Department of Biology, University of Ottawa, Ottawa, Canada *Presenting Author Merkel-like cells as putative oxygen chemoreceptors in larval zebrafish In adult fish, it is generally assumed that neuroepithelial cells (NECs) located on gill filaments function as peripheral chemoreceptors. However, fish experiencing total gill denervation can still sense hypoxia, with

106 this response being abolished only through further denervation of the orobranchial cavity. These results suggest that not all oxygen chemoreceptors are confined to the gills but could also be located in the orobranchial cavity. One population of cells located within the orobranchial cavity that share similar characteristics to NECs are Merkel-like cells (MLCs). MLCs are neurosecretory, receive innervation from discoid aggregations of nerve fibers, and retain serotonin (5-HT)-filled synaptic vesicles oriented within the cytoplasm toward adjacent innervations, suggesting that they are involved in sensing the environment. Using in vivo confocal imaging in concert with genetically encoded calcium indicators, it was demonstrated that a sub-population of MLCs experience increased calcium event frequencies when exposed to NaCN, which induces chemical hypoxia. Data also suggest that when exposed to hypoxia, both MLCs and peripheral sensory neurons with nerve endings impinging on MLCs exhibit increased calcium event frequencies. In addition, peripheral sensory ganglia exhibit an increase in baseline calcium levels when exposed to hypoxia. Using nitroreductase-mediated ablation of peripheral sensory neurons and ganglia, it was shown that larvae with MLCs lacking innervation exhibited a heightened hypoxic ventilatory response compared to those with innerved MLCs. Taken together, these data suggest that MLCs are responsive to hypoxia and thus able to serve as O2 chemoreceptors, sending an inhibitory signal to the ventilation control center in the central nervous system via peripheral sensory neurons.

Parkinson, R. H.1,2,3*, Fecher, C.2,4, Gray, J. R.3 1 Department of Zoology, University of Oxford, Oxford, United Kingdom 2 Grass Foundation, Marine Biological Laboratory, Woods Hole, MA 3 Department of Biology, University of Saskatchewan, Saskatoon, SK, Canada 4 Institute of Neuronal Cell Biology, Technical University of Munich, Munich, Germany *Presenting Author Honeybee optomotor behaviour is impaired by chronic exposure to insecticides Honeybees use optic flow visual information to determine the distance they have flown from the hive, and this information is communicated to conspecifics during the waggle dance. Seed treatment insecticides, including neonicotinoids and novel insecticides like sulfoxaflor, display detrimental effects on wild and managed bees, even when present at sublethal quantities. These effects include deficits in flight navigation and homing ability, resulting in decreased survival of exposed worker bees. Neonicotinoid insecticides additionally disrupt visual motion detection in the locust, resulting in impaired escape behaviours, but it had not previously been asked whether seed treatment insecticides may disrupt wide- field motion detection in the honeybee. Here, we show that sublethal exposure to commonly used insecticides, imidacloprid (a neonicotinoid), and sulfoxaflor, or a mixture of these compounds results in impaired optomotor behaviour in the honeybee. This behavioural effect correlates with altered central nervous system stress and detoxification gene expression and increased programmed cell death in the optic lobes. These novel findings provide a mechanistic explanation for previously described effects of neonicotinoid insecticides on navigation and link these effects to the novel sulfoxaflor insecticide for which there is a gap in scientific knowledge.

Pidwerbesky, A. J.¹*, Bollinger, T. K.2, Berkvens, C. N.3, Detwiler, J. T.¹ 1Department of Biological Science, University of Manitoba, Winnipeg, Canada 2Department of Veterinary Pathology, Western College of Veterinary Medicine, Saskatoon, Canada 3Assiniboine Park Zoo, Winnipeg, Canada *Presenting Author Using gastropods to predict hotspots for meningeal worm transmission to moose Meningeal worm (Parelaphostrongylus tenuis) is a parasite commonly found in white-tailed deer (Odocoileus virginianus) that causes a neurological disease to dead-end hosts such as moose (Alces alces). Meningeal worms are present in Manitoba, but their contribution to moose population health is unknown. While white-tailed deer are vectors that are able to spread meningeal worm to new areas, terrestrial gastropods must be present to infect subsequent deer, or moose. Therefore, to understand the infection risk to moose, we must investigate terrestrial gastropods. To determine whether gastropod abundance or diversity is associated with areas where there is concern for moose populations, we are sampling terrestrial snails from four game hunting areas in western Manitoba over two years. In each year, we are sampling one area where moose populations are of concern and one of less concern. In each area, we sample three times from June-September to compare gastropod density and diversity between the game hunting areas (and thus moose population status) and among months. We are also

107 determining whether certain habitat types are more conducive to gastropod host abundance. In 2020, we collected a total of 1165 gastropods from 19 different species. Of those, 440 individuals from 5 species are known hosts of meningeal worm. Preliminary results suggest host abundance and host diversity differ by area. In the area of concern, host abundance and diversity did not change among months. In the area of less concern, host abundance and diversity increased in certain months. We also found that most of the host species collected were found in areas with a higher percentage of forest cover. More sampling in 2021 will determine whether these patterns are consistent in other regions of western Manitoba. Our results will help those involved with moose conservation to pinpoint hotspots of meningeal worm transmission.

Pleizier, N. K.1*, Algera, D.2, Nelson, C.1, Rost-Komiya, B.1, Cooke, S. J.2, Brauner, C. J.1 1Department of Zoology, University of British Columbia, Vancouver, Canada 2Department of Biology, Carleton University, Ottawa, Canada *Presenting Author Too much of a good thing; factors affecting the relationship between total dissolved gas supersaturation and gas bubble trauma in fish Features such as dams can generate total dissolved gas (TDG) supersaturation, which can lead to harmful bubble growth in the tissues of aquatic animals, known as gas bubble trauma (GBT). With 59 000 large dams worldwide (International Commission On Large Dams, 2019) and thousands more under construction (Zarfl et al., 2015), GBT is an important conservation issue for freshwater fishes. Despite numerous previous studies, there remain many unknowns about the factors that affect GBT and the indirect effects of GBT. We conducted a series of studies to determine how key factors affect the progression of GBT and associated outcomes in fish. We did a meta analysis of the relationship between TDG and GBT in fish. The resulting models identify depth, dissolved oxygen to nitrogen ratios, temperature, body size, and species as important factors affecting the progression of GBT. Depth is a key factor because it has a protective effect against GBT, but the empirical relationship was untested. We tested the relationship between depth, TDG, and GBT in rainbow trout. Our results indicate that 47 cm of depth compensated for 4.1% (±1.3% SE) TDG supersaturation. Based on the results, we propose an equation for the threshold for GBT at depth. Conversely, locomotion is predicted to promote GBT in tissues. We tested the relationship between locomotion and GBT in rainbow trout. Our results suggest that there is no significant effect of locomotion on the progression of GBT. We also conducted an experiment to determine whether fish can detect and avoid harmful TDG supersaturation. We found no statistically significant difference in the duration spent by fish in a channel with a lethal level of TDG supersaturation compared with a channel containing air-equilibrated water. Our findings address some of the key unknowns in GBT and indicate avenues for future research on the topic.

Po, B. H. K.¹*, Wood, C. M.¹ 1Department of Zoology, University of British Columbia, Vancouver, Canada *Presenting Author Transepithelial Potential Remains Indicative of Major Ion Toxicity After 4-Day Exposure to Major Salts in Rainbow Trout Oncorhynchus mykiss In accord with the Multi-Ion Toxicity (MIT) Model of salt toxicity, very short-term responses in transepithelial potential (TEP) in fish during acute exposures to major ions have been proven as indicative of their toxicity. But what happens after 4 days, the standard period for acute toxicity tests? To extend the knowledge on how extended sublethal exposure to salts might change the responses, the current study investigated the TEP responses to serial concentrations of major salts and the plasma ions levels in rainbow trout after they were exposed separately to 50 % of the 96-h LC50 levels of 10 major salts for 4 days. The plasma levels of most major ions were generally well-regulated. Only a few ions were mildly changed and, interestingly, this mostly happened in exposures to the salts of sulphate. Overall, the indications of toxicity by the TEP responses remained similar to those of trout without prior exposure – all salts caused concentration-dependent increases in TEP and the ∆TEP (difference between the TEP in the salt solution versus baseline tap water) reached close to the maximum at the LC50 levels. Extended exposure did not often affect the absolute TEP values, but in some cases (CaSO4 and MgCl2) lowered the TEP in baseline tap water. Using the Michaelis-Menten model, the derived ∆TEPmax and affinity constant (Km) were compared to aid in understanding any differences resulting from extended exposure. Overall, the results provide support for the evolving MIT model (EPRI, NSERC).

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Priest, J. M.¹*, Stewart, D. T.¹, Boudreau, M.², Shutler, D.¹ 1Department of Biology, Acadia University, Wolfville, Canada 2 Department of Lands and Forestry – Wildlife Division, Kentville, Canada *Presenting Author Effects of, and Interactions among, Helminths in Coyotes (Canis latrans) Variables that can influence health include age, sex, diet, condition, and parasites. Parasitism, by definition, is a relationship in which a parasite exploits (e.g., by feeding on tissue) its host. Animals are exposed to parasites frequently, including from feeding, interacting with conspecifics, and being in contact with their environment, which may result in an individual harbouring multiple species of parasites. Parasites can cause hosts to upregulate their immunity, to spend energy repairing tissue damage, and to lose nutrients. It is assumed that these three demands will decrease host health. To help understand effects of parasites, I quantified coyote health using three indices, and quantified their helminth intensities. Negative associations between host health and parasite intensity/species richness were observed for some helminth species, but associations were not detected for most. Future studies could quantify tapeworm biomass per infected host as an additional measure of intensity, survey as much of the host parasite community as possible, and focus on quantifying tissue damage, nutrient consumption, and immune suppression from parasites. The coexistence of multiple helminth species within a single host is dependent on parasite community interactions, and it is still unclear how interspecific parasite interactions influence the parasite community. I tested if helminth interactions were synergistic, antagonistic, or negligible. I tested if a coyote infected with one species of helminth was more or less likely to be infected with a second species of helminth (i.e., whether coinfections were dependent), and whether parasite intensities differed in single-species vs. coinfections. I detected some synergies between pairs of helminth species, but most interactions were negligible. To further this work, future methods could visually inspect organs, and consider intermediate hosts when assessing dependence of infection because the latter may play a greater role in promoting apparent synergies than the environment of definitive hosts.

Procopio, S. M.*, Laberge, F., Axelrod, C. J., Robinson, B. W. Department of Integrative Biology, University of Guelph, Guelph, Canada *Presenting Author Functional divergence of seasonal heart plasticity in Pumpkinseed sunfish (Lepomis gibbosus) Experimental work on temperature acclimation suggests that ectothermic fish can preserve cardiac function over a range of environmental temperatures by means of reversible cardiac remodeling, suggesting that remodeling of the heart should be observed in seasonal environments varying in temperature. Such heart plasticity may be costly and thus subject to evolutionary reduction or loss when the source of selection, for example amplitude of temperature seasonality, is weakened. We investigated whether pumpkinseed sunfish (Lepomis gibbosus) exhibit cardiac remodeling under natural seasonal conditions, and whether heart plasticity is reduced or lost in pumpkinseed transplants adapted to reduced temperature seasonality. Pumpkinseed were transplanted from a regime of high-amplitude temperature seasonality in Canada (amplitude = 30 °C) into low-amplitude temperature seasonality in Spain (amplitude = 15 °C) approximately 100 years ago, where they currently persist. Pumpkinseed sampled from two Canadian and one Spanish population were stocked into semi-natural outdoor research ponds in Lindsay, ON in 2008 where they were all subject to Canada’s high-amplitude temperature seasonality. We compared relative heart size in pumpkinseed sampled across four seasons from each population between 2017 and 2019. Canadian pumpkinseed demonstrated considerable cardiac remodeling in response to seasonality, where the hearts of non-summer fish were between 41-65% larger than their summer counterparts; consistent with functional phenotypic plasticity. In contrast, the Spanish pumpkinseed demonstrated no significant seasonal variation in relative heart size; consistent with costs to heart plasticity. This novel evidence of cardiac remodeling in pumpkinseed represents a rare demonstration of cardiac remodeling induced by natural seasonal cues. Furthermore, we demonstrate the rapid evolutionary divergence of seasonal heart plasticity among populations in less than 50 generations. Implications for the loss of heart plasticity in ectothermic fish with changing global climate are discussed.

Puar, P.¹*, Niyogi, S.2,3, Kwong, R. W. M.¹ 1Department of Biology, York University, Toronto, Canada

109 2Department of Biology, University of Saskatchewan, Saskatoon, Canada 3Toxicology Center, University of Saskatchewan, Saskatoon, Canada *Presenting Author Using zebrafish as a model to investigate the physiological responses to zinc exposure during development Zebrafish larvae were used as a model to investigate the effects of chronic exposure to environmentally relevant concentrations of waterborne and dietary zinc (Zn; individually or combined) during development (5 to 28 days post-fertilization; dpf). A delayed Zn accumulation was observed in all treatment groups exposed to elevated levels of Zn with accumulation increasing with exposure time. Interestingly, the highest Zn accumulation was observed in larvae exposed simultaneously to both waterborne and dietary Zn. Additionally, whole body calcium (Ca) contents were reduced in larvae exposed to waterborne and/or dietary Zn, suggesting that the interactions of Zn and Ca can occur at both the gill and the gut. Furthermore, whole body Mn contents also appeared to be negatively impacted by Zn exposure but only at later developmental stages (14-28 dpf). On the other hand, the tissue localization of the different members of the ZIP family (Zn transporter proteins) were found to vary at the early life stage. Interestingly, this pattern of expression differed from that in the adult stage. Further examination demonstrated that waterborne Zn exposure consistently increased expression of zip8 across all the developmental ages tested. In contrast, a decrease in zip4 and zip13 expression was recorded with exposure to either waterborne and/or dietary Zn, which likely occurred as a mechanism to reduce Zn uptake during exposure to elevated Zn. The results suggest that these zip transporters may play a role in maintaining Zn homeostasis during periods of increased Zn loading. Overall, the present study demonstrated that fish at the developmental stages are sensitive to waterborne and dietary Zn exposure at levels commonly observed in Zn-contaminated aquatic habitats.

Quéméneur, J. B., Collet, S., Salin, K. Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), France Link of mitochondrial performance and animal growth rate differs between past and future growth Although the growth of an individual depends on its environmental conditions, intraspecific differences persist even when conditions are standardised. These differences can result from several physiological mechanisms. The contribution of mitochondrial performance is one of the key factors as they produce more than 90% of the cell's ATP, which can then be used for making new cells during growth. Despite this knowledge, the interpretation of the link between growth and mitochondrial performance remains vague. Is mitochondrial performance a consequence of past growth or a cause of future growth? The aims of this study is to determine the timeline between individual variations in growth and variations in mitochondrial performance. We quantified mitochondrial performance in red muscle as rates of oxygen consumption to make ATP, ATP production, proton leak respiration, and cytochrome c oxidase (COX) activity. We then examined their relationships with anterior (20 weeks) and posterior (4 weeks) specific growth rates (SGR) in juvenile sea bass (Dicentrarchus labrax). As expected, the anterior and posterior SGR, as the mitochondrial performance, show large inter-individual variations. Anterior SGR were related to mitochondrial COX activity: the greater the past growth, the lower the COX activity. Most interestingly, the SGR posterior of the mitochondrial assay was related to mitochondrial proton leak respiration: the higher the leak respiratory rate, the lower the future growth rate. These results highlight that intraspecific variation in past and future growth are linked to different mitochondrial performance.

Rafiqi A. M.2†, Rajakumar A.¹†*, Abouheif E.¹ 1Department of Biology, McGill University, Montreal, Quebec, Canada 2 Beykoz Institute of Life Sciences and Biotechnology, Bezmialem Vakif University, Istanbul, Turkey † Contributed equally * Presenting Author Origin and elaboration of a major evolutionary transition in individuality Obligate endosymbiosis, in which distantly related species integrate to form a single replicating individual, represents a major evolutionary transition in individuality. Although such transitions are thought to increase biological complexity, the evolutionary and developmental steps that lead to integration remain poorly understood. Here we show that obligate endosymbiosis between the bacteria Blochmannia and the hyperdiverse ant tribe Camponotini originated and also elaborated through radical alterations in embryonic development, as compared to other insects. The Hox genes Abdominal A (abdA)

110 and Ultrabithorax (Ubx)—which, in arthropods, normally function to differentiate abdominal and thoracic segments after they form—were rewired to also regulate germline genes early in development. Consequently, the mRNAs and proteins of these Hox genes are expressed maternally and colocalize at a subcellular level with those of germline genes in the germplasm and three novel locations in the freshly laid egg. Blochmannia bacteria then selectively regulate these mRNAs and proteins to make each of these four locations functionally distinct, creating a system of coordinates in the embryo in which each location performs a different function to integrate Blochmannia into the Camponotini. Finally, we show that the capacity to localize mRNAs and proteins to new locations in the embryo evolved before obligate endosymbiosis and was subsequently co-opted by Blochmannia and Camponotini. This pre-existing molecular capacity converged with a pre-existing ecological mutualism to facilitate both the horizontal transfer and developmental integration of Blochmannia into Camponotini. Therefore, the convergence of pre-existing molecular capacities and ecological interactions—as well as the rewiring of highly conserved gene networks—may be a general feature that facilitates the origin and elaboration of major transitions in individuality.

Reeve, C. 1,2*, Rowsey, L. E.2, Speers-Roesch, B.2 1Dept. of Biology, Carleton University, Ottawa, Canada. 2Dept. of Biological Sciences, University of New Brunswick, Saint John, Canada. Inactivity as the Common Mechanism Underlying the Metabolic Phenotype of Winter-Dormant Fishes Winter-dormant (hibernating) endotherms actively depress their energy expenditure via metabolic rate depression (MRD). However, controversy exists over the involvement of MRD in winter-dormant ectotherms, including many temperate fishes. Previous studies have argued both for and against the presence of MRD in winter-dormant fish, suggesting interspecific variation in the capacity for MRD. However, these studies may suffer from confounding influences of temperature-dependent variation in activity on metabolic rate. Recent work on a winter-dormant fish species, cunner (Tautogolabrus adspersus), showed that the low winter metabolic rate was explained not by MRD, but rather by inactivity combined with passive physicochemical effects of cold on metabolism. To test if inactivity is the common mechanism underlying the metabolic phenotype of winter-dormant fish, we first assessed the dormant behaviour during acute cooling of pumpkinseed (Lepomis gibbosus), American eel (Anguilla rostrata), and mummichog (Fundulus heteroclitus) using activity tracking software. Characteristic dormant behaviours (activity reductions, sheltering, feeding cessation) were monitored to identify the temperature of dormancy onset (i.e., dormancy threshold temperature). All species showed reductions in activity and feeding, but the magnitude of change and dormancy threshold temperatures differed among species. The relationship between activity level and metabolic rate was then assessed with video and automated respirometry in pumpkinseed, mummichog, and American eel during acute cooling and long-term acclimation to winter temperatures. Strong relationships were observed between activity and metabolic rate in all species at all test temperatures. Standard metabolic rates (SMR) were estimated using the activity-metabolic rate relationships. When comparing SMR or otherwise controlling for variation in activity across temperatures, the metabolic rate decrement observed in the cold was shown to result from inactivity combined with passive physicochemical effects (Q10<3.5) rather than MRD. Overall, there is now stronger evidence that the energetic savings during winter dormancy in fishes result from inactivity in a frigid environment, not MRD.

Rempel, E. M.1*; Detwiler, J. T.1 1 Biological Sciences, University of Manitoba, Winnipeg, Canada Integrative taxonomy suggests morphological delimitation insufficiently captures species diversity in freshwater snails (Planorbidae: Planorbella and Helisoma) Species-level resolution is critical to understanding the ecological role and evolutionary history of taxa. However, confounding factors like cryptic species, phenotypic variation, and subjective interpretations of morphology have led to species misidentifications and poor taxonomic resolution. To test whether these factors have resulted in inaccurate estimates of species-level diversity in freshwater snails, we used integrative taxonomy to characterize the diversity of 5 nominal planorbid species (4 Planorbella and 1 Helisoma species). These species commonly occur in North America and have been subject to taxonomic controversy. We explore whether shell morphology is sufficient to reliably distinguish the 5 nominal species by comparing putative morphology-based identifications with phylogenetic analyses and

111 geometric morphometric analyses of shell shape. Snails were collected from 7 sites (n = 212) ranging across 2 watersheds in central North America. Specimens were digitally imaged and a subset (n = 55) were sequenced at the mitochondrial COI gene (586 bp). Phylogenetic analysis of 52 unique sequences (including 18 from GenBank) revealed 5 clades that were at least 5% different. However, multiple nominal species were assigned to 3 of the 5 clades according to both GenBank identifications and our putative shell-based identifications. Geometric morphometric analysis differentiated 3 of the 5 clades, while the remaining 2 overlapped. We have shown that the genetic and morphological differences among 3 nominal species are congruent and that shell-based identification of species is mostly reliable. In contrast, the best method to discriminate the remaining 2 species is DNA barcoding as morphological analyses did not reveal clear and reliable delimiting traits. The inability of phylogenetic and geometric morphometric data to reliably differentiate 2 species indicates that additional genetic characters and examinations of other aspects of their biology are needed to better understand their ecological evolutionary relationship.

Ridgway, M. R.1*, Tunnah, L2, Bernier, N. J.2, Wright, P. A.2 1 Department of Biology, McMaster University, Hamilton, Canada 2Department of Integrative Biology, University of Guelph, Guelph, Canada *Presenting author Novel spikey ionocytes in an amphibious fish are regulated by cortisol Gills are the primary site of ionoregulation for most fishes. However, amphibious fishes experience the challenge of diminished gill function during terrestrial sojourns due to a lack of water flow over the gills. Some amphibious fish species use cutaneous ionocytes to facilitate ion exchange on land. Previous work has shown an increase in the size and number of skin ionocytes during air-exposure in the amphibious mangrove rivulus (Kryptolebias marmoratus), presumably to maintain ion-balance. However, the factors regulating ionocyte remodelling during air-exposure were unknown. Using K. marmoratus as a model, and metyrapone as a pharmacological inhibitor of cortisol synthesis, we tested the hypothesis that cortisol regulates ionocyte remodeling and ion balance during the transition of amphibious fishes from water to land. Our data show that the transition from water to air induces a rapid (within 5 minutes), robust (10- fold), and transient (maintained for the first 24 h in air, but subsequently return to resting levels by 7 days) increase in whole-body cortisol levels, and that exposure to metyrapone completely inhibits the rise in cortisol without impacting survival. We measured the morphometrics of skin ionocytes and found that a fish’s ability to mount a cortisol response significantly impacts their capacity for skin ionocyte remodeling. Following air-exposure, we also observed that a subset of skin ionocytes in each fish were of a novel morphology, with an irregular shape, multiple processes and a larger surface area. Thus, cortisol plays a similar role in the skin of K. marmoratus as it does in the gills of fish moving from freshwater to seawater, suggesting conserved hormonal function across diverse environmental disturbances.

Rossi, G. R.,1 Wright, P. A.1 1Department of Integrative Biology, University of Guelph, Guelph, Canada Leaving water makes fish smarter: Terrestrial exposure and exercise improves spatial learning in an amphibious fish Amphibious fishes transition between aquatic and terrestrial habitats, and must therefore learn to navigate two dramatically different environments. We used the amphibious killifish Kryptolebias marmoratus to test the hypothesis that the spatial learning ability of amphibious fishes would be altered by exposure to terrestrial environments because of neural plasticity in the brain region linked to spatial cognition (i.e., dorsolateral pallium). We subjected fish to either 8 weeks of fluctuating air-water conditions or terrestrial jumping exercise before assessing spatial learning using a food reward in a bifurcating T- maze, as well as neurogenesis in the dorsolateral pallium by immunostaining for proliferating cell nuclear antigen (PCNA). In support of our hypothesis, we found that fluctuating air-water conditions and terrestrial exercise improved spatial learning in K. marmoratus. Moreover, fish from the air-water and exercise groups had 39% and 46% more proliferating cells in their dorsolateral pallium relative to the control group, respectively. Overall, our findings suggest that fish with more terrestrial tendencies may have a cognitive advantage over those that remain in water, which ultimately may influence their survival and reproduction in both aquatic and terrestrial settings. More broadly, understanding the factors that promote neural and behavioural plasticity in extant amphibious fishes may provide insights into how ancestral fishes successfully colonized novel terrestrial environments before giving rise to land-dwelling tetrapods.

112 Roth, S. F.1*, Allen, P. J.2, and Wilson, J. M.1,3 1Department of Biology, Wilfrid Laurier University, Waterloo, Canada 2Department of Wildlife, Fisheries and Aquaculture, Mississippi State University, Starkville, USA 3CIIMAR, Portugal *Presenting Author Two Nephron Types; Unique Renal Adaptations in the Euryhaline Marine Catfish Ariopsis felis (Ariidae) for Osmoregulation Ariidae catfishes are one of only two families that have independently invaded the marine environment of the mostly freshwater Order Siluriformes. Teleost fishes primarily use their gills for ion-regulation although in the marine catfishes this does not appear to be the case since there are relatively few branchial ionocytes capable of ion secretion. The present study has focused on the potential role of the kidney in Ariidae by studying the euryhaline species Ariopsis felis using histology and immunohistochemistry for renal ion-transporters. We hypothesized that Ariidae concentrate their urine using a similar mechanism to Plotosidae which are the other marine family. We identified two nephron types: type-I nephrons contained a simple distal tubule ampulla, whereas type-II nephrons contained a unique structure that consisted of a small ampulla surrounded by convoluted cecae and a cone-shaped structure that drains into the collecting tubule (CT). We collectively refer to this structure as the ‘medusa’ which has never been reported before in a vertebrate kidney. The cecae were also Na+/K+-ATPase (NKA)-rich with apical + + - - NHE3b (Na /H -exchanger 3b) and Slc26a6 (Cl /HCO3 -exchanger) expression suggesting a role in ion absorption and/or acid-base regulation. Type-II nephrons also had a ciliated, convoluted early distal tubule (EDT) that wrapped around the ceca and displayed basolateral NKA and Na+:K+:2Cl--cotransporter (NKCC) staining, which suggests a role in ion secretion. The EDT was similar to the distal tubule wrapping around the Plotosidae ampulla, although convergent evolution is unclear. In freshwater- acclimated catfish, there was a decrease in the NKCC staining intensity in the EDT, and appearance of apical staining in the CT, suggesting a role in salt reabsorption. Although there is evidence of hyperosmotic urine production in Plotosidae catfishes, future studies are needed to address this possibility in Ariidae and the functional significance of its unique renal architecture.

Rowsey, L. E.¹*, Watson, M. D.¹, Speers-Roesch, B.¹ 1Department of Biological Sciences, University of New Brunswick, Saint John, Canada *Presenting Author Fasting in winter-dormant fish is a behavioural response rather than a consequence of constraints of cold on digestion and growth The cold of temperate winters slows, and may constrain, ectotherm physiology. Yet many fish species remain active in the winter, with their continued performance facilitated by physiological compensation. Conversely, certain species (e.g. cunner, Tautogolabrus adspersus) enter winter dormancy – an energy savings strategy characterized by inactivity, fasting, and slow metabolism – which allows them to endure the frigid and food-poor winter and persist at poleward latitudes. We hypothesized that winter dormancy is a consequence of severe constraints on digestion and growth in the cold, which make it untenable to remain active and feeding. Cunner enter dormancy below ~7.5°C, so we predicted to see negative growth and zero feeding below that temperature even when provided food. In voluntarily-feeding fish acclimated to 15, 9, or 3°C for 6 weeks, daily food consumption and biweekly specific growth rates decreased significantly with declining acclimation temperature, and dormant fish at 3°C had near-zero feeding rates and negative growth. To determine if these responses were a consequence of physiological constraints of cold, we repeated the experiment with force-feeding 1% body weight every third day of acclimation. Contrary to our hypothesis, force-fed cunner showed positive growth at 3°C, indicating that the fasting, inactive, non-foraging phenotype characteristic of dormancy is a behavioural response rather than a consequence of intrinsic physiological constraints of cold. These findings are consistent with an overarching conclusion emerging from our work on cunner: physiological performance is not severely constrained by cold in winter-dormant fishes, and ecological factors are more likely to be driving winter dormancy.

Rudko, S. P.1, McPhail, B. A.1*, Reimink, R. L.2,3, Froelich, K.3, Turnbull, A.,1 Hanington, P. C.1 1School of Public Health, University of Alberta, Edmonton, Canada 2Office of Campus Ministries, Hope College, Michigan, USA 3Fresh Water Solutions LLC, Michigan, USA

113 *Presenting Author Identifying Schistosome Community Structure using qPCR Swimmer’s itch is an irritating ailment caused by members of the trematode family Schistosomatidae. Over the better part of the last century, Michigan has employed a myriad of approaches in an attempt to solve their pervasive swimmer’s itch problem. More recently, the favoured approach has been to interrupt the life cycles of swimmer’s itch-causing parasites by controlling populations of their definitive hosts. Trichobilharzia stagnicolae was shown to be a major contributor to swimmer’s itch-causing parasites in the state. As such, this schistosome became the focus of the control efforts. The definitive host of T. stagnicolae, the common merganser (Mergus merganser), was relocated from several lakes in Michigan with the purpose of interrupting the life cycle of T. stagnicolae, and thus reducing the incidence of swimmer’s itch at these lakes. To understand the schistosome community structure at lakes both with merganser control and without, we undertook a two-year study that employed qPCR-based cercariometry. We initially focused on five schistosomes found to be emerging from snails at these lakes. Previous research indicated that T. szidati and Anserobilharzia brantae were rarely present in water samples, while Trichobilharzia stagnicolae, T. physellae, and a novel species of schistosome emerging from a planorbid snail were the main contributors at the study lakes. Thus, we focused on tracking the relative abundance of these three species. qPCR results revealed that T. stagnicolae was still present and abundant at lakes with merganser relocation programs. Because T. stagnicolae does not parasitize other waterfowl as a definitive host, this parasite must be contributed to the lakes by non-resident spring and fall migrant birds. These results suggest that definitive host control alone is not enough to interrupt the schistosome life cycle, reduce parasite transmission, and decrease the incidence of swimmer’s itch.

Sajadi, F.¹*, Paluzzi, J. P.¹ 1Department of Biology, York University, Toronto, Canada *Presenting Author The Role of the V-type H+-ATPase in Malpighian ‘Renal’ Tubule Secretion in the Female Mosquito, Aedes aegypti Female Aedes aegypti mosquitoes face the challenge of excess ion and water intake after engorgement on a blood meal. To cope with this, A. aegypti have a specialized excretory system that includes the Malpighian ‘renal’ tubules (MTs), which are under rigorous control by several diuretic/anti-diuretic factors to regulate transepithelial movement of electrolytes and water. Active ion transport in A. aegypti MTs is driven by the V-type H+-ATPase (VA), serving as the primary energizer for transepithelial secretion. CAPA neuropeptides have been shown to inhibit fluid secretion of MTs stimulated by select diuretic factors, 5HT and DH31 through the NOS/cGMP/PKG pathway, however, the signalling mechanism and cellular targets remains unclear. Bafilomycin, a VA inhibitor, was found to significantly inhibit DH31- and 5HT-stimulated secretion, whilst having no inhibitory action on CRF-stimulated MTs. CAPA and bafilomycin treatment led to alkalization of the secreted fluid suggesting inhibition of the VA, which may lead to constrained entry of cations across the apical membrane. Moreover, adult female MTs treated with DH31 resulted in an increase of VA activity, while CAPA-treated tubules resulted in a lower VA activity resulting in activity levels comparable to saline control levels. Furthermore, to determine whether CAPA causes V1 dissociation from the membrane, cytosolic and membrane protein fractions were isolated from DH31- and CAPA-incubated MTs. V1 protein expression was found to be higher in the membrane fractions of DH31- incubated MTs while higher levels were seen in the cytosolic fractions of CAPA-treated tubules. The current results advance our knowledge of the anti-diuretic control of the A. aegypti MTs, suggesting that CAPA targets the VA to inhibit diuresis. Studying the excretory system and discerning the underlying mechanisms behind ion and fluid transport may aid in developing novel pest management strategies to better control Aedes population and lessen its prominence as a disease vector.

Schoen, A. N.1, Bouyoucos, I. A.2,3, Anderson, W. G.1, Wheaton, C. J.4, Planes, S.2,5, Mylniczenko, N. D.4, Rummer, J. L2 1 Department of Biological Sciences, University of Manitoba, Winnipeg, Manitoba, Canada 2 Australian Research Council Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, Queensland, Australia 3 PSL Research University, EPHE-UPVD-CNRS, USR 3278 CRIOBE, Université de Perpignan, Perpignan Cedex, France

114 4 Disney Animals, Science and Environment, Disney’s Animal Kingdom® and the Seas with Nemo and Friends®, Lake Buena Vista, FL, USA 5 Laboratoire d’Excellence ‘CORAIL’, EPHE, PSL Research University, UPVD, CNRS, USR 3278 CRIOBE, Papetoai, Moorea, French Polynesia Simulated heatwave and fishing stressors alter corticosteroid and energy balance in neonate blacktip reef sharks, Carcharhinus melanopterus The increasing frequency and duration of marine heatwaves attributed to climate change threatens coastal ectotherms, particularly tropical species. In nearshore habitats, such as nursery areas, thermal stressors may exacerbate existing anthropogenic stressors. Here, we analyze the roles of corticosteroids, 1α-hydroxycorticosterone (1α-OHB) and corticosterone, in the mobilization of energy metabolites, glucose and 3-hydroxybutyrate (3-HB), in response to various stressors in a protected tropical shark species, the blacktip reef shark, Carcharhinus melanopterus. In a controlled laboratory experiment, wild-caught neonates were exposed to either ambient (27°C) or heatwave conditions (29°C) and then subjected to an acute simulated fishing stressor (1min air exposure). Blood samples were taken prior to temperature exposure, prior to air exposure, and 30min, 1h, 24h, and 48h post-air exposure at treatment temperatures. Plasma 1α-OHB increased following air exposure in sharks at 27 and 29°C, but this was not correlated with either metabolite. Plasma 1α-OHB remained elevated for 48h in 27°C-exposed sharks but declined over time in 29°C-exposed sharks. Plasma glucose was higher and plasma 3-HB was lower in 29°C-exposed sharks. Next, to decern differences between age classes, blood samples were collected from both neonate and adult sharks immediately following and five minutes after capture, and analyzed for corticosteroids and metabolites. Plasma 1α-OHB was lower and glucose was higher in neonates relative to adults. We conclude that although 1α-OHB was elevated following the simulated stressors, it does not serve a classic glucocorticoid role of energy mobilization in C. melanopterus neonates under these stress paradigms. Furthermore, we show for the first time, ontogenetic differences in circulating levels of 1α-OHB. Ultimately, our findings provide important insights into the hormonal mechanisms involved in energy mobilization during stress in C. melanopterus, particularly during heatwave conditions, which seem to alter both endocrine and energy mobilization in this species.

Schwieterman, G. D.¹*, Hardison, E. ¹, Eliason, E. J.1 1Department of Ecology, Evolution, and Marine Biology, University of California Santa Barbara, Santa Barbara, California, USA *Presenting Author A Change of Heart: Jensen’s Inequality in a eurythermal marine teleost Most animals live in complex, thermally variable environments. Due to logistical constraints, experimental physiology studies have generally tested animals under static thermal regimes representing average conditions. According to Jensen’s Inequality, however, an individual acclimated to fluctuating temperatures should exhibit lower performance than an individual acclimated to a single temperature when measured within the concave portion of the Thermal Performance Curve (TPC). The utility of experiments relying on static thermal conditions may, therefore, be limited. To investigate the role of thermal variability on physiological performance, we acclimated a eurythermal fish, opaleye (Girella nigricans), to three static temperature treatments (13, 16, and 19°C) as well as two oscillating treatments which cycled between maximum and minimum temperatures every twelve hours (13-19°C and 16-22°C). These temperatures and daily thermal ranges were chosen to mimic the conditions observed in the rocky intertidal environments in Santa Barbara, CA, USA where the fish were collected. We measured maximum heart rate during acute warming to determine cardiac thermal performance (i.e., the temperature corresponding to the onset of cardiac arrythmia, the temperature at maximum heart rate, absolute maximum heart rate, and the Arrhenius breakpoint temperature) and construct acute TPCs. Fish acclimated to variable conditions exhibited higher thermal tolerances than fish acclimated to static conditions with the same mean temperature. More research regarding the frequency and duration of high temperature exposure on cardiac thermal capacity and plasticity is warranted.

Shaftoe, J, B.1*, Gillis, T. E.1 1Department of Integrative Biology, University of Guelph, Guelph, Canada *Presenting author Functional Consequences of Cardiac Remodeling in Zebrafish (Danio rerio): Differences Between the Atrium and the Ventricle During Thermal Acclimation

115 A decrease in physiological temperature impairs cardiovascular function by decreasing contractile function, increasing blood viscosity, and increasing myocardial stiffness. Zebrafish (Danio rerio) remain active throughout the year in waters where temperatures range from ~17oC to 38oC. Previous work demonstrates that cold acclimatation of zebrafish causes a decrease in myocardial collagen and the thickness of the ventricular compact myocardium. In the current study we hypothesized that such structural changes help compensate for the effects of low temperature on cardiac function. To test this hypothesis, we used high frequency cardiac ultrasound to characterize the function of zebrafish acclimated to 20oC and 27oC at test temperatures of 20oC and 27oC. Our results demonstrate that, when compared at a test temperature of 20oC, cold acclimated zebrafish had a higher heart rate, higher atrial contractile ejection time and blood velocity, and constant ventricular blood velocity, ventricular ejection time, and fractional area change. These results suggest that cold acclimation increased cardiac output for the whole heart and increased cardiac power in the atrium but did not increase cardiac power in the ventricle. Atrial contraction is important for filling the ventricle in the low-pressure system of fish. The increase in atrial power may increase ventricular inflow to increase stretch in the ventricle. This would exploit the Frank-Starling response to compensate for temperature and would increase cardiac output for the whole heart. Therefore, we propose that cardiac remodeling of the atrium and ventricle occurs differentially but synergistically to increase cardiac output during cold acclimation.

Shahriari A.1*, Stewart C. B.1, Dhaliwal G.1, Tierney K. B.1,2 1Department of Biological Sciences, University of Alberta, Edmonton AB, Canada T6G 2E9 2School of Public Health, University of Alberta, Edmonton, AB, Canada T6G 1C9 * Presenter The Effects of Aging and Sex on Zebrafish (Danio rerio) Olfaction Animals are enveloped in a chemosensory world. Olfaction, in particular, drives important behaviours such as foraging, avoiding predators, and finding mates. The olfactory system is also considered to be one of the first sensory systems to decline as animals age. This may come from decreases in the number of olfactory sensory neurons, which are arranged into lamellae within an olfactory epithelium. In the aging population, differences in olfactory functionality may be due to sex as the olfactory system of female vertebrates is usually more effective than that of males. Using the popular vertebrate model, the zebrafish, we investigated via behavioural and histological endpoints if aging affects olfactory functionality and determined if this change is sex-dependent. Male and female fish were categorized as either young, middle or old-aged. Zebrafish from the three age groups were then exposed to a mixture of L-alanine and L-cysteine, and their behavioural responses were observed. Young-aged female fish and middle-aged male fish avoided the mixture while old-aged fish of either sex were indifferent to the mixture. Aging also removed increases in sharp turn frequency and in border-dwelling that were elicited by female zebrafish responding to the odorant mixture. Within the olfactory epithelium, lamellae thickness was not affected by aging or by sex. Overall, we demonstrated that old-aged zebrafish have declined chemosensory awareness, which may also mean a lower quality of life.

Shartau, R. B.1, Turcotte, L.1, Caballero Solares, A.2, Snyman, H.3, McCarron, P.4, Bradshaw, J. C.1, Rise, M.2, Johnson, S. C.1 1 Pacific Biological Station, Fisheries and Oceans Canada, Nanaimo, Canada 2 Ocean Sciences, Memorial University, St. John’s, Canada 3 Animal Health Laboratory, University of Guelph, Kemptville, Canada 4 National Research Council, Halifax, Canada. Physiological response of juvenile Atlantic Salmon (Salmo salar) and Chinook Salmon (Oncorhynchus tshawytscha) exposed to toxic cyanobacteria in coastal waters of British Columbia Net-pen liver disease (NPLD) is a severe liver disease first reported in farmed Atlantic Salmon histological signs of which also occur in Chinook and Pink Salmon. NPLD is characterized by hepatic lesions that include prominent megalocytosis and loss of gross liver structure and is believed to be caused by microcystin (MC) exposure. Despite the suggested link between MC and NPLD, the etiology of NPLD is not known and it is uncertain if salmon are naturally exposed to MC in BC coastal waters. Our objectives were to assess the presence of MC in coastal BC and to compare the physiological and cellular effects of sub-lethal environmentally relevant MC exposure in Atlantic and Chinook Salmon. Sampling over a two- year period at five sites revealed the presence of MC and other algal toxins (domoic and okadaic acid) at

116 all sites throughout the year. Levels were generally low, but comparable to levels in San Francisco Bay. The effect of sub-lethal MC exposure on salmon was investigated by orally gavaging post-smolt Atlantic and Chinook Salmon with MC-producing cyanobacteria. Fish were sampled over 2-week period post- gavage and tissues collected for histopathology and gene expression. No mortality was associated with MC exposure but histopathological and gene expression changes occurred. Lesions in liver appeared by 6h but were resolved 2-weeks post-exposure. In Atlantic Salmon liver and head kidney, there was upregulation of genes associated with stress and inflammatory responses at 6h that returned to control levels 2-weeks post-exposure. There was no evidence for NPLD due to the absence of hepatic megalocytosis. This suggests the development of NPLD in salmon is not due to acute MC exposure but instead by may be associated with higher MC concentration occurring in food, long-term exposure through drinking of contaminated seawater, and/or synergistic interactions with other toxins detected in the marine environment.

Shutler, D.¹*, Priest, J. M.1,2, Stewart, D. T.¹, Boudreau, M.2 1Department of Biology, Acadia University, Wolfville, Nova Scotia, Canada 2Nova Scotia Department of Lands and Forestry, Wildlife Division, Kentville, NS, Canada *Presenting Author Collection Biases in Coyotes Collection methods can be biased, leading to misperceptions of population composition. We tested if collection method (footholds, snares, and shooting) gave different perceptions of demography or morphology of 3539 eastern coyotes (Canis latrans Say, 1823). We found no differences in sex ratios of animals among methods, but did find some evidence that younger, lighter, and smaller animals were more likely to be collected by footholds than with snares. Female reproductive histories (placental scars) did not differ among methods. In a subsample of 232 animals, we found no evidence of differences in helminth parasitism relative to collection method. Overall, our large sample for the non-parasite analyses facilitated finding statistical significance; the biological implications hinge on the precision required in estimating population composition and the focal characteristics being compared. For example, mass was 5.3% lower for coyotes caught with footholds versus snares and 10.4% lower for coyotes caught with footholds versus being shot, whereas linear trait measurements of coyotes caught with footholds were generally smaller by at most 4.5% compared with other methods (broadly consistent with linear versus volumetric measurements). Our study provides important baseline information for making inferences about populations of coyotes (and other species) sampled using only a single collection method.

Smith, M. E.¹*, Easy, R. H.¹. 1Department of Biology, Acadia University, Wolfville, Canada *Presenting Author Exploring Expression of tp53 in Zebrafish, Danio rerio, in Response to Exogenous Cannabinoids and Stress The endocannabinoid system (ECS) is an essential signaling network in vertebrates that includes essential receptors, enzymes, and transporter proteins of the central and peripheral nervous systems. The ECS includes cannabinoid receptors divided into CB1R and CB2R subtypes, which are part of the G- protein-coupled receptors (GPCRs) family. These, in turn, activate the c-JUN N-terminal kinases (JNK) pathway. The JNK pathway facilitates a range of abiotic and biotic stress effects that regulate physiological processes such as inflammation, neuronal functions, cell death and survival pathways, and more. In this experiment, zebrafish (Danio rerio) received no treatment (control), or treatment with cannabinoids CBD or THC, and were then subjected to a novel tank diving test. Gills and brain tissue underwent RT-qPCR with target gene tp53 and housekeeping gene elfa. Statistical analyses were conducted on the results, ∆∆Cq was used to normalize the expression of tp53 using qPCR, expression levels were compared based on the treatment group. The data indicated evidence of no statistical significance in tp53 expression for zebrafish exposed to a stress condition do treated with CBD or THC.

Sogabe, S.¹*, Hill, A. L.², Riesgo, A.3, Leys, S. P.¹ 1Faculty of Science - Biological Sciences, University of Alberta, Edmonton, Canada 2 Biology Department, Bates College, Maine, USA 3 Department of Biodiversity and Evolutionary Biology, National Museum of Natural Sciences, Madrid, Spain

117 *Presenting Author Developing transfection methods in the emerging freshwater sponge model Ephydatia muelleri Sponges are one of the earliest branching metazoan phyla, and while there is an ongoing debate on whether they were the earliest metazoan lineage, their remarkable regenerative capacities and ability to coordinate behaviour without neurons and conventional muscles, makes them an important phylum to help answer key evolutionary and developmental questions. While many research groups focusing on numerous species has highlighted the vast variation within Porifera, the lack of concentrated effort on a single species has made it difficult to keep up with the rapid advancement of molecular tools and techniques in recent years. The freshwater sponge Ephydatia muelleri produces clonal cysts called gemmules that develop into a functional sponge within days after hatching. Gemmules are stable and ready to hatch for months when kept under 3°C and can be kept frozen at -80°C for years, which has allowed gemmules to be shipped and hatched successfully at numerous locations including labs in the UK and Spain. With a recently published high-quality chromosome-level genome assembly along with RNASeq data of four stages of development, as well as 6 transcriptomes from different populations and 16S sequence data for the microbiomes from 3 regions globally, this system provides an ideal platform that enables comparative molecular and genomic studies across multiple research groups worldwide. In this project, we aim to establish the first stable transfection method in sponges using E. muelleri, ultimately making gene-editing techniques an accessible tool in this phylum. We will first try out multiple transfection methods including chemical transfection with lipofectamine, and various electroporation techniques (Neon system, 4-D nucleofection, etc.), and use the most effective tool to conduct CRISPR/Cas9 pilot studies. We aim to advance the molecular tools available in sponges to allow for more functional and comparative studies with other metazoan phyla.

Somo, D. A.1*, Onukwufor, J. O.2, Wood, C. M.1, Richards, J. G.1 1 Department of Zoology, The University of British Columbia, Vancouver, Canada 2 Department of Pharmacology and Physiology, University of Rochester Medical Center, Rochester, USA *Presenting Author Interactive effects of temperature and hypoxia on diffusive water flux and oxygen uptake rate in the tidepool sculpin, Oligocottus maculosus Recent investigations of the osmorespiratory compromise in hypoxia tolerant fish suggest some species can down-regulate effective permeability to water and ions in hypoxia. This may partially offset the cost of the hypoxic ventilatory response. Although hypoxia and warming are often experienced simultaneously in nature, we do not know how warming stress may affect this regulatory ability when combined with hypoxia exposure. We measured diffusive water flux (DWF) and oxygen uptake rate (Ṁo2) in hypoxia tolerant tidepool sculpins (Oligocottus maculosus) exposed to acute hypoxia, acute warming or cooling, and combined acute warming and hypoxia. Although temperature effects on DWF and Ṁo2 were consistent with classic osmorespiratory compromise predictions, DWF was suppressed in hypoxia, similar to observations in other hypoxia tolerant fishes. However, DWF in combined acute warming and hypoxia did not differ from elevated DWF observed in normoxic warm water, possibly suggesting a failure of the mechanism regulating suppression of DWF in hypoxia at mild temperature. An analysis of the time dependence of DWF responses to hypoxia and normoxic recovery further supports the notion that the DWF response to hypoxia at mild temperature is a regulated response, though the regulation appears to be complex. Together these data suggest that tidepool sculpins can downregulate water permeability in hypoxia which may reduce the cost of the hypoxic ventilatory response, but only if temperatures are mild. If the increase in DWF in combined high temperature and hypoxia exposure is due to loss of the suppression of effective water permeability, tidepool sculpins exposed to both conditions may face the combined cost of elevated tissue oxygen demand and increased osmoregulatory costs. These kinds of physiological tradeoffs are masked if only considering univariate (e.g. Ṁo2) responses to multiple stressors and could contribute to “ecological surprises” frequently found in multiple stressor studies. (NSERC Discovery Grants: JGR and CMW)

Soto-Davila, M. A.¹*, Webb, R. A.¹, Dixon, B.1 1Department of Biology, University of Waterloo, Waterloo, Canada *Presenting Author Effect of Dietary Supplementation of Jamieson Probiotic on Growth and Immune Response in Chinook Salmon (Oncorhynchus tshawytscha) Challenged with Vibrio anguillarum

118 Chinook salmon is a native species of the Canadian Pacific coast with potential economic and environmental benefits for aquaculture. Chinook salmon farming is jeopardized by the risk of escapees diluting the genetic diversity of wild populations. Sterile triploid salmon offer a solution however, they have an a 10-30% higher disease mortality rate compared to diploid fish. An important non-toxic and non- polluting tool in aquaculture to improve fish growth, stress tolerance and nonspecific defense is probiotic treatment. In finfish aquaculture, many probiotics have been tested, including lactic acid bacteria (LAB; Lactobacillus and Carnobacterium) and Bacillus spp. Commercially available, low-cost Jamieson probiotic contains 14 different strains and has shown beneficial effects in humans. There is currently no evidence of its effects in Chinook salmon. To determine its impact on Chinook salmon growth and immune response, fish were randomly assigned to four net pens and given either regular feed control or probiotic treatment for a year. After this, fish were transferred to troughs and challenged with Vibrio anguillarum. There were no statistically significant differences in weight (g) and length (cm) among treatments. Probiotic supplementation did not modulate expression of the pro-inflammatory chemokine il-8. In contrast, probiotic treatment did enhance the expression of key innate immune response genes (e.g. il- 1β, il-10, and tnf-α). Finally, there was down-regulation of antimicrobial peptide production genes (e.g. camp, hamp, and transferrin) compared to control, suggesting that probiotic supplementation does not enhance this antimicrobial pathway. Collectively, Jamieson probiotic supplementation can positively modulate the early inflammatory response against V. anguillarum infection and help improve Chinook salmon aquaculture in an environmentally sustainable manner.

Sprenger, R. J., Milsom, W. K. Department of Zoology, University of British Columbia, Vancouver, B.C., Canada Modification of ventilatory responses to CO2 during steady and changing states in hibernation: temperature or state? Seasonal mammalian hibernators display extraordinary physiological changes in response to resource deprivation. Among these changes are reductions in metabolic rate (~2% of euthermic rates) and body temperature (TB) (as low as -2°C). Despite these reductions, several vital processes, such as ventilation, are maintained. In golden-mantled ground squirrels, breathing pattern shifts to episodic in torpor and their ventilatory response (HCVR) to 7% CO2 (~600% increase) dwarfs that of a euthermic squirrel (~60% increase). When this same species was made hypothermic, but not torpid, the HCVR to 7% CO2 mirrored that of a euthermic animal (~70% increase). We therefore hypothesized that this switch in ventilatory control was the result of the change in state (from euthermic to torpid) and not due to the change in core body temperature. To test this we used whole body plethysmography to assess the HCVR in 13-lined ground squirrels immerging, arousing, and in steady state torpor at various body temperatures to assess how the shift in the HCVR occurs. As core TB decreases in torpor, the HCVR increases substantially until the minimum TB was met. Torpid squirrels at a core TB of 15°C increase ventilation by 250% from normocarbia when given 7% CO2, while squirrels at a TB of 10°C increase ventilation by 550% and at 7°C by 650%. At 5°C the HCVR was ~600%. On arousal the increase in ventilation to 7% CO2 progressively fell from 600% (7°C) to 300% (10°C) and to 100%(15°C), all of which were markedly lower than their torpor counterparts. Because core TB lags behind metabolic rate on arousal, the HCVR appears to more closely track metabolic rate rather than TB. These results suggest that changes in TB and state both play a role in the control of breathing during hibernation. This research was funded by NSERC of Canada (NSERC 22R87150).

Steffen, J. B. M.¹*, Sokolov, E. P.², Sokolova, I. M.¹ 1 Department of Marine Biology, Institute of Biological Sciences, University of Rostock, Rostock, Germany 2 Leibniz Institute for Baltic Research, Leibniz Science Campus Phosphorus Research Rostock, Warnemünde, Germany *Presenting Author Low salinity acclimation affects mitochondrial resilience and reactive oxygen species production during short-term hypoxia/reoxygenation stress in the Pacific oyster, Crassostrea gigas Coastal environments commonly experience fluctuations in salinity and hypoxia/reoxygenation (H/R) stress that can negatively affect mitochondrial functions of marine organisms. Marine intertidal bivalves are adapted to fluctuating oxygen and salinity, yet the underlying molecular mechanisms that sustain mitochondrial integrity and function under these conditions are not yet well understood. We hypothesised

119 that mitochondria of the hypoxia-tolerant Pacific oyster Crassostrea gigas can maintain respiration and avoid excessive production of reactive oxygen species (ROS) during H/R stress under the normal salinity whereas hypoosmotic stress will sensitize the mitochondria to H/R stress. We determined respiration and ROS production in the mitochondria of the oysters acclimated to high (33) or low (15) salinity, and exposed to either normoxic conditions (control; 21% O2) or to short-term hypoxia (24 h at <0.01% O2) and subsequent reoxygenation (1.5 h at 21% O2). Further, we exposed isolated mitochondria to anoxia in vitro to assess their ability to recover from acute (~10 min) oxygen deficiency (<0.01% O2). Acclimation to low salinity increased baseline LEAK respiration and corresponding ROS production during H/R stress in vivo, while in vitro anoxia combined with hypoosmotic exposure led to elevated oxygen consumption and ROS production of OXPHOS and LEAK state. These findings suggest that acclimation to low salinity increases susceptibility of oyster mitochondria to H/R stress, while the mitochondria of oysters acclimated to the normal habitat salinity remain unaffected by H/R stress. Increased sensitivity to oxygen fluctuations in low salinity acclimated oysters may have implications of their survival in coastal waters experiencing salinity stress due to terrestrial run-off, precipitation and freshening of the surface waters.

Stevens, S. A.1*, Clark, K. F.1 1 Department of Animal Science & Aquaculture, Dalhousie University, Bible Hill, Canada Behavioural and physiological effects of the nectonematiid Nectonema agile on its host, the Atlantic rock crab (Cancer irroratus) Horsehair worms belong to the phylum Nematomorpha, which comprises the orders Gordioidea (gordiids) and Nectonematoidea (nectonematiids). These worms are exclusively parasitic as juveniles, using arthropods as hosts. Gordiids, or freshwater horsehair worms, are known to affect both the behaviour and physiology of their insect hosts. These worms manipulate host behaviour to facilitate their transmission from a juvenile to a free-living aquatic adult form. Gordiids also affect the mate-calling of crickets and gonad development of both crickets and mantids. Comparatively, little is known about Nectonematiids, or marine horsehair worms, a group containing only one genus, Nectonema. There is debate as to whether significant behavioural and physiological effects commonly occur in their decapod hosts. In this study, Atlantic rock crabs were collected from Borden-Carleton, PEI, Canada, an area shown to have higher incidences of Nectonema agile-parasitism. These crabs were subjected to two sets of behavioral tests: predator evasion and aggression. The objective was to determine if significant behavioural differences occurred between parasitized and non-parasitized crabs. Histological examination of hepatopancreas tissue was performed to determine whether parasitism was associated with the size and number of glycogen-containing reserve inclusion bodies.

Stone, J. R.¹ ² * 1Department of Biology, McMaster University, Hamilton, Canada 2 Origins Institute, McMaster University, Hamilton, Canada *Presenting Author Establishing Developmental Flexibility and Testing Phenotypic Plasticity in Sea Urchin Skeletons to Make Rudimentary Speculations on Morphological Evolution (as well as Sense o’ Sand Dollars) Echinoids, such as sea urchins and sand dollars, can exhibit dramatic morphological change, flexibility in response to nutrient variation as larvae and plasticity in response to geometric constraints as adults. Previous experimental investigation into the extent to which a juvenile structure, the rudiment, exhibits flexibility have documented rudiment regression and complete resorption in response to starvation during development; rudiment regrowth in response to refeeding is reported for the first time. Previous experimental investigation into the extent to which an adult structure, the test, exhibits plasticity have documented test morphologies becoming more spheroidal in response to pseudo-zero-g-force conditions during growth; test morphologies becoming more discoidal in response to geometric constraint is reported. Given these observations, speculations on the morphological evolutionary implications among echinoids for rudiment flexibility and test plasticity are offered.

Stroud, T. H. ¹*, Higham, T. E 2, Selvitella, A. M. 3, Foster, K. L. ¹. 1Department of Biology, Ball State University, Muncie, Indiana 2 University of California Riverside, Riverside, California 3 Purdue University Fort Wayne, Fort Wayne, Indiana *Presenting Author

120 Comparative Locomotor Kinematics of Puerto Rican Anolis Ecomorphs in Response to Changes in Incline and Perch Diameter Locomotion is essential for nearly all aspects of an organism’s ecology, including foraging, reproduction, and evading predators. The environmental context in which species have evolved to perform these activities is often highly heterogeneous and imposes several structural and functional demands. The arboreal environment is particularly variable, and Anolis lizards have convergently evolved into distinct ecomorphs specialized for different arboreal and arboreal-like substrates. Although our understanding of how the locomotor strategies of individual species shift when they encounter changes in substrate is growing, very little work has been performed in a comparative context to determine how the limb kinematics of ecomorphs, and species within ecomorphs, have evolved. We used high-speed video to record the three-dimensional forelimb and hind limb movements of Anolis species moving across two different perch diameters (narrow and broad) oriented at three different inclines (0, 30, and 90 deg). Traditional statistical analyses showed several common strategies utilized by all ecomorphs with regards to modulation of forelimb and hindlimb kinematics, but also indicated that grass-bush species differed from trunk-ground and trunk-crown ecomorphs. Additionally, forelimb modulation between A. pulchellus and A. krugi differed. A. krugi had greater humerus retraction and rotation, while A. pulchellus exhibited greater pectoral girdle rotation and less humerus retraction. These results suggest that ecomorph categories may not paint a complete picture of the locomotor diversity in Anolis lizards, as some common strategies span all ecomorphs while species within ecomorphs can employ disparate locomotor strategies. We complement these results with an analysis from a modern, machine learning perspective to determine the degree to which the locomotor strategies of a single species can be used to predict the locomotion of other species encountering the same arboreal substrate.

Thompson, W. A*., Vijayan, M. M. 1Department of Biology, University of Calgary, Canada *Presenting Author Zygotic venlafaxine deposition disrupts the circadian behaviour of zebrafish larvae Due to increased antidepressant usage, venlafaxine (Effexor), a selective serotonin and norepinephrine reuptake inhibitor, is commonly being detected in waterways receiving municipal wastewater effluent. The presence of this pharmaceutical in aquatic habitats has raised concerns of potential impacts on the development of non-target organisms, such as fish. We have previously shown that venlafaxine can disrupt the neurodevelopment of zebrafish (Danio rerio), altering the activity of larval fish. Venlafaxine appears to disrupt serotonin in the pineal and raphe, regions critical for the onset of circadian behaviour, but whether venlafaxine disrupts the circadian rhythm of fish had not been explored. Here we tested the hypothesis that zygotic exposure to venlafaxine perturbs the circadian rhythm of larval zebrafish. To test this, we microinjected zebrafish embryos with venlafaxine (1 or 10 ng) and recorded the behaviour of larval fish (5 days post-fertilization) over a full 24-hour period. The deposition of venlafaxine leads to diminishments in activity levels throughout the day (ambient light), with movement similar at night (total darkness). Investigations into melatonin levels demonstrated that disturbed activity during the day was not driven by changes in melatonin content. Exposure to luzindole, a melatonin receptor antagonist/inverse agonist, appears to exert opposing effects in treated fish relative to controls, stimulating activity in 10 ng exposed fish compared to the reductions noted in controls. Overall, zygotic exposure to venlafaxine disrupts the activity of larval fish throughout the day, and we propose that this change in activity may be due to the disruption in melatonin sensitivity.

Thorat, L. J.*, Patel, S., Paluzzi, J-P. V. Department of Biology, York University, Toronto, Canada *Presenting Author Involvement of a Glycoprotein Hormone Receptor in Desiccation Stress Tolerance and Reproductive Biology in the Fruit Fly, Drosophila melanogaster G protein-coupled receptors (GPCRs) are crucial for regulating various physiological processes including development and reproduction. Among these, the leucine-rich repeat-containing GPCRs (LGRs) are known to be conserved among vertebrates and invertebrates. The Drosophila melanogaster LGR1, a receptor for the thyrostimulin-like heterodimeric glycoprotein hormone, has been established as a vital factor in larval development and pupariation. However, the role of LGR1 in the endocrine regulation of reproductive biology and environmental stress tolerance remains underexplored. We therefore aimed to

121 determine the involvement of LGR1 in desiccation tolerance and reproductive function in D. melanogaster adults. Using the UAS/Gal4 molecular genetic approach to achieve GAL4-driven expression of the lgr1- RNAi transgene, we generated flies possessing depleted levels of lgr1 transcripts. Through this targeted knockdown, we demonstrate that these flies were significantly more vulnerable to desiccation exposure compared to the controls. We observed striking sex-specific differences in desiccation tolerance threshold, water loss rates and survival, wherein females were more robust and showed higher endurance to desiccation compared to males. Since LGR1 enrichment was prominent in the reproductive and excretory systems, we are interested in studying these organs and the mechansims regulated by LGR1 for reproductive fitness and the maintenance of osmoregulatory homeostasis in response to challenges of physiological water deficits. Malpighian tubules (MTs) of D. melanogaster perform excretory as well as osmoregulatory functions and ongoing research involves conducting assays to examine secretion rate and efflux activity of MTs to judge the consequences of LGR1 knockdown. Furthermore, studies examining the sex-specific involvement of LGR1 with respect to adult fertility and fecundity as well as life histroy traits and developmental heterochrony are underway. Taken together, this research heps to spotlight the understudied pleiotrophic roles of LGR1 on fly desiccation tolerance and reproductive biology, thereby advancing our understanding of insect physiology.

Tigert, L. R.¹*, Gilmour, K. M 1Department of Biology, University of Ottawa, Ottawa, Canada Developmental plasticity and the osmorespiratory compromise in zebrafish (Danio rerio) raised in a low pH environment Freshwater teleost fish are hyper-ionic to their environment. To counter the resultant passive ion loss, specialized cells known as ionocytes actively take up ions from the surrounding fresh water. Exposure to low pH exacerbates ion loss, and zebrafish (Danio rerio) acclimate to this challenge by increasing ionocyte abundance and ion uptake. However, increases in ionocyte abundance have the potential to alter gill morphology by increasing the blood-to-water diffusion distance, thereby impairing gas transfer, a trade-off described as the osmorespiratory compromise. The present study tested the hypothesis that zebrafish (Danio rerio) reared in pH 4 water experience reduced gas transfer capacity in accordance with the osmorespiratory compromise. Ionocyte abundance, gill morphology and indicators of gas transfer were measured at 6-, 15-, 30- and 90-days post-fertilization (dpf). Across all ages examined, fish reared in pH 4 water had higher ionocyte abundances and thicker gills than control fish. These differences were accompanied by higher ventilation frequencies and, at 90 dpf, higher critical PO2 (Pcrit), suggesting reduced hypoxia tolerance. These results are consistnet with the hypothesis that development in water of low pH impairs gas transfer, as predicted by the osmorespiratory compromise. In addition, they suggest that developmental plasticity of gill morphology cannot save developing zebrafish from limitations imposed by the osmorespiratory compromise.

Todd, L. A.¹*, Bui-Marinos, M. P.¹, Katzenback, B. A.¹ 1Department of Biology, University of Waterloo, Waterloo, Canada *Presenting Author Are microRNAs involved in amphibian innate antiviral responses? microRNAs are key regulators of innate antiviral immunity in vertebrates, yet the roles of miRNAs in amphibian innate antiviral immunity remain uncharacterized. As amphibian skin represents the first line of defense against pathogens, we sought to profile the changes in microRNA expression in a Xenopus laevis (African clawed frog) skin epithelial-like cell line (Xela DS2) in response to poly(I:C) – a synthetic analogue of viral double-stranded RNA and a known inducer of antiviral responses – or Frog virus 3 (FV3), an emerging infectious disease associated with frog mortality events. Xela DS2 cells were infected with FV3 or treated with poly(I:C), and small RNA sequencing was performed on RNA extracted at 24 h and 72 h post-treatment. Using mirDeep2 software, we detected 134 known X. laevis microRNAs and discovered 133 novel X. laevis microRNAs, and 80 of these X. laevis microRNAs were differentially regulated in response to FV3 infection or poly(I:C) treatment compared to controls. Interestingly, a subset of differentially expressed microRNAs were unique to each treatment. Target prediction analyses revealed that many differentially expressed X. laevis microRNAs target important regulators of innate antiviral immunity including stim1, sod2, trim25, stat1, and irak2. Gene ontology analysis of the predicted targets revealed the enrichment of functional categories such as “cell surface receptor signalling pathway”, “response to cytokine”, “intracellular signal transduction”, and “response to hydroperoxide”. Our

122 study is the first to suggest that microRNAs play important roles in the regulation of innate antiviral immunity in amphibians and raises the possibility that frog microRNA expression may be manipulated by FV3 as a mechanism of immunoevasion. [Funded by NSERC]

Torabi-Marashi, A*, Torson, A. S., Duell, M, Sinclair, B. J. Department of Biology, Western University, Ontario, Canada *Presenting Author De novo assembly and annotation of a draft genome of Gryllus veletis The spring field cricket, Gryllus veletis (Orthoptera: Gryllidae) in an emerging model for insect freeze tolerance. The goal of this study was to de novo assemble and annotate the 1.96 Gbp G. veletis genome and to design a pipeline that is able to assemble, assess and annotate a genome using both long and short sequencing data. We created two separate pipelines, one utilizes the tool Canu2.1.1 to assemble long read data and then uses Proovread2.14.1 to error correct and polish the assembly with short read data. The other pipeline uses the tool Masurca4.0.1 to assemble the short and long read data at once. We extracted DNA from the carcass (excluding the gut) of a single adult male G. veletis and sent the DNA for long (PacBio) and short (Illumina) read sequencing. We initially assessed the quality of the sequencing reads and then inputted them into the pipelines for assembly. We sequenced the genome at a depth of 19X with Illumina Novaseq (99.9975% accurate with an average read length of 151 bp) and 49X with PacBio Sequel II (average read length of 8.1 Kb) for a total coverage of 68X. The assembled, annotated genome will add to the resources available to G. veletis and allow future CRISPR, alternative splicing and epigenetic studies.

Trudeau, V. L.* 1Department of Biology, University of Ottawa, Canada *Presenting Author Secretoneurin is a new sex hormone with a distant past The central tenet of reproductive endocrinology is that hypothalamic gonadotropin-release hormone (Gnrh) neurons regulate the release of Lh and Fsh from the pituitary. It is the Gnrh-driven Lh surge that is responsible for inducing ovulation in females. Research in fish is challenging this widely-held view. Frame shift mutations in Gnrh and other classical neuropeptides have little to no impact on reproduction in zebrafish (ZF) or medaka. These observations led my group to search for new neuroendocrine systems. We have shown that TALEN-mediated mutations in the secretogranin-2 (Scg2) genes lead to reduced fertility in ZF. Most vertebrates have one Scg2 precursor of ~600 amino acids. Selective Scg2 processing produces the conserved bioactive peptide secretoneurin (SN) which is 31-34 amino acids long. In contrast, teleosts have paralogous Scg2a and Scg2b, indicating a lineage-specific gene duplication event giving rise to distinct SNa and SNb peptides. Double Scg2a/Scg2b mutant females are poor ovulators and spawning success in double mutant couples is <10%. This defect is partially rescued by a single injection of SNa but not SNb. Deep phylogenetic analysis indicates that Scg2a appeared first in Agnatha and is expressed in all vertebrate taxa. In contrast, Scg2b is teleost-specific: mutations do partially impair ZF reproduction, but the peptide domain responsible is not known. The data indicate that SNa is an ancient neuropeptide and is an emerging new sex hormone. Acknowledgements: NSERC-DG, University Research Chair Program, Drs. K. Mitchell, W. Hu and D. Zhang.

Tunnah, L.¹*, Wilson, J. M.2, Wright, P. A.¹ 1 Department of Integrative Biology, University of Guelph, Guelph, Canada 2 Department of Biology, Wilfrid Laurier University, Waterloo, Canada *Presenting Author Retention of larval skin ionocytes in adult killifishes For most fishes the gills are the primary site of exchange with the environment. However, reliance on gill- exchange varies over both developmental time and amongst life-history strategies. For example, many larval fishes hatch with poorly developed gills and rely instead on the skin for exchange in early life. Some fishes with amphibious life-histories experience diminished gill function during terrestrial sojourns and also rely on the skin for exchange, similar to larval fishes. Given these similarities between larval and amphibious fishes we tested the hypothesis that larval skin traits (i.e. cutaneous ionocytes and neuroepithelial cells) are retained in adult amphibious killifishes to enable the skin to be a major site of exchange on land. We used 6 closely related species spanning a range of amphibiousness to test this

123 hypothesis. We found skin barrier properties (i.e. thickness and complexity) increased over development in all species. Surprisingly, all species, whether amphibious or not, retained a larval skin trait - cutaneous ionocytes – from hatch to maturity, albeit at varying densities. Ionocyte density tended to increase across development in amphibious species, while in exclusively water-breathing species ionocytes were retained at consistently low-levels. Thus, in support of our hypothesis cutaneous ionocyte density was correlated with degree of amphibiousness. For example, we found that a highly amphibious species (Kryptolebias marmoratus) had >150-fold more cutaneous ionocytes in the adult skin than an exclusively water- breathing species (Oryzias woworae). In contrast, cutaneous neuroepithelial cells were only present in the skin of K. marmoratus in appreciable numbers in post-larval life-stages; indicating that oxygen- sensing by the skin is not a universal larval or amphibious trait. Overall, our results show that amphibious killifishes continuously express larval ionoregulatory traits until adulthood and at much higher densities than water-breathing species, highlighting distinct differences in skin function between these two groups.

Turko, A. J.1,2*, Faiczak, A.2, Balshine, S.2, Scott, G. R.1 1Department of Biology, McMaster University, Hamilton, Canada 2Department of Psychology Neuroscience and Behaviour, McMaster University, Hamilton, Canada *Presenting Author Thermal preference and aerobic performance of the endangered redside dace Fishes can use thermoregulatory behaviour in environments where water temperature varies spatially, and thermal preferences are often thought to reflect the temperature at which fitness is maximized. However, relatively few studies have tested the hypothesis that fish make such optimal decisions, termed the ‘behavioural optimization hypothesis’. Aerobic scope – the capacity to increase aerobic metabolism – is a key fitness-related trait that is highly temperature sensitive. We tested the prediction that fish would choose temperatures that maximize aerobic scope using the endangered redside dace Clinostomus elongatus as a model. Thermal preference of juveniles and adults acclimated to either 10 or 20 °C was measured using a shuttlebox system, and aerobic scope was determined across 5 to 25°C as the difference between resting and maximal metabolic rates measured before and immediately after chasing fish to exhaustion. Overall, fish acclimated to 10°C (typical spring/autumn temperature) preferred ~14°C, while fish acclimated to 20°C (typical summer temperature) preferred ~18°C. Adults consistently preferred temperatures 2-3°C warmer than juveniles. The aerobic scope of adults was largest at the preferred temperature in both acclimation groups, consistent with the behavioural optimization hypothesis. Aerobic scope of juveniles, however, was maximized at the highest temperatures we tested despite a preference for cooler temperatures than adults. This suggests that behavioural thermoregulation in juveniles is non- optimal and improves with age, or may optimize other physiological processes (e.g. growth). Regardless, our data emphasize that thermal preference and performance are highly dependent on life stage, a factor rarely considered in other studies.

Turko, A. J.1,2*, Rossi, G. S.1,*, Blewett, T. A.3, Currie, S.4, Taylor, D. S.5, Wright, P. A.1, Standen, E. M.6* 1 Department of Integrative Biology, University of Guelph, Guelph, Ontario, Canada 2 Department of Biology, McMaster University, Hamilton, Ontario, Canada 3 Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada 4 Department of Biology, Acadia University, Wolfville, Nova Scotia, Canada 5 Brevard County Environmentally Endangered Lands Program, Melbourne, Florida, USA 6 Department of Biology, University of Ottawa, Ottawa, Ontario, Canada *Presenting Authors Context-dependent relationships between athletic performance and body composition in the amphibious fish Kryptolebias marmoratus Understanding the mechanisms that create phenotypic variation within and among populations is a major goal of physiological ecology. Variation is often hypothesised to be a consequence of functional trade-offs – i.e. improvement in one trait comes at the expense of another trait. Alternatively, phenotypic variation may reflect intrinsic quality of an organism – i.e. some individuals are simply better overall performers than others. There is strong evidence for both hypotheses in the literature, suggesting that environmental context may determine which hypothesis applies to a given situation. We tested this “context- dependence” hypothesis by comparing the aquatic and terrestrial athletic performance of the amphibious fish Kryptolebias marmoratus captured from two wild habitats, a large pond and small burrows. Overall, pond fish were superior terrestrial athletes but burrow fish were better burst swimmers, suggestive of a

124 performance trade-off at the population level. Within each population, however, there was no evidence of a performance trade-off. In burrow fish, athletic performance was positively correlated with the amount muscle and body condition, consistent with the individual quality hypothesis. In pond fish, there was only a relationship between glycolytic white muscle and aquatic burst performance. Notably, pond fish were in better body condition, which may mask a relationship with athletic performance. Overall, our data highlight that population-level trends are insufficient evidence for the existence of phenotypic trade-offs in the absence of similar within-population patterns. Furthermore, we only found evidence for the individual quality hypothesis in one population, suggesting that patterns of phenotypic covariance are context dependent.

Turnbull, K. F.1*, Elliot-Graves, A.2,3, Anthony, S. E.1, Roland, J.4, Matter, S. F.4,5, Sinclair, B. J.1 1Department of Biology, University of Western Ontario, London, Canada 2The Rotman Institute of Philosophy, University of Western Ontario, London, Canada 3Present address: Department of Philosophy, Bielefeld University, Bielefeld, Germany 4Department of Biological Sciences, University of Alberta, Edmonton, Canada 5Department of Biological Sciences, University of Cincinnati, Cincinnati, USA *Presenting Author Vulnerability of alpine butterfly eggs (Parnassius smintheus) to early-winter warming Parnassius smintheus is an alpine butterfly that overwinters as a first-instar caterpillar within its egg beneath the snow. Although elevated and extreme temperatures in early winter appear pivotal to year-to- year population change of P. smintheus in the Rocky Mountains of Canada, the sources of mortality for these eggs are unclear. We hypothesized that early-winter warming (1) disrupts the acquisition of cold tolerance, making eggs susceptible to subsequent cold snaps; (2) drives premature development and hatch, such that precocious hatchlings either starve or freeze; and/or (3) depletes the energy stores of dormant eggs. We found that early winter warming (i.e. the upper quartile of daily maximum and minimum microclimate temperatures) did not interrupt the acquisition of cold tolerance, or appreciably drawdown the energy stores of eggs. However, early-winter warming increased the risk of premature hatching during a subsequent warm spell, and precocious larvae were less cold-tolerant than eggs. We used these empirical data and our hypotheses to guide a simulation of the risk of winter mortality for eggs over 60 years (1958 – 2018) at a site in the Rocky Mountains of Canada. Eggs risked lethal freezing in simulated winters, but only when extreme low temperatures coincided with an absence of snow cover. Our simulation found eggs hatched early in some winters, typically in spring following a warm early-winter with little snow cover. Precocious larvae risked lethal freezing during rare spring cold snaps in our simulation, and hatched when their host plant may be seasonally unpalatable. Eggs had sufficient energy stores to not only fuel overwintering, but tolerate several days of starvation after hatch. We suggest that P. smintheus eggs risk precocious development after early winter warming and, less frequently, lethal freezing, and are likely most vulnerable in winters with little early snowfall.

Van der Burg, K. R. L.¹,²*, Lewis, J. J. L.¹, Brack, B. J.¹, Fandino, R.¹, Mazo-Vargas, A.,¹ Reed, R. D.¹ 1Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, New York, USA 2Department of Zoology, University of British Columbia, Vancouver, Canada *Presenting Author Genomic architecture of a genetically assimilated seasonal color pattern Phenotypic plasticity allows genomes to encode multiple distinct phenotypes that can be revealed in response to specific environmental cues. It has long been known that selection can cause an ancestrally plastic trait to become fixed, thereby decoupling environmental versus genetic induction—a process called genetic assimilation—yet the molecular basis of this process is still poorly understood. Here we used artificial selection to genetically assimilate a red seasonal wing phenotype from a naturally plastic population of butterflies. Through genetic mapping and gene editing, we show that three genes are responsible for fixing a phenotype. Combined with endocrine and chromatin accessibility assays, we infer that transition of wing coloration from an environmentally determined trait to a fixed, genetic trait can occur rapidly through selection on cis-regulatory alleles of trait-specific regulatory and effector genes, not environmental cue detection or endocrine genes. We propose that this mode of genetic evolution is favored by selection because it allows tissue- and trait-specific tuning of reaction norms, while avoiding pleiotropic effects that would be caused by upstream changes to core cue and response mechanisms.

125 Veilleux, H. D.¹*, Ryu, T.2, Donelson, J. M.3, Ravasi, T.², Goss, G. G.¹, Munday, P. L.3, Glover, C. N.¹,4 1Department of Biological Sciences, University of Alberta, Edmonton, Canada 2 Marine Climate Change Unit, Okinawa Institute of Science and Technology Graduate University (OIST), Okinawa, Japan 3ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville , Australia 4 Faculty of Science and Technology and Athabasca River Basin Research Institute, Athabasca University, Athabasca, Canada *Presenting Author Developmental Plasticity in Warm- and Cold-Adapted Fishes As global temperatures rise at unprecedented rates, stenothermal species – animals that have evolved in relatively stable thermal environments – may be incapable of physiologically adjusting to new thermal conditions. To investigate the capacity for thermal plasticity in stenothermal species, we conducted two long-term studies: a comparative transcriptome analysis in a tropical reef fish and an ongoing study on cold-adapted rainbow trout. In the first study, we sequenced the transcriptomes of the spiny chromis reef fish from two populations with known differences in developmental thermal plasticity of aerobic performance. Fish from these populations were exposed to current day (+0°C) and predicted end-of- century temperatures (+3°C) from shortly after hatching and throughout life (2 years). There were no shared differentially expressed genes between populations, suggesting these populations respond differently to the same magnitude increase in temperature. Thyroglobulin, involved in growth and homeostasis, was upregulated 8.6-fold in the treatment that showed developmental plasticity and, therefore, may play an important role in adjusting to warmer temperatures. Cold-adapted rainbow trout were exposed to control (+0°C) or predicted increased temperatures (+2 and +4°C) during embryogenesis and early development to evaluate their capacity for thermal plasticity. Data to date has examined changes in growth and aerobic and anaerobic metabolism after 3 months of exposure to elevated temperatures. Together these studies have provided, and will continue to yield, novel data as to the capacity of stenothermal fish to adjust to a warming climate and the mechanisms by which this is achieved. von Herff, W., Elliott, K. H., Guigueno, M. Department of Biology, McGill University, Montréal, Canada Variation in hematocrit across the tetrapod tree of life Hematocrit is widely used in conservation physiology to infer physiological condition. Understanding the factors that influence hematocrit is crucial to effectively use hematocrit as a metric of condition. We used a recursive search in a scientific database to identify papers that included hematocrit measurements of wild tetrapods (445 studies from 548 species), and examined how those values varied with methodological, demographic, and life history factors. We used general linear mixed models to examine the relative importance of those factors and phylogeny. In almost all cases, study (i.e method) and taxonomy outweighed all other factors. Family explained most of the variation in hematocrit, with order, genus, and species playing less significant roles. This study highlights how internal physiology (hematocrit) tends to evolve at the level of family, perhaps representing fundamentally different body plans and associated oxygen demands, and also the difficulties associated with interpreting hematocrit results across studies due to differences in methodology.

Wang, L. A.1*, Vargas Soto, S. J.2, Kotwa, D. J.3, Peregrine, S. P.4, Molnár, K. P.2 1Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Canada 2Department of Biological Sciences, University of Toronto Scarborough, Toronto, Canada 3Division of Microbiology, Sunnybrook Health Sciences Centre, Toronto, Canada 4Department of Pathobiology, Ontario Veterinary College, Guelph, Canada *Presenting Author Comprehensive Species Distribution Modelling of Echinococcus multilocularis in Southern Ontario Echinococcus multilocularis is a zoonotic pathogen with a global distribution. Understanding the fine- scaled distribution and spatial ecology of this parasite is integral to implementing effective public health measures. Here, we used species distribution modelling to characterize the distribution and ecological niche of Echinococcus multilocularis in Southern Ontario. We took a comprehensive approach with the modelling process by using a 4x3 nested-cross validation framework to select the optimal combination of

126 algorithm, feature subset, and hyperparameter setting. We found that parasite suitability was high in the southern region and peaked in areas with high ambient temperature and high daytime land surface temperature. The projected parasite distribution encompassed multiple population centers, suggesting that Echinococcus multilocularis might pose a public health risk in Southern Ontario.

Weinrauch, A. M.1,2*, Anderson, W. G1,2 1Department of Biological Sciences, University of Manitoba, Winnipeg, Canada 2 Bamfield Marine Sciences Centre, Bamfield, Canada *Presenting Author Effects of time (post-feeding) and (anatomical) space: Endocrine and exocrine functions of the Pacific spiny dogfish pancreas The Pacific spiny dogfish (Squalus acanathias suckleyi) has a discrete pancreas, divided into the dorsal and ventral lobes that drain into the anterior intestine via a common duct. Secretions of the exocrine pancreas acinar cells contain digestive enzymes aiding digestion by the breakdown of macronutrients, while endocrine islet cells produce important digestive regulatory hormones including insulin, glucagon, and somatostatin. Herein, we sought to investigate the endocrine and exocrine functions of the dogfish pancreas and how a single feeding event (2% body weight ration) may influence these parameters over an extended time course (0, 20, 48, 72, 168 h post-feeding). We confirmed the presence of amylase, lipase and trypsin activity in the pancreas and further determined that the activities are consistent between lobes and over an extended duration post-feeding. Morphometric analysis revealed a significant increase in acinar cell area following feeding that returns to fasting conditions by 72 h post-feeding. Finally, we investigated the relative mRNA abundance of keys genes involved in the endocrine (e.g. insulin, glucagon) and exocrine (e.g. glucose transporters) functions of the pancreas. We propose that the consistency in our results over the entire post-prandial time course is the result of the slow rate of digestion in these animals, paired with a relatively large pancreas capable of slow but persistent release and replenishment of contents. This strategy maintains fully functional digestive capabilities over time, which could be particularly important given the unpredictable feeding events of these opportunistic feeders.

Wilkie, M. P.*1, Birceanu, O.1, Sunga, J.1, Neal, J.1, Ferreira, P.1, Edwards, S. L.2, Wilson, J. M.1, Youson, J. H.3, Vijayan, M. M.4 1Department of Biology & The Laurier Institute for Water Science, Wilfrid Laurier University, Waterloo, Ontario. 2Department of Biology, Wright State University, Dayton, Ohio. 3Department of Biological Sciences, University of Toronto Scarborough, Toronto, Ontario. 4Department of Biological Sciences, University of Calgary, Calgary, Alberta. *Presenting Author Diverging pathways of ammonia and urea production and excretion by the sea lamprey (Petromyzon marinus): Effects of metamorphosis and a blood diet. Sea lamprey are an extant jawless fish that begin life as filter-feeding larvae (ammocoetes) before undergoing a complex, true metamorphosis into parasitic juveniles that feed on the blood of large fishes. The switch from a filter-feeding diet of detritus, algae and dissolved organic matter to blood by juvenile lampreys leads to massive increases in protein ingestion and rates of nitrogenous waste (N-waste) production and excretion. Given that major changes in the gills and kidneys also take place during metamorphosis, our goal was to characterize how patterns, routes and mechanisms of ammonia (JAmm) and urea (JUrea) excretion change during the sea lamprey life cycle. Both JAmm and JUrea decreased at the beginning of metamorphosis and were lowest during mid-metamorphosis. In later stages, however, total N-waste excretion (JAmm+JUrea) increased just prior to the parasitic juvenile period. Feeding resulted in 10- to 15-fold higher JAmm and 5-fold higher JUrea by juvenile lamprey, as well as higher plasma ammonia and urea. The routes of JAmm and JUrea diverged following metamorphosis, with JAmm more or less equally split between branchial (gills) and extra-branchial (skin plus renal) routes in larval lamprey. However, more than 80% of JAmm was via the gills in juvenile lamprey and virtually all ammonia (> 95%) was excreted via the gills in adult, spawning phase lamprey. Urea was mainly excreted via extra-branchial routes, and to a lesser extent the gills in larval and juvenile lamprey. However, all urea was excreted via the urine in adult lampreys. Follow-up analysis using RT-PCR and in silico approaches indicated that JUrea was likely excreted via a urea transporter coded for by a slc4a2-like gene in the gills. We conclude that the

127 divergent pathways of JAmm and JUrea reflect the striking changes in habitat, lifestyle and diet of sea lampreys.

Wilson, B.*, Gilmour, K. M., Standen, E. M. Department of Biology, University of Ottawa, Ottawa, Canada *Presenting Author Does chronic stress contribute to lower growth rates in Polypterus senegalus held under terrestrial conditions? Polypterus senegalus is a basal ray-finned fish that breathes both air and water, and can move across land. Previous research reported that Polypterus held on land for several months exhibited lower growth rates than fish that were fed equal amounts of food but held under aquatic conditions. Thus, the present study aimed to identify the cause of this lower growth rate. One possibility is that terrestrial conditions are a chronic stressor for Polypterus; chronic stress alters metabolism and reduces growth rate in fishes. Because stress axis function is not well characterized in basal ray-finned fishes, we carried out a tissue distribution for stress axis genes and used immunohistochemistry to identify steroidogenic cells. To test the hypothesis that chronic stress reduces growth in terrestrial fish, we housed Polypterus under aquatic or terrestrial conditions for 1, 2, 4 or 8 weeks, using a paired-feeding approach. Specific growth rate was significantly lower in terrestrial fish at all time points, although the difference between aquatic and terrestrial fish tended to decrease over time. To date, measurement of circulating cortisol has not revealed elevated levels in terrestrial fish, although it remains possible that there are tissue differences in the sensitivity to cortisol between terrestrial and aquatic fish that alter metabolism and therefore growth. Alternatively, differences in growth rate may reflect other factors, such as differences in physical activity between aquatic and terrestrial fish.

Wilson J.Y.¹*, Pankov, K.V.¹, McArthur, A.G.2, Gold, D.A.3, Nelson, D.R.4, Goldstone, J.V.5 1Department of Biology, McMaster University, Hamilton, Canada 2 Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Canada 3 Department of Earth and Planetary Sciences, University of California Davis, Davis, USA 4 Department of Microbiology, Immunology and Biochemistry, University of Tennessee, Memphis USA 5 Department of Biology, Woods Hole Oceanographic Institution, Woods Hole USA *Presenting Author The Cytochrome P450 (CYP) Superfamily in Cnidarians The cytochrome P450 (CYP) superfamily is a diverse and important enzyme family, playing a central role in chemical defense and in synthesis and metabolism of major biological signaling molecules. The CYPomes of four cnidarian genomes (Hydra vulgaris, Acropora digitifera, Aurelia aurita, Nematostella vectensis) were annotated; phylogenetic analyses determined the evolutionary relationships amongst the sequences and with existing metazoan CYPs. 155 functional CYPs were identified and 90 fragments. Genes were from 24 new CYP families and several new subfamilies; genes were in 9 of the 12 established metazoan CYP clans. All species had large expansions of clan 2 diversity, with H. vulgaris having reduced diversity for both clan 3 and mitochondrial clan. We identified potential candidates for xenobiotic metabolism and steroidogenesis. That each genome contained multiple, novel CYP families may reflect the large evolutionary distance within the cnidarians, unique physiology in the cnidarian classes, and/or different ecology of the individual species.

Wishart, A. E.¹*, Guerrero-Chacón, A. L.¹, Hawkshawk, D. M.¹, Smith, R.¹, Boutin, S.2, McAdam, A. G. 3, Dantzer, B. 4,5, Lane, J. E. ¹ 1 Department of Biology, University of Saskatchewan, Saskatoon, Canada 2 Department of Biological Sciences, University of Alberta, Edmonton, Canada 3 Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, USA 4 Department of Psychology, University of Michigan, Ann Arbor, USA 5 Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, USA *Presenting Author The Efficacy of Body Condition Indices in Predicting Body Composition Depends on Natural History and Phenology: A Comparative Study of Three Sciurids For capital-breeding organisms that temporally decouple resource acquisition from energy expenditure on reproduction, energy reserves individuals have either as on-body fat or lean mass, or off-body food

128 caches, can fluctuate throughout the year. Body mass is a widely used metric to study such fluctuations in energetic condition, but in many studies, it is metabolizable energy reserves that are the variables of interest, for which body mass is used to estimate either alone or with linear morphological measurements to generate a so-called body condition index (BCI). Whether BCIs accurately reflect energy reserves consistently across time and across modes of energy storage is not well understood. We hypothesized that the strength of the correlation between body condition, as estimated by BCI, and the absolute quantities of metabolically important tissues (fat mass and lean mass) would depend on natural history and phenological considerations as they relate to energy storage. To investigate these relationships, we studied three sciurid species with varying degrees of dependence on on-body energy reserves, in their respective natural ranges: an obligate hibernator (Columbian ground squirrel, Urocitellus columbianus, Sheep River Provincial Park, Alberta), a facultative hibernator (black-tailed prairie dog, Cynomys ludovicianus, Grasslands National Park, Saskatchewan), and a food-caching non-hibernator (North American red squirrel, Tamiasciurus hudsonicus, Kluane, Yukon). For adult males and females in all three populations, we measured body mass, zygomatic width, and right hind foot length to generate species- specific BCIs. To directly assess body composition, we measured fat and lean mass using quantitative magnetic resonance (QMR). We found that relationships between the morphological measurements to calculate BCI varied with sex and species, and that the ability of BCI to predict body composition, varied with season and species. This research discusses the physiological, ecological, and evolutionary implications of energy reserves and how they are estimated.

Wood, C. M.¹,2* and Po, B. H. K1,2. 1Department of Zoology, University of British Columbia, Vancouver, Canada 2Bamfield Marine Sciences Centre, Bamfield, Canada *Presenting Author The Invasive Green Crab Carcinus maenas Exercising in Air At low tide, this amphibious crab may leave the water to feed on the foreshore. When exercised in air on a treadmill, crabs could run at high speed [1.5-2.0 body lengths (BL) sec-1] for only a few minutes, but could sustain low velocity (0.25 BL sec-1) for 60 min. The latter treatment resulted in a marked metabolic acidosis accompanied by elevations in haemolymph lactate, ammonia, urea-N, urate-N, glucose, osmolality, Ca2+, and Mg2+ concentrations, and weight loss (dehydration). There were also marked increases in O2 consumption and ammonia excretion after exercise. During post-exercise recovery in seawater, some of these disturbances persisted past 5 h, but control levels were restored by 18 h. Air exposure alone, without exercise, caused many of these same disturbances, but to a much lesser degree. Mechanisms of compensation in acid-base balance and nitrogen metabolism will be discussed (NSERC Discovery).

Yusishen, M. E.1 *, Cox, G. K.2, Gillis, T. E.1 1Department of Integrative Biology, University of Guelph, Guelph, Canada 2School of Biological Sciences, Washington State University, Washington, United States of America *Presenting Author Adaptations to reoxygenation in Pacific hagfish (Eptatretus stoutii) following prolonged anoxia exposure Pacific hagfish (Eptatretus stoutii) can survive up to 36 hours of anoxia through a combination of low basal metabolism, hypometabolism during anoxia, and extensive glycogen stores to support anaerobic metabolism. Interestingly, cardiac function is maintained during anoxia exposure. However, the cellular strategies used by the hagfish heart to survive reoxygenation have not been determined. In aerobic animals, reoxygenation is a dangerous period as the unbalancing of the electron transport chain during anoxia primes the mitochondria to produce excessive reactive oxygen species (ROS). Such ROS production has the potential to cause widespread, and potentially lethal, oxidative damage. Based on their impressive anoxia tolerance it is reasonable to assume that Pacific hagfish possess adaptations to survive the potential challenges of reoxygenation. In this presentation we will describe our ongoing research examining reoxygenation in Pacific hagfish. This project involves exposing hagfish to anoxia and subsequent reoxygenation and then collecting the systemic heart, liver, and white muscle tissue for NMR metabolomic analysis. By examining the effect of anoxia/reoxygenation on metabolite concentrations we are working to determine if hagfish can reduce the driving force responsible for the surge in ROS associated with reoxygenation injury. Metabolites of interest are succinate, fumarate, ATP, ADP,

129 xanthine, and hypoxanthine. We will present results from cardiac tissue comparing the change in metabolites from anoxia exposed and control fish. In addition to the whole body anoxia and reoxygenation trials, we are studying the tolerance of hagfish mitochondria to anoxia exposure. We have successfully measured mitochondrial respiration in cardiac and white muscle tissues using a permeabilized fiber method. To our knowledge, this is the first time mitochondrial respiration has been measured in a hagfish species and we will present our results from the first respiration assays.

Zhang, S. *, Gray, J. R. Department of Biology, University of Saskatchewan, Saskatoon, SK, Canada *Presenting Author Population Coding of Locust Motion-Sensitive Neurons Encodes Changes in Object Trajectory and Velocity Locusts can perform complicated flying maneuvers, which relies on rapid detection of moving objects present in the surroundings to generate appropriate behavioural responses. An identified neural pathway, comprised of the LGMD (lobula giant motion detector) and the DCMD (descending contralateral motion detector), responds preferentially to approaching objects. LGMD receives retinotopic inputs from ipsilateral ommatidia and generates spikes at a 1:1 ratio in the DCMD, which synapses with multiple locomotion-related neurons. As an angular threshold detector, the DCMD has been implicated as critical for initiating evasive behaviours, although its specific role remains to be fully described. Importantly, other motion-sensitive neurons in locusts show distinct firing rate modulation in response to variable stimulus properties. Information from these neurons likely contributes to production of avoidance behaviour. However, few studies have investigated the contribution of these neurons on a neural population level. To better understand how visual information is perceived by locusts, we constructed a multichannel recording system within an existing flight simulator and presented various complex visual stimuli to rigidly tethered locusts. Preliminary analyses have identified functional units that responded to visual stimuli. Common trends, which reflect the activity of neural ensembles, were extracted from these functional units.

Zhang, Y. a* aDepartment of Zoology & Faculty of Land and Food System, University of British Columbia, Vancouver, British Columbia, Canada *Presenting author Better characterizing a fish's respiratory phenotype to interpret species, intraspecific and intra- individual variability Mieux caractériser la phénotype respiratoire des poissons pour interpréter la variabilité specifique, intra spécifique et intra-individuelle Individual variation, which is the raw material for natural selection, can manifest at the higher ecological levels through species and intraspecific differences. Such differences have fascinated comparative physiologists and biochemists. Indeed, comparative respiratory physiologists, who study how life is sustained through aerobic metabolism and punctuated bursts of life-supporting anaerobic metabolism that have a delayed O2 cost, have studied mechanistic variations in respiratory performance as a mean to understand how animals respond to environmental changes following the pioneer studies of Nobel Laureate August Krogh over a century ago (Krogh 1929). Fishes are a powerful model system in this regard because they are the most specious vertebrate taxa and are at the mercy of prevailing environmental conditions, which are currently being altered in profound ways by anthropogenic influences. A key evolutionary question is whether or not the standing variation in a population can deal with such changes. But, to address questions such as this, respiratory physiologists first must be able to accurately, precisely, repeatably and comprehensively characterize the respiratory phenotype of individual fish in a high-throughput manner. I hypothesized that Integrated Respiratory Assessment Protocol (IRAP), which can generate 14 indices of aerobic & anaerobic performance capabilities during a 72-h measurement period with 8 fish simultaneously, goes a long way to achieving such a goal. Hence, I present three pillars of experimental data that addressed specific issues towards this larger goal: 1) Improving maximum ṀO2 (ṀO2max) measurements with standardized respirometry; 2) Characterizing the temporally repeatable IRAP metrics with a precision-&-repeatability matrix; and 3) Performing proof-of- principle studies to resolve different respiratory phenotypes among strain, with acclimation and with pathogen challenges.

130

Zhang, Y., Goss, G. G. Department of Biological Sciences, University of Alberta, 11455 Saskatchewan Drive, Edmonton, Alberta, T6G 2E9, Canada. Potentiation of polycyclic aromatic hydrocarbons uptake in zebrafish embryos by nanoplastics The presence of microplastics in the environment and their potential effects on organisms' health is a subject of great concern. However, with further weathering through UV radiation, mechanical force, and microbiological activity, most of these microplastics will degrade into nano-sized particles with exponentially higher surface areas compared to microplastics. Moreover, given that plastics' hydrophobic surface adsorbs hydrophobic persistent organic pollutants (POPs), the possibility of nano-sized plastic particles potentiating POPs sorption has been postulated. We developed a novel radiotracer-based method to investigate the sorption of a model POP, phenanthrene, onto the surface of two different sized polystyrene nanoplastics (PS-NPs). Using radiotracer analysis, we compared the transport and uptake of 14C-phenanthrene in zebrafish embryos with two different plastic particle sizes. We also evaluated whether nano-sized plastics altered phenanthrene's toxicity and the acute sub-lethal responses to phenanthrene in zebrafish embryos. Our results demonstrate that 20 nm PS-NPs have a higher sorption capacity for phenanthrene due to increased total surface area per gravimetric mass. Moreover, we demonstrate increased phenanthrene across the chorion and into zebrafish embryos with nano-sized plastics compared to sub-micron-sized plastics. Co-exposure of nano-sized plastics and phenanthrene delayed hatching and induced higher EROD activity in zebrafish embryos when compared to sub-micron sized plastics. Our study results demonstrate nano-sized plastics facilitate the transport and uptake of hydrophobic organic pollutants and increase their bioavailability and potential toxicity in aquatic organisms.

Zimmer, A. M.1*, Giacomin, M.1, Glover, C. N.2, Goss, G. G.1 1Department of Biological Sciences, University of Alberta, Edmonton, Canada 2Faculty of Science and Technology and Athabasca River Basin Research Institute, Athabasca University, Athabasca, Canada *Presenting Author Ionoregulatory mechanisms underlying the acclimation of rainbow trout to varying levels of freshwater acidification In freshwater systems, the occurrence of acidified conditions of both natural and anthropogenic origins is widespread and many of the physiological impacts on aquatic fauna are well-known. In the moderately acid-sensitive rainbow trout (Oncorhynchus mykiss), exposure to pH 4 results in Na+ and Cl- loss, driven by a simultaneous inhibition of active ion influx and stimulation of passive ion loss, which is typically lethal owing to subsequent cardiovascular failure. However, rainbow trout are tolerant of less acidic regimes (pH 4.5-5.5), even up to months of exposure. The goal of this work was to characterize the mechanisms underlying acclimation to environmentally relevant, moderately acidic conditions. Juvenile rainbow trout (8 g) were exposed to pH 7.5 (control), 5.5 or 4.5 for 8 d in Edmonton tap water; several ionoregulatory parameters were measured at 0, 1, 2, and 8 d. In acidic conditions, Na+ influx was reduced relative to controls throughout the entire 8 d period, with the effect being more pronounced at pH 4.5 compared to pH 5.5. Na+ efflux was reduced in both exposures, thereby limiting Na+ loss, but the larger reduction in Na+ influx was such that acid-exposed fish still experienced a net Na+ loss, compared to the generally net Na+ gain in control fish. Despite this net Na+ efflux, however, whole-body Na+ content in acid-exposed trout was not substantially different from that of controls. Therefore, it is likely that an extra-branchial mechanism for Na+ acquisition exists in these conditions, in agreement with previous work suggesting dietary uptake to be an important route under acid stress. Experiments are planned to characterize the molecular mechanisms by which Na+ efflux is reduced under moderately acidic conditions and to evaluate the role of gastrointestinal Na+ uptake in regulating Na+ balance under acidic conditions.

Zucker, E. A.1*, MacCormack, T. J.¹, Morash, A. J.2 1Department of Chemistry and Biochemistry, Mount Allison University, Sackville, Canada 2Department of Biology, Mount Allison University, Sackville, Canada *Presenting Author The Effects of Hypoxia on Ketone Body Metabolism and Cardiac Function in the Shortnose Sturgeon (Acipenser brevirostrum)

131 The goal of this study was to understand the effects of chronic hypoxia on ketone body metabolism and cardiac contractile function in the Shortnose sturgeon (Acipenser brevirostrum). Ketone bodies can be used in metabolic processes during a hypoxic exposure. They have the ability to protect tissues during hypoxia, while being energetically efficient. They also produce more ATP per mole of oxygen consumed compared to glucose, while decreasing the production of reactive oxygen species. To understand ketone body metabolism during hypoxia, sturgeon were exposed for 10 days in one of three conditions: control (9mg/L dissolved oxygen, fed), starved (9mg/L dissolved oxygen, fed) and hypoxia (2.5mg/L dissolved oxygen, starved). Cardiac contractile function was measured following this exposure and blood and tissue samples were collected for glycogen and ketone body concentration analysis. We found that liver glycogen was significantly decreased following the hypoxic exposure. However, liver ß-hydroxybutyrate dehydrogenase activity, total plasma ketone body concentration and heart and skeletal muscle succinyl- Coa:3 ketoacid Coa transferase (SCOT) activity did not change following the hypoxic exposure. Furthermore, the maximum cardiac contractile force of the ventricles was not affected by substrate supplementation with glucose or ketones. Cardiac contractile function was maintained in the chronic hypoxic group but decreased in the starved group. These findings do not support our hypothesis that chronic hypoxia would elicit a ketogenic response. It is likely that the energetic requirements were still being met by limited glucose throughout the 10-day hypoxic exposure, providing evidence for their innate hypoxia tolerance and ability to sustain cardiac function in harsh environments.

132 Contributed Posters

Afifi, S. H.1*, Paluzzi, J-P. V.1 1Department of Biology, York University, Toronto, Canada. *Presenting Author Mapping the distribution of adipokinetic hormone/corazonin-related peptide and determining key receptor regions critical for binding of this peptidergic ligand in the mosquito, Aedes aegypti Mosquitoes are an important research model as they are a major vector responsible for transmitting arboviruses leading to diseases such as Zika virus and Yellow fever. The adipokinetic hormone/corazonin-related peptide (ACP) is an insect neuropeptide structurally intermediate between corazonin (CRZ) and adipokinetic hormone (AKH). Despite the close evolutionary relationship and the structural similarity between the ACP and the AKH, their signalling systems function independently. Several studies have characterized the AKH and CRZ signalling systems within diverse insect species, and the most notable functions include energy mobilization and cardio-acceleratory activity, respectively. In contrast, the role of the ACP signalling system remains unknown. In this study, we aimed to map the distribution of ACP in the Aedes aegypti nervous system using immunohistochemistry combined with in situ hybridization. In adult mosquitoes, ACP immunostaining is localized in two pairs of lateral neurosecretory cells in the brain and 2-3 cells in the thoracic ganglia. Extensive ACP-immunoreactive axonal projections emanating within each abdominal ganglia was also observed. These results provide some evidence that ACP might act as a neuromodulator and/or neurotransmitter. Further, we also aimed to determine the specific regions of the ACP receptor (ACPr) most critical for ligand fidelity and specificity by creating ACPr chimera by singly replacing the native ACPr extracellular loops (ECL1, ECL2, and ECL3) and incorporating those from the AKH receptor. Using a heterologous functional assay, it was determined that the three ACPr-ECL mutants receptors showed no response to either ACP or AKH. These results suggest the complete replacement of each extracellular loop is detrimental to the ligand- binding activity.

Arnaout, B.¹*, Mackenzie, E.1, Lantigua, K.1, Brzezinski, K.2, McKinnell, I2, and Maddin, H.1 1 Department of Earth Sciences, Carleton University, 1125 Colonel By Drive, Ottawa, ON, Canada 2 Department of Biology, Carleton University, 1125 Colonel By Drive, Ottawa, ON, Canada *Presenting Author Suture histology in the chicken skull: implications for the homology of the avian frontal bone The study of vertebrate evolution relies heavily on the identification of homologs in different lineages. A variety of definitions, including morphological and developmental, have been used to identify homologs, which when applied to the same feature, have sometimes led to conflicts of the homology of particular traits. An example of such a conflict concerns the homology of the avian frontal bone. According to the morphological definition, the supra- and postorbital ossifications in the avian skull comprise what is traditionally called a frontal bone. However, based on more recent embryological data, these ossifications have been proposed to be homologs of an ancestral frontal and parietal, respectively; implying/indicating that the element is instead a frontoparietal. Since sutures are known to occur between discrete cranial bones, the frontoparietal hypothesis was tested by examining the histology of the gap between the two ossification centres of the frontal bone, in an ontogenetic series of chicken (Gallus domesticus), for structural signs of a suture. Comparisons were made with the histological structure of four known sutures, as well as a region of early bone formation where no suture exists, in the skull of chicken. It was determined that the histology of the gap between ossification centres did not resemble that of any of these four sutures, which does not support the hypothesis that an ancestral frontal and parietal fused to form a frontoparietal.

Ben Youssef, M1, Ouedraogo, C1, Bastarache, P1, Dumas, P1, Vickruck, J2 & Morin, P, Jr1 1Department of Chemistry and Biochemistry, Université de Moncton, Moncton, New Brunswick, Canada 2 Fredericton Research and Development Centre, Agriculture and Agri-Food Canada, New Brunswick, Canada Expression status of targets involved in the synthesis of small non-coding RNAs in Colorado potato beetles exposed to heat, cold and insecticides

133 The Colorado potato beetle (CPB), Leptinotarsa decemlineata (Say), is a serious potato pest endangering the potato industry. This insect has an impressive ability to adapt to multiple stresses including insecticides and fluctuating temperatures. The mechanisms underlying these adaptations are not yet fully understood, but previous studies have shown that microRNAs, small non-coding RNAs, are modulated in response to such conditions. This study therefore aims to characterize the expression status of key targets involved in the synthesis of small non-coding RNAs in response to heat, cold stress and insecticides such as imidacloprid, chlorantraniliprole, spinosad and clothianidin. To achieve this objective, a qRT-PCR-based approach was performed to quantify the expression of transcripts of interest in L. decemlineata exposed to stressful conditions. The results showed a significant increase in the transcript levels of Ago 2 in CPBs exposed to 40 °C compared to controls. On the other hand, all targets, including Ago 2, showed the same response to the four tested temperatures during cold exposure. For insecticide- treated insects, the most pronounced change in the expression levels of targets was observed in imidacloprid-treated insects. Following this treatment, the mRNA levels of Ago 2, Ago 3, Dicer-2-a, Expo- 5 and Piwi-like protein siwi (LOC11505514) were significantly decreased, with a highly significant decrease for Ago 2 with 0.22-fold. An RNAi-based approach was then performed to better understand the role of Ago 2 in cold tolerance. Insect survival was monitored in insects injected with dsRNA or saline and exposed to cold. On the 25th day, 43.48 % of insects injected with saline survived versus 21.74 % for those injected with dsRNA. Overall, this study improves the general understanding of the molecular basis related to stress tolerance in L. decemlineata and provides insight into the role played by Ago 2 in these adaptations.

Blackett, L.* , Brady, L., Fraser, M., Hodgson, M., Webber, R., Wyeth, R. Department of Biology, St. Francis Xavier University, Antigonish, Canada *Presenting Author Absence of Temporal Behavioural Differences in American Lobster, Homarus americanus The American Lobster, Homarus americanus, is the target of an economically important fishery in Atlantic Canada. Current bait use in the fishery is not sustainable, and thus comparative tests to find suitable replacements are underway. An important question to answer at the outset of comparing baits is whether there are temporal differences in behaviour that could confound those tests. To answer this question, underwater video cameras were deployed in mid-July and again six weeks later at the beginning of September, 2020. Each camera faced the substrate 1.5 m above a fixed bait bag containing 200 g of bait (either herring, mackerel, mussels, rock crab, or an empty control). Preliminary analysis based on lobsters counts in view and at the bait bag showed no significant differences between the two time points for any of the baits. More detailed behavioural analyses currently underway are similarly not expected to show differences in aggression (meral spreads, lunges, retreats, and tail flips) and foraging (bait bag approaches, grasping the bait bag, feeding, and tail flips while grasping the bait bag). These findings would suggest that such behaviours are similar between July and September (at least in 2020). Consequently, greater scope for comparisons of different bait types could be achieved by comparing responses to a greater variety of baits tested at different times, without concern for a temporal confound.

Bouafoura, R1, Ouedraogo, C1, Bastarache, P1, Dumas, P1, Vickruck, J2 & Morin, P, Jr1 1Department of Chemistry and Biochemistry, Université de Moncton, Moncton, New Brunswick, Canada 2Fredericton Research and Development Centre, Agriculture and Agri-Food Canada, New Brunswick, Canada Characterizing the molecular changes underlying insecticide response in the Colorado potato beetle Leptinotarsa decemlineata Leptinotarsa decemlineata (Say) (CPB), also known as Colorado potato beetle, is a pest that can cause substantial harm to potato plants leading to significant losses in potato industries. Many insecticides have been used to control this pest, however CPB has developed resistance to many of these compounds. The aim of this study was to better our understanding of the molecular basis of insecticides response in CPB insects. Four insecticides were chosen: chlorantraniliprole, imidacloprid, spinosad and clothianidin. To reach this goal, multiple targets involved in detoxification processes were quantified via qRT-PCR in insects exposed to insecticides. Select targets included transcripts coding for cytochrome P450, Glutathione-S-transferase and cuticle proteins. Treatments to chlorantraniliprole, imidacloprid and spinosad showed a significant over-expression of only one target each, respectively: 597 Lar, CYP4g15 and CYP6a23. No significant change was observed in the rest of targets in treated versus control insects.

134 On the other hand, clothianidin exposure showed six differentially expressed targets compared to their control insects: CYP4g15 (8.6-fold), CYP4c1(5.6-fold), CYP6a13 (12.7-fold), CYP9e2 (4.2-fold), 100GST (1.7-fold), 122GST (2.9-fold) and 254GST (2.3-fold). Since clothianidin exposure showed a variety of targets being differentially expressed, we decided to further investigate this insecticide. An RNAi-based technique was used to silence CYP9e2. Mortality was assessed for 14 days to investigate the impact of CYP9e2 in the underlying response of CPB towards clothianidin exposure. Results showed a more rapid mortality in insects injected with CYP9e2 dsRNA versus control insects even though a similar mortality percentage was observed in all insects at the end of the study. Overall, these results highlight the variation of expression in targets relevant to insecticides response in L. decemlineata exposed to clothianidin and generate molecular leads that warrant further investigation in this insect pest.

Brady, L. E., Webber, R. L., Hodgson, M. L., Blackett, J., Frazer, M., and Wyeth, R.C. Department of Biology, St. Francis Xavier University, Antigonish, Canada Sounds produced by American Lobsters (Homarus americanus) in situ This study aims to enhance understanding of the natural marine soundscape. Acoustic behaviours of marine mammals are well studied, but we know less about the bioacoustics of other taxa. Recent studies have shown that marine decapods such as crab and lobster also produce waterborne sounds. However, studies of sound production by American lobsters (Homarus americanus) have dealt only with acoustic behaviour in tanks while using artificial stimuli to elicit an acoustic response. Thus, our goal was to identify sounds produced by American lobster in their natural habitat. These may include communication signals or sound by-products of other behaviours. We recorded American lobsters interacting with various baits off the northern coast of Nova Scotia, using hydrophones and video cameras. Synchronized audio and video were used to catalog behaviours and corresponding sound events, either by associating sounds events with known behaviours or vice versa. Meral spreads did not co-occur with any consistent sound events. Tail flips and some claw behaviours were occasionally associated with sound events, which we hypothesize were by-products of the animal’s movements. Two sound events, designated as squeak and crackle, where repeatedly observed across multiple trials. These sounds were only recorded when at least one lobster was in view of the camera. Comparison of spectrograms showed that squeaks are short (100 - 200 ms), broadband, single pulse sound events that contain more spectral energy in the higher frequency range. Crackles consisted of multiple broadband pulses with more spectral energy in the lower frequency range, and typically occurred in pairs spanning 50 to 100 ms. No visible behaviours consistently co-occurred with these sound events. It is not yet clear whether these sounds match those recorded in previous lab studies. Nonetheless, our findings suggest that lobsters produce sounds when foraging, both as by-products of other behaviours and potentially as communication behaviours.

Britney, S. R.1,2*, Nowlan J. P.2, Lumsden, J. S.1, Balmori-Cedeno, J. 3, Russell, S.2 1 Department of Pathobiology, University of Guelph, Guelph, Ontario, Canada 2 Center for Innovation in Fish Health, Vancouver Island University, Nanaimo, British Columbia, Canada 3 Fish Health Laboratory, Mowi Canada West, Campbell River, British Columbia, Canada *Presenting Author Minimum Inhibitory Concentration of Florfenicol for Tenacibaculum Field Isolates Tenacibaculum is an etiological agent of tenacibaculosis, a disease which causes extensive mortality in farmed Atlantic salmon Salmo salar L. in Canada and worldwide. Outbreaks of this disease are treated using per os antibiotics as no vaccine is currently available for Atlantic salmon. With no standardized epidemiological cut-off values defined for Tenacibaculum, establishing localized cut-off values (CO) for wildtype (wt) isolates is essential for identifying emerging trends in antibiotic resistance. The minimum inhibitory concentration (MIC) of florfenicol for 94 isolates of Tenacibaculum was determined using a novel broth microdilution methodology. Samples were collected from 2017-2020 from 20 Atlantic salmon netpen sites surrounding Vancouver Island, British Columbia experiencing outbreaks of tenacibaculosis. COwt values for T. dicentrarchi (Tdice) were 4 μg/ml for florfenicol and 11 (16.67%) Tdice isolates were non-wildtype (nwt). There was a wide variability in MIC values between isolates, including isolates collected from the same outbreak and over time. This variability may contribute to the succession of outbreaks observed at netpen sites where nwt isolates are positively selected with the application of antibiotics. The regular monitoring of Tenacibaculum isolates for MIC and the development of epidemiological cut-off values is necessary for ongoing treatment efficacy and to identify emerging trends in antibiotic resistance.

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Hang C.¹*, Daniel M.¹, Kenny H.¹, Matthew E. P.¹2 1 Department of Biology, University of Ottawa, Ottawa, ON, Canad 2 University of Ottawa Brain and Mind Research Institute, Ottawa, ON, Canada *Presenting Author Naked mole-rat skeletal muscle mitochondria exhibit minimal functional plasticity in acute or chronic hypoxia Oxidative phosphorylation is compromised in hypoxia, but many organisms live and exercise in low oxygen environments. Hypoxia-driven adaptations at the mitochondrial level are common and may enhance energetic efficiency or minimize deleterious reactive oxygen species (ROS) generation. Mitochondria from various hypoxia-tolerant animals exhibit robust functional changes following in vivo hypoxia and we hypothesized that similar plasticity would occur in naked mole-rat skeletal muscle. To test this, we exposed adult subordinate naked mole-rats to normoxia (21% O2) or acute (4 h, 7% O2) or chronic hypoxia (4–6 weeks, 11% O2) and then isolated skeletal muscle mitochondria. Using high- resolution respirometry and a fluorescent indicator of ROS production, we then probed for changes in: i) lipid- (palmitoylcarnitine-malate), ii) carbohydrate- (pyruvate-malate), and iii) succinate-fueled metabolism, and also iv) complex IV electron transfer capacity, and v) H2O2 production. Compared to normoxic values, a) lipid-fueled uncoupled respiration was reduced ~15% during acute and chronic hypoxia, b) complex I-II capacity and the rate of ROS efflux were both unaffected, and c) complex II and IV uncoupled respiration were suppressed ~16% following acute hypoxia. Notably, complex II-linked H2O2 efflux was 33% lower after acute hypoxia, which may reduce deleterious ROS bursts during reoxygenation. These mild changes in lipid- and carbohydrate-fueled respiratory capacity may reflect the need for this animal to exercise regularly in highly variable and intermittently hypoxic environments in which more robust plasticity may be energetically expensive.

Dave, P. H.¹*, Peng, C.1, Kwong, R. W. M¹. 1Department of Biology, York University, Ontario, Canada *Presenting Author Assessing the role of the endocannabinoid system in reproduction in zebrafish The endocannabinoid system (ECS) plays a crucial role in maintaining reproductive success. In vertebrates, dysregulation in ECS leads to impairments in reproductive function, including processes involved in oocyte maturation, folliculogenesis, and embryo development. However, the mechanisms underpinning these impairments remain unclear. Our research uses zebrafish (Danio rerio) as a vertebrate model system to characterize the functional involvement of ECS in reproduction. We first determine possible stage-specific expression of ECS-related genes in follicles isolated from female zebrafish. We assess the effects of endogenous cannabinoids, anandamide (AEA) and 2-arachidonoyl glycerol (2-AG), on oocyte maturation and dissect underlying signaling mechanisms using an in vitro ovarian bioassay. Additionally, we employ CRISPR-Cas9 technology to understand the in vivo role of two cannabinoid receptors, CB1 and CB2, on folliculogenesis, fertility, and embryonic development. Our research will provide the first direct evidence that reveals the involvement and the regulatory pathways of ECS in zebrafish fertility and reproduction.

Dolezal, A.J.D.¹*, MacDougall, A.S.¹ 1Department of Integrative Biology, University of Guelph, Ontario, Canada *Presenting Author Re-designing agricultural landscapes: The effect of habitat on arthropod communities Arthropods are critical components in agricultural landscapes, representing most of the biodiversity and providing important ecosystem services. Nevertheless, we have an incomplete understanding of how arthropod communities are assembled in agroecosystems. We conducted a comprehensive survey of arthropod communities within three major habitat types of Southern Ontario farmed landscapes, including prairie grasslands, crop fields and woodlots. Previous studies have focused on impacts of habitat at one scale, for one trophic level, and quantitatively document diversity without measuring functional implications. In this study, we used a spatially nested design to examine how factors occurring at the regional, farm and local scale filter arthropod communities in agroecosystems. Importantly, we also investigate how this applies to the ecosystem function of pest control and how changes in on-farm habitat cover may impact function through increased arthropod biodiversity. Results at the regional-scale show

136 that arthropods utilized farmed landscapes, as similar numbers of arthropod families were seen in semi- natural areas surrounding farms compared to within our agricultural field sites. The farm-scale results showed a strong relationship between habitat and arthropod abundance, richness, and functional group composition. Each habitat contributed to different community composition, which resulted from tissue quantity and quality factors at the local scale. Overall, prairie grassland habitat had the greatest arthropod abundance and richness, contributing to crop damage reduction in adjacent crop fields. Understanding how habitat influences arthropod community assembly and processes will help manage, design, and plan our agroecosystems to best support biodiversity and ecosystem services.

Du Plooy, M1*. Millar, Z. D.1 Kecheliev, D.1 Lumsden, J. S.1 1Department of Pathobiology, University of Guelph, Guelph, Canada *Presenting Author Ricordea florida polyp density and rate of growth and regeneration Over half of the worlds coral reefs have been lost in the past 30 years, with destruction to Caribbean reefs being particularly devastating. Previously, larger scleractinian coral colonies were found to regenerate faster than smaller. The current study examines the effects of polyp density on growth and regeneration rate of the Corallimorpharian, Ricordea florida, a coral commonly found in the Caribbean. R. florida are collected in large numbers for the aquarium trade and better aquaculture techniques would be beneficial to conservation and the aquarium industry. R. florida polyps (n=60) from a commercial supplier were acclimated for two weeks and then separated into duplicate experimental tanks. Within each tank polyps were subsequently divided into two groups – nine polyps as singles and the 21 remaining polyps grouped into a colony. Polyp growth (ImageJ measurements of the oral disc) was monitored for two weeks. Polyp density did not significantly affect (p > 0.05) the growth rate of R. florida polyps. A size difference was seen between polyps in the colony and singles group, but polyps in both groups grew at similar rates. Twenty polyps were then bisected through the oral cavity (producing 40 halves) and monitored for a 24- day period. Polyp density did not have a significant effect (p > 0.05) upon the regeneration rates of R. florida polyps. The first polyps regenerated on Day 7, and identical numbers of polyps regenerated (90%) in both the single and colony groups. Four of the 40 polyps (two per group) entered a state that we have termed ‘stasis’, in which no detectable growth or regeneration occurred. Continued research into factors affecting regeneration of Corallimorpharians is important to understand the conditions by which successful and rapid regeneration of these corals can occur.

Duffy, B. D.¹*, Staples, J. F.¹ 1Department of Biology, Western University, London, Canada *Presenting Author Hibernation Hurts: Mitochondrial ROS production and Oxidative Damage in the 13-lined Ground Squirrel During hibernation Ictidomys tridecemlineatus (thirteen-lined ground squirrels; TLGS) cycle between torpor and interbout euthermia (IBE). Before body temperature increases during arousal to IBE, metabolic rate starts increasing and heart rate increases almost 20-fold (from two bpm to as high as 412 bpm; MacCannell et al., 2018). Due to drastic changes in heart rate, blood pressure, and blood flow, each arousal has been considered similar to an ischemia-reperfusion event, where hypoperfused, hypoxic, and cold tissues are rapidly reoxygenated and warmed by increased blood delivery (reperfusion). In non- hibernators ischemia-reperfusion events can cause excess reactive oxygen species (ROS) production and subsequent macromolecule damage. My previous work suggests oxidative damage to protein and lipids differs among torpor, IBE and summer in TLGS tissues (Duffy and Staples, 2021 submitted). TLGS survive dozens of arousals during a hibernation season suggesting that they are resistant to ischemia- reperfusion injury, however the nature of this resistance remains unclear. I hypothesize that suppression of mitochondrial metabolism during hibernation protects against oxidative damage. My objectives were to assess mitochondrial ROS production associated with simulated ischemia-reperfusion and then compare markers of lipid and protein damage. I isolated liver mitochondria from torpid, IBE and summer TLGS and performed high-resolution measurements of mitochondrial respiration and hydrogen peroxide production after 5 minutes of anoxia, then reoxygenation. I later compared markers of oxidative damage in freshly- isolated mitochondria and those exposed to anoxia-reoxygenation among torpid, IBE and summer TLGS. Results show reduced maximal respiration rates following anoxia-reoxygenation, but constant levels of ROS production during torpor and IBE. Further, anoxia-reoxygenation increases oxidative damage to

137 mitochondrial proteins and lipids but preliminary results suggest oxidative damage markers do not vary by hibernation state. Overall, this suggests anoxia-reoxygenation leads to functional oxidative damage, but results in consistent levels of ROS production, resulting in similar markers of damage to mitochondria.

Eaton, L.1*, Roy, M.1, Pamenter M. E.1,2 1 Department of Biology, University of Ottawa, Ottawa, Canada 2 University of Ottawa Brain and Mind Research Institute, Ottawa, Canada *Presenting Author Hypoxia-mediated changes in N-methyl-D-aspartate-evoked calcium flux in the naked mole-rat cortex Hypoxia induces neuronal excitotoxicity and excitotoxic cell death (ECD) in the brains of most adult mammals. ECD is mediated by Ca2+ influx through N-methyl-D-aspartate (NMDA) receptors and consequently, reductions in Ca2+ influx may be neuroprotective. Channel arrest is a reduction in membrane permeability through down-regulation of ion channel activity and has been documented in the NMDA receptors of some anoxia-tolerant vertebrates as a neuroprotective mechanism against hypoxia. Naked mole rats (NMRs; Heterocephalus glaber) are among the most hypoxia-tolerant mammals and avoid neuronal ECD during hypoxia through unknown mechanisms. In this study, we hypothesize that hypoxia-induced channel arrest occurs in NMDA receptors in the NMR cortex. NMDA-evoked Ca2+ currents were measured through fluorescent calcium imaging using Fura-2AM dye in cortical neurons from NMR live brain slices during normoxia and hypoxia (approximately 1% O2). Although we predicted a decrease in NMDA-evoked Ca2+ currents during hypoxia, we found no differences in the peak NMDA- evoked changes in cytosolic Ca2+ ([Ca2+]c) between treatments. Conversely, during normoxia, [Ca2+]c recovered completely during the ten minutes following NMDA application, whereas during hypoxia, [Ca2+]c remained elevated until normoxia was restored. Our findings suggest that in the hypoxic NMR cortex, either NMDA-mediated Ca2+ conductance remains elevated, or neuronal Ca2+ clearance mechanisms are inhibited. This is inconsistent with the extreme hypoxia-tolerance of the NMR brain and suggests that the NMR achieves its resistance to ECD by mechanisms other than acute modulation of NMDA receptors during hypoxia.

El Nabbout, A.¹*, Ferguson, L.¹, Adamo, S.¹ 1Department of Biology, Dalhousie University, Halifax, Canada *Presenting Author Overwintering success of Ixodes scapularis ticks in Nova Scotia This research observed interactions between the tick Ixodes scapularis and the bacteria Borrelia burgdorferi in Nova Scotia, where Lyme Disease cases have increased in recent years. Climate change may contribute to Lyme Disease prevalence, as warmer winter weather may correlate with higher tick overwintering survival. Since reducing tick survival can decrease the prevalence of Lyme Disease, this research examined the overwintering survival of infected and uninfected ticks in various winter temperatures at different sites. We built microcosms to replicate two different microclimates in Nova Scotia: site 1 (forest) and site 2 (dune grass). The microcosms contained 5 cm of mixed sand and vermiculite and 1 cm of mixed leaf litter. Ticks were randomly distributed in microcosms from site 1 (n=34) and site 2 (n=35). In the following year, we added two more locations for each site, and each location had the same number of ticks (n=72). Each site contained an hourly temperature and humidity data logger. Microcosms were carefully sieved to retrieve ticks (living or dead) at the end of each winter season and the ticks were tested for the presence of B. burgdorferi. Results suggested that infected ticks had greater overwintering survival than uninfected ticks in both winter seasons. Furthermore, ticks in site 1 (forest) had significantly increased overwintering survival compared with site 2 (dune grass) in the 2018-2019 winter season. Preliminary analysis suggested that infected ticks are more likely to survive in winter temperatures than uninfected ticks. Further analysis is required to determine the extent of infected and uninfected tick survival for different locations in the winter 2019-2020 season.

El-Saadi, M. I.*, MacMillan, H. A. Department of Biology, Carleton University, Ottawa, Canada A gut feeling: Investigating the link between cold stress and bacterial septicemia in migratory locusts – Locusta migratoria

138 Following prolonged low temperature exposure, chill-susceptible insects can incur chilling injuries that manifest as motor deficits and muscle tissue damage. This tissue damage is thought to be driven by a loss of ion and water homeostasis, characterized by a buildup of potassium in the hemolymph (hyperkalemia). The insect gut plays a major role in the maintenance of ion and water balance. After a cold stress, gut epithelial barrier function is compromised which can contribute to the leak of water and solutes across the gut wall. This cold-induced leakiness of the gut following a cold exposure partly contributes to the hemolymph hyperkalemia. The insect gut also houses a diverse bacterial population which has been shown to contribute to the insect’s cold tolerance. In recent years, a growing number of studies have reported increased activation of the insect immune system following a cold stress. In this study, we hypothesized that prolonged cold stresses result in the leak of bacteria from the gut into the surrounding hemolymph as a possible explanation for the immune activation. With locusts as our model insect, we used a fluorescent strain of E. coli (GFPmut3) as a marker of bacterial leak from the gut. Strands of wheat were soaked in a concentrated solution of bacteria before being fed to locusts for 24 h. Locusts were then exposed to -2°C for 12, 24, 36, or 48 h before hemolymph was extracted and plated on agar media to facilitate bacterial colony growth. To our surprise, we found no evidence of bacterial leak as no colonies were observed regardless of cold exposure length. Gut barrier disruption could also be caused by cell death to the gut, and we are currently investigating this using a LIVE/DEAD cell viability assay.

Flatt, E. E.¹*, Alderman, S. L.¹ 1Department of Integrative Biology, University of Guelph, Guelph, Canada *Presenting Author Does 11β-hydroxysteroid dehydrogenase type 2 protect against cortisol-induced changes to neurogenesis in the adult zebrafish (Danio rerio) brain? Stress-induced increases in cortisol during acute or mild stress can have stimulatory effects on cell proliferation enhancing adult neurogenesis, contrary to chronic stress where prolonged increases in cortisol can suppress cell proliferation. The cortisol-inactivating enzyme, 11β-hydroxysteroid dehydrogenase type 2 (11β-hsd2) is a potential pathway by which teleost fish may modulate this differential response to cortisol. 11β-hsd2 is localized in known neurogenic regions of the adult zebrafish brain, but its role in regulating adult neurogenesis is unknown. We tested the hypothesis that an increase in 11β-hsd2 after acute stress modulates cortisol-induced changes to brain cell proliferation. Zebrafish were exposed to a 1-min acute air exposure stressor and then temporally sampled during a 48h recovery period. A subset of fish experienced a second air exposure stressor 24 h after the first stress and were sampled at 15 min and 24 h recovery. Plasma cortisol was significantly elevated 15 min after acute stress and recovered within 24 h, and this same pattern was observed in fish that experienced a second stressor. Preliminary results for gene expression suggest that the neurogenic markers, proliferating cell nuclear antigen (pcna) and brain-derived neurotrophic factor (bdnf), increased in the brain 15 min after a single acute stress but not in the repeat stress group. While no changes in 11β-hsd2 gene expression were observed, previous studies have shown that the activity of 11β-hsd2 is elevated 24 h after an acute air exposure. This could explain why the repeated stressor did not impact pcna or bdnf and supports a role for 11β-hsd2 in regulating cortisol-induced changes to neurogenesis during acute stress.

Flewwelling, L. D.*, Scott, G. R Department of Biology, McMaster University, Hamilton, Canada *Presenting Author Effects of Climate Warming on the Activity and Metabolic Physiology of Deer Mice (Peromyscus maniculatus) Increasing ambient temperature (Ta) due to climate change could challenge an endotherm’s ability to thermoregulate and maintain a normal body temperature (Tb), and thus contribute to latitudinal range shifts occurring for many species. It is often assumed that climate warming will have minimal effects on endotherms that maintain a high stable body temperature (Tb), but this may be untrue during periods of activity when metabolic heat production is high. We will examine this issue in deer mice (Peromyscus maniculatus), a species that maintains high levels of activity in the wild. Voluntary wheel running, food consumption, and water consumption will be measured during exposure to a period of ecologically relevant seasonal temperature acclimation. Effects of Ta on resting physiology (metabolism, evaporative water loss, breathing frequency, Tb), running endurance, and VO2max will be measured before and after

139 acclimation. Our findings will help understand whether climate change is reducing the ability of endotherms to remain active and to thus carry out the range of behaviours that contribute to survival and fitness in the wild.

Gair, C. J.*, Pidwerbesky, A. J., Detwiler, J. T. Department of Biological Sciences, University of Manitoba, Winnipeg, Canada *Presenting Author Gastropod collection and identification can improve our understanding of moose disease ecology Terrestrial gastropods play an integral role in ecosystems along with being required hosts in parasite life cycles. Measuring the abundance and diversity of gastropods could help predict areas where the next host in the life cycle is most at risk for infection. However, issues related to the collection and identification of terrestrial gastropods can impede or create confusion in the interpretation of ecological models. Collection methods for terrestrial gastropods differ relative to their consideration of spatial and temporal variability. Although it is ideal to account for both factors, often this is not feasible. In a preliminary experiment, we tested whether terrestrial gastropod abundance and diversity differed depending upon the day it was sampled. From June-August 2020, we sampled in two areas where there is more and less concern about moose populations, respectively. In each area, two transects consisting of 68 dampened cardboard squares (0.25 m2) were sampled on three different days. All snails were identified to species using morphological keys and a subset were also DNA barcoded (CO1 gene). We collected a total of 175 terrestrial gastropods (140 and 35 where moose are more and less concern, respectively) and identified them to 20 species. Morphological identifications of 14/20 species were corroborated by genetic similarity (≥92% identity) to specimens with the same identification in GenBank. Using these identifications, we found that abundance differed between areas and by day. However, bootstrap analysis suggested that abundance estimates were similar in either area on 2 of 3 days. This preliminary sampling suggests the importance of considering the temporal variation in gastropod sampling. If studies are designed to test the effect of spatial variation, then some additional assessments of temporal variation may help better understand what the estimates of biodiversity are reflecting.

Gunby, S. M.1*, Millar, Z. D.1, Lumsden, J. S.1 1Department of Pathobiology, University of Guelph, Guelph, Canada *Presenting Author Fixation of Amoebocytes for Proteomic Analysis For invertebrates, including corals, amoebocytes play a crucial role in host defense. These cells have been observed in many Anthozoans migrating to the site of damage, acting as the first line of defense and removing debris from a wound site. However, access to these cells in corals, which lack a haemolymph, is challenging and hence, there are currently few tools available. Corallimorphs specifically have wide seams of copious mesoglea surrounding numerous amoebocytes. This morphology provides an opportunity to investigate the proteomic profile of these cells using laser capture microdissection (LCM) and mass spectrometry (MS). The goal is to develop tools for immunohistochemical localization and further study of cell function and also, the makeup of the mesogleal tissue. The purpose of the initial part of this study was to, based on the most recent literature, determine a fixation method that successfully preserved amoebocytes in the corallimorph Ricordea florida. Two fixation methods, 95% methanol and dimethyl 3,3'-dithiobispropionimidate (5 mM DTBP), also known as Wang and Richard’s Reagent, were compared at various time points, 15 min, 2, 8 and 24 h, stained with hematoxylin and eosin without further fixation, and observed microscopically. From each sample, five sections of mesoglea were haphazardly chosen and the number of intact or necrotic amoebocytes was determined. Fixation time (two-way ANOVA) had a significant effect (p<0.05) on amoebocyte preservation and the relationship between time and fixative was dependent on the fixative used. When comparing fixation combinations, a Tukey’s post-hoc test showed the only significant difference occurred between methanol 15 min and DTBP 2h (p<0.05), the latter being superior. Ongoing work uses cryopreserved and cryosectioned R. florida for optimal protein preservation followed by fixation as above. Amoebocyte and mesogleal tissue excised using LCM should provide protein sequences that will be used to generate antibodies to detect amoebocytes in tissues.

Hutchinson, A. J.¹*, Duffy, B.¹, Staples, J. F..1 1Department of Biology, Western University, London, Canada

140 *Presenting Author Hibernation is Super Complex: Dynamics of Electron Transportation Supercomplexes. Thirteen-lined ground squirrels (TLGS, Ictidomys tridecemlineatus) hibernate during winter months. Hibernation consists of two distinct steady states: torpor (low metabolic rate (MR)) and interbout euthermia (IBE, high MR), with transition states of entrance and arousal between. Previous findings in the lab suggest that changes to the electron transport system (ETS) contribute to suppressing metabolism during hibernation. Each ETS complex consists of 4-45 individual protein subunits. These complexes can also combine to form different supercomplexes (SCs) within the inner mitochondrial membrane (IMM). SCs are thought to improve ETS efficiency by limiting diffusion of intermediates and decrease the escape of electrons which may form reactive oxygen species (ROS). I hypothesize that SCs decrease with mitochondrial metabolic suppression. My research question is as follows: If the abundance of SCs increases to fulfill a higher metabolic demand2, do SCs decrease to facilitate metabolic suppression seen during hibernation? We isolated mitochondria from liver, brown adipose tissue, and heart of hibernating and torpid TLGS, and performed high-resolution respirometry. State 3 (phosphorylating) respiration is significantly lower in torpor compared to IBE in all tissues. I then separated mitochondrial proteins by molecular mass using blue-native gels following solubilization with a gentle detergent. This allowed me to quantify SC abundance by staining intensity. I then cut each lane from the native gel and further separated proteins using SDS gels. This will separate SC bands into subunit components of the ETS complexes which I identified using western blotting. Preliminary results from brown adipose tissue demonstrate higher abundance of CIII in a CI/CIII2/CIV SC during IBE but higher abundance in a CIII2/CIV1-2 SC in torpor. These findings suggest a dynamic transition of the location of CIII within the ETS during the transition from torpor to IBE, perhaps contributing to changes in mitochondrial respiration and ROS production among phases of torpor bouts.

Huynh, K. W.1*, Pamenter, M. E.1,2 1Department of Biology, University of Ottawa, Ottawa, Canada 2University of Ottawa Brain and Mind Research Institute, University of Ottawa, Ottawa, Canada * Presenting Author pH-Induced Regulation of Cardiac Mitochondrial Respiration in Naked Mole-Rats Energetically demanding conditions such as hypoxia, exercise, and cancer, favour anaerobic metabolism (glycolysis), lactate buildup, and acidification of cellular pH. This pH change can inhibit healthy cellular processes including metabolism, if they exceed the cellular buffering capacity. Changes in pH, or the concentration of protons in the cell, may modulate mitochondrial function because respiration in these organelles relies on the mitochondrial proton gradient, which would be directly impacted by changes in cellular pH. The naked mole-rat (NMR) is one of the most hypoxia tolerant mammals and appears to also be tolerant to pH changes accompanying exercise and cancer; indeed, NMRs live in variable and intermittently hypoxic burrows while exercising/working, and they are resistant to cancer. Previous studies in NMR brain and heart demonstrate that mitochondrial respiration is a hub for plasticity during acute hypoxia; however, our understanding of the mechanisms underlying mitochondrial adaptations to these metabolic challenges in NMRs, remains incomplete. We hypothesized that cellular pH change may regulate mitochondrial respiration to maintain metabolic function in NMRs during periods of energetic stress. We further hypothesized that NMR mitochondria would have a more robust resistance to pH change than those of less-tolerant mice. To test this, cardiac muscle fibres from NMRs and mice were isolated and permeabilized. Using high-resolution respirometry, we examined the effect of pH 6.6, 6.9, 7.1, 7.3, and 7.6 on the function of respiration through complexes I, II, and IV of the electron transport system (ETS), and uncoupled respiration. In both animals, pH had significant influence on respiration, most notably at complex IV and in total ETS capacity. NMRs demonstrated less sensitivity to inhibitory effects of pH compared to mice. These differences may highlight unique adaptations of NMRs to metabolic stressors and related acidity found in cancer, hypoxia, and exercise.

Kandil, A.1*, Rempel, E.M.1, Friesen, O.C.1, Detwiler, J.T.1 1Department of Biological Sciences, University of Manitoba, Winnipeg, Canada *Presenting Author Costs of Trematode Metacercarial Exposures to Freshwater Snails Density-dependent prophylaxis predicts hosts will invest more in immune function in response to increased population density, as infection risk is expected to increase with host population density. This

141 hypothesis assumes that investment in immune defense to avoid or minimize infection is costly for hosts. Freshwater snails are common second intermediate hosts for trematode parasites, and they could be used as a model system to better understand the role of density-dependent immunity in aquatic invertebrate-trematode interactions. However, the assumption that trematode metacercariae (encysted stage) are costly to snails is unclear. To investigate the potential cost of metacercarial infection, we exposed lab-raised Lymnaea elodes snails to Echinostoma trivolvis lineage A cercariae in low and high doses (10 and 100 cercariae, respectively), and sham exposed a control group. We repeated exposures once a week for 5 weeks to mimic repeated exposures that snails experience in nature. We imaged snails weekly to determine whether metacercarial exposure and infection affected growth (shell length and mass). To measure infection success, we counted the cercariae that did not penetrate the snail after each weekly exposure, and the number of metacercariae in the snails at the end of the experiment. Percent penetration success differed between low and high exposure groups with a mean of cercariae penetration of 95% and 89%, but percent infection success did not differ with a mean of 30% and 29% of total cercariae encysted. Control snails increased in length at a faster rate than low and high exposure groups. However, the groups did not differ in snail mass. Our preliminary evidence suggests that metacercarial infection is costly for snail hosts suggesting our system meets an important assumption of the density- dependent prophylaxis hypothesis. Similar encystment success between low and high exposure groups suggests that the immune response is not affected by differences in exposure.

Kecheliev, D. K.1*, Millar, Z. D.1, Sykes, K.1, Lumsden, J. S.1 1Department of Pathobiology, University of Guelph, Guelph, Canada *Presenting author Morphology and Histology of Regenerating Ricordea florida Corals reefs are threatened by a myriad of anthropogenic activities and environmental impacts leading to physical damage of live coral tissue. Cnidarians mitigate effects of damage in part through tissue regeneration. Wild corals are also harvested for the aquarium trade but fragmentation can be used to propagate specimens in captivity, reducing this impact. Investigation of the intricate process of coral regeneration through gross morphological and histological examination is therefore warranted. Previous research also demonstrated that mitosis occurred in scleractinian corals only at night. Duplicate trials with Ricordea florida (N = 43 and N = 48) were subjected to bilateral fragmentation through the oral cavity using sterile scalpel blades to simulate physical damage and to establish consistent regeneration timelines spanning 26 d. Gross morphological characteristics utilized to denote complete regeneration included re-circularization, fusion of damaged tissue, and re-growth of tentacles. The first polyp regenerated in 4 d, 33% of the population in 7 d and 66% by 12 d. Based on previous studies and on the timeline established by morphology, histology samples were taken day and night (t = 0, 24, 36, 96, and 108 h post-fragmentation). Mitotic figures of coral tissues and symbiotic zooxanthellae were semi- quantified based on standardized mitotic count (MC) of 2.37 mm2 per polyp side (5 mm2 total) and compared with hematoxylin & eosin as well as Brown-Hopps stains. Mitoses from all timepoints predominantly occurred in zooxanthellae (97%) and rarely coral cells, with 2% and 1% present in the gastrodermis and epithelium, respectively. Mitoses were present in R. florida sampled during the day and at night with a significant increase (p = 0.046) in MC in gastrodermal and epithelial cells at 24 to 36 h compared to pre-fragmentation. There was no difference in mitotic figures at the lesion edge compared with the rest of the polyp.

Lavoie-Rochon, A. S.¹*, Melanson, C.¹, Boudreau, M.², Chiasson, A.1, Lamarre, S. G.¹ 1Départment de Biologie, Université de Moncton, Moncton, Canada 2Département de physique, Université de Moncton, Moncton, Canada *Presenting Author Fish live outside: a new autonomous intermittent-flow respirometry system to measure fish metabolism directly in the field Measuring the metabolic rate (ṀO2) of fish using respirometry is a common and effective way of assessing its response to a stressor. Traditional respirometry equipment is large, expensive, has numerous components and requires a lot of electrical power; this makes it almost exclusively useful in laboratory settings. Therefore, most experiments on ṀO2 are performed in the laboratory using fish in the stable conditions of captivity. There is, however, a need for ṀO2 data on wild fish populations that either can’t be transported in laboratories or that would benefit in having tests done directly in their habitats.

142 Stemming from that need, a simple and autonomous intermittent-flow respirometry system was designed and built, using mainly low cost and readily available materials. During the summer of 2019, we tested the system by measuring the effect of daily temperature fluctuations on wild brook charr ṀO2 (Salvelinus fontinalis) in the field. In the subsequent summer, due to the global pandemic preventing fieldwork, we tested the effect of diel cycling hypoxia on Arctic charr ṀO2 (Salvelinus alpinus) in the laboratory using an adapted version of our respirometer. Data shows ṀO2 values that are in accordance with those found in literature. Brook charr ṀO2 is correlated with water temperature in the field. Contrary to what is observed for other salmonids, Arctic charr ṀO2 stays stable during diel cycling hypoxia. The new respirometer has proven to be versatile and completely autonomous in the field for at least 24h, in addition to being light and portable. It is also easily adaptable to laboratory work. Data gathered with this new and accessible system could be used to gain a new kind of understanding of dynamics of fish metabolic rates in relation to their habitat, as well as help the conservation and management of species facing current and future climactic challenges.

Lazaro-Côté, A*. and Vijayan, M. M. Department of Biological Sciences, University of Calgary, 2500 University Drive NW, Calgary, Alberta T2N 1N4, Canada *Presenting Author Is egg cortisol level a predictor of maternal stress-responsive gene transfer in a population of coho salmon? Females transfer nutrients, lipids, and hormones to their eggs, which are required for the proper development and growth of their offspring. In eggs, cortisol is maternally-derived and may alter the developmental trajectory of the offspring when levels are high. Pacific salmonids have elevated plasma cortisol during spawning and appear to possess the ability to buffer their eggs from excess cortisol. In zebrafish, the addition of stressed levels of cortisol to the ovarian follicle in vitro lead to an increase in the expression of 11-beta hydroxysteroid dehydrogenase 2 (11β-HSD2), an enzyme responsible for converting cortisol into its inactive form cortisone. However, little is known about the buffering of cortisol in wild Pacific salmonids and how cortisol in the eggs varies between females within a population. Therefore, we tested the hypothesis that cortisol levels in the eggs would remain fairly constant regardless of higher circulating cortisol levels in the mothers, owing to the buffering capacity by 11β- HSD2 in the ovarian outer membrane or within the egg itself. Coho salmon (Oncorhynchus kisutch) females were collected from the Coldwater River, British Columbia, during their migration and held at a Department of Fisheries and Oceans operated hatchery until they were ready to spawn. Unfertilized eggs and plasma were collected from each female, while the remaining eggs were fertilized and reared at the hatchery to determine embryo mortality. We measured cortisol in the eggs and plasma of each female. We also measured the transcript abundance of the cortisol-responsive gene 11β-HSD2, as well as MR, GR1, and GR2 in the eggs. We show that egg cortisol increased with plasma cortisol, and that buffering by 11β-HSD2 was not evident. Furthermore, our study is examining whether plasma and/or egg-cortisol levels may be a predictor of the level of transfer of stress-responsive genes to the eggs.

Lyons, S.A. ¹*, & McClelland, G.B.¹ 1Department of Biology, McMaster University, Canada *Presenting Author From rest to cold-induced V̇ O2max: Lipid utilisation in thermoregulating high-altitude deer mice. Small endotherms must maintain stable body temperatures and undergo the metabolically demanding process of thermogenesis (heat production) to survive the cold and hypoxic environment of high altitude. Deer mice (Peromyscus maniculatus) native to high altitudes have been observed to have higher capacities for lipid oxidation during maximal cold challenge in hypoxia (cold-induced V̇ O2max) compared to low altitude deer mice. We have also observed that deer mice acclimated to simulated high altitude conditions (cold hypoxia) increase their lipid oxidation capacities, regardless of altitude ancestry. How the lipid metabolic pathway responds to the increased thermogenic demand during cold-induced V̇ O2max in deer mice is currently unclear. The objective of this study was to compare the capacities for lipid mobilization, transport to, and uptake and oxidation by thermogenic tissues in high- and low-altitude deer mice acclimated to control (23oC, 21kPa O2-normoxia) or cold hypoxic conditions (5oC, 12 kPa O2- hypoxia). We tested the hypothesis that high-altitude ancestry and cold hypoxia acclimation promotes an increased supply of fat for fueling heat production, by measuring the amount of fat being released,

143 transported, and taken up by heat producing tissues at rest and during cold-induced V̇ O2max. Our results reveal that with a maximal cold challenge, high- and low-altitude deer mice increase whole-body fatty acid availability and utilization. Interestingly, high-altitude deer mice acclimated to cold hypoxia greatly increase plasma triglycerides concentration. These findings suggest either an increase in the use of circulating triglycerides, or an increase use of intracellular triglycerides (in brown adipose tissue, or muscle). Future research will focus on determining the proportion of each heat-producing tissue plays in thermogenesis in high-altitude deer mice.

Middleton, K.G.1,2*; Speers-Roesch, B.1; Kieffer, J.D.1,2 1 Biological Sciences, University of New Brunswick, Saint John, Canada 2 MADSAM Sturgeon Eco-physiology lab, University of New Brunswick, Saint John, Canada. *Presenting Author The physiological effects of cold temperatures in two sturgeon species Fish living at poleward latitudes are exposed to challenging environmental conditions in the winter, such as cold that slows physiological processes (e.g. metabolic rate, swimming activity) and poor food availability that constrains energy supply. In general, the cold water/winter biology of fishes is understudied, even though winter constrains the persistence of fish populations. Sturgeons (Acipenseriformes) are an ancient group of fishes with a distribution restricted to the temperate northern hemisphere where they have evolved strategies to survive winter. Atlantic sturgeon (A. oxyrhynchus oxyrhynchus) and shortnose (A. brevirostrum) sturgeon co-exist in the Saint John River basin in New Brunswick, but have divergent overwintering strategies. During winter, adult Atlantic sturgeon leave the river and move into the warmer seawater of the Bay of Fundy (~6-8°C), while shortnose sturgeon remain in the colder freshwater (~1°C), where they appear to be less active and possibly dormant on the riverbed. However, there is a lack of knowledge on the effects that cold winter temperatures have on these species’ physiological and behavioural processes, and whether they show divergent physiological responses to the cold. Through laboratory experiments, I am investigating how acute cold challenge (15°C-2°C) and low temperature acclimation (2-3°C) affects the routine activity, food consumption, and swim performance of juvenile (< 1 year) shortnose and Atlantic sturgeon. During an acute cooling challenge both food consumption and activity declined in juvenile Atlantic and shortnose sturgeon, but never ceased. Atlantic sturgeon showed a drastic decline in activity at 12°C, whereas shortnose had a more gradual change and overall, were more active at lower temperatures. By comparing the thermal sensitivities and acclimation potential of these variables in Atlantic and shortnose sturgeons, it appears that these two species have distinct responses to cold that may be associated with their divergent overwintering strategies.

Middleton, E. K.¹*, Gilbert, M. J. H.¹, Speers-Roesch, B.¹ 1Biological Sciences, University of New Brunswick, Saint John, Canada *Presenting Author The metabolic impacts of environmental variability associated with winter conditions in a temperate char (Salvelinus fontinalis) Winter can be a physiologically challenging time for aquatic ectotherms such as fishes due to the cold and reduced food availability. Cold temperatures can limit the ability to acquire energy and slow life processes including metabolism, activity and food intake. Winter is conventionally thought to result in stable environmental conditions, but in freshwaters temperature and food availability may vary considerably during winter and food may become available sporadically. Climate change is expected to exacerbate this variability, yet the physiological consequences of winter environmental variation is understudied. Cold-adapted species, including many salmonids such as brook char (Salvelinus fontinalis), thrive at low temperatures and tend to remain active and feeding if given the opportunity. However, little is known about how variation in temperature and food availability may affect salmonid overwintering performance. To address this gap, we first characterized the response of brook char to cold, finding that while their spontaneous activity did decline, they remained active and their feeding rate was relatively unchanged during acute cooling (14oC to 2oC) and subsequent acclimation to 2oC. Next, we are running two long-term (5 months) fully factorial experiments to examine the combined effects of stable or variable winter temperature and food availability on the overwintering physiology of brook char. First, we will expose brook char to two stable temperatures, 2oC or 8oC, with two feeding regimes, fed (0.5% body weight day-1) or fasted. Second, we will investigate the effects of a stable (2oC) or variable (2oC – 9oC –

144 2oC twice per week over 24h) thermal regime while fed (0.5% body weight day-1) or fasted. We will measure body condition, swim performance, metabolic performance, activity and tissue energy density of fish in both experiments in order to understand how environmental variation over winter impacts the physiological performance of brook char.

Miller, L.A., McDougall, L.M., Edwards, M., Goetz, F.X., Hamilton, A.M., Manzon, R.G. Department of Biology, University of Regina, Regina, Saskatchewan, Canada Effects of acclimation temperature and temperature shifts on Walleye swim performance and oxygen consumption Walleye (Sander vitreus) may experience temperature stress associated with catch and release angling and live-release competitive angling tournaments. The purpose of this study was to determine the effects of acclimation temperature and a shift in temperature (e.g. from deep, cool water to warm, surface water) on oxygen consumption and swim performance. We measured oxygen consumption and maximum sustained swimming speed (UCrit) in fish acclimated to 15 and 21⁰C and following a shift, over 3 hours, from the acclimation temperature to the other temperature (i.e. acclimated to 15⁰C tested at 21⁰C and vice versa). Our data show that routine and maximum oxygen consumption and aerobic scope were elevated when testing occurred at 21°C, irrespective of acclimation temperature or a temperature shift. Collectively, these data support other data that indicate impacts on walleye can be minimized if temperature shifts are minimized and live-well temperatures are maintained at or below 21°C.

Möckel, D.¹, Groulx, T¹, Faure, P.A.¹* 1Department of Psychology, Neuroscience & Behaviour, McMaster University, Hamilton, Ontario, Canada *Presenting Author Development of Hearing in the Big Brown Bat Bats have excellent hearing which they use for orientation, alerting functions, communication, and prey detection. We studied the development of hearing in newborn pups of the big brown bat, Eptesicus fuscus. In the majority of pups, the opening of both outer ear canals occurred on or before postnatal day (PND) 7, but in some it extended to PND 11. We documented the progressive development of auditory sensitivity with repeated auditory brainstem response (ABR) recordings. The ABR is a synchronous, neural response evoked by acoustic stimulation and represents the summed activity of neurons in the auditory pathway between the cochlea and upper brainstem. Recording ABRs is a relatively non-invasive procedure, with measurements conducted in awake or lightly anaesthetized animals, and repeated in the same individual to track hearing onset and development. We measured hearing thresholds in 22 E. fuscus every three days between PND 10 and PND 31, with additional recordings in a subset of bats at 2 months, 3 months and 1 year of life. Nursing pups were returned to their mothers between recordings. There was a dramatic decrease in thresholds and increase in bandwidth across development for frequencies between 4 and 100 kHz. Prior to PND 13-16 when pups were still non-volant, most bats were unable to hear frequencies above 48 kHz; however, sensitivity to higher ultrasonic frequencies increased with age. Notably, these changes occurred near the ages when young bats started learning how to fly and echolocate.

Moffatt, K. M.1*, Wilson, J. M.1,2 1Department of Biology, Wilfrid Laurier University, Waterloo ON Canada 2CIIMAR Universidade do Porto, Matosinhos, Portugal *Presenting Author Effects of omeprazole, a proton pump inhibitor, on gastrointestinal tract pH, and enzyme expression in the Nile tilapia The presence of an acid-secreting stomach has been reported to provide many selective advantages to higher vertebrates. However, phenotypic stomach loss is quite common in fishes and is linked to loss of expression of both the gastric proton pump and pepsinogen, an aspartic protease. Elucidating the contribution of gastric acid-secretion to digestion, growth and the metabolic costs of digestion (specific dynamic action; SDA) will provide essential information for understanding stomach conservation and loss. We have used omeprazole, a gastric proton pump inhibitor, to simulate the agastric phenotype by ‘knocking-out’ acid-production. In our earlier work we showed that growth rate was decreased and SDA altered in Nile tilapia (Oreochromis niloticus) fed omeprazole-supplemented feed (25 mg · kg -1 body mass (BM) · day -1) fed at 2% BM · day -1. In order to better understand the underlying causes of these effects,

145 in situ gut pH was subsequently measured and tissues collected for analysis of gastric proton pump and digestive enzyme expression using Western blot analysis and enzymatic assays. The pH measurements gathered show a clear reduction in gastric acid production (p<0.05) for up to 12 hours after administration of omeprazole-feed, returning to control levels by 24h. Pepsin activity in the omperazole fed fish stomach samples was significantly higher (p<0.01) when expressed as units/mg protein; however, Western blots did not show differences in expression of pepsinogen or pepsin. The gastric proton pump Atp4b subunit also showed higher expression with omeprazole treatment (p=0.05) suggesting an incomplete compensatory response to pump inhibition and reduced acidification. However, the increase in the Atp4a subunit was not significant (p=0.09). Intestinal pH and enzyme (trypsin, amylase) activates were not affect. In summary, our recent results show omeprazole is having a negative effect on digestion that contributes to the reduced growth rate.

Myrka, A. M.¹*, Frost, R.2, Distefano, D.¹, Plotnikov, S. V.¹, Buck, L. T.¹ 1 Department of Cell and Systems Biology, University of Toronto, Toronto, Canada 2 Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Canada *Presenting Author Cold and Chemical Anoxia Promote Cytoskeleton-Mediated Shrinkage in Hepatocytes of the Western Painted Turtle The western painted turtle (Chrysemys picta belli) overwinters in ice-covered water bodies, surviving without oxygen (anoxia) for months. Overwintering metabolic rate decreases so that ATP demand does not exceed anoxic ATP supply. In order to characterize the contribution of the cytoskeleton to overwintering metabolic rate depression in non-excitable turtle cells, we have optimized a hepatocyte primary cell culture system. Actin and tubulin cycling are large consumers of cellular ATP pools, and we hypothesized that their cycling activity, and consequently capacity for structural rearrangement, would be downregulated by cold and anoxia. Turtles were acclimated to 4°C for at least 20 days and isolated hepatocytes were plated on either fibronectin or polylysine at varying temperatures, or in cyanide containing media, which acted as a chemical proxy for anoxia. Low temperature, but not cyanide, prevented hepatocytes from forming stable attachment to fibronectin, suggesting inhibition of cell spreading and arrest of structural rearrangement by low temperature. Passive electrostatic attachment to polylysine was not inhibited by cold or cyanide. Hepatocytes isolated from 4°C acclimated turtles were 30% smaller in 2D area than those of 22°C acclimated turtles. Three-hour cyanide exposure of hepatocytes from 22°C acclimated turtles also resulted in a 30% shrinkage of 2D area, indicating that temperature depression and anoxia may have overlapping inhibitory effects on cell spreading and underlying cytoskeletal turnover. Chronic 4°C incubation of hepatocytes from 22°C acclimated turtles resulted in withdrawal of lamella, suggesting an inhibitory effect of cold on actin structures. Pharmacological depolarization of mitochondrial membrane potential (signalling present during anoxia) mimicked the effect of cyanide and mitochondrial depolarization was also observed at 4°C, suggesting that mitochondrial signalling may regulate the activity of the cytoskeleton in turtle cells.

Nelson, C.¹*, Jung, E.¹, Harter, T.², Tresguerres, M.², Brauner, C.¹ 1Department of Zoology, University of British Columbia, Vancouver,, Canada 2 Scripps Institute of Oceanography, University of California, San Diego, USA *Presenting Author Absent in the gills but present elsewhere: Rainbow Trout possess a heterogeneous distribution of plasma accessible carbonic anhydrase The unique teleost oxygenation system is comprised of three major components: a highly pH sensitive haemoglobin (Root effect), red blood cell (RBC) intracellular pH (pHi) protection by way of a beta- adrenergically stimulated sodium proton exchanger (β-NHE), and a heterogeneous distribution of plasma accessible carbonic anhydrase (paCA). Together these components allow for efficient gas exchange at the gill, enhanced O2 unloading at specific tissues, and protection of O2 transport mechanisms during a generalized acidosis. While the Root effect and β-NHE have been relatively well studied among teleosts over the past century, much less is known about the distribution of paCA in tissues of teleosts. Previous work in salmonids has established the presence of paCA in specific tissues e.g. heart atrium and red muscle, however many gaps in our knowledge remain. In this study we aimed to test the hypothesis that paCA is present in all tissues except the gills in the model teleost, the Rainbow Trout (Oncorhynchus mykiss). We used an array of techniques (ultracentrifugal washing, specific inhibition,

146 immunohistochemistry) to build a qualitative atlas of presence/absence of paCA in 14 separate tissues. We show that paCA appears to be generally present throughout most of the tissues investigated, but absent in branchial capillaries of all four gill arches. This work confirms previous assumptions on the heterogeneous distribution of paCA and broadens our knowledge of the unique teleost oxygenation system.

Nipu, N.*, Vijayan, M. M. Biological Sciences, University of Calgary, Calgary, Canada Cortisol affects brain nutrient sensing in zebrafish Stress is often associated with reduced food intake, and a generalized non-specific response to stress is the elevation of circulating corticosteroid levels in animals. In teleosts, cortisol is the primary corticosteroid, and the stressor-mediated elevation of this hormone leads to an increase in plasma glucose levels. While cortisol has been shown to affect feeding behaviour in fish, the mechanisms are far from clear. Here we hypothesized that elevated plasma glucose levels in response to the stressor- mediated cortisol elevation inhibits feeding by activating the brain glucose sensors. We tested this hypothesis using the zebrafish (Danio rerio) as a model. Waterborne exposure to cortisol, mimicking stressed levels of this steroid, significantly decreased food intake in zebrafish. This treatment also led to elevated blood glucose levels. Signals involved in appetite regulation and nutrient-sensing mechanisms were measured in the brain to determine the molecular mechanisms. Cortisol treatment decreased the ratio of phosphorylated to total protein kinase B (Akt) and the phosphorylation of mammalian target of rapamycin (mTOR), but not the ratio of phosphorylated to total AMP-activated kinase (AMPK) expression in the brain of zebrafish. The transcript abundance of key brain peptides involved in appetite regulation, including NPY, POMCa, CRH, MC3R, MC4R, Lepa and lepR, were not significantly affected by cortisol. To test if elevated glucose may play a role in the cortisol-mediated cessation of feeding, we treated fish to waterborne glucose to elevate plasma glucose levels, and this reduced food consumption. However, glucose exposure decreased the ratio of phosphorylated to total AMPK, but did not affect Akt or mTOR expression in the brain. Overall, our results suggest that the reduced feeding seen with stressed levels of cortisol may not be due to altered glucose sensing in the brain.

Nowlan, J. P.¹,²*, Britney, S. R.¹, Lumsden, J. S.², Russell, S.¹ 1 Centre of Innovation for Fish Health, Vancouver Island University, Nanaimo, British Columbia, V9R 5S5. 2 Department of Pathobiology, University of Guelph, Guelph, Ontario, N1G 2W1. *Presenting Author Application of quantitative PCR to monitor netpen sites in British Columbia (Canada) for Tenacibaculum species Tenacibaculum are frequently detected from fish with tenacibaculosis at aquaculture sites; however, information on the ecology of these bacteria is sparse. Quantitative-PCR assays were used to detect T. maritimum and T. dicentrarchi at commercial Atlantic salmon (Salmo salar L.) netpen sites throughout several tenacibaculosis outbreaks. T. dicentrarchi and T. maritimum were identified in live fish, dead fish, other organisms associated with netpens, water samples and on inanimate substrates, which indicates a ubiquitous distribution around stocked netpen sites. Before an outbreak, T. dicentrarchi was found throughout the environment and from fish, and T. maritimum was infrequently identified. During an outbreak, increases in the bacterial load in were recorded and no differences were recorded after an outbreak supporting the observed recrudescence of mouthrot. More bacteria were recorded in the summer months, with more mortality events and antibiotic treatments, indicating that seasonality may influence tenacibaculosis; however, outbreaks occurred in both seasons. Relationships were identified between fish mortalities and antimicrobial use to water quality parameters (temperature, salinity, dissolved oxygen) (p < 0.05), but with low R2 values (<0.25), other variables are also involved. Furthermore, Tenacibaculum species appear to have a ubiquitous spatial and temporal distribution around stocked netpen sites, and with the potential to induce disease in Atlantic salmon, continued research is needed.

Perugini, G.¹*, Gillis, T. E.¹, Alderman, S. L.¹ 1Department of Integrative Biology, University of Guelph, Guelph, Canada *Presenting Author

147 Early Life Stage Specific effects of Diluted Bitumen Exposure on Pacific Coho Salmon (Oncorhynchus kisutch) As Canada’s crude oil industry expands, so too does the risk of diluted bitumen (dilbit) spills in Canadian waterways. Early life stages (ELS) of Pacific salmon reside in these at-risk freshwater environments and may be more sensitive to dilbit exposure as a result of greater surface area to volume ratio increasing the uptake of crude oil contaminants. Understanding life stage-specific sensitivities to dilbit exposure is critical for risk assessment and spill management. To test the hypothesis that the sensitivity of salmon to dilbit decreases with age, Coho (Oncorhynchus kisutch) fry (~4 months) and parr (~12 months) were exposed to environmentally relevant control (no dilbit), low (1.13 μg/L PAC) and high (3.90 μg/L PAC) concentrations of the water-soluble fraction of dilbit (WSFd) for either 48h or 4wk. Changes in the expression of the phase I biotransformation enzyme, cytochrome p450 1a (cyp1a), and phase II antioxidant enzyme glutathione s-transferase (gst) were quantified in liver samples. There was a significant interaction between life stage and concentration at both 48h and 4wk of exposure. At 48h, fry showed a greater magnitude of cyp1a response relative to parr, but changes in parr cyp1a occurred at a lower WSFd concentration relative to fry. At 4wk, cyp1a expression was only elevated in parr exposed to the high WSFd concentration. These life stage differences were driven by a greater baseline expression of cyp1a in fry relative to parr. In contrast, no differences in gst expression were observed between life stages or WSFd concentrations. Taken together, results of this study indicate that ontogenic differences in the maturation of the phase I biotransformation pathway may contribute to the biological response of salmon to dilbit exposure, underscoring the importance of targeted studies on specific life stages when considering the potential impacts of a pipeline spill in salmon habitat.

Picinic, B.N. 1*, Paluzzi, J.P. 1, Donini, A. 1 1Department of Biology, York University, Toronto, Canada *Presenting Author The Effects of a Blood Meal on Aquaporin Abundance in Female Disease Vector Mosquitoes, Aedes aegypti The disease vector mosquito, Aedes aegypti is responsible for the transmission of deadly arboviral diseases around the globe, particularly in subtropical and tropical regions. Adult female mosquitoes require a blood meal to acquire the appropriate nutrients needed to produce mature, viable eggs. As terrestrial insects, A. aegypti are normally inclined to conserve their water levels; however, when females ingest a blood meal, the load is approximately three times the volume of their hemolymph and thereby poses an osmoregulatory challenge. The primary organ responsible for the production of urine in A. aegypti is the Malpighian tubules (MTs). There are five blind-ended tubules that are attached at their proximal end to midgut/hindgut junction, with two main cell types comprising this epithelium: the principal and stellate cells. These cells are responsible for the production of primary urine, which involves the active secretion of ions driven by an apical V-type H+-ATPase in the principal cells. The movement of water in the MTs occurs via osmosis, following the movement of ions into the tubule lumen. The movement of water is made possible by the expression ofaquaporin proteins in the MTs of A. aegypti. It has been shown that a blood meal taken by female mosquitoes significantly increases the secretion of ions and water by the MTs and previous research by the Hansen lab (New Mexico) showed that dsRNA knockdown of AaAQPs reduced urine output in PBS injected mosquitoes.In this study the effects of a blood meal on the AaAQP protein abundance and localization in the MTs of A. aegypti are assessed. Our results show that AaAQP1 and AaAQP4 abundance increases in the MTs ~0.5hr and ~24hr post blood meal. The localization of AaAQP1 and AaAQP4 in the MTs is the subject of continuing work.

Purvis, K. I.*, Hunter, A., Trevors, A., Wilson, E., Wyeth, R. C. Department of Biology, St. Francis Xavier University, Antigonish, Canada *Presenting Author Single ultraviolet-C light treatments of marine biofilms delay subsequent biofouling by macroorganisms Marine biofouling, the growth of organisms on submerged surfaces, has driven the development of a range of antifouling technologies, some with substantial environmental harms. Ultraviolet-C (UV-C) radiation offers a potentially useful alternative to current marine antifouling methods. Past studies of UV-C antifouling performance have found repeated doses can reduce or eliminate macroscopic biofouling. Our objective was to apply a single treatment of UV-C radiation to pre-formed microbial biofilms to observe

148 subsequent effects on macrofouling development. Biofilms formed over a 2-week immersion at 2 m depth in the nearshore Northeast Atlantic (in Port Hawkesbury, Cape Breton Island) received a UV-C radiation treatment of either 0 (control), 4, 20, or 120 min. Biofouling progression was then monitored weekly for 112 days. The 20 and 120-minute treatments caused an immediate decline in measurable biofouling in the following week and also significantly reduced macrofouling for up to 112 days. All species that were either settling or recently settled at the time of treatment were affected by the UV-C radiation treatment. Species that appeared to settle after the treatment showed no effect from the treatments Overall, the results demonstrate a single UV-C radiation treatment of biofilm can have potentially substantial consequences on longer-term macrofouling growth. This suggests UV-C treatments spaced by days or even weeks could be an option for applications of UV-C radiation as an antifoulant.

Reid, K.J.¹*, Daniels, E.G.², Houtkooper, R.H.², Standen, E.M.¹, Menzies, K.J.3 ¹Department of Biology, University of Ottawa, Canada 2Translational Medicine, University of Amsterdam Medical Centers, The Netherlands 3Interdisciplinary School of Health Sciences, University of Ottawa, Canada *Presenting Author Inducing the Mitochondrial Unfolded Protein Response Does Not Increase Lifespan or Confer Healthy Aging in a Mammalian Model Mitochondria communicate with the nucleus to maintain metabolic homeostasis. They are responsive to nutritional status, reactive oxygen species, changes in membrane potential, and protein homeostasis. They integrate these inputs and send signals to the nucleus, adapting the cell to its environment. Over time, mitonuclear metabolic communication impacts aging and lifespan. An imbalance between mitochondrial- and nuclear-encoded proteins (mitonuclear imbalance), induces the mitochondrial-specific unfolded protein response (UPRmt), regulating genes like Hsp60, which are involved in protein folding and clearance. In the worm model Caenorhabditis elegans, reducing mitochondrial ribosomal protein (MRP) expression induces the UPRmt through mitonuclear imbalance, lengthening lifespan and improving the aging phenotype. We generated a mouse with reduced Mrpl54 expression and asked whether constitutive induction of UPRmt affects mammalian lifespan or aging. Initial reports suggested that young mice heterozygous for Mrpl54 (Mrpl54 HET) have improved grip strength, a potential signal for improved mitochondrial-mediated muscle function. Compared to wildtype (WT), we found few differences in 6-, 18-, or 24-month metabolic health outcomes, or growth in Mrpl54 HET mice. Using mitochondria isolated from male liver, we found no difference in respiratory capacity, proteomics, or HSP60 protein expression. There were no differences in male or female median, 24-month, or maximum lifespan. Among a subgroup of singly housed males, significantly more Mrpl54 HET animals reached an age of 24-months, suggesting the UPRmt signal may confer a healthy aging advantage in a stressful external environment. Unlike the worm, our results show that inducing the UPRmt alone does not confer healthy aging or a lifespan advantage. However, recent research suggests the mammalian UPRmt is part of a cellular integrated stress response, acting in a tissue-specific manner to affect aging phenotypes. In mammals, the UPRmt is a mitonuclear signal that helps re-establish metabolic homeostasis, especially in tissues such as the brain, heart, or skeletal muscle.

Santa Rita, Z.1*; Gray J.R.1 1 Department of Biology, University of Saskatchewan, Saskatoon, SK, Canada *Presenting Author A Locust Visual Neuron Responds to Object Trajectory Changes in the Elevation Plane Animals respond to numerous biologically relevant environmental stimuli by performing various behaviours. Organisms such as locusts swarm during unfavorable conditions in complex, dynamic visual environments that requires collision detection systems to successfully orient themselves amongst stationary objects and conspecifics to avoid threats such as an approaching predator. Locusts (Locusta migratoria) and their visual motion-detection pathway, comprised of the Lobula Giant Movement Detector (LGMD) and the Descending Contralateral Movement Detector (DCMD), responds selectively to objects approaching on a direct collision course. We presented the locusts with biologically relevant stimuli of 3D objects with trajectory changes within the elevation plane. We found that DCMD responses to stimuli that change in trajectory in the elevation plane are consistent with objects that change in trajectory within the azimuthal plane. There is a slight delay in firing in the motion-detection pathway after the stimulus changes trajectory. This allows us to infer that there is a generalized system within the locust to recognize

149 approaching objects regardless of its origin. This tractable insect system provides information on generalizable processing of complex visual cues for orientation in natural environments.

Schoen, A. N., Anderson, W. G. Department of Biological Science, University of Manitoba, Winnipeg, Canada Energy mobilization in response to hormonal de-liver-y: a novel hepatic perfusion prep in an elasmobranch species (Squalus acanthias suckleyi). Organisms must acquire, store, and catabolize energy molecules in order to stay alive. The vertebrate endocrine system plays a critical regulatory role in controlling energy balance, particularly during periods of increased energy demand. An important function of glucocorticoids is to stimulate the catabolism of hepatic glycogen and the process of gluconeogenesis when available plasma metabolites decrease. In elasmobranchs the dominant glucocorticoid is largely unknown; thus, to determine the potential glucocorticoid effects of a variety of hormones, we have developed a novel in situ liver perfusion preparation in a representative elasmobranch, the north Pacific spiny dogfish (Squalus acanthias). Fish were euthanized and the hepatic portal vein was immediately cannulated to allow for perfusion of the liver in situ at ~1.8mL.min-1. A ligature was placed around the connection between each lobe of the liver and viscera, and the hepatic sinus was cannulated via the heart to facilitate collection of perfusate once it had passed through both lobes of the liver. Perfusate was collected every 10 minutes for four to five hours and analyzed for changes in glucose and ß- hydroxybutyrate concentrations to determine the stability and repeatability of the in situ preparation. There were predictable changes in perfusate concentration of glucose and ß-hydroxybuterate. Effects of insulin, epinephrine, and glucagon on the hepatic production or use of the two key metabolites were assessed.

Schwegel, M.A1,2, Filazzola A.2, Chapman C.A.3, Schoof V.A.M.1,2,* 1 Bilingual Biology Program, Department of Multidisciplinary Studies, York University – Glendon College, Toronto, Canada 2 Department of Biology, York University, Toronto, Canada 3 Department of Anthropology, George Washington University, Washington DC, USA * Presenting Author Breeding seasonality, interbirth intervals, and stacked reproductive investment in female vervet monkeys at Lake Nabugabo, Uganda Resource availability is intricately linked to female reproduction in mammals, and poor timing in relation to food availability or delaying reproduction even when in good maternal condition can be costly. We expand upon preliminary research by examining birth/conception seasonality, interbirth interval (IBI), and stacked investment (i.e., investing in lactation and gestation simultaneously) in relation to food availability, weather, and female dominance rank in three groups of vervets living in a forest-agriculture matrix at Lake Nabugabo, Uganda. Births (N=126; July 2012-June 2020) occurred year-round; 60.1% of births occurred in October-December (i.e., moderate seasonal breeders with 34-66% of births in 3-month); two groups were moderate seasonal breeders (56.3 and 61.5%) while the third group exhibited strict seasonality with 71.4% of births in November-December (i.e., >67% in 3-months). There was no seasonal variation in ripe and unripe fruit available, and neither fruit availability nor weather were predictors of birth or conception seasonality. However, there was an interaction between rainfall and temperature, such that conceptions were more likely in months when rainfall was high if temperature was also high. Mean IBI for infants that survived to six months was 369.9±145.9 days (n=65), did not differ between groups (Welch ANOVA: F(2, 17.9)=0.459, p=0.64), and was shorter than in other wild populations. The best LMM indicated that high-ranking females had shorter IBIs (F=4.018, p=0.05). Stacked investment was determined by comparing the last date of nipple contact (breastfeeding) to the date of conception of the following infant, but none of our predictors (rank, infant sex, group ID, maternal ID) were significant predictors. The moderate breeding seasonality, shorter interbirth intervals, and presence of stacked investment may relate to environmental (woodland versus savanna, access to anthropogenic foods) or social differences (e.g., male immigration) between the Nabugabo vervets and other populations, as well as between groups in the Nabugabo population.

Scovil, A.M.1*, Boloori, T.2, de Jourdan, B.P.3, Speers-Roesch, B.1 1Department of Biological Sciences, University of New Brunswick, Saint John, Canada 2Aquatic Toxicology, Huntsman Marine Science Centre, St. Andrews, Canada

150 3Environmental and Molecular Toxicology, Huntsman Marine Science Centre, St. Andrews, Canada *Presenting Author The effects of physically and chemically dispersed crude oil on the metabolic and cardiac function of larval American lobster (Homarus americanus) The petroleum industry is a major component of the Canadian economy. It is associated, however, with the risk of spills that can impact marine ecosystems. The offshore oil industry in Atlantic Canada necessitates a greater understanding of the potential impacts of oil exposure and application of spill response measures on commercially important cold-water marine species. Our study evaluated the effects of water-accommodated fraction (WAF) and chemically enhanced WAF (CEWAF) of conventional crude oil on the metabolic and cardiac function of larval American lobster (Homarus americanus). Stage I larvae were exposed to four sublethal concentrations of WAF and a seawater control, and four sublethal concentrations of CEWAF and a dispersant control (Slickgone EW) for 24 hours. We performed respirometry and heart rate recordings on a subset of stage I larvae immediately post-exposure (n=10 per treatment). Another subset was transferred to individual flasks with clean filtered seawater until post-moult (i.e., stage II larvae), at which point we carried out respirometry and heart rate recordings (n=10 per treatment). Routine mass-specific oxygen consumption rates were measured using a 24-channel optical fluorescence oxygen reading device, and heart rate was determined by visualizing and counting the number of beats under a video microscope. We found no acute effects of crude oil exposure or dispersant addition on the metabolic and cardiac function of stage I American lobster larvae. Furthermore, no persistent metabolic or cardiac effects of exposure were observed in post-moult larvae. Overall, our results suggest that stage I American lobster larvae are physiologically resilient to physically and chemically dispersed crude oil at the sublethal concentrations and exposure duration tested in this study.

Shadwick, R.E.¹*, Vogl, A.W.² 1Department of Zoology, University of British Columbia, Vancouver, Canada 2Life Sciences Institute and the Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, Canada *Presenting Author Structural characterization of the swimming muscles of the Greenland shark, Somniosus microcephalus Greenland sharks (Somniosus microcephalus) live in deep, cold water in high northern latitudes, grow to a large size (>5 m), have a lifespan of hundreds of years (Hansen, 1963; Nielsen et al., 2016) and appear to be very sluggish with little capacity for sustained high-speed swimming. To complement a study of the contractile properties of the lateral skeletal muscles we examined their structural features by light (LM) and electron (EM) microscopy. As is typical of other sharks, the majority of the myomeres are composed primarily of fast white muscle (WM) fibres, while slow red muscle (RM) fibres are located in lateral bands just below the skin. Cell diameters averaged 79µm for red muscle and 260µm for white. The most prominent feature in both muscle cell types was the large amount of lipid deposits within the cells. In RM cells these were observed as 3-6µm vesicles located in a peripheral band as well as centrally among the myofibrils, and comprising about 25% of cell cross-sectional area. In WM cells, similar sized vesicles were more homogeneously distributed throughout the myofibrillar bundles, occupying about half of the cell area. Mitochondria were sparse in WM but very abundant in RM, residing primarily among the lipid vesicles. Sarcomere spacing averaged 1.5µm in RM and 1.2µm in WM.

Thoral, E.1*, Quispe, L.1, Roussel, D.1, Voituron, Y.1, Teulier, L.1 1Univ Lyon, Université Claude Bernard Lyon 1, CNRS, ENTPE, UMR 5023 LEHNA, F-69622, Villeurbanne, France *Presenting Author Effects of simulated heatwaves on mitochondrial respiration in red muscle of zebrafish Danio rerio Global changes will lead to a higher frequency of intense and extreme harmful events. For example, heatwaves, which are characterised by an acute increase in temperature that can last several days before returning to normal, are expected to have greater effects in aquatic ectotherms, especially fish, which have an environment-dependent metabolism. Indeed, fish metabolism increases with higher temperature, due to an increase in biochemical, mitochondrial and cellular activities. Mitochondria are the main producers of cellular energy in the form of ATP through the consumption of oxygen and substrates.

151 Therefore, the aim of our study was to investigate the physiological consequences of heatwaves on the mitochondrial metabolism of the red muscle in the zebrafish Danio rerio. Fish were divided in 3 groups with different housing conditions: (i) stall at 26°C, (ii) stall at 31°C or (iii) stall at 26°C with 2 periods of 5 days at 31°C to mimic heatwaves. After 2 months, the respiration rate of red muscle fibres was measured at both 26°C and 31°C using sequential addition of substrates and inhibitors. Globally, the housing conditions did not change the rates of mitochondrial respiration. However, there was an acute thermal effect on the basal respiration rates, with an increase at 31°C compared to 26°C for all groups, whereas the phosphorylating respiration rates were not affected. This acute effect of warming leads to a decrease in the respiratory control ratio whatever the housing conditions, suggesting a decrease of the mitochondrial efficiency at 31°C. These results suggest an acute effect of warming on mitochondrial efficiency, but no effect of the heatwave protocol used in the present study. Further investigations could be done to measure the effects of multiple environmental stress, such as hypoxia and acidification that could be associated with heatwaves, to mimic natural environment.

Ucciferri, C. U.¹, Wyeth, R.¹, 1Department of Biology, Saint Francis Xavier University, Antigonish, Canada Extracellular Recording of Chemosensory Neurons in the Tentacles of the Great Pond Snail, Lymnaea stagnalis The gastropod Lymnaea stagnalis has been studied to investigate both behavior and its neural control. The tentacles and lips comprise the cephalic sensory organs of L. stagnalis, which are involved in mechanosensation and chemosensation. The chemosensory function of the cephalic sensory organs has been supported by behavioral studies, as well as neuroanatomical evidence at the cellular level. The goal of our research was to record from the chemosensory neurons in the tentacle using extracellular electrophysiological techniques. We hypothesized that applying a food stimulus to the tentacles would increase the firing rate of the chemosensory neurons. This was tested by recording the neural activity while food odors that have been shown to elicit behavioral responses in L. stagnalis are applied to the tentacle. Specifically, we used algae and shrimp food sources to account for the omnivorous diet of this snail. The major results showed that we were able to record from the chemosensory neurons. In some channels, there was an increase in the neuronal firing rate as a food stimulus was applied to the tentacle when compared to applying a control solution. This suggests that food odors stimulate the chemosensory neurons while a neutral solution does not elicit this response. However, some aspects of the methods do not meet typical electrophysiological standards and weaken support for our hypothesis. Overall, the results provided some support for our hypothesis and the goal of this experiment. Immediate future directions include improving the recording of the biological signals and improving the stimulus set up. Other possibilities for future work include locating the chemosensory neurons within the tentacle, as well as investigating the integration process of sensory odor signals in the context of the central nervous system.

Van Oordt, F.; Silva, J; Elliot, K.H. McGill University, Montreal, Canada Birds in hot water: foraging effort of boobies and cormorants in Northern Peru in varying oceanic conditions For “central place foragers” environmental variability can be decisive, modifying their behavior and performance, since they cannot abandon their central place to follow their prey (eg nesting seabirds). El Niño, the most extreme example of variability in the Pacific Ocean off Peru, modifies the distribution of Peruvian Anchovy, prey item of Peruvian guano seabirds (Guanay, Booby, Pelican). Biologgers (GPS, accelerometers, etc.) help observe changes in bird behavior at sea which reflect changes in prey availability, which defines foraging effort, reproductive success, and general physical condition of the parenting birds. Movements of breeding Boobies and Cormorants were recorded in northern Peru in November 2018 and 2019. Maximum distance traveled was greater for 2018 (Niño like conditions). Since the distribution of Anchovy is variable in warm periods, breeding seabirds fly much farther and require more energy, which ultimately is unsustainable, and chronically leads to reproductive failure.

Wagler, B.1* Millar, Z. D.1, Kecheliev, D.1, Pham, J. 1, Lumsden, J. S.1 Department of Pathobiology, University of Guelph, Guelph, Canada *Presenting author

152 Micro-fragmentation of Scleractinian Corals Coral reef ecosystems, and the goods and services they provide are being threatened by anthropogenic activities. This study aims to better understand how micro-fragmentation may aid in reef restoration efforts, by understanding how fragment size and coral morphologies influence regeneration processes. Two hypotheses were proposed; 1. That larger initial coral fragment sizes would regenerate and grow faster than smaller fragments and 2. That coral species classified as weedy will grow at faster rates then competitive corals. After fragmentation, Montipora capricornis and Pocillopora damnicornis (both competitive strategists) and Seriatopora hystrix (weedy strategist) were observed via photos and weight measurements. We initially compared the growth method for the branching coral types (P. damnicornis and S. hystrix) but there was no significant difference (p-value> 0.05) between suspension versus attachment to a substrate (coral plug). Therefore, subsequent trials attached the corals to plugs. A second trial indicated that small fragment sizes completed regeneration and grew significantly better than the large fragments of the same species, with greater percent change relative to day zero (p-value< 0.01). However, the third, although shorter, trial did not confirm these results and the outcome of the first hypothesis remains to be determined. The lack of difference regarding fragmentation size for optimal growth in the present study may reflect the controlled environment compared to observations with coral restoration in the field, where larger fragments have an overall better growth and survival rates then smaller fragments. The weedy species, S. hystrix, demonstrated significantly greater percent change relative to day zero compared to the other two competitive coral species observed (p-value< 0.0001), supporting our second hypothesis. This result coincide with research on damaged reefs, suggesting that weedy coral strategists can proportionately increase in abundance, homogenizing reef ecosystems. Further analysis of histology and proteomics may aid in understanding some of the biotic factors that influence regeneration, regarding if Scleractinian corals use similar differentially abundant proteins during regeneration or not.

Wang, Y.¹*, Robertson, R. M.¹ 1Department of Biology, Queen’s University, Kingston, Canada *Presenting Author The role of anaerobic glycolysis in the anoxic spreading depolarization of Locusta migratoria The migratory locust (Locusta migratoria) can survive through periods of environmental anoxia by entering a reversible state of coma, marked by neuromuscular inactivity and metabolic depression. Spreading depolarization (SD) is the mechanism underlying coma induction in the locust central nervous system (CNS), which involves the near complete depolarization of neural cells and the silencing of electrical activity. During severe metabolic insults such as anoxia, glycolytic flux is considered to be neuroprotective; yet the precise involvement of anaerobic glycolysis in anoxic SD progression and recovery remains elusive. Here, we investigate the role of anaerobic glycolysis in locust anoxic SD through pharmacological manipulations of glycolytic capacity. Semi-intact locusts were pre-treated with either glucose, trehalose, or monosodium iodoacetate (MIA, GAPDH inhibitor) before N2-induced anoxia. The characteristics of SD onset and recovery were studied with an electrophysiological approach. We found that glycolytic capacity minimally influences the time course of SD induction; however, glucose considerably enhanced SD recovery rate and reduced the amplitude of the negative DC shift. Moreover, MIA slowed down the recovery and depressed the extracellular DC potential after anoxia. Taken together, these observations suggest anaerobic glycolysis may serve to maintain ion homeostasis during coma and provide a significant energy boost during SD recovery. Furthermore, MIA potentially exacerbates anoxia- dependent oxidative damage to the perineurial glia, resulting in depression of DC potential. Our research contributes to the broader mechanistic understanding of insect anoxic SD, and provides a basis for further exploration in the interplay between neural anaerobic metabolism and SD parameters – an often overlooked aspect in both insect and mammalian SD literatures.

Wearing, O. H., Scott, G. R. Department of Biology, McMaster University, Hamilton, Canada Cardiovascular function is regulated to maintain mean arterial pressure in mice during chronic hypoxia Despite a rich literature addressing the effects of chronic hypoxia on human cardiovascular function, little is understood about how cardiovascular control is adjusted during chronic hypoxia in other mammals. Based on findings in humans, we hypothesised that chronic hypoxia increases the influence of the

153 sympathoadrenal system on the heart and vasculature, leading to sustained and potentially maladaptive increases in heart rate (fH) and mean arterial pressure (MAP). We tested this hypothesis in CD-1 mice that were surgically implanted with physiological telemeters in normoxia or after chronic exposure to hypoxia (12 kPa O2) for 6-8 weeks. We measured MAP, fH, body temperature (Tb) and locomotory activity continuously for 48 h to examine natural circadian rhythms in this nocturnal species. We then used pharmacological manipulations to measure alpha-adrenergic and nitric oxide tones on blood pressure, as well as beta-adrenergic and vagal tones on heart rate. Routine fH and Tb were lower during the daytime inactive phase in chronic hypoxia compared to normoxia. MAP was similar between groups across most of the daily cycle, but MAP tended to be higher in hypoxia at low heart rates during the inactive phase. Chronic hypoxia also reduced alpha-adrenergic tone and increased nitric oxide tone. Therefore, mice make effective adjustments in cardiovascular regulation during chronic hypoxia that help offset systemic hypertension, and thus attenuate this maladaptive response to chronic hypoxia that can occur in humans. Funded by NSERC.

White, A.D.1,2*, Boudreau M.2, Priest, J. M. 1,2, Airst, J.2, Shutler, D.1 1 Department of Biology, Acadia University, Wolfville, Canada 2 Department of Lands & Forestry – Wildlife Division, Kentville, Canada *Presenting Author Coyote (Canis latrans) demography during sustained harvest: Tests for and a review of reproductive compensation Targeted removal of problem wildlife may fail to measurably reduce populations because of compensation via enhanced reproduction, reduced mortality, reduced emigration, and/or enhanced immigration. Following a human fatality attributed to coyotes (Canis latrans) in Nova Scotia, Canada in 2009, the provincial government implemented an incentive program to reduce coyote populations; sustained harvest continued through 2018. Critics argued that reproductive compensation would outpace harvest; we tested this by quantifying placental scars over time as a measure of reproductive output. We also tested for other mechanisms of compensation by evaluating changes in population age-sex structure and morphology during the harvest. Placental scars per female remained essentially constant over time. Similarly, there were no marked changes in proportions of coyotes breeding or in population age- sex structure. Subadult females were smaller at the end of the study, whereas condition (mass corrected for size) increased significantly for all age-sex categories. However, effect sizes were small, and other factors, such as natural fluctuations in food supply, may have been responsible for changes in condition. Reproductive compensation is entrenched in the literature, but formal tests for it are frequently not undertaken. A literature review on terrestrial carnivores found that only 10 of 26 tests provided evidence of reproductive compensation. Significant problems with many tests are small sample sizes and open populations in which immigration likely overwhelms even sustained harvests so that there is no selection for reproductive compensation. Our study had the advantage of large sample sizes (4000 animals) and a population with limited immigration because of an inhospitable isthmus that joins Nova Scotia to mainland North America. Our results suggest either limited proximate control of reproductive output in coyotes (and other terrestrial carnivores), or insufficient harvest that did not reduce populations. We conclude that reproductive compensation is not as common as is frequently assumed.

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