Vrije Universiteit Brussel Chemical

Vrije Universiteit Brussel

Chemical “versus” visual cues in newts (Salamandridae): experiments in total darkness and in a Y-maze Treer, Dag; Bossuyt, Franky

Published in: 17th Benelux Congress of Zoology, Ghent - Oral presentation

Publication date: 2010

Document Version: Final published version

Link to publication

Citation for published version (APA): Treer, D., & Bossuyt, F. (2010). Chemical “versus” visual cues in newts (Salamandridae): experiments in total darkness and in a Y-maze. In 17th Benelux Congress of Zoology, Ghent - Oral presentation: Classic Biology in Modern Times (pp. 87-87). (17th Benelux Congress of Zoology, Ghent - Oral presentation). Universiteit Gent.

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Download date: 24. Sep. 2021 17 th Benelux Congress of Zoology Classic Biology in Modern Times

Programme and Abstracts

22-23 October 2010 Ghent University, Belgium Congress Venue

Botanical garden Lunch (ICC) Registration desk

Auditorium 3 coffee breaks Staircase to to Staircase Museum Zoological

Auditorium 4 Courtyard Peristilium

Poster Auditorium 5 Sessions Speaker Ready Room

Main entrance K.L. Ledeganckstraat 35

TH 17 BENELUX CONGRESS OF ZOOLOGY

CLASSIC BIOLOGY IN MODERN TIMES 22-23 OCTOBER 2010, GHENT

Royal Belgian Zoological Society (RBZS) http://www.naturalsciences.be/institute/associations/rbzs_website/

Royal Dutch Zoological Society (RDZS) http://www.kndv.nl/

GeneralInformation

information General

Animal Biology

Managing Editor: M. Muller, Wageningen University, The Netherlands

Animal Biology, the oﬃ cial journal of the Royal Dutch Zoological Society, publishes articles from all quarters of zoology, including ecology, behaviour, evolution, morphology, neurobiology, developmental biology, physiology, cognition, endocrinology, systematics, genomics and theoretical biology.

Impact Factor (2009): 1.069 For more information see brill.nl/ab

Behaviour

Managing Editors: P.C.H. Albers, Groningen, The Netherlands and B.D. Wisenden, Moorhead, MN, USA Reviews Editor: M. Kempes, Utrecht, The Netherlands

Behaviour publishes original research pursuing Tinbergen’s four questions and questions resulting from the interrelationship among the four. In addition, the editorial board encourages reviews of behavioural biology that illuminate emergent trends and new directions in behavioural research.

Impact Factor (2009): 1.471 For more information see brill.nl/beh

INDEX

Welcome 7

Practical information 10

Meet the Expert session 13 information General

Benelux Scientific Network 17

BCZ Awards – Kets Award 19

Scientific programme 21

Plenary abstracts 39

Lecture abstracts 43

Poster abstracts 107

Participants list 163

Notes 169

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Dear fellow zoologists,

It is my pleasure to welcome you in Ghent, at the 17th Benelux Congress of Zoology. The response by you all to participate at this meeting has been very information General positive, which promises this congress already to be a success even before it started. It also makes clear that we are valuing the classical biology as an essential base for modern day biology. I hope that the congress will meet all your expectations, whether you are a ‘fresh’ zoologist who just graduated, a researcher involved in PhD or postdoctoral research, or a scientist rather involved in coordinating research. It is also clear that the Benelux Congress of Zoology, with its broad scope of zoological topics being presented, can still attract a lot of enthusiasts, which is a guarantee for continuous integrated and broad-minded zoological research. The fact that Benelux Zoologists are still eager to do the effort to present their results to a broad zoological audience is evident from the high number of presenters competing for the best presentation awards. The importance of doing this effort to communicate comprehensible science to a broad audience cannot be emphasized enough.

So please enjoy the meeting, the talks, the posters, the discussions, the new contacts, the colleagues, ... and Ghent!

Dominique Adriaens in name of the organizing committee

Biological Sciences

The Royal Society publishes three biological science journals

Each journal provides high-quality peer review and rapid, broad dissemination to an international audience.

Please pick up sample copies of our journals from the Royal Society Publishing exhibit

royalsocietypublishing.org

Scientific committee Organizing committee

Dominique Adriaens (Universiteit Gent – Dominique Adriaens (Universiteit Gent – coordinator) coordinator) Tom Moens (Universiteit Gent) Tom Moens (Universiteit Gent) Dries Bonte (Universiteit Gent) Dries Bonte (Universiteit Gent) Maxime Willems (Universiteit Gent) Tom Geerinckx (Universiteit Gent) Tom Geerinckx (Universiteit Gent) Maxime Willems (Universiteit Gent) Jos Snoeks (Africa Museum) Barbara Verstraeten (Universiteit Gent)

Bieke Vanhooydonck (Universiteit Barbara De Kegel (Universiteit Gent) information General Antwerpen) Hilde Van Wynsberge (Universiteit Gent) Franky Bossuyt (Vrije Universiteit Brussel) Celine Ide (Universiteit Gent) Tom Artois (Universiteit Hasselt) Inge Borghgraef (Universiteit Gent) Eric Parmentier (Université de Liège) Emilie Descamps (Universiteit Gent) Serge Aron (Université Libre de Bruxelles) Annelies Genbrugge (Universiteit Gent) Jean-Louis Deneubourg (Université Libre de Miranda Naert (Universiteit Gent) Bruxelles) Heleen Leysen (Universiteit Gent) Marcel Visser (Nederlands Instituut voor Niels Desmet (Universiteit Gent) Oecologisch Onderzoek) Joachim Christiaens (Universiteit Gent) Frans Witte (Universiteit Leiden) Tim tkint (Universiteit Gent) Sam Vandenplas (Universiteit Gent) Patrick Dauby (Université de Liège) Tom Artois (Universiteit Hasselt) Roger Huybrechts (Katholieke Universiteit Leuven) Pièrre Devos (Faculté Universitaire Notre Dame de la Paix, Namur – president Royal Belgian Zoological Society) Guy Josens (Université Libre de Bruxelles) Erik Verheyen (Royal Belgian Institute for Natural Sciences – treasurer Royal Belgian Zoological Society) Patricia Mergen (Africa Museum) Zjef Pereboom (Royal Zoological Society of Antwerp) Nico Van Straalen (Vrije Universiteit Utrecht – president Royal Dutch Zoological Society) Marcel Visser (Nederlands Instituut voor Oecologisch Onderzoek

GeneralInformation Practical information

– Congress venue –

Registration desk Opening hours: Friday 8:00-18:00

Saturday 8:30-15:00

Speaker ready room Please upload your presentation here, well before the start of your session (the sooner the better). Opening hours: Friday 8:00-11:40 and 13:00-14:00 Saturday 8:30-9:50 and 12:00-13:30

Congress venue Ghent University, Campus Ledeganck and secretariat K.L. Ledeganckstraat 35 9000 Ghent

Contact information [email protected] +32 9 264 52 09 during conference: +32 479 91 05 05 (please only for urgent matters)

Internet (wifi) network: UGentGuest user name: guestZoolog password: kubObHVc (best coverage around speaker ready room)

UGent Botanical Garden will be open during congress hours (greenhouses open on Friday as well)

UGent Zoological Museum open Friday 18h-22h (during reception & social)

Practical Information

– Surroundings –

Emergencies 112 (general), 101 (police)

Money Several ATM’s and banks are nearby, see map on information General inside back cover.

Taxi service Gentax (+32 9 245 45 45) Taxi Gent (+32 9 333 33 33) Airport service: contact registration desk

Parking information As there is no free parking around the congress venue, we recommend to park at the large parking at Sint-Pietersplein (see map on inside back cover).

Bus / train information Buses to railway station and to town center are numerous, see map on inside back cover. To train station is a pleasant 10-15 min. walk.

Dassault Systemes Simulia - Realistic simulations of animals

Historically, simulation has not played as large a role in Life Sciences as it has in more traditional engineering industries like Automotive or Aerospace. This is due to the fact that the Life Sciences industry is often driven by innovators - a select few inventors who create products that are then marketed by larger companies. In addition, the simulation of human/animal systems and their interaction is considerably more difficult and less evolved than the simulation of metal components. Human/animal tissue response is complex and not easily simulated with simplified models. Material modeling of medical devices is also challenging. Finally, the loads applied to both tissue and devices are often not well understood. Enter SIMULIA, the leading brand in realistic simulation. Our Abaqus Unified FEA product suite contains a wide variety of materials, procedures, and load types to simulate the human/animal body and the manner in which the equipment is used. Abaqus has been used to simulate implanted devices, orthopedics, and mechanics of feet, among other applications. Solution capabilities - Complete large strain capability in all element types - Wide variety of material models suitable for tissue modeling of various kinds - Complex load histories are easily modeled - Easily defined contact modeling with sophisticated interaction models available - Fast, robust solver - Interactive numerical diagnostic tools to assist you on the toughest problems SIMULIA is the Dassault Systèmes brand that delivers a scalable portfolio of Realistic Simulation solutions including the Abaqus product suite for Unified Finite Element Analysis, multiphysics solutions for insight into challenging engineering problems, and SIMULIA SLM for managing simulation data, processes, and intellectual property. http://www.simulia.com/

‘Meet the Expert’ session During social, Friday, from 19h-20h.

The ‘Meet the Expert’ session will be held during the Friday evening social. The aim of this session is to facilitate contacts between master students, PhD students, post-docs and group leaders with different levels of expertise, in order to exchange knowledge and ideas and to set up collaborations. Unlike a poster session where scientific contacts can be scarce and unilateral, we hope that this networking event information General will provide a platform where students (MSc – PhD) can easily approach experts in their field. Apart from the attending group leaders offering the possibility for face to face talks, five other experts from different fields will be present at out ‘meet the expert’ session.

Dimitri Brosens (Belgian Biodiversity Platform, BBPF & Institute for Nature and Forest, INBO) works as data acquisition manager for the Belgian Biodiversity Platform (http://www.biodiversity.be), an initiative by the Belgian Science Policy (Belspo). One of the goals of the Platform is to valorize Belgian Biodiversity research by promoting and enabling the publication of, and access to, biodiversity data on the world wide web, through dedicated web portals. The Platform also inventories biodiversity-related research and resources in Belgium (http://biobel.biodiversity.be) and serves as a science policy interface. Dimitri will present the BBPF as a node for the Global Biodiversity Information Facility and the dedicated Belgian Data Portal.

The expertise of Karel du Gardein (Olympus Belgium NV) ranges from how to set-up Köhler illumination to current advances in microscopy. If you’re thinking “Köhler what?” or you cannot choose between microscope types, please meet with Karel. http://www.olympus.be

GeneralInformation A representative of the Universitair Centrum voor Talenonderwijs (UCT, Ghent University) will present the courses and services the centre is offering. This expert is an expert on proofreading as well. If a referee/editor ever commented your paper stating “check language by native speaker” or if you have no idea how to begin your first paper then this is your chance to learn the tips and tricks on how to build a well-written research paper or proposal. Please bring your own texts as the expert

can give on site advice on small text fragments. http://www.uct.ugent.be

Imaging is pivotal in Biology. Therefore a representative of UGCT (Centre for X-ray Tomography at Ghent University) will be present at the session. UGCT is an open facility. They offer scientists access to nondestructive X-ray imaging and image analysis for visualizing features in the interior of objects in 2D and or 3D. Various modular CT instruments are available which allow for very high quality micro and nano CT scans. By combining different X-ray tubes and different X-ray detectors (e.g. a-Si flat panel, CMOS flat panel, low energy CCD X-ray detector, image intensifier, ...) the scanner configuration can be optimized to the sample or experiment. http://www.ugct.ugent.be

The UGCT centre also successfully founded the spin-off company inCT. inCT provides services in high resolution X-ray tomography with the goal to retrieve structural information on a micrometer scale for tiny objects and to investigate the macro structure of larger objects. http://www.inct.be/en/home

When you finally have good images, you want to analyze them properly (e.g. particle analysis, cell counting, morphometry, colocalization, etc…). Therefore Dr. Winnok De Vos will be present at the session. Winnok (Bio-imaging and Cytometry Unit, Dept. Molecular Biotechnology, Ghent University) will share his expertise on bio-imaging, image analysis and

the imaging Image J software (http://rsbweb.nih.gov/ij/). Share your imaging information General problem with him; he could well come up with a solution.

THE MOST COMPREHENSIVE RESEARCH IN ZOOLOGY

Pick up your free sample copies or visit these and other journals online at wileyonlinelibrary.com/subject/zoology

21331 zoology - JR - benelux conference ad.indd 1 8/19/10 8:53 AM

Benelux Scientific Network on Facebook

The aim of this group is to connect researchers in life sciences from the Benelux (and beyond) to initiate collaborations and to exchange protocols, techniques, expertise, literature, facts, hints,

ideas, etc... information General This group is open to all life science fields in the hope to stimulate exchange and discussions across fields (e.g. micro CT technology, biological samples, (bio)informatics, phylogeny), using current social networking facilities. When joining this group we would like you to post keywords that reflect your interest and expertise. These are the same keywords you would provide when, for example, submitting a paper or giving a short description of your work (e.g. zoology, development, zebrafish, tooth, wnt pathway, stem cell proliferation, immunohistochemistry, histology, etc.). In return we will regularly translate these keywords (‘characters’) into a tree connecting scientists with common interests. Thereby, we hope to make you aware of potential new and/or unexpected collaborations, and stimulate new channels of exchanging ideas before, during and after the congress. http://www.facebook.com – Benelux Scientific Network

Zoology Journals from Taylor & Francis www.informaworld.com/cbps www.informaworld.com/tsab 11181J`Q`I:1Q`CR8HQIL

0Q`1``VV1:HHV331QcV`31:JR1JV131QJ1Q%`1HQI]CV V1 `:J$V1Q`1

BCZ Student Awards 2010

This year a record number of students, both PhD and recently graduated MSc students, compete for the yearly BCZ student awards. A jury consisting of 15 experts will evaluate talks and posters during the two days of the congress, in order to select: - the Best MSc Student Oral Presentation - the Best MSc Student Poster Presentation General information General - the Best PhD Student Oral Presentation - the Best PhD Student Poster Presentation Awards will be announced and given during the closing ceremony on Saturday. Of course the competitors are expected to attend this ceremony, as the awards will be handed over in person.

Jacques Kets Biology Award 2010

In 1953 the “Jacques Kets” Biology Award was handed out for the first time by the Royal Zoological Society of Antwerp. With this award the RZSA wants to stimulate young people their love for nature and to study it. The award is named after Jacques Kets, a naturalist and taxidermist from Antwerp who in 1843 became the director of the RZSA. Starting from 2004 the Walloon partner Parc Pairi Daiza joined forces.

Who could participate? Every Master student who studies biology, molecular biology, biotechnology, biomedical sciences, … and made a thesis during the academic year 2009-2010, with a subject related to nature (animal or plants) or conservation.

How were candidates evaluated? Evaluation of the abstracts was done by a jury of experts and consisted of two rounds. First the six best submitted abstracts (three from Walloon and three from Flemish universities) were selected. The six selected candidates then gave an oral presentation of their work (in English) on Saturday October16th, upon which the jury selected one Walloon and one Flemish finalist, whom were awarded the Kets prize.

Who won? This year the two winners were asked to give a talk on the Benelux Congress in Ghent. So come and see at the BCZ17, Friday at 14h!

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SCIENTIFIC PROGRAMME

Friday October 22nd Morning

Scientific Programme Scientific 08:30 Registration and coffee (Peristilium) 09:15 Welcome and opening (Aud. 3)

Plenary session 1 (Aud. 3) Chair: Dries Bonte 9:30 From individuals to populations and back again: linking life- histories to dynamics

Benton Tim

Session 1 - Physiology and Behaviour (Aud. 3) Chair: Roger Huybrechts 10:20 The orexine receptor pathway in insects Huybrechts R., Vuerinckx K., Tobback J., Verlinden H., Lindemans M.

10:50 Leptin attenuates the stress axis in common carp (Cyprinus carpio) de Gelder S., Gorissen M., Bernier N.J., Manuel R., Metz J.R., Huising M.O., Flik G.

11:10 Coffee (Peristilium)

11:40 Reciprocity in grooming and food sharing among captive bonobos Stevens J.M.G., Jaeggi A.V., Staes N.

12:00 Transcriptome analysis of the sexually dimorphic gland of the African dwarf clawed frog Hymenochirus sp. (Pipidae) Matthijs S., Bossuyt F.

12:20 Polychlorinated biphenyls affect histological appearance of European sea bass (Dicentrarchus labrax) thyroids Schnitzler J.G., Klaren P.H.M., Celis N., Blust R., Covaci A., Dirtu A., Thomé J-P., Das K.

12:40 Acaricidal activity of Santolina africana and Hertia cheirifolia against Tetranychus urticae Attia S., Lebdi Grissa K., Lognay G., Mailleux A.C., Hance T.

13:00 Lunch (ICC) 22

Session 2 - Functional Ecology & Morphology I (Aud. 5) Chair: Peter Aerts 10:20 Classic Biology in Modern Times: linking animal morphology and

morphosis to robotics Aerts P., Berillon G., D’Août K.

10:50 The relation between behaviour and biting performance in a chisel-tooth digger (Fukomys micklemi, Bathyergidae, Rodentia) Desmet N., Van Daele P.A.A.G., Adriaens D.

11:10 Coffee (Peristilium)

11:40 Feeding kinematics and bite forces of a true molluscivorous lizard, Scientificprogramme Dracaena guianensis Schaerlaeken V., Herrel A., Holanova V., Rehak I.

12:00 Evolutionary rates of morphological change for a Holocene morphospace expansion in Bellamya gastropods from Lake Malawi Van Bocxlaer B.

12:20 Sound production in red bellied piranhas (Pygocentrus nattereri): acoustical, behavioural and morphological study Millot S., Vandewalle P., Parmentier E.

12:40 Nature-inspired design: kinematic modelling of the seahorse tail Praet T., Van Cauter S., Adriaens D., Kannan S., Srigiriraju S., Masschaele B., De Beule M., Verhegghe B.

13:00 Lunch (ICC)

MSc award competitor Phd award competitor

Friday October 22nd Afternoon

Scientific Programme Scientific Kets Award Presentations (Aud. 3) Chair: Zjef Pereboom 14:00 See p.19 for details

Session 3 - Behavioural Ecology (Aud. 3) Chair: Samuel Caro 14:50 The influence of male song quality on female brain and behaviour in Lincoln’s sparrows Caro S.P., Sewall K.B., Aldredge R.A., Salvante K.G., Sockman K.W.

15:10 Do great spotted cuckoo (Clamator glandarius) chicks benefit from having extra nest mates? De Neve L., Macías-Sánchez E., Soler M.

15:30 Coffee (Peristilium)

16:00 Woodlice aggregation results from individual preferences and from social interactions Broly P., Devigne C.

16:20 Demographic structure, activity budget and ranging pattern of an unusually large group of agile mangabeys (Cercocebus agilis) at Bai Hokou, Central African Republic Devreese L., Todd A., Stevens J., Huynen M-C.

16:40 Sex-specific effects of nutritional condition on innate immunity in a passerine bird De Coster G., Verhulst S., Koetsier E., Lens L.

17:00 Chemical "versus" visual cues in newts (Salamandridae): experiments in total darkness and in a Y-maze Treer D., Bossuyt F.

17:20 Poster Session + Reception (Peristilium) 19:00 Social + 'Meet the Expert' (Peristilium)

Session 4 - Ontogeny and Regeneration (Aud. 4) Chair: Maxime Willems 14:50 Characterization of the Macrostomum lignano ageing phenotype

Crucke J., Mouton S., Claeys M., Houthoofd W., Willems M.

15:10 Stem cell dynamics during homeostasis and regeneration in Macrostomum lignano (Platyhelminthes) Dhondt I., Verdoodt F., De Vos W., Houthoofd W., Willems M.

15:30 Coffee (Peristilium)

16:00 Characterization of the putative epithelial stem cells involved in continuous tooth replacement in Salmo salar Scientificprogramme Vandenplas S., Willems M., Soenens M., Witten P.E., Hansen T., Fjelldal P.G., Huysseune A.

16:20 Ultrastructure of the gonads in basal Bilateria Boone M., Houthoofd W., Claeys M., Artois T.

16:40 Matrix metalloproteinase-2 and -9 in scleroblasts and osteoclasts of ontogenetic and regenerating zebrafish scales de Vrieze E., Sharif F., Metz J.R., Flik G., Richardson M.K.

17:00 Mechanisms of cartilage subdivision in the pectoral endoskeleton of zebrafish Dewit J., Witten P.E., Huysseune A.

17:20 Poster Session + Reception (Peristilium) 19:00 Social + 'Meet the Expert' (Peristilium)

Session 5 - Evolution (Aud. 5) Chair: Tom Geerinckx 14:50 Evolutionary diversification of a sex pheromone in Salamandridae

Scientific Programme Scientific Janssenswillen S., Bossuyt F.

15:10 Evolutionary origin of structural proteins in anuran toe pads Vandebergh W., Bossuyt F.

15:30 Coffee (Peristilium)

16:00 The success story of invasive androgenetic clams Pigneur L.-M., Marescaux J., Etoundi E., Descy J.-P., Van Doninck K.

16:20 Parallel habitat specialization within the wolf spiders of Galapagos De Busschere C., Hendrickx F., Van Belleghem S.

16:40 To fly or not to fly, that is the selection: Pogonus chalceus (Coleoptera) as a test case for adaptive genetic divergence in the absence of a geographic barrier Van Belleghem S., Hendrickx F.

17:00 DNA repair in putative ancient asexual darwinulids (Ostracoda) Van den broecke L., Schön I., Vanfleteren J., Martens K.

17:20 Poster Session + Reception (Peristilium) 19:00 Social + 'Meet the Expert' (Peristilium)

Saturday October 23rd Morning

Plenary session 2 (Aud. 3) Chair: Jeroen Stevens 09:00 Prosocial primates: the altruism question de Waal Frans

Session 6 - Diversity and Distribution (Aud. 3)

Chair: Jean-Henri Hecq Scientificprogramme 09:50 Problematic of the Pelagia noctiluca outbreaks in the Bay of Calvi (Corsica) Hecq J.-H., Collignon A., Garrido M., Lejeune P., Pasqualini V., Goffart A.

10:20 Monitoring a recovering estuary: the Zeeschelde in Belgium Breine J.

10:40 Trophic structure and diversity of macro-organisms associated with Posidonia oceanica litter in the bay of Calvi Remy F., Borges A.V., Darchambeau F., Dauby P., Gobert S., Lepoint G.

11:00 Bite force in the African Fukomys mole-rats (Bathyergidae, Rodentia) Van Daele P.A.A.G., Bappert M.-T., Desmet N., Burda H., Adriaens D.

11:20 Hybridization in the pipefish genus Syngnathus: implications for paleobiogeography and present genetic structure Hablützel P.I.

11:40 Poster Session + Coffee (Peristilium) 12:30 Lunch (ICC)

Session 7 - Molecular and Cellular Zoology (Aud. 4) Chair: Ellen Decaestecker 09:50 Candidate immune gene expression in the ecological functional

Scientific Programme Scientific genomics model Daphnia Decaestecker E., Labbé P., Ellegaard K., Allen J.E., Little T.J.

10:20 In search of underlying stress mechanisms using RNAi and gene expression profiling Stevens A.-S., Plusquin M., Saeren C., Artois T., Smeets K.

10:40 Does non-random segregation of DNA-strands occur during stem cell division in the flatworm Macrostomum lignano? Verdoodt F., Willems M., Mouton S., Houthoofd W., Ladurner P.

11:00 The cadherin-catenin complex during zebrafish tooth development Verstraeten B., Sanders E., D’Heuvaert T., van Hengel J., Huysseune A.

11:20 The zebrafish scale as model for glucocorticoid-induced osteoporosis: effects of prednisolone on scale regeneration Peters H.M., van Kessel M.A.H.J., de Vrieze E., Metz J.R., Flik G.

11:40 Poster Session + Coffee (Peristilium) 12:30 Lunch (ICC)

Session 8 - Functional Ecology and Morphology II (Aud.5) Chair: Joost Raeymaekers 09:50 Natural vs. anthropogenic impacts on the morphology of the small

ground finch, Geospiza fuliginosa Raeymaekers J.A.M., De León L.F., Podos J., Hendry A.P.

10:20 Kinematic modulation and feedback control of suction feeding in function of escape responses of prey in a piscivorous fish Van Wassenbergh S., De Rechter D., Aerts P.

10:40 Contemporary morphological changes in Lake Victoria cichlids van Rijssel J.C., Witte F. Scientificprogramme 11:00 Do colour traits signal individual quality in the lizard Podarcis siculus? Vroonen J., Fulgione D., Maselli V., Van Damme R.

11:20 Salinity effects on competition between cryptic species of the nematode Rhabditis (Pellioditis) marina De Meester N., Moens T., Derycke S.

11:40 Poster Session + Coffee (Peristilium) 12:30 Lunch (ICC)

Saturday October 23rd Afternoon

Scientific Programme Scientific Plenary session 3 (Aud. 3) Chair: Dominique Adriaens 13:30 The age of aquarius and the revival of morphology as a key discipline in evolutionary biology Herrel Anthony

Session 9 - Spatial Ecology (Aud. 3) Chair: Sofie Vandewoestijne 14:20 Population genetic differences along a latitudinal cline between original and recently colonized habitat in a butterfly Vandewoestijne S., Van Dyck H.

14:40 Do different life-history decisions affect migration in breeding adult herring gulls Larus argentatus and lesser black-backed gulls Larus fuscus? Bosman D., Vercruijsse H.J.P., Stienen E.W.M., Vincx M., Lens L.

15:00 Changing landscapes - consequences for the recruitment of animal-dispersed plants Lehouck V., Spanhove T., Bonte D., Lens L.

15:20 Spatiotemporal variation in the diversity of orb weaving spiders in a fragmented Afrotropical forest Wiersma E., Bonte D., Lens L.

15:40 Genetic signature of population fragmentation varies with mobility in seven bird species of a fragmented Kenyan cloud forest Callens T., Galbusera P., Matthysen E., Durand E., Lens L.

16:00 Coffee (Peristilium) + Jury Deliberations 16:30 Awards and Closing (Aud 3)

Session 10 - Evolutionary Ecology (Aud. 4) Chair: Isa Schön 14:20 Study of the life cycle of two species of forensic interest carrion

beetles (Coleoptera, Silphidae): Thanatophilus sinuatus F. & Necrodes littoralis L. Dekeirsschieter J., Verheggen F., Brostaux Y., Haubruge E.

14:40 Wolbachia-induced sex-ratio distortion in the solitary spider Oedothorax gibbosus and its potential implications on sexual selection Vanthournout B., Hendrickx F.

15:00 Clusters formation in Eisenia fetida (Oligochaeta, Lumbricidae) Scientificprogramme Zirbes L., Deneubourg J.-L., Brostaux Y., Haubruge E.

15:20 Cryptic species in non-marine ostracods Schön I., Pinto R., Birky B., Bode S., Halse S., Butlin R., Martens K.

15:40 A vocal ethogram for Fukomys micklemi (Bathyergidae, Rodentia) Vanden Hole C., Van Daele P.A.A.G., Desmet N., Mertens J., Adriaens D.

16:00 Coffee (Peristilium) + Jury Deliberations 16:30 Awards and Closing (Aud. 3)

Session 11 - Anthropogenic Effects & Human Use (Aud. 5) Chair: Glenn Vermeersch 14:20 The effect of sheep grazing on the breeding success of the

Scientific Programme Scientific woodlark (Lullula arborea) Vermeersch G., Strubbe D., De Bruyn L.

14:40 Nematodes as potential bio-indicator of the composting process Steel H., Moens T., Buchan D., Houthoofd W., de Neve S., Bert W.

15:00 Different levels of anthelmintic resistance in the facultative parasitic nematode Halicephalobus gingivalis Fonderie P., Moens T., Houthoofd W., Bert W.

15:20 Comparative gut morphology of mnn yeast and wild type yeast fed Artemia franciscana nauplii Gunasekara R.A.Y.S.A., Rekecki A., Casteleyn C., Cornelissen M., Bossier P., Van den Broeck W.

15:40 Use of physiologically based pharmacokinetic models in marine mammal toxicology Weijs L., Yang R.S.H., van Elk N., Jauniaux T., Das K., Covaci A., Blust R.

16:00 Coffee (Peristilium) + Jury Deliberations 16:30 Awards and Closing (Aud. 3)

Poster Presentations (Peristilium) Friday October 22nd 17u20-19u00 rd

Saturday October 23 11u40-12u30

P.1 Biodiversity informatics give wings to your research Brosens D., Gonzalez B.

P.2 DNA barcoding as identification tool in fruitfly interception and surveying activities Jordaens K., Breman F., De Meyer M., Virgilio M.

Scientificprogramme P.3 Changes in surface waters: a malacological analysis of a Late Glacial and early Holocene palaeolake in the Moervaartdepression (Belgium) Serbruyns L., Van Damme D., Antrop M., Bats M., Bourgeois J., Court- Picon M., Crombé P., De Maeyer P., De Reu J., De Smedt P., Finke P., Van Meirvenne M., Werbrouck I., Zwertvaegher A., Verniers J.

P.4 Towards a revision of Western Australian Bennelongia (Crustacea, Ostracoda, Cyprididae) Martens K., Halse S., Schön I.

P.5 Soil mite diversity from Ivory Coast N’Dri J.K., André H.M., Hance T.

P.6 Discovering marine biodiversity through integrative taxonomy, 2 case studies: the Triphoridae, a family of micromolluscs and the Mediterranean sponge genus Hexadella Vanmaele S., Allewaert C.

P.7 Molar shape differentiation between subspecies of the edible dormouse Glis glis in the North of Anatolia and Turkish Thrace (Mammalia: Rodentia) Helvacı Z., Renaud S., Ledevin R., Adriaens D., Çolak R., Kankiliç T., Kandemir I., Çolak E.

P.8 Bioindications of night moths for maintaining biodiversity in vineyards Šafář J.

P.9 Collembola assemblages under the invasive Senecio inaequidens and the native S. jacobaea De Bruyn L., Janssens F., Vanparys V.

Scientific Programme Scientific P.10 EAG Response of Helicoverpa armigera Hubn and its predator Chrysoperla carnea Steph. to volatiles of different varieties of cotton and sunflower Pandey A.

P.11 Corbicula invasion in European rivers: three mitochondrial lineages and an unique mode of reproduction Etoundi E., Marescaux J., Pigneur L.-M., Van Doninck K.

P.12 Histology and ultrastructure of the midgut of germ-free Artemia franciscana nauplii Gunasekara R.A.Y.S.A., Rekecki A., Casteleyn C., Cornelissen M., Bossier P., Van den Broeck W.

P.13 GFP-labelled Listonella anguillarum HI610 visualized within the gut of gnotobiotic sea bass larva Rekecki A., Gunasekara R.A.Y.S.A., Dierckens K., Boon N., Favoreel H., Cornelissen M., Bossier P., Van den Broeck W.

P.14 Shading and alterations of the sediment: in situ experiments to mimic impacts of fish farms on a Mediterranean coastal ecosystem Pête D., Velimirov B., Lepoint G., Gobert S.

P.15 Daphnia-symbiont community structure under different productivity regimes Lange B., Muylaert K., Decaestecker E.

P.16 The development of transgenic Daphnia in the Daphnia- Pasteuria interaction Decaestecker E., Vanoverberghe I.

P.17 Genotype-genotype interactions between the cyanobacterium Microcystis and its grazer, the waterflea Daphnia Brusciotti S., Lemaire V., van Gremberghe I., Vanoverbeke J., De Meester L.

P.18 Top-down role of fish predators in structuring amphipod community associated to Posidonia oceanica seagrass meadows Sturaro N., Lepoint G., Panzalis P., Navone A., Gobert S.

P.19 Impact of grazing by amphipods on the epiphytic cover of the Posidonia oceanica leaves: an in situ experiment Loïc M., Dupont A., Gobert S., Dauby P., Lepoint G.

P.20 The role of meiofauna in energy transfer in a Mediterranean seagrass bed (Calvi, Corsica) Mascart T., Lepoint G., Borges A.V., Darchambeau F., Dauby P., De Troch M. Scientificprogramme P.21 Spatial variability of the Siphonophorae along the radial Calvi- Nice (Corsican side) Collignon A., Hecq J.-H., Goffart A.

P.22 Selection of Perciforms: functional genomic potential of natural and cultured populations Daneels D., Raeymaekers J.,Volckaert F.A.M.

P.23 Basin-linked population genetic structure of turbot Vandamme S.G., Maes G.E., Moreau K., Robbens J., Volckaert, F.A.M.

P.24 Habitat change in a network of ponds in an endangered newt species, Triturus cristatus Timmermann M., Hanoy M., Denoël, M.

P.25 The effects of land use on soil food webs and ecosystem functioning Middelveld R., Hemerik L., Mulder C., de Ruiter P.C.

P.26 Experimental study of metapopulation dynamics and viability in Tetrahymena thermophila microcosms Pennekamp F., Schtickzelle N.

P.27 Gradual adaptation toward a range-expansion phenotype initiated the global radiation of toads Van Bocxlaer I., Loader S.P., Roelants K., Biju S.D., Menegon M., Bossuyt F.

P.28 Impacts of an invasive species: Corbicula spp. in the River Meuse Falisse E., Pigneur L.-M., Leporcq B., Viroux L., Van Doninck K., Descy J.-P.

Scientific Programme Scientific P.29 Increased mitosis in the bleached gastrodermis of the sea anemone Aiptasia pallida Fransolet D., Roberty S., Plumier J.-C.

P.30 Photoacclimation responses of a symbiotic sea anemone reveal an important host cellular plasticity Roberty S., Fransolet D., Ladrière O., Poulicek M., Plumier J.-C., Franck F.

P.31 Sound production and sexual dimorphism in sonic apparatus of Ophidion rochei (Teleostei) Kéver L., Parmentier E.

P.32 Developing an acoustic map of the north coast of Moorea, French Polynesia: a roadmap for settling larvae Berten L., Lecchini D., Simpson S.D., Parmentier E.

P.33 Essential and non-essential elements in the eggs of sea turtles from Lesser Antilles Leroy C., Dyc C., Bouquegneau J.-M., Das K.

P.34 Genetic and morphological differentiation of the crab Dissodactylus primitivus, ectoparasite of two sympatric echinoids Jossart Q., De Ridder C., De Bruyn C.

P.35 A study of the underlying pathways of exposure to cadmium and hexavalent chromium on the cell proliferation in Schmidtea mediterranea Van Roten A.

P.36 The acute toxicity of ZnO and SiO2 nanoparticles to aquatic organisms Adam N., Knapen D., Blust R.

P.37 Short-term effects of an organochloride pesticide (endosulfan) on amphibian tadpoles D’hooghe B., Brasseur C., Kestemont P., Denoël M.

P.38 Toxicity of Endosulfan on the tadpole stage of an amphibian (Rana temporaria): a video-tracking analysis Lavorato M., Libon S., De Pauw E., Kestemont P., Denoël M.

P.39 Impact of pit-tagging on behaviour, growth and survival in Alpine newts, Mesotriton alpestris Winandy L., Denoël M.

P.40 Entamoeba spp. infections in wild Barbary macaques (Macaca sylvanus), Morocco. Scientificprogramme Verschave S., Stevens J., Majolo B., Dorny P., Vercammen F., Vercruysse J., Levecke B.

P.41 Foraging bats in a dynamically changing harbour area: can creation of new artificial lakes be a mitigation measure? Gyselings R., Spanoghe G., Van den Bergh E.

P.42 The impact of social hierarchy on the parasitic burden in Soay sheep in Belgium Brakel I., Levecke B., Stevens J.

P.43 Behavioural analysis of leaders during group recruitment in the ant Tetramorium caespitum Collignon B., Cervantes L., Detrain C.

P.44 Movements, habitat choice and breeding success of the marsh harrier, Circus aeruginosus in fragmented landscapes Anselin A., De Bruyn L.

P.45 The effect of zoo visitor numbers on the behaviour of Congo peafowl (Afropavo congensis) at Antwerp Zoo Dams J.R.M., Galbusera P., Stevens J.G.M.

P.46 Cranial variation in the Persian jird (Meriones persicus, Rodentia, Gerbillinae): shape changes across geoclimatical ranges Tabatabaei Yazdi F., Adriaens D., Darvish J.

P.48 Hydrodynamics of prey capture in the semi-aquatic snakes: a broad taxonomical study Brecko J., Van Wassenbergh S., Herrel A., Aerts P., Van Damme R.

Scientific Programme Scientific P.49 Head Morphology of the pelican eel, Eurypharynx pelecanoides (Saccopharyngoidei: Eurypharyngidae) Eagderi S., Dierick M., Van Hoorebeke L., Adriaens D.

P.50 An increased mechanical loading accelerates growth and osteogenesis in zebrafish (Danio rerio) Fiaz A.W., Schulte-Merker S., van Leeuwen J.L., Kranenbarg S.

P.51 Expression of matrix metalloproteinase 9 in regenerating and ontogenetic scales of adult zebrafish Sharif F., de Vrieze E., Metz J., Flick G., Richardson M.K.

P.52 A study of the genomic integrity and the gene expression pattern of an asexual bdelloid rotifer species submitted to desiccation Hespeels B., Li X., Van Doninck K.

P.53 Identification of novel isoforms of PVF-1 and icarapin in honeybee venom glands using an RT-PCR-based approach Van Vaerenbergh M.C., Devreese B., de Graaf D.C.

P.54 Twenty-three unique venom proteins of Nasonia vitripennis recombinant expressed for functional analysis Formesyn E., Danneels E., Jacobs F., de Graaf D.

P.55 Evaluation of host immune responses to envenomation by the ectoparasitic wasp Nasonia vitripennis with antibacterial assays Danneels E.L., Formesyn E., Jacobs F. J., de Graaf D.C.

PLENARY ABSTRACTS

From individuals to populations and back again: linking life- histories to dynamics

Tim Benton

Institute of Integrative and Comparative Biology, University of Leeds, Leeds, UK

Plenary Abstracts Plenary Population dynamics arises from changes in individuals' life-histories summed across the population, and individuals' life-histories, in turn, depend on the environment in which the organism lives. There is therefore a feedback loop: what an individual does affects population size and population size affects what an individual does. Following years of playing with a simple laboratory system - a soil mite - I'll discuss the way that individuals' life-histories respond to the environment by changing allocation patterns (affecting growth, maturity, egg size and egg number), and how these can lead to complex dynamical signals such that changes in the environment can lead to effects that last several generations. The complexity in the way that environmental change affects dynamics means that predicting how a population will respond is tricky. Changes in the environment also can lead to selection on life-histories, and these will lead to evolved changes in population dynamics; I'll present some recent empirical results showing this. In summary, our experience with this simple system suggests that understanding dynamics requires understanding what individuals do, and that population dynamics cannot be divorced from evolutionary dynamics. These insights have clear implications for conservation.

E-mail: [email protected]

Prosocial primates: the altruism question

Frans de Waal

Living Links Center, part of the Yerkes National Primate Research Center, EMORY University, Atlanta, USA

Evolutionary theory postulates that altruistic behaviour evolved for the return- benefits it bears the performer. For return-benefits to play a motivational role, however, they need to be experienced by the organism. Motivational analyses should restrict themselves, therefore, to the altruistic impulse and its knowable consequences. Empathy is an ideal candidate mechanism to underlie so-called “directed altruism,” i.e. altruism in response to another’s pain, need, or distress. The possibility that animals have empathy and sympathy has received little systematic attention, however, due to an excessive fear of anthropomorphism and a taboo on animal emotions. Actual animal behaviour, however, would lead one to agree with Charles Darwin that "Many animals certainly sympathize with each other's distress or danger." In my own work Plenary Abstracts with monkeys and apes, I have found many cases of one individual coming to another's rescue in a fight, putting an arm around a previous victim of attack, or other emotional responses to the distress of others. Empathy has many levels, from basic perception-action mechanisms (probably related to mirror neurons) to ever greater cognitive elaborations that include perspective-taking. The basic forms probably exist in all mammals as they serve important survival functions for animals with vulnerable young. The higher forms of empathy require a sharp self-other distinction found only in humans over the age of two, and a few other large-brained species: apes, dolphins, and elephants. Perception of the emotional state of another automatically activates shared representations causing a matching emotional state in the observer. With increasing cognition, state-matching evolved into more complex forms, including concern for the other and perspective-taking. Empathy-induced altruism derives its strength from the emotional stake it offers the self in the other’s welfare. The dynamics of the empathy mechanism agree with predictions from kin selection and reciprocal altruism theory.

E-mail: [email protected]

The age of aquarius and the revival of morphology as a key discipline in evolutionary biology

Anthony Herrel

Département d'Ecologie et de Gestion de la Biodiversité, C.N.R.S/M.N.H.N, Paris, France

The realization that evolutionary processes can only be understood in the light of selection on the phenotype of an organism in its ecological context has put Plenary Abstracts Plenary morphology on the forefront of modern day integrative biology. Advances in current day morphology are characterized by spectacular advances in imaging and measurement technology allowing a better, more rapid, and more comprehensive quantification of an organism’s phenotype and its function. Consequently, the rapid 3-D quantification of external and internal structures using modern imaging techniques and associated mechanical and morphometric analyses now take up a central place in morphology. In conjunction with developmental approaches and analyses of the underlying genetic and genomic basis of phenotypic variation, these approaches have the power to dramatically change our insights into the processes underlying evolutionary change, and our understanding of the mechanisms allowing organisms to adapt to the dramatic and rapid human-induced changes in the environment. I will illustrate the central role of morphology as a key discipline in integrative biology using examples involving the beak of finches and the locomotor system in frogs as examples.

E-mail: [email protected]

LECTURE ABSTRACTS

Session 2.1 Classic Biology in Modern Times: linking animal morphology and morphosis to robotics

Aerts P.1, Berillon G.2, D’Août K.1

1 University of Antwerp, Belgium 2 CNRS, Dynamique de l’Évolution Humaine, 75014 Paris, France

Altering morphology (i.e. morphing) according the specific and instantaneous needs imposed by the environment is a point of interest in current robotics. This is for instance illustrated in the ongoing EU-project (7th FWP) entitled: Lecture Abstracts Lecture “LOCOMORPH: Robust robot locomotion and movements through morphology and morphosis”. In this project, roboticists, biologists and biomechanicists join efforts in order to transfer insights gained from zoology into robot design and control. Morphing in response to environmental and behavioral challenges occurs on different time scales in nature. Evolutionary and ontogenetic morphing represent long scale changes. Hence, functional and ecological morphological analyses can be inspiring and helpful when tuning robot ‘morphology’ to specific needs and circumstances. Adjusting posture or segmental configuration in response to specific tasks (like e.g. object manipulation) or events (like e.g. losing a limb) represents ‘morphing’ on a nearly instantaneous time scale. Animals do so seemingly effortlessly, and insights in the neuromechanics involved can provide information useful to optimize robot control. From this point of view we study the mechanics of baboons making instantaneous transitions from quadrupedal to bipedal locomotion – i.e. ‘loco-morphing’. Based on the angular momentum-impulse relationship, it can be argued that the overall ground reaction force vector must generate an upwards moment about the body centre of mass to induce such transition. This can theoretically be achieved in three (not mutually exclusive) ways: a forelimb upward impulse, a sudden forward acceleration exceeding the boundary conditions and a repositioning of the hind limbs. Baboons, specialist quadrupeds, seem not to exploit the potential of the sudden forward acceleration to achieve an upright position. Neither do they apply a pronounced forelimb push-up. The transition is induced by a repositioning of the centre of pressure of the hind limbs with respect to the body centre of mass in a few successive steps. Surprisingly, this strategy seems also to be used by species with the position of the centre of mass of the trunk- head-segment differing from that of the baboons [i.e. by a specialist biped (human) and a quadrupedal generalist (bonobo)].

E-mail: [email protected]

Session 1.6 Acaricidal activity of Santolina africana and Hertia cheirifolia against Tetranychus urticae

Attia S.1, Lebdi Grissa K.2, Lognay G.3, Mailleux A.C.1, Hance T.1

1 Earth and Life Institute, Biodiversity Research Centre, Université Catholique de Louvain, 4-5, Place croix de sud, B- 1348 Louvain-la-Neuve, Belgium. 2 Laboratoire d’Entomologie-acarologie. Institut National Agronomique de Tunisie, 1082 Cité Mahrajène, Tunis, Tunisia. 3 Université de Liège Gembloux Agro-Bio Tech Unité de Chimie analytique. Passage de Déportés,

2. B-5030 Gembloux, Belgique.

The aim of this study was to explore the acaricidal activity of two plants endemic to North Africa, Santolina africana and Hertia cheirifolia (Asteraceae), against a major pest of many cultivated plants Tetranychus urticae. The essential oils of these plants were obtained by hydrodistillation. GC and GC–MS analyses revealed the presence of 11 and 6 components accounting, respectively, for 73.79% and 46.67% of S. africana and H. cheirifolia, the most

abundant compounds were alpha terpineol (11.31%) for S. africana and Lecture Abstracts Camphor (15.11%) for H. cheirifolia. A series of laboratory experiments was conducted to determine the efficiency of these essential oils on females and eggs of Tetranychus urticae. Twelve concentrations of essential oil were applied (from 0.07 to 6.75 mg l-1). A Potter spray tower was used to determine the susceptibility of adult female to suffocation by the oils. H. cheirifolia and S. africana essential oils exhibited potent activity against T. urticae with LC50 and LC90 values of 3.43 mg l-1 and 5.07 mg l-1 for H. cheirifolia and 2.35 mg l-1 and 3.79 mg l-1 for S. africana, respectively. A reduction of fecundity was already observed for concentrations of 0.07, 0.09 and 0.29 mg l-1 ( 26, 23 and 25 eggs for S. africana and 38, 12 and 10 eggs for H. cheirifolia at 0.07, 0.09 and 0.29 mg l-1 , respectively, compared with 50 eggs for the control solution) while at the same concentrations few mortality was observed.

Keywords: Essential oils, Tetranychus urticae, toxicity E-mail: [email protected]

Session 4.4 Ultrastructure of the gonads in basal Bilateria

Boone M.1,2, Houthoofd W.1, Claeys M.1, Artois T.2

1 Ghent University, Ghent 2 Hasselt University, Diepenbeek

Acoela and Nemertodermatida are two taxa that are of great interest, because of their debated basal phylogenetic position. This has raised growing interest in the study of these groups, on both the molecular and the morphological level, but there is still much unknown about these animals. In order to increase the

Lecture Abstracts Lecture morphological knowledge on these challenging groups, we study the male germ line at the ultrastructural level in different species of Acoela and Nemertodermatida (Isodiametra pulchra, Nemertoderma westbladi, Flagellophora apelti,…), because it is known that the characteristics (paired or unpaired, follicular or non-follicular, compact or diffuse) and organization of the testes can vary within and between these taxa. Light and transmission electron microscopy were used to define the different stages of spermatogenesis in each species and to infer their spatial arrangement within

the testes. We present the results here, and make a comparison of the ultrastructure of the testes in different species. Acknowledgements: This research is funded by an aspirant grant from the Research Foundation Flanders (FWO) to MB.

Keywords: morphology, germ line, basal Bilateria E-mail: [email protected]

Session 9.5 Do different life-history decisions affect migration in breeding adult Herring Gulls Larus argentatus and Lesser Black-backed Gulls Larus fuscus?

Bosman D.1,4, Vercruijsse H.J.P.2, Stienen E.W.M.1, Vincx M.3, Lens L.4

1 Research Institute for Nature and Forest (INBO), Kliniekstraat 25, 1070 Brussels, Belgium; 2 Girostraat 38, 5038 DN Tilburg, The Netherlands; 3 Marine Biology Section, Department of Biology, Ghent University, Krijgslaan 281, Campus Sterre-S8, 9000 Ghent, Belgium Belgium; 4 Terrestrial Ecology Unit, Department of Biology, Ghent University, K. L. Ledeganckstraat 35, 9000 Ghent

Migration is associated with considerable life-history variation. The way various organisms incorporate this behavior into their annual schedule in relation to other costly activities is bound to differ among species, but also between populations and individuals. In the latter situation, gender is a clear-cut determinant of individual life-histories and sex differential migration may be a general ecological trait of many migratory species. The study of sexual Lecture Abstracts segregation can help us understand how life-history traits have helped to mold migratory behavior. Especially, comparison of such intraspecific migration patterns between closely-related species might provide insight into the nature of the trade-offs related to migratory decisions. Within the framework of the major univariate hypotheses, we examined sex-specific patterns in timing, extent and direction of movements in breeding populations of Herring Gull Larus argentatus and Lesser Black-backed Gull Larus fuscus. We identified similar patterns of sexual segregation in both species, but the underlying causes and mechanisms seem to be related to different sex-dependent trade- offs between reproduction and survival. In L. argentatus, the outcome of individual migrations is dispersal of the breeding population along a size gradient. Sexual segregation can then be best explained by decreased localized competition for limited resources between differently-sized individuals through the mechanism of social dominance. In L. fuscus, sex differential migration seems to be largely affected by factors related to reproduction and results in autumn protandry by means of differential behavior between the sexes during migration.

Keywords: sexual segregation, life-history, trade-offs E-mail: [email protected]

Session 6.2 Monitoring a recovering estuary: the Zeeschelde in Belgium

Breine J.

Research Institute for Nature and Forest, Groenendaal

The Belgian part of the tidal Schelde is called the Zeeschelde. Together with its tributaries under tidal influence it has a total surface area of almost 53 km² with 890 ha of tidal marshes and 950 ha of tidal mudflats. Although its ecological values are potentially very high, the Zeeschelde is heavily impacted anthropogenically. Historically tidal marshes were reclaimed for agriculture and

Lecture Abstracts Lecture agglomerations and industries developed close to the riverbank. Tidal wetlands also disappeared due to the large dikes of the SIGMA flood control plan. The navigation requisites for the Zeeschelde, and especially for the port of Antwerp, call for extended maintenance dredging. Estuarine dynamics increased under the combination of reduced space for the estuary, channel deepening and widening, and the general sea level rise. As a result also indirect habitat loss through erosion was observed in the past decade. Until 2007 the untreated sewage from Brussels reached the Zeeschelde through the rivers

Zenne and Rupel. Since a new sewage treatment plant in Brussels is functioning spectacular changes are being observed in the estuarine fish assemblages. The Flemish Research Institute for Nature and Forest assesses different aspects of fish in the Zeeschelde. Different fishing gears are applied depending on the monitoring program. Results from long time surveys are presented.

Keywords: fish diversity Zeeschelde E-mail: [email protected]

Session 3.3 Woodlice aggregation results from individual preferences and from social interactions

Broly P. 1,2, Devigne C. 1,2

1 Univ. Lille Nord de France, F-59000 Lille, France 2 UCLille, FLST, Labo. Environnement & Santé, F-59046 Lille, France

Woodlice are intensively studied to understand the adaptation to land-life of crustaceans. It is well known that aggregation participates to this adaptation by reducing the water loss. However, even if the benefits of such behavior have long been known, little evidence reveal its dynamics. In this study, the aggregation of 40 Porcellio scaber was followed. First of all, experiments were carried out in homogeneous environment. Secondly, experiments were carried out in heterogeneous environment where woodlice could choose between two shelters with different brightness. Our results describe for the first time the dynamics of aggregation: whatever the experimental condition, most of woodlice were aggregated in 5 minutes possibly in several aggregates. Subsequently, during the experiments, the proportion of aggregated woodlice remained high but was relocating in only one big aggregate. Main differences Lecture Abstracts were observed in high brightness were aggregates seemed less stable. Our results also show the implication of a strong social component in this aggregation process. Indeed, 88% of experiments carried out in heterogeneous environment showed the selection of only one of both shelters. This kind of results can only be explained by the social interaction between congeners. Finally, aggregation in woodlice results from a trade-off between individual preferences of woodlice (that means to be in obscurity) and strong inter- attraction in this species (that induces to be near congeners). We discuss about the implication of such inter-attraction in the behavioral ecology of woodlice since, it can induce group of woodlice in non optimal decision by selecting unfavorable bright places.

Keywords: woodlice, aggregation, social interaction E-mail: [email protected]

Session 9.2 Genetic signature of population fragmentation varies with mobility in seven bird species of a fragmented Kenyan cloud forest.

Callens T.1, Galbusera P.2, Matthysen E.3, Durand E.4, Lens L.1

1 Terrestrial Ecology Unit, Dept. of Biology, Ghent University, Belgium 2 Royal Zoological Society Antwerp, Centre for Research and Conservation, Belgium 3 Evolutionary Ecology Group, Dept. of Biology, University of Antwerp, Belgium 4 Department of Integrative Biology, University of California, Berkeley, California, USA Lecture Abstracts Lecture Habitat loss and fragmentation are considered to be key drivers of biodiversity loss, especially in tropical rainforests. Habitat fragmentation can affect genetic population structure by restricting geneflow, reducing effective population size, and increasing genetic drift. Here we apply a Bayesian clustering algorithm to study the genetic population signature of past habitat fragmentation in seven sympatric, forest-dependent bird species of a Kenyan cloud forest archipelago, and compare their levels of historic (genetic differentiation) and

current (mark-recapture) mobility. Species significantly varied in current genetic population structure - with more mobile species showing lower genetic differentiation and least mobile ones showing strongest evidence of mutation- drift and migration-drift disequilibria - and in presumed loss of mobility over time. Taking into account potential pitfalls when linking historical and current levels of mobility, results of this study indicate that historic loss of mobility, rather than current mobility per se, may be the strongest predictor of population viability. If confirmed by future studies, this may explain why poor dispersers continue to persist in fragmented landscapes, while more mobile species may be in higher need of conservation than presently assumed.

Keywords: Dispersal, genetic equilibria, genetic differentiation E-mail: [email protected]

Session 3.1 The influence of male song quality on female brain and behaviour in Lincoln’s sparrows

Caro S.P.1,2, Sewall K.B.1, Aldredge R.A.1, Salvante K.G.1, Sockman K.W.1

1 University of North Carolina, Chapel Hill, USA 2 Netherlands Institute of Ecology, Heteren, The Netherlands

During mate choice, female songbirds often assess the quality of available males based, in part, on the quality of their song. In Lincoln’s sparrows (Melospiza lincolnii), several components of the population’s mean song quality, including song length, song complexity, and trill performance, vary annually. This suggests that the average attractiveness of males and the choosiness of females can fluctuate. Using female Lincoln's sparrows, we studied how variation in male song quality and females’ recent song experience simultaneously affect their behaviour and forebrain responses in terms of immediate early gene expression and secretion of monoamines, which in some species modulate behaviour based on experience. We found a higher level of behavioural activity in females exposed to high quality songs than in those exposed to low quality songs. This was especially true for females that had first Lecture Abstracts been exposed to low quality songs, suggesting a role for recent song experience in the modulation of behavioural responses to song. We also found that females moved more toward songs with experimentally elevated trill performance than toward songs with experimentally reduced trill performance, suggesting that trill performance per se is an important component of male song quality. Finally, we found that the females’ recent experience with song modulates how their brains respond to song quality. We propose that complex behaviors such as mate-choice can be influenced by recent experience with ecologically dependent social cues. Understanding how these decisions are orchestrated at the physiological level is an important challenge for understanding the evolution of mate-choice.

Keywords: mate-choice, bird song, sexual selection E-mail: [email protected]

Session 4.1 Characterization of the Macrostomum lignano ageing phenotype

Crucke J., Mouton S., Claeys M., Houthoofd W., Willems M.

Ghent University, K.L. Ledeganckstraat 35, B-9000 Ghent, Belgium

Ageing is hypothesized to occur through a failure to maintain and renew tissues with advancing age. In the flatworm Macrostomum lignano morphological data exists to support this hypothesis. As these animals grow older their body color changes into an opaque grey and they start to develop distinct body deformities, such as liquid-filled cysts. This study aimed at characterizing these

Lecture Abstracts Lecture cysts in more detail by giving an overview of the diversity, and by describing what type of structure it is. We have found that these malformations can be seen anywhere in the adult body ranging in size from small to large. They consist of a hollow liquid-filled cavity encircled by a single layer of epidermal cells. Furthermore, we wanted to assess what causes these cysts to form. We have shown a lowered functionality of the stem cells in older animals when compared to young individuals. Moreover, we have also demonstrated that it is possible to induce the formation of cysts in young individuals by making a local

wound. Finally, we argue that the cysts in M. lignano probably arise because of wounding to the epidermis, and the subsequent reduced stem cell capacity of older animals to adequately repair this. These findings can aid in establishing this flatworm as a new model organism for studying the reciprocal interaction between stem cells, tissue renewal and the ageing process.

Keywords: flatworms, ageing, tissue homeostasis E-mail: [email protected]

Session 5.4 Parallel habitat specialization within the wolf spiders of Galapagos

De Busschere C. 1, Hendrickx F. 2, Van Belleghem S. 1

1 University Ghent, Ghent 2 Royal Belgian institute of Natural Sciences, Brussels

Within most island archipelagos, such as Galápagos, similar ecological gradients are found on geographically isolated islands. Species radiations in response to these ecological gradients may follow different scenarios being (i) a single habitat specialization event followed by secondary colonization of each ecotype on the different islands or (ii) repeated and parallel habitat specialization on each island separately. At least for Galapagos, this latter scenario has been considered less likely as gene flow might hamper such ecotypic differentiation. Within the wolf spider genus Hogna on Galápagos, seven species are described that can be divided into three different ecotypes based on general morphology and habitat preference i.e. species that inhabit the pampa vegetation in the highlands, species that occur in coastal dry habitats and one generalist species. Previous comparison of the species Lecture Abstracts phylogeny based on allozymes and one mitochondrial (COI) and one nuclear (28S) gene fragment convincingly demonstrated that ‘high’ and ‘low’ elevation species evolved in parallel on the islands Santa Cruz and San Cristóbal. Therefore the genus Hogna provides an interesting example of within island habitat specialization on Galápagos. Here, we present an overview of the ongoing research which aims at further describing each ecotype and contrasting the divergence in ecological and sexual traits.

Keywords: ecological divergence, radiation, parallel habitat specialization E-mail: [email protected]

Session 3.5 Sex-specific effects of nutritional condition on innate immunity in a passerine bird

De Coster G.1, Verhulst S.2, Koetsier E.2, Lens L.1

1 Ghent University, Ghent 2 University of Groningen, Haren

Unfavourable environmental circumstances can have immediate negative effects on the condition of organisms. Furthermore, they can also affect performance in the long run, especially when experienced during development. Lecture Abstracts Lecture While there is evidence for sex-specific effects of former and current nutritional condition on fitness and survival of zebra finches (Taeniopygia guttata), it is unknown whether such sex-specific differences can be extended to immune responses. We studied the combined effects of nutritional condition during development and adulthood on the innate immune response of male and female zebra finches. To that purpose, a brood size manipulation during early life and a foraging costs manipulation during adulthood were performed. Results of our experiment will be presented and discussed within an evolutionary-ecological framework.

Keywords: immunocompetence, zebra finch E-mail: [email protected]

Session 1.2 Leptin attenuates the stress axis in common carp (Cyprinus carpio)

de Gelder S.1, Gorissen M.1, Bernier N.J.2, Manuel R.1, Metz J.R.1, Huising M.O.3, Flik G.1

1 Department of Animal Physiology, Radboud University Nijmegen, Toernooiveld 1, 6525 ED Nijmegen, the Netherlands; 2 Department of Integrative Biology, University of Guelph, 50 stone Road East, Guelph, Ontario, Canada N1G 2W1;

3 The Clayton Foundation Laboratories for Peptide Biology, Peptide Biology Laboratories, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, California 92037, USA

Nowadays, obesity is an epidemic in the Western world and an increasing problem, also in developing countries. Leptin, a hormone considered key in the regulation of food intake and energy homeostasis, is primarily produced by adipocytes, and circulates in the blood stream, in proportion to the amount of body fat. In the brain, leptin signals to terminate food intake and increase Lecture Abstracts metabolism. Besides these well-established roles, it has been suggested that leptin regulates the stress axis. The stress axis is evolutionarily well conserved and present in teleostean fish. In response to a stressor, hypothalamic corticotropin-releasing factor (CRF) stimulates the pituitary gland to secrete adrenocorticotropic hormone (ACTH), the principal stimulator of cortisol release from interrenal cells (the teleostean equivalent of the adrenal gland). Leptin receptor is expressed in key organs of the stress axis, i.e. the pituitary gland and the head kidney, which adds fuel to the hypothesis that leptin signalling and the stress axis are highly integrated. In this study we provide a broader evolutionary perspective on leptin physiology. Recombinant human leptin suppresses the stress axis of the teleost fish common carp (Cyprinus carpio) at multiple levels. Pituitary glands exposed to leptin ex vivo, show a dose-dependently decreased ACTH secretion. Besides, leptin reduces basal, but not ACTH induced cortisol secretion from head kidney tissue. Incubation of liver tissue with increasing doses of dexamethason results in a dose-dependent decrease of leptin mRNA levels.

Keywords: leptin, stress axis, energy homeostasis E-mail: [email protected]

Session 8.5 Salinity effects on competition between cryptic species of the nematode Rhabditis (Pellioditis) marina

De Meester N., Moens T., Derycke S.

Marine Biology, Department of Biology, Ghent University, Krijgslaan 281/S8, 9000 Ghent, Belgium

Behind the morphological similarity of many species, a substantial hidden genetic diversity can be found. This cryptic diversity has been well documented in the marine nematode Rhabditis (Pellioditis) marina, where several cryptic Lecture Abstracts Lecture species occur sympatrically. Despite the growing knowledge about its cryptic diversity, little is known about potential differences in the ecology and functional roles of the different species. In this experiment, we investigated differences in salinity preferences of different cryptic species and how these differences may affect the outcome of their competitive interactions. The juvenile and adult population dynamics of mono-specific cultures of four cryptic species of Rhabditis (Pellioditis) marina were examined under standardised conditions at two different salinity concentrations to investigate the effect of salinity on the life history traits. In addition, these four cryptic species were reared together, starting from identical initial abundances at two different salinity concentrations to investigate the effect of salinity on competition. Every fifth day of the experiment one third of the adult population was removed for analyzing the genetic composition of the population; adult and juvenile population dynamics were also examined. The first results show (1) an effect of salinity on the life history of one cryptic species, (2) an effect of competition on the life history of all cryptic species but one and (3) an effect of salinity on the competition with higher competition at lower salinity. These results show that salinity has a potential effect on the coexistence of cryptic species of Rhabditis (Pellioditis) marina.

Keywords: cryptic diversity, competition, life history E-mail: [email protected]

Session 3.2 Do great spotted cuckoo (Clamator glandarius) chicks benefit from having extra nest mates?

De Neve L.1, Macías-Sánchez E.2, Soler M.2

1 Terrestrial Ecology Unit, Dep. Biology, KL Ledeganckstraat 35, B-9000 Gent, Belgium; 2 Dep. Biología Animal, Facultad de Ciencias, Universidad de Granada, ES-18071 Granada, Spain

The great spotted cuckoo is a brood parasite where the chicks haven’t developed egg/chick rejection behaviour. Therefore, cuckoo chicks sometimes share the nest with host chicks or with other cuckoo chicks. One of the hypotheses proposed to explain this behaviour is that cuckoo chicks would be better off sharing the nest than being alone in the nest. Extra nestlings in the nest would contribute to increasing begging levels so that parents bring more food. If the parasitic chick is a better competitor, it would obtain more feedings than when it was alone in the nest. We tested this hypothesis by experimentally manipulating magpie Pica pica, the main host of great spotted cuckoos, nest composition. We created five different nest-types (1 cuckoo, 1 magpie, 3 cuckoos, 3 magpies, 1 cuckoo+2 magpies). When chicks were 10 days Lecture Abstracts old, we installed a micro-camera to register parent feeding and chick begging behaviour (N=30 nests). Nest begging level was indeed higher in nests with 3 chicks. However, nest visiting rate did not change with respect to nest composition and chicks that were alone in the nest received a higher feeding rate. In mixed nests, both species received a similar feeding rate. We conclude that cuckoos, in terms of feeding rate, do not seem to benefit from extra nest mates and are better off when alone in the nest. We suggest that the reasons for nest tolerance by great spotted cuckoos should be searched in other behavioural strategies.

Keywords: brood parasitism, begging, brood manipulation E-mail: [email protected]

Session 4.5 Matrix metalloproteinase-2 and -9 in scleroblasts and osteoclasts of ontogenetic and regenerating zebrafish scales

de Vrieze E.1, Sharif F.2, Metz J.R.1, Flik G.1, Richardson M.K.

1 Institute of Water and Wetland Research, Radboud University, Nijmegen 2 Institute of Biology Leiden (IBL), Leiden University, Leiden

Matrix metalloproteinases (MMPs) are key enzymes in the turnover of extracellular matrix inhealth and disease, as well as in developmental and regenerative processes. We have studied zebrafishscale regeneration to Lecture Abstracts Lecture ascertain the role of mmp-2 and mmp-9 expressing cells in this process. Scales were plucked from the surface of anaesthetized adult male zebrafish, and the scales that regenerated inthe scale pocket were recovered at various times after plucking. Analysis consisted of (i) in situhybridization with mmp-9 probe, followed by histological sectioning; (ii) qRT-PCR for mmp-2 andmmp-9, and (iii) zymography for gelatinase activity. We found that ontogenetic scales hadmultinucleated aggregates of mmp-9 expressing cells along their lateral margins, as well asmononucleated mmp-9 expressing cells along the radii. The multinuclear aggregates were not always in the same location in different scales and varied considerably in scales from different individuals. In 2and 4 day regenerated scales, aggregates along the lateral margins were not present, butmononucleated cells were abundant, particularly along the episquamal side of the matrix at 4 days. During this early phase of scale regeneration, mmp-2 and mmp-9 transcripts increased in abundancein the scale, and gelatinase activity increased. Later (up to day 8), all of these parameters returned tothe basal values seen in the ontogenetic scales, as did the histological distribution and appearance ofmmp-9 positive cells. These findings suggest that MMPs play an important role in remodelling of thescale during regeneration, and that this function may reside in mononuclear cells. The multinuclearmmp-9 positive aggregates on the margins of ontogenetic scales may be associated with normal scalegrowth during the animal's lifetime. Our findings suggest that the fish scale regeneration model may bea useful system in which to study the cells and mechanisms responsible for regeneration, developmentand skeletal remodelling.

Keywords: MMP, osteoclasts, scale regeneration E-mail: [email protected]

Session 7.1 Candidate immune gene expression in the ecological functional genomics model Daphnia

Decaestecker E.1,2, Labbé P.3,4, Ellegaard K.5, Allen J.E.3, Little T.J.3

1 Aquatic Biology, Science & Technology, IRF-Life Sciences, K.U.Leuven-Campus Kortrijk, Belgium 2 Aquatic Ecology and Evolutionary Biology, K.U.Leuven, Belgium 3 University of Edinburgh, IEB, Edinburgh, UK 4 ISEM, University of Montpellier 2, France 5

Department of Molecular Evolution, Evolutionary Biology Centre, Uppsala University, Sweden

The last ten years have witnessed increasing interest in host-parasite interactions involving invertebrate hosts. The innate immune system is now relatively well characterised, but in a limited range of genetic model organisms and under a limited number of conditions. Immune systems have been little studied under real-world scenarios of environmental variation and parasitism. Thus, we have investigated expression of candidate immune genes in the water

flea Daphnia magna, a model organism for ecological genetics. We chose a Lecture Abstracts subset of candidate genes that code for immune effectors and developed tools to perform qRT-PCR in D. magna. We tested for differential expression of these effector candidate genes following exposure to the bacterial parasite Pasteuria ramosa. A unique characteristic of the Daphnia clones and parasite strain combinations used is that they have been shown to be involved in specific host- parasite coevolutionary interactions in natural systems. None of the genes appeared to show a major modification of expression level in response to P. ramosa exposure, although constitutive expression levels differed between host genotypes, and some genes appeared to show correlated expression. By applying knowledge from genetic models (e.g. Drosophila) to models for the study of evolutionary ecology and coevolution (i.e. Daphnia), the candidate gene approach is temptingly efficient. However, such an approach is by its very essence high risk, and future work on the Daphnia-Pasteuria system will need to balance the inherent risks of a candidate gene approach with more comprehensive approaches to de novo identify immune genes specific to the Daphnia-Pasteuria interaction.

Keywords: host-parasite coevolution, qRT-PCR, innate immunity E-mail: [email protected]

Session 10.1 Study of the life cycle of two species of forensic interest carrion beetles (Coleoptera, Silphidae): Thanatophilus sinuatus F. & Necrodes littoralis L.

Dekeirsschieter J.1, Verheggen F.1, Brostaux Y.2, Haubruge E.1

1 Department of functional and evolutionary Entomology, Gembloux Agro-Bio Tech, University of Liege, Gembloux, Belgium 2 Department of Applied Statistics, Computer Science and Mathematics,Gembloux Agro-Bio Tech, University of Liege, Gembloux, Belgium Lecture Abstracts Lecture Carrion beetles (Coleoptera, Silphidae) are a small group of Coleoptera counting less than 200 species that are worldwide spread. Silphidae are mainly carrion feeder (necrophagous species) but can also prey on other carrion inhabitants such as fly eggs or maggots and other small carrion beetles (necrophilous species). These beetles have been referred to as being part of the entomofaunal colonization of a dead body but very few studies have looked at them in forensic context. However, the use of beetles could be

relevant in forensic entomology. Silphids could provide information on postmortem colonization on remains and time since death. Typically, beetles life cycles are typically longer than that of flies and may improve the postmortem interval estimation. Among their ecological preference for large vertebrate carcasses, Silphinae may have a more important value as forensic indicators than Nicrophorinae. This study focuses on two Palearctic silphine species of forensic interest: Necrodes littoralis Linnaeus and Thanatophilus sinuatus Fabricius. The beetles’ life cycles were studied at two constant temperatures (18°C & 23°C) during their complete development. Each individual has been measured (4 measures of length per individual) twice a day with a geometrical micrometer during its active growth. Developmental milestones were also recorded. Three instars were identified for both species and their rate of development were also calculated for both temperatures. In addition to previous observations on Diptera conducted to calculate the minimum PMI (temperatures models), this study of the rates of development of the immature stages of Silphinae may extend the minimum PMI.

Keywords: Forensic entomolgy, carrion beetles, life cycle E-mail: [email protected]

Session 2.2 The relation between behaviour and biting performance in a chisel-tooth digger (Fukomys micklemi, Bathyergidae, Rodentia)

Desmet N., Van Daele P.A.A.G., Adriaens D.

Evolutionary Morphology of Vertebrates, Ghent University, K.L. Ledeganckstraat 35, B-9000 Gent, Belgium

African mole-rats are obligatory subterranean rodents which dig tunnels using their incisors. Digging large tunnel systems requires an efficient jaw apparatus. For the highly social mole-rats of the genus Fukomys a caste system has been described based on the amount of work that is being performed. Using bite force as a proxy for biting performance, morphological evolution can be studied at the colony level. It can be hypothesized that variation in biting performance is related to variation in work behaviour. During an explorative study behavioural observations were carried out on a colony of wild-caught Fukomys micklemi, in order to test for the existence of different worker castes. Maximal bite force was measured and related to morphology and work behaviour. Although considerable interindividual variation in the amount of work was apparent within the colony, no clear worker castes could be defined. Lecture Abstracts Also, differences in biting performance were strongly correlated with morphological parameters, but no relation between work and biting performance was found. These results suggest that a subdivision of the worker caste into frequent and infrequent workers does not reflect the pattern of continuous variation in work behaviour, as reported earlier for Fukomys damarensis. Since the jaw apparatus also plays an important role in social interactions, it can be hypothesized that bite force is linked to dominance. Further research will integrate work behaviour and dominance with biting performance. Individual digging efficiency will be tested and related to bite force and cranial morphology.

Keywords: adaptation, Cryptomys, sociality E-mail: [email protected]

Session 3.4 Demographic structure, activity budget and ranging pattern of an unusually large group of agile mangabeys (Cercocebus agilis) at Bai Hokou, Central African Republic

Devreese L.1, Todd A.2, Stevens J.3, Huynen M-C.4

1 University of Antwerp, Antwerp 2 WWF-CAR, Bayanga, Central African Republic 3 Centre for Research and Conservation, Antwerp 4 University of Liège, Liège Lecture Abstracts Lecture Based on molecular and morphological data, mangabeys are considered to be a diphyletic group containing the arboreal genus Lophocebus (baboon- mangabeys) and the semi-terrestrial genus Cercocebus (drill-mangabeys). The latter genus remains relatively little studied in its natural habitat. Drill- mangabeys are reported to live in multimale/multifemale groups ranging in size from some 10-20 to exceptionally more than one hundred individuals. However, at the Bai Hokou field site in the Central African Republic a group of

estimated 230 individual agile mangabeys (Cercocebus agilis) has been reported (Knights et al., 2008). Based on a five-month study of the same study group, we provide new data on its size and composition. Group size averaged 135 individuals, which is considerably lower than estimated before. Additionally, we collected data on activity and ranging patterns and compared our results to those from other populations of drill-mangabeys. The group has a larger home range (ca. 9km²) and longer day ranges (ca. 3km) than smaller mangabey groups. Their activity budget is affected as well. Individuals spend more time travelling and less time resting and in social activities in comparison with smaller groups within the genus Cercocebus. These preliminary results suggest that individuals in this group have to pay a price to live in such a large group. An interesting question to be answered now is what favours the unusually large group size at this site.

Keywords: Cercocebus, ranging, group size E-mail: [email protected]

Session 4.6 Mechanisms of cartilage subdivision in the pectoral endoskeleton of zebrafish

Dewit J., Witten P.E., Huysseune A.

Ghent University, Ghent

The pectoral fins of the zebrafish (Danio rerio) develop relatively early, but they transform completely during the larval-to-juvenile transition. In the endoskeleton this transformation includes multiple subdivisions of pre-existing cartilage. This cartilage subdivision is unique to pectoral fin development in teleost fish. Here we present the development and timing of these subdivisions and we discuss some developmental variation caused by differences in growth rate. Furthermore we present data on the mechanisms of these cartilage subdivisions at the cellular level. Using various techniques, we evaluate the presence of apoptosis, resorption by chondroclasts and metaplasia or transdifferentiation of chondrocytes. Neither apoptosis, nor resorption by chondroclasts contributes to these cartilage subdivisions. However, ultrastructural observations reveal strong indications of chondrocyte transdifferentiation in the subdivision zones, suggesting that chondrocyte Lecture Abstracts transdifferentiation plays a major role in the maturation of the pectoral fin endoskeleton. We thus contribute to the growing consensus that the phenotype of skeletal tissues is not terminal and that transdifferentiation of mature connective tissues can play an important role in various developmental and homeostatic processes.

Keywords: cartilage, transdifferentiation E-mail: [email protected]

Session 4.2 Stem cell dynamics during homeostasis and regeneration in Macrostomum lignano (Platyhelminthes)

Dhondt I.1, Verdoodt F.1, De Vos W.2, Houthoofd W.1, Willems M.3

1 Nematology, Ghent University, K.L. Ledeganckstraat 35, B-9000 Gent, Belgium; 2 Department of Molecular biotechnology, Ghent University, Coupure Links 653, B-9000 Gent, Belgium; 3 Evolutionary Developmental Biology, K.L. Ledeganckstraat 35, B-9000 Gent, Belgium

Lecture Abstracts Lecture Macrostomum lignano is an emerging model system to study stem cell biology, because of its experimentally accessible stem cell system (the neoblast system) and its regeneration capacity. Proliferating neoblasts can be easily labeled in vivo and visualized. The goal of this research is to analyse cell-cycle characteristics in Macrostomum lignano, performing in vivo analysis. First of all, the maximum length of S-phase was estimated during homeostasis en regeneration by means of a double labeling technique with the thymidine analogs CldU and IdU. A plugin in ImageJ was created to perform colocalization analysis of both labels. Our data suggest the existence of two subpopulations of somatic neoblasts, each of which having its own cell-cycle. During regeneration, heterogeneity of the stem cell system of Macrostomum lignano was also confirmed. Comparing the results of homeostasis and regeneration, experiments revealed that the duration of DNA synthesis remains relatively constant. Secondly, the presence of quiescent stem cells in Macrostomum lignano was confirmed using a label retaining assay. During homeostasis, these cells were mostly inactive, but were quickly activated as a response to amputation. The overall goal of this study was to contribute to the fundamental knowledge of stem cell biology of Macrostomum lignano. Studying the S-phase was the first step for future analysis of the entire cell- cycle. Furthermore, this model organism is well suited to study stem cell quiescence.

Keywords: cell-cycle, stem cells, Platyhelminthes E-mail: [email protected]

Session 11.3 Different levels of anthelmintic resistance in the facultative parasitic nematode Halicephalobus gingivalis

Fonderie P.1, Moens T.2, Houthoofd W.1, Bert W.1

1 Nematology section, Department of Biology, Ghent University, K.L. Ledeganckstraat 35, B- 9000 Ghent 2 Marine Biology section, Department of Biology, Ghent University, Krijgslaan 281 S8, B-9000 Ghent

In recent years many studies have proved that most equine parasites have some form of resistance to all main classes of anthelmintic drugs. However, studies on anthelmintic resistance in equine parasites only include obligatory parasites, not facultative parasites. Halicephalobus gingivalis is a free-living bacterivorous nematode and a known facultative parasite of horses. In all reported infections the horses were regularly treated with common anthelmintics, strongly indicating the possibility that H. gingivalis has some form of resistance to these anthelmintic drugs. We present the results of an in

vitro study on the resistance of several isolates of H. gingivalis, both free-living Lecture Abstracts and parasitic. All were tested in vitro for the extent of their resistance to two different anthelmintic drugs, ivermectine and thiabendazole, using an adaptation of the micro-agar larval development test and focusing on egg hatching and larval development. Main conclusion is that the anthelmintic resistance of H. gingivalis was considerably higher than that of closely related panagrolaimid nematode species, with the parasitic isolates having a higher resistance than the free-living ones.

Keywords: facultative parasitism, induced resistance, model organism E-mail: [email protected]

Session 11.4 Comparative gut morphology of mnn9 yeast and wild type yeast fed Artemia franciscana nauplii

Gunasekara R.A.Y.S.A.1, Rekecki A.1, Casteleyn C.1, Cornelissen M.2, Bossier P.3, Van den Broeck W.1

1 Department of Morphology, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, B-9820, Merelbeke, Belgium 2 Department of Basic Medical Sciences, Faculty of Medicine and Health Sciences, De Pintelaan 185 6B3, Ghent University, 9000 Ghent, Belgium

Lecture Abstracts Lecture 3 Laboratory of Aquaculture and Artemia Reference Center, Ghent University, Rozier 44, 9000 Ghent, Belgium

Germ-free Artemia nauplii were fed daily with Baker’s yeast (wild type strain) and dead Aeromonas hydrophila and named group WTY. The other group was fed daily with yeast mutant strain, mann9, and dead Aeromonas hydrophila (group mnY). For histology, two live nauplii per group were fixed at days 2, 4 and 6 in 100% ethyl alcohol, 40% formaldehyde and acetic acid for 5 min, dehydrated in graded alcohols and embedded in paraffin. Five µm thick sections were stained with haematoxylin and eosin and subsequently examined by light microscopy. For TEM, nauplii were fixed overnight in Karnovsky’s fixative, post-fixed overnight in 1% osmium tetroxyde and embedded in SPURR’s resin. Blocks were sectioned at 60 nm and sections were mounted on formvar coated grids and post-stained with uranyl acetate and lead citrate. They were examined using a Jeol 1200 EXII TEM at 80kV accelerating voltage. On day 2 no significant morphological differences in the mid- and hindgut could be observed between both groups. However, on days 4 and 6, significantly longer mid- and hindguts with larger diameters were seen in nauplii of the MnY group. Mnn9 yeast mutant strain sustains better growth under the described culture conditions. This could be due to high amounts of cell-wall chitin and glucans in combination with low amounts of mannose present in mnn9 yeast strain. Since Artemia exhibits low mannase activity in the digestive tract, diets with less mannose content make digestion easy. Furthermore, high levels of chitin and glucan make the diet more nutritious.

Keywords: yeast, transmission electron microscopy, histology E-mail: [email protected]

Session 6.5 Hybridization in the pipefish genus Syngnathus: Implications for paleobiogeography and present genetic structure

Hablützel P.I.

Laboratory of Animal Diversity and Systematics, K.U. Leuven, Ch. Deberiotstraat 32, B-3000 Leuven, Belgium

Although considered not so important for a long time, cases of interspecific hybridization are nowadays considered to be key systems in evolutionary research. Hybridization events can leave traces in the genome of the species involved over a long period of time and can give use insights into ancient evolutionary processes. In pipefish of the genus Syngnathus males take care of the brood and invest more resources in offspring production than females. This investment is coupled with male choosiness and a complex mating behavior. Nevertheless several occasions of ancient as well as present natural hybridization are known within this genus. S. taenionotus has a mixed ancestry based on mitochondrial and nuclear sequences. Mitochondrial haplotypes are completely sorted and population structure analysis based on neutral microsatellite markers clearly separates S. taenionotus from its putative Lecture Abstracts parental species. It points to an ancient hybridization event, dated to the late Pleistocene. Neither of the putative parental populations co-occur with S. taenionotus which is endemic to the northern Adriatic Sea (flooded after the end of the Last Glacial Maximum), therefore indicating major shifts in the distributions of several species during the late Pleistocene and early Holocene.

Keywords: ancient hybridization, Syngnathus, Europe, Pleistocene E-mail: [email protected]

Kets Award presentation Characterisation of the nematode community of a low-activity cold seep in the recently ice-free Larsen B area, Eastern Antarctic Peninsula

Hauquier F., Ingels J., Vanreusel A.

Ghent University, Ghent

The metazoan meiofauna of a low-activity cold seep beneath the former Larsen B ice shelf (Eastern Antarctic Peninsula) was analysed with special emphasis on the nematode community. The recent collapse of both Larsen A and B ice Lecture Abstracts Lecture shelves (1995-2002) formed an unprecedented opportunity to assess sub-ice- shelf benthic community structure. Following the large-scale disintegration of both ice shelves, new habitats have been discovered in the area, including a methane seep in the trough formed by two glaciers at a depth of 820m. Identification of nematodes from this area was carried out at genus level, and at species level for the dominant ones, and the composition of these seep samples was compared to other recently ice-free Larsen A and B stations and other Antarctic shelf areas (Weddell Sea and Drake Passage). Nematode communities in the seep area differed significantly from the other stations in terms of dominant genera, diversity and abundance. Densities in the seep samples were relatively high compared to adjacent non-seep stations and showed subsurface maxima at a sediment depth of 2-3cm. All samples were dominated by one species of the family Monhysteridae, which was identified as a Halomonhystera species. The combination of high densities, subsurface maxima and dominance of one species indeed implied a dependence upon a chemosynthetic food source, hence cold seep activity. It seems that climate- induced ice shelf disintegration in the Larsen area has uncovered unique and complex benthic communities which will require more detailed studies if we want to understand their ecology to a full extent.

Keywords: Nematoda, Antarctica, cold seep E-mail: [email protected]

Session 6.1 Problematic of the Pelagia noctiluca outbreaks in the Bay of Calvi (Corsica)

Hecq J.-H.1,3, Collignon A.1,3, Garrido M.2, Lejeune P.3, Pasqualini V.2, Goffart A.1,3

1 University of Liège, Oceanology-MARE Center- Belgium. 2 University of Corsica Pasquale Paoli, Corte (Corsica), France. 3 STARESO SA, Calvi (Corsica), France.

The interannual variations of the Schyphozoan jellyfish and especially Pelagia noctiluca was studied by weekly measurements in the Bay of Calvi (Corsica) from 2003 to 2010. The mean annual abundance reaches a dramatic maximum in 2006, potentially correlated to the very intense mesozooplankton bloom in 2005. Active swarms of Pelagia appear on the shelf and at the external limit of the Bay by vertical migration, following some days of North-East wind. The swarms maintain at the same place for a few days. In these active swarms, 5 to 10 P. noctiluca per m³ were observed between 10 to 60 meters depth. The individuals were equidistant, swimming actively with the extended tentacles Lecture Abstracts and capturing the food. In certain cases, individuals partially destroyed, dying or at the end of their biological cycle, escape from active swarms and derive passively in the first meters of the water column towards the coastal zones and embayment’s under the effect of the wind and the movements of the water. The degraded individuals, which have lost tentacles or manubrium, move slowly and accumulate in large number (sometimes more than 200 /m2), edge to edge, in passive patches limited to the first three meters of water column. These swarms undergo an active predation by numerous sparid fishes. They disappear in a few hours, reduced by this predation or by massive sedimentation of the dead animals.

Keywords: jellyfish, Pelagia noctiluca, Mediterranean E-mail: [email protected]

Session 1.1 The orexine receptor pathway in insects

Huybrechts R., Vuerinckx K., Tobback J., Verlinden H., Lindemans M.

Kuleuven, Leuven

Tribolium expresses the Orexin type two like receptor (OX2R) in different organs. Three isoforms with minimal differences in amino acid composition are detected. Apart from the brain a sexual dimorphism in OX2R expression is observed both in the fat body and the gonads, in males the expression always being higher compared to females. The pathway is also present in the midgut

Lecture Abstracts Lecture but here the expression is rather low. A first experimental setup to study the OXR pathway in the locust, Schistocerca gregaria, indicated an enhanced expression level of OXR in the brain following starvation. All together we hypothesize a role of the OX2R pathway in feeding regulation overall energy metabolism and sexual maturation.

Keywords: Energy metabolim, feeding, starvation E-mail: [email protected]

Session 5.1 Evolutionary diversification of a sex pheromone in Salamandridae

Janssenswillen S., Bossuyt F.

Amphibian Evolution Lab, Vrije Universiteit Brussel, Brussels

During courtship, male newts of the family Salamandridae wave their tail to channel cloacal pheromones towards receptive females. In the Asian genus Cynops, this pheromone is a decapeptide called sodefrin, which is cleaved from a larger precursor protein called SPF (Sodefrin Precursor Factor). Behavioural tests have demonstrated that sodefrin has the ability to attract and excite gravid females. To understand the evolution of SPF in Salamandridae, we sequenced cloacal SPF mRNA from sexually active males and females of six species in five genera with an aquatic courtship. We found substantial differences between sexes, and recovered up to seventeen unique SPF transcripts per species. Phylogenetic analyses indicate that this diversity arose by duplication events that happened both before and during the radiation of these aquatic salamander genera. Structural variation not only originated by DNA substitutions, but also by a frameshift mutation and by the gain and loss Lecture Abstracts of alternative peptide cleavage sites. Our findings indicate that SPF represents a fast-evolving protein complex that may have contributed more to the evolution of salamandrid pheromone communication than currently thought.

Keywords: SPF, evolution, Salamandridae E-mail: [email protected]

Session 9.3 Changing landscapes- consequences for the recruitment of animal-dispersed plants

Lehouck V.1,2, Spanhove T.1,2,3, Bonte D.1, Lens L.1

1 Terrestrial Ecology Unit, Ghent University, K.L. Ledeganckstraat 35, 9000 Ghent, Belgium; 2 Ornithology Section, Zoology Department, National Museums of Kenya, P.O. Box 40658, 00100, Nairobi, Kenya; 3 Research institute for nature and forest (INBO), Kliniekstraat 25, 1070 Brussels, Belgium

Lecture Abstracts Lecture Seed dispersal by frugivores plays a key role in plant community and population dynamics, yet direct and indirect effects of habitat and landscape changes on the recruitment of animal-dispersed plants remain poorly known. We examined how seed dispersal and recruitment of a bird-dispersed tropical tree species varies spatiotemporally in a heavily fragmented cloud forest system. High-resolution data on seed removal, gut passage and dispersal were combined with experimental data on post-dispersal seed germination and seedling establishment to predict how recruitment of a forest interior tree may be affected by habitat change. We simulated relative effects of frugivore composition, forest size and landscape type on dispersal distances of seeds and of established seedlings and on rates of seed germination and seedling survival after two years with the use of Individual Based Models. While changes in frugivore composition and forest size affected potential distance distribution patterns of seeds and seedlings, post-dispersal germination and early survival were more affected by the structure of the embedding landscape matrix. Models predict a 90% recruitment increase in tiny forest remnants buffered by exotic plantations compared to those surrounded by farmland, this nursing effect being less effective under dryer conditions. We conclude that habitat changes affect frugivorous seed dispersal and plant recruitment in complex and context-dependent ways, having important implications for on-site habitat management in view of current global change.

Keywords: regeneration, frugivore, seed dispersal E-mail: [email protected]

Kets Award Presentation Contribution to the study of an invasive lineage: the clam Corbicula spp.

Marescaux J.

University of Namur

Freshwater biodiversity is threatened by several mechanisms of which the introduction of non-indigenous species is one of the most important. Alien species are of particular interest because of the major impacts they have on both aquatic ecosystems and industrial installations. Corbicula is described as one of the most important molluscan pest species being native to Asia, Africa and Australia. In the early 1980s, the presence of Corbicula clams was reported in France and in Portugal indicating the start of its invasion in Europe. Since then, it spread across most of Western Europe and nowadays reaches high densities. Although the genus is quite defined, the species determination remains uncertain. This can, among others, be explained by the high phenotypic plasticity found within the phylum mollusc and by its unique mode of reproduction. Indeed androgenesis is a rare form of asexual male reproduction which occurs when the offspring carry nuclear chromosomes Lecture Abstracts from only the male parent. During such phenomenon, after fertilization by a biflagellate sperm cell that contains a full complement of nuclear chromosomes, the entire maternal nuclear genome is extruded as two polar bodies but the mitochondria are retained. The purpose of this master thesis is to contribute to the study of the invasive lineage Corbicula spp. in Europe. This work contained different parts: (i) a morphological analysis of individuals of sampled French Corbicula populations; (ii) a phylogenetic analysis showing the relatedness of French Corbicula individuals based on the mitochondrial genes 16S, Cyt b and COI and one nuclear gene (28S); (iii) a study of spermatozoon morphology. We could conclude from our morphological and phylogenetic analyses that there are three distinct Corbicula lineages that invaded the French rivers, defined as form R, form Rlc (light coloured) and form S. Our sperm morphological analyses indicate that these three lineages reproduce through androgenesis. Indeed, the spermatozoa have two flagella, which is a characteristic of androgenesis. Our mitochondrial analyses also demonstrated that in one sampled Corbicula population where the two forms R and S live in sympatry, a “mitochondrial-morphotype mismatch” was observed. Indeed, one of our studied individuals was morphologically identical to form R while it had the mitochondrial haplotype of form S. This can only happen through androgenesis when a spermatozoon of form R fertilizes an oocyte of form S, causing a disjunction between the two forms.

E-mail: [email protected]

Session 1.4 Transcriptome analysis of the sexually dimorphic gland of the African dwarf clawed frog Hymenochirus sp. (Pipidae)

Matthijs S., Bossuyt F.

Amphibian Evolution Lab, Vrije Universiteit Brussel, Brussels

The African dwarf clawed frog Hymenochirus sp. is a fully aquatic frog that belongs to an ancient anuran lineage. Behind each front leg, males of this species have a subdermal gland, called a postaxillary breeding gland, that substantially enlarges when they are sexually active and calling. The secretion Lecture Abstracts Lecture of this gland has been shown to contain pheromonal activity, but the molecules involved have not yet been identified. To search for pheromones in the African dwarf clawed frog, we constructed a cDNA library and randomly sequenced transcripts from the breeding gland of a sexually active male. BLAST analyses reveal a prevalence of two groups of molecules that are each present in multiple transcripts. These sequences contain a signal peptide, indicating that they are likely secreted, making them candidate pheromone precursors. The most abundant sequence of the two encodes for a new protein, i.e. showing no significant similarity to known proteins. The second most abundant sequence has a four-disulfide core domain like that found in whey acidic proteins. Additionally, we found sequences that show high similarity with toxins not yet reported in frogs. To understand the evolution and predict the function of these transcripts, we used phylogenetic analyses to further identify their evolutionary relationships with known vertebrate genes. Behavioral and anti- microbial assays will be necessary to further pinpoint the function of these molecules in the Hymenochirus breeding gland.

Keywords: Amphibia, pheromones, sexual behaviour E-mail: [email protected]

Session 2.5 Sound production in red bellied piranhas (Pygocentrus nattereri): acoustical, behavioural and morphological study.

Millot S., Vandewalle P., Parmentier E.

University of Liège (Ulg), Liège

During this study, three different kinds of sound were recorded for the first time in Pygocentrus nattereri living in aquarium. The first sound was usually produced during frontal display between two fish, had numerous pulses and lasted 100 ± 3 ms with a dominant frequency of 100 ± 20 Hz. The second sound was produced during agonistic interactions, was characterised by a single pulse lasting 10 ± 3 ms and had a frequency of 40 ± 10 Hz. The third sound corresponded to chasing behaviour, was generally composed of 3 to 4 pulses lasting each 4 ± 2 ms and its frequency was between 300 and 600 Hz. The first and second sounds were likely produced by the sonic muscles around the swimbladder, whereas the third sound was associated to jaw mechanism. To study the sound-producing mechanism, sonic muscles were stimulated at different frequencies (1Hz, 100Hz, 200Hz, 300Hz) and the swimbladder vibrations were observed simultaneously with a laser vibrometer. It showed Lecture Abstracts the vibration frequency of the swimbladder corresponded exactly to the muscle contraction rate. Sonic muscles were able to sustain a stimulation of 100Hz, corresponding to the first kind of sound. Stimulation at a frequency of 1 Hz showed a single vibration of 20 to 40Hz that corresponds to the second kind of sound. Muscles tetanised at 200 and 300Hz. This study experimentally showed the swimbladder is a highly damping structure, unable of resonance. Its output simply follow muscle contraction rate.

Keywords: swimbladde, sonic muscles, laser vibrometer E-mail: [email protected]

Session 7.5 The zebrafish scale as model for glucocorticoid-induced osteoporosis: effects of prednisolone on scale regeneration

Peters H.M., van Kessel M.A.H.J., de Vrieze E., Metz J.R., Flik G.

Institute of Water and Wetland Research (IWWR), Department Organismal Animal Physiology, Radboud University Nijmegen

Glucocorticoid-induced osteoporosis is a risk factor in prolonged steroid treatment of patients with chronic inflammations, such as rheumatoid arthritis and multiple sclerosis. Animal models for osteoporosis research are often Lecture Abstracts Lecture inaccurate, slow and expensive. An upcoming model in bone research is the regenerating scale of zebrafish (Danio rerio). Scales share many traits with bone: a mineralized collagen matrix with osteoblasts and osteoclasts attached. We investigated the influence of prednisolone on scale remodeling. From 4 days of regeneration onwards the Ca/P ratio in both ontogenetic and regenerating scales was higher in controls than in prednisolone-exposed animals. In a widespread gene-expression profile, we found that typical osteoblast markers, collagen 1alpha, osterix and runx2 were substantially up- regulated during regeneration. Prednisolone significantly attenuated expression of these genes 2 to 5-fold. On the other hand, expression of osteoclast markers such as cathepsin k, tartrate-resistant acid phosphatase and matrix-metalloproteinase-9 remained unchanged during the initial phase of regeneration, but then increased. Under influence of prednisolone, expression of these genes was differently up- or down-regulated. We conclude that prednisolone inhibits scale regeneration: it disturbs mineral balance, decreases expression of bone formation-promoting genes and increases those of bone degradation-associated genes. These effects highly resemble human glucocorticoid-induced osteoporosis. This experiment establishes the zebrafish scale as valuable model in osteoporosis research.

Keywords: glucocorticoids, scale, bone model E-mail: [email protected]

Session 5.3 The success story of invasive androgenetic clams

Pigneur L.-M., Marescaux J., Etoundi E., Descy J.-P. , Van Doninck K.

Unit of Research in Organism Biology (URBO), University of Namur (FUNDP)

Basket clams of the Molluscan genus Corbicula are native to Africa, Australia, Asia and the Middle East. These clams are also successful aquatic invaders in America since the 1920s and in Europe since 1980. Interestingly the genus Corbicula exhibits various reproductive modes with sexually reproducing species as well as hermaphrodites reproducing by androgenesis, an “all-male” asexuality. In androgenetic Corbicula clams, the oocyte is fertilized by an unreduced sperm. After fertilization, the maternal chromosomes are extruded as two polar bodies and the whole nuclear genome is inherited from the father. We investigated the phylogenetic relationships of Asian, American and European Corbicula populations combining morphometrics, mitochondrial gene sequencing and microsatellite analysis. Mitochondrial/ nuclear mismatches were observed and indicate androgenesis between lineages with the spermatozoon from one lineage fertilizing the egg of another lineage. As a consequence, the descendant inherits the paternal nuclear chromosomes of Lecture Abstracts one lineage while the mitochondria and other organelles of the oocyte of the other lineage are retained, resulting in discrepancies between the nuclear and mitochondrial phylogenies. This phenomenon challenges species delimitation and highlights the need of combining mitochondrial and nuclear data in androgenetic taxa. Furthermore, we emphasize the role of androgenesis in the invasiveness of this clam genus since only androgenetic taxa seem to be widespread while their sexual relatives are mostly restricted to their native areas.

Keywords: androgenesis, clams, invasive species E-mail: [email protected]

Session 2.6 Nature-inspired design: Kinematic modelling of the seahorse tail

Praet T.1, Van Cauter S.1, Adriaens D.2, Kannan S.3, Srigiriraju S.3, Masschaele B.4, De Beule M.1, Verhegghe B.1.

1 Institute Biomedical Technology (IBiTech-bioMMeda), Ghent University, Ghent, Belgium 2 Evolutionary Morphology of Vertebrates (Dept. of Biology), Ghent University, Ghent, Belgium 3 SIMULIA HQ, Providence, RI, USA 4 Centre for X-ray Tomography (UGCT), Ghent University, Ghent, Belgium

Lecture Abstracts Lecture Technological advances are often inspired by nature. Through millions of years of evolution, nature has produced elegant and efficient solutions to all sorts of real-world problems. Therefore, more and more engineers turn to nature for inspiration on new designs, considering it to be an enormous database on field tested solutions. Seahorses (belonging to the genus Hippocampus) show a remarkable adaptation to their environment. Being slow swimmers, seahorses rely on their camouflage and highly specialised skeleton for survival. Functioning as an armour, the multi-segmented bone complex most likely

makes the seahorse very resilient to bites of predatory fish, while specialized articulation of the segments keeps the skeleton flexible, especially in the tail section. The constructional morphology of the tail skeleton of the longsnout seahorse (Hippocampus reidi) is therefore investigated from an engineering point of view. Each segment of the seahorse tail skeleton consists of five skeletal elements (one vertebra surrounded by four dermal plates), connected by articulating joints. Kinematic models containing these elements and joints are constructed from micro-CT scans of the seahorse, together with the muscles involved in ventral tail bending (myomere muscles and median ventral muscles). Because of the highly uniform shape of the segments throughout the tail, the model building is automated using the open-source software package pyFormex, while the kinematic analyses consist of multi-body simulations within Abaqus. Obtaining a profound insight in the kinematics involved in seahorse tail bending holds promise for new designs for engineering applications that require high radial stiffness combined with bending flexibility.

Keywords: kinematic modelling, seahorse E-mail: [email protected]

Session 8.1 Natural vs. anthropogenic impacts on the morphology of the small ground finch, Geospiza fuliginosa

Raeymaekers J.A.M.1, De León L.F.2, Podos J.3, Hendry A.P.2

1 KULeuven, Leuven, Belgium 2 McGill University, Montreal, Canada 3 University of Massaschusetts, Amherst, USA

Evolutionary trajectories may be influenced by natural components as well as anthropogenic impacts, but the latter are often much stronger. In Darwin's finches (Galapagos Islands, Ecuador), natural selective forces have been shaping strong divergence in beak morphology, feeding performance, and resource use. Research on Isla Santa Cruz has suggested that human activities have locally been weakening these selective forces in the medium ground finch (Geospiza fortis). This suggestion was made based on the observation that a population that was historically strongly bimodal for beak size has trended over the past three decades toward unimodality, along with a dramatic increase in the local resident human population and the number of tourists. Here we investigate the factors that have been shaping the adaptive landscape of the Lecture Abstracts small ground finch, Geospiza fuliginosa. Beak size in this species is unimodal and smaller than in G. fortis, but it has been hypothesized that its beak size distribution is influenced by interspecific competition as well as hybridization. Furthermore, it has been suggested that differential resource use in lowland and highland populations of G. fuliginosa on Isla Santa Cruz is causing phenotypic shifts as well. As a way to test the strength of natural versus human impacts on G. fuliginosa, we compared a human-disturbed lowland population, a relatively undisturbed lowland population, and a relatively undisturbed highland population for beak dimensions, head dimensions and tarsus length.

Keywords: human impacts, adaptive landscape E-mail: [email protected]

Session 6.3 Trophic structure and diversity of macro organisms associated with Posidonia oceanica litter in the bay of Calvi

Remy F.1, Borges A.V.2, Darchambeau F.3, Dauby P.4, Gobert S.1, Lepoint G.1

1 Oceanology, University of Liège ,Liège 2 FUNDP Namur, URBO-Freshwater ecology, Namur 3 Chemical oceanography, University of Liège, Liège 4 Animal Systematic and Diversity, Liège

Lecture Abstracts Lecture The purpose of this work was the evaluation of the trophic structure, diversity and small scale variation of macro organisms associated with Posidonia oceanica litter in the bay of Calvi (Corsica). Gammaridean Amphipods largely dominate our samples and G. fucicola accounts for 55% of the whole sample. Differences we observed between diversity and abundance at sample sites are probably caused by litter composition, degradation and conditions. Stable isotope analysis and gut contents showed that the food web is based on detritivores but with higher trophic levels and carnivore species. Most of these organisms probably play an important role in litter degradation and carbon flux from the litter, through the food webs.

Keywords: Posidonia, isotope, diversity E-mail: [email protected]

Session 2.3 Feeding kinematics and bite forces of a true molluscivorous lizard, Dracaena guianensis.

Schaerlaeken V.1, Herrel A.2, Holanova V.3, Rehak I.4

1 Department of Biology, University of Antwerp, Universiteitsplein 1, B-2610 Antwerpen, Belgium 2 UMR 7179 ‘Mécanismes Adaptatifs: des Organismes aux Communautés’, Muséum National d’Histoire Naturelle, équipe ‘Mouvements et Structures : Aspects Fonctionnels et Evolutifs’, Département EGB Ecologie et Gestion de la Biodiversité, 57, rue Cuvier BP55, F- 75231 Paris

cedex 5, France. 3 Department of Zoology, Charles University, Vinicna 7, 128 44 Praha, Czech Republic 4 Prague Zoo, Praha, Czech Republic.

Most lizards feed on a variety of food items that may differ dramatically in physical and behavioural characteristics. Several fossil and extant lizard families are known to feed upon hard-shelled prey (durophagy), which is correlated with changes in cranial morphology. Yet, for only a few species true molluscivory has been documented and as snails are hard and brittle food Lecture Abstracts items, higher bite forces have been suggested to be important for these lizards. Here we compare the feeding kinematics of a snail-crushing teiid lizard genus Dracaena with a close relative Tupinambis. Dracaena guianensis is characterized by enlarged blunt molariform teeth. This special dentition, partly also present in Tupinambis, may help avoid tooth damage and increases the contact area with the food item. Our data show that juvenile Dracaena are morphological different from the closely related Tupinambis by having bigger heads, resulting in larger jaw muscles and higher bite forces. A comparison of feeding kinematics in adult Dracaena and Tupinambis, revealed that Dracaena typically use more transport cycles. During transport, the tongue plays an important role in manipulating and expelling shell fragments before swallowing. Although, Dracaena is slow, these animals are very effective in crushing and processing hard-shelled prey in comparison to the closely related Tupinambis and other snail specialists (e.g. Varanus ornatus; Chamaeleolis).

Keywords: durophagy, feeding kinematics, bite forces E-mail: [email protected]

Session 1.5 Polychlorinated Biphenyls affect Histological Appearance of European sea bass (Dicentrarchus labrax) Thyroids

Schnitzler J.G.1, Klaren P.H.M.2, Celis N.3, Blust R.3, Covaci A.4, Dirtu A.4, Thomé J-P.5, Das K.1

1 University Liege B6C, Laboratory for Oceanology, MARE Centre, B-4000 Liege, Belgium 2 Radboud University Nijmegen, Faculty of Sciences, Departement of Animal Physiology, NL- 6525 ED Nijmegen, The Netherlands 3 University Antwerp, Laboratory for Ecophysiology Biochemistry & Toxicology, Dept Biol, B-

Lecture Abstracts Lecture 2020 Antwerp, Belgium 4 University Antwerp, Toxicology Centre, B-2610 Antwerp, Belgium 5 University Liege, Laboratory for Animal Ecology & Ecotoxicology, B-4000 Liege, Belgium,

Polychlorobiphenyls (PCBs) are well-described endocrine disrupters and of particular interest are effects on thyroid function. We propose here a thorough approach to assess effects of these compounds on the thyroid function of European sea bass (Dicentrarchus labrax). An experimental exposure of sea bass to commercial PCB mixtures has been designed to understand underlying toxicity mechanisms and effects on the thyroid system. After 120 days of exposure histological appearance of thyroid tissue was assessed by light and electron microscopy. The follicle area, perimeter, diameter, length and with of every follicle cross section were interactively measured. The shape of the follicles was described with three dimensionless shape descriptors: roundness, form factor and aspect ratio. The histomorphometrical analysis showed a greater heterogeneity of thyroid follicle diameter and especially higher epithelial cell heights in sea bass exposed to environmental relevant doses of PCB (from 0.3 to 0.9 μg g-1 [7 ICES PCB]). Ultrastructural histological investigations showed that the epithelial cells surrounding the bigger follicles present an higher accumulation of colloid droplets. This was interpreted to be the result of increased stimulation of follicular cells. No differences in shape could be identified among the different treatment groups The size of the follicles and the form of the follicular cells gives an indication of the secretary activity of the gland. These observations support the hypothesis that the contamination of PCB mixtures can induce a hyperactivity of the thyroid tissue. These observations were confirmed by measurements of muscular thyroid hormone concentrations and activity thyroid hormone metabolism.

Keywords: PCB, thyroid, sea bass E-mail: [email protected]

Session 10.4 Cryptic species in non-marine ostracods

Schön I.1, Pinto R.2, Birky B.3, Bode S.1, Halse S.4, Butlin R.5, Martens K.1

1 Royal Belgian Institute of Natural Sciences, Freshwater Biology, Brussels, Belgium 2 University of Brasília, Institute of Geosciences, Brasília, Brazil 3 University of Arizona, Dept. of Ecology and Evolutionary Biology, Tucson, AZ 85721, USA 4 Bennelongia Pty Ltd, 5 Bishop Street, Jolimont WA 6014, Perth, Australia 5 Department of Animal and Plant Sciences, University of Sheffield, SheffieldS10 2TN, UK

In the last years, genetic research using the mitochondrial COI gene has discovered countless cryptic species in various animal groups. These are morphological similar but genetically different species. Here, we present four case studies on cryptic species in non-marine ostracods. The morphospecies Eucypris virens displays up to 40 cryptic species in Europe and Northern Africa, which follow neither the reproductive mode nor does it shows a clear geographic pattern. This explains the exceptionally high genetic diversity, which had been previously reported of this morphospecies.Within the ancient asexual darwinulids, no cryptic species were observed in Penthesilenula aotearoa and two in Darwinula stevensoni. In P. brasiliensis, however, we find Lecture Abstracts eight cryptic species. One occurs in Europe, a second in Australia, a third in North America and the remaining five are found in Brazil from similar habitats and in close geographic proximity. Genetic data also support the species status of P. reidae.

Keywords: cryptic species, asexuality, ostracods E-mail: [email protected]

Session 11.2 Nematodes as potential bio-indicator of the composting process

Steel H. 1, Moens T.2, Buchan D.3, Houthoofd W.1, de Neve S.3, Bert W.1

1 Nematology section, Department of Biology, Ghent University, K.L. Ledeganckstraat 35 , B- 9000 Ghent, Belgium 2 Marine Biology section, Department of Biology, Ghent University, Krijgslaan 281 S8, B-9000 Ghent, Belgium 3 Soil Fertility and Nutriënt Management section, Department of Soil Management, Ghent University, Coupure Links 653, B-9000 Ghent, Belgium

Lecture Abstracts Lecture Composting is the heat-producing, aerobic disintegration of organic materials by several organisms which make up a complex and rapidly changing community. Although there has recently been growing interest in the biology of compost, the fauna of compost remains largely unknown. This study examines nematodes as potential representatives of compost biology and quality, mainly focusing on the taxonomical composition and the succession of the nematode community during the composting process. Next to the nematode community, these data were complemented with non-nematode biotic data, i.e. on fungal and bacterial biomass and their ratio, obtained by performing PLFA (Phospholipid Fatty Acid) analyses. The quantitative and taxonomical analysis of the compost showed an abundant presence of nematodes during the process (except for the compost heat peak where nematodes were less abundant). The taxonomic/functional structure of the nematode community clearly changes during the composting process and is linked to several abiotic variables (temperature, pH and moisture). This nematode succession showed an informative pattern and the relation with the succession of their microbial food resource is discussed. Finally two nematode based indices (f/b ratio and Maturity Index (MI)) are evaluated as potential indicators of compost maturity.

Keywords: free-living nematodes, compost maturity, microbial community E-mail: [email protected]

Session 7.2 In search of underlying stress mechanisms using RNAi and gene expression profiling

Stevens A.-S., Plusquin M., Saeren C., Artois T., Smeets K.

UHasselt, Diepenbeek

In recent years, much progress has been made in the characterization of cellular parameters during heavy metal stress. However, a better understanding of underlying molecular mechanisms is highly necessary, especially concerning their carcinogenic effects. Schmidtea mediterranea and Macrostomum lignano are innovative model organisms in stem cell research, because they possess a large and experimentally accessible population of somatic stem cells (neoblasts). Taken together with the experimental ease of these organisms to perform RNAi screening, they are very interesting to investigate cellular processes after exposure to the carcinogenic metal cadmium. S. mediterranea and M. lignano have a high cadmium tolerance in comparison with other invertebrates. Their neoblasts keep proliferating, or even increase their proliferation, during cadmium stress. Also, a decrease in the activity of anti-oxidative enzymes and in the expression of anti-oxidative Lecture Abstracts genes has been observed in S. mediterranea. A disturbed redox balance, resulting in altered gene expression profiles in function of (stem) cell proliferation, could therefore be the underlying mechanism of the cadmium- induced proliferation. As heat shock proteins (HSP) appeared to play a significant role herein, they were subsequently knocked down. A blocking of the heat shock response resulted in a higher cadmium sensitivity of S. mediterranea and a RNAi silencing of HSP60 and HSP90 in M. lignano produced a decrease in the number of mitotic cells and induced the expression of the HSP70 gene. The RNAi experiments as well as gene expression profiling are highlighted in this study, and an overview of activated stress mechanisms and their interactions is given.

Keywords: cadmium stress, molecular mechanisms, stem cells E-mail: [email protected]

Session 1.3 Reciprocity in grooming and food sharing among captive bonobos

Stevens J.M.G.1,2, Jaeggi A.V.3, Staes N.1,2

1 Royal Zoological Society of Antwerp, Antwerp 2 University of Antwerp, Antwerp 3 University of Zurich, Zurich

Primates are well known for the exchange of social services such as grooming behaviour and food sharing, which is often ultimately explained by reciprocity. Lecture Abstracts Lecture Research in chimpanzees and humans suggests that reciprocity is facilitated by an egalitarian social structure, where all individuals can potentially provide these services. Here we present results of our recent studies on the exchange of grooming and food sharing among captive bonobos, which we have shown to be less egalitarian. We found steep dominance hierarchies in all captive groups we studied. As predicted grooming and food sharing were less reciprocal than among chimpanzees. Grooming was not exchanged reciprocally on a short term basis, but only over longer periods of time. Food sharing interactions were generally not tolerant as dominant individuals claimed food by force, thus precluding reciprocal exchange. However, subordinates could sometimes increase their short-term food-getting success by grooming dominants beforehand. These results support the prediction that an egalitarian social structure is necessary for reciprocal exchange. We conclude that reciprocity may be less common among bonobos, as opposed to chimpanzees and humans, thus emphasizing their importance in the comparative study of social evolution among extant hominoids.

Keywords: Pan paniscus, reciprocity, dominance E-mail: [email protected]

Session 3.6 Chemical "versus" visual cues in newts (Salamandridae): experiments in total darkness and in a Y-maze

Treer D., Bossuyt F.

Amphibian Evolution Lab, Vrije Universiteit Brussel, Brussels

The use of pheromones for sexual communication has been observed in many species of the family Salamandridae. Most research was done on a species of the genus Cynops, where a species-specific male decapeptide was identified and pheromonal activity was described in detail. Here we performed two tests to analyze the relative importance of intersexual chemical and visual communication in two genera of newts during their reproductive season. To check for female attraction by a pheromone, we designed an experiment using a Y-maze apparatus. It demonstrated that female newts are significantly more attracted to a male experimentally accompanied by a pheromone, than to a male without that stimulus (p=0.008, N=13). However, after sensing the chemical stimulus, the visual stimulus seems to become equally important (p=0.048, N=13). To better understand the relative importance of pheromone communication, we subsequently observed courtship behaviour in complete Lecture Abstracts darkness using a camera and an infrared reflector. Here we observed that courtship could be induced, i.e. the female approached the male and the male responded by tail waving, but there was no reproductive success. We conclude that, in experimental conditions, chemical signals from both sexes are necessary and sufficient for attraction and initiation of courtship behaviour, but visual cues become equally important after chemical stimulus has been recognized by the animal.

Keywords: Lissotriton vulgaris, Ichthyosaura alpestris, sexual behaviour E-mail: [email protected]

Session 5.5 To fly or not to fly, that is the selection: Pogonus chalceus (Coleoptera) as a test case for adaptive genetic divergence in the absence of a geographic barrier

Van Belleghem S., Hendrickx F.

Ghent University, Ghent

There is an increasing interest in detecting genes, or genomic regions, that have been targeted by natural selection. During ecological specialization of populations in sympatry, signals of natural selection can be detected more Lecture Abstracts Lecture unambiguously due to effective recombination around divergently selected genes. The sympatric theory of divergence and speciation posits that ecological specialization to different environmental conditions can result in divergence and/or speciation in the absence of complete geographic isolation. Theory predicts that sympatric speciation is plausible, but only under very specific ecological and genetic conditions. However, owing to the lack of convincing examples in nature, sympatric speciation remains fiercely debated in evolutionary biology and, therefore, the occurrence and mechanisms of genetic population divergence in sympatry remain extremely difficult to test. Nevertheless, previous research revealed a striking example of sympatric divergence in progress in the ground beetle Pogonus chalceus. Two different ecotypes diverged in response to disruptive selection for at least two genetically based traits: wing size and allozymes of Isocitrate Dehydrogenase (IDH). Variation in neutral genetic markers, moreover, revealed that both ecotypes evolved in sympatry, but are already partly reproductively isolated. Given the incipient stage of this sympatric divergence, this model system offers a unique opportunity to test whether the theoretically assumed conditions for sympatric divergence indeed occur in nature. Moreover, the molecular genetic basis of the divergence in the IDH gene is being investigated.

Keywords: sympatric divergence, natural selection, genetics E-mail: [email protected]

Session 2.4 Evolutionary rates of morphological change for a Holocene morphospace expansion in Bellamya gastropods from Lake Malawi

Van Bocxlaer B.

Research Unit Palaeontology, Department of Geology and Soil Science, Ghent University, Krijgslaan 281 S8, B-9000 Ghent, Belgium. Tel: 003292644605; Fax: 003292644608.

Evolutionary punctuations are hard to study because they occur faster than is

observable in the fossil record, but generally too slow for study on biological timescales. We studied a potential evolutionary punctuation in four endemic Bellamya gastropod species derived from a common ancestor that is preserved in early to middle Holocene, radiocarbon-dated lacustrine deposits in the Malawi Basin. Morphometric comparison of extant and fossil morphs with semi-landmark analysis and traditional measurements documents a 3.1-5.4 times morphospace expansion since the middle Holocene. We combine modeling of evolutionary divergence and calculation of evolutionary rates of

phenotypic change to show that morphological divergence could have Lecture Abstracts completed within 25 to 500 years for each species depending on trait heritabilities and the strength of selection. The divergence results from rates of morphological change within or above the genetic drift range but slower or equal to those commonly observed in selection experiments. We also illustrate that geographic isolation in separate drainage basins allowed cladogenesis and morphological conservatism in riverine taxa, which may result in the recognition of pseudo-stationary lineages, while speciation in lacustrine environments led to increased disparity by morphological adaptation following greater ecological opportunity.

Keywords: punctuated equilibrium, speciation, phenotype adaptation E-mail: [email protected]

Session 6.4 Bite force in the African Fukomys mole-rats (Bathyergidae, Rodentia)

Van Daele Paul A.A.G.1, Bappert M.-T.2, Desmet N.1, Burda H.2, Adriaens D.1

1 Evolutionary Morphology of Vertebrates, Ghent University, K.L. Ledeganckstr. 35, B-9000 Ghent, Belgium 2 Universität Duisburg –Essen, Algemeine Zoologie, Universitätsstr. 5, 45141 Essen, Germany

In an ecomorphological context bite force measurements are used as a proxy to estimate biting performance. We compared two approaches for gauging bite Lecture Abstracts Lecture force in a study of inter- and intraspecific variation in African mole-rats. Fukomys (syn. Cryptomys) are chisel-tooth diggers which excavate extensive tunnel systems along which they forage for geophytes. Their obligatory subterranean activities as well as agonistic encounters require an efficient jaw apparatus. Firstly in vivo measurements were compared with data obtained from a static bite model. Maximal bite force data were collected in several species of the Fukomys radiation from the Zambezian region using a Kistler force transducer. The bite model used PCSA, mass, density and insertion coordinates of the jaw muscles as input data. Secondly results of the bite force trials were related to skull size and skull shape variation using landmark-based geometric morphometrics. Results: 1. the giant mole-rat (F. mechowii) has the highest mass-specific bite force among extant mammals, 2. cross-breeds between chromosomal species of the F. micklemi clade show a negative heterotic effect, larger animals producing the lower bite-force and 3. interspecific comparisons among Fukomys show subtle but significant differences in cranial shape, which may help explain observed differences in maximal bite force between Fukomys species. Taken together our results provide evidence that considerable variation in the whole jaw apparatus among Fukomys is present in spite of the thresholds set by the underground environment. Changes in the form of the skull are related to biting performance and hence may have an adaptive value.

Keywords: adaptation, biting performance, geometric morphometrics E-mail: [email protected]

Session 5.6 Dna repair in putative ancient asexual darwinulids (Ostracoda)

Van den broecke L.1,2, Schön I.2, Vanfleteren J.1, Martens K.2

1 Departement of Biology, Ghent University , K.L.Ledeganckstraat 35, 9000 Gent, Belgium. 2 Departement of Freshwater Biology, Royal Belgian Institute of Natural Sciences, Rue Vautier, 1000 Brussels, Belgium. [email protected]

The paradox of sex remains the queen of questions in evolutionary biology1. The existence of putative ancient asexuals defies standing evolutionary theory on the disadvantages of asexuality, which is why they have been called “ancient asexual scandals” 2. One out of three examples of the putative ancient asexual scandals from the animal kingdom are the darwinulid ostracods: they have been asexual for as long as 200 million years3. The species Darwinula stevensoni has most likely reproduced without sex for 25 myr4. It shows exceptionally low levels of genetic diversity in its nuclear genome and has a general purpose genotype (GPG) with a broad tolerance towards temperature and salinity5, while some other darwinulids do not have such a GPG6.One of the most likely explanations for the long-term persistence of D. stevensoni without sex is highly efficient DNA repair7. The major types of DNA damage induced by Lecture Abstracts UVB are cyclebutane pyrimidine dimers (CPDs) and (6-4) photoproducts (6- 4PPs). The amount of Cyclobutane Pyrimidine dimers (CPDs) at different doses being introduced into the whole genome by UV-B will be estimated using Anti- CPD monoclonal antibodies. Up to now, 450 bp of the mt COI gene is all the sequence information available from the mitochondrial genome of D. stevensoni and its close relatives. This is why we will try to unravel the sequence of the entire mitochondrial genome of D. stevensoni.

Keywords: Darwinula stevensoni, ancient asexual, DNA repair E-mail: [email protected]

Session 8.3 Contemporary morphological changes in Lake Victoria cichlids

van Rijssel J.C.1,2, Witte F.1,2

1 Leiden University 2 NCB-Naturalis

Lake Victoria's cichlids have drawn the attention of many evolutionary biologists all over the world. The dramatic ecological changes in the lake during the past three decades provide a unique opportunity to study environmental effects on cichlid morphology. Preliminary research has revealed that the lake's

Lecture Abstracts Lecture haplochromine cichlids tend to be extremely plastic and sensitive to the environmental changes. Some species were able to adapt their morphology within a period of two decades. Through geometric morphometric analyses at three year intervals, this study shows how different haplochromine species changed their body shape over the past 30 years. Different zooplanktivorous species show a considerable amount of morphological convergence. Male cichlids seem to respond stronger to environmental modifications than females. Remarkably, Lake Victoria currently seems to change into the

direction of the situation of the early 1970s and cichlid morphology tends to follow the same path. These fascinating changes are likely the result of phenotypic plasticity and genetic modifications and might reveal why some species recovered, whereas others did not.

Keywords: Lake Victoria, cichlids, geometric morphometry E-mail: [email protected]

Session 8.2 Kinematic modulation and feedback control of suction feeding in function of escape responses of prey in a piscivorous fish

Van Wassenbergh S., De Rechter D., Aerts P.

Universiteit Antwerpen, Antwerpen

Previous studies have shown that evasive prey generally elicit a different kinematic pattern of prey capture from suction feeding fish compared to non- evasive types of prey. However, no evidence exists that predatory fish can modulate their prey capture kinematics in response to whether or not an elusive prey performs an escape response. Here, we analysed prey capture kinematics of a specialist piscovore (asp, Aspius aspius) during feeding on untethered, live goldfish, which regularly displayed escape attempts when attacked by the asp. Significant modulation occurred in function of the escape attempts of prey: mouth opening was prolonged and increased in magnitude, and one individual also showed an increased hyoid depression when feeding on prey trying to escape. As the orientation of the prey with respect to the predator prior to the start of mouth opening was related to the probability of observing an escape attempt, asp could theoretically perform this type of Lecture Abstracts modulation by a priori choosing a pre-programmed motor pattern. However, since contact between the prey and the asp’s mouth appeared to be a factor improving the timing of mouth closing, this fine-tuning of prey capture kinematics is more likely to be caused by peripheral feedback control.

Keywords: prey-capture, kinematics, modulation E-mail: [email protected]

Session 5.2 Evolutionary origin of structural proteins in anuran toe pads

Vandebergh W., Bossuyt F.

Amphibian Evolution Lab, Vrije Universiteit Brussel, Brussels

Toe pads are an intriguing example of an ecological adaptation to an arboreal or riparian lifestyle in amphibians. By adjusting their sticking abilities to dry and wet circumstances, the typical hexagonal cell pattern with micro-projections and channels in between the cells of the toe pad are essential in creating the perfect fit to different surface types. Toe pad cells consist of structural proteins

Lecture Abstracts Lecture that are capable in withstanding mechanical stresses while maintaining proper elasticity. Although the importance of such proteins is well acknowledged, there are no studies on their molecular background. We designed subtracted cDNA libraries from the toe pads of Hyla cinerea and Dendrobates auratus and screened for the presence of specific structural proteins, i.e. present in the toe pad but not in the adjacent finger or toe, and performed phylogenetic analyses to address the evolutionary origin of these structural proteins. We used gene expression data to further determine tissue specificity and reconstruct the

functional evolution of proteins required for toe pad cell integrity and flexibility. Our study reveals specialized structural proteins in anuran toe-pads and reveals their evolutionary relationships with other vertebrates. These data suggest a common molecular basis for the structural capacity of toe pads in anurans and sheds light on how this complex structure could originate multiple times in anuran evolution.

Keywords: toe pads; structural proteins; amphibians E-mail: [email protected]

Session 10.5 A vocal ethogram for Fukomys micklemi (Bathyergidae, Rodentia)

Vanden Hole C., Van Daele P.A.A.G., Desmet N., Mertens J., Adriaens D.

Ghent University, Ghent

African mole-rats (Bathyergidae) are subterranean rodents which live in social groups. To enhance integration of individuals into a social group, the development of efficient communication signals is necessary. Communication in African mole-rats, however, is severely constrained by the properties of the subterranean habitat and by the specialized auditory system. This study focused on acoustic communication. The main aim was to construct a vocal ethogram. To this end more than 4000 vocalizations were recorded, of which 2208 were analyzed in spectrograms. In combination with information from molecular and morphological studies, ethological data will ultimately help to gain further insight into the complex species relations in the genus Fukomys. In one colony of Fukomys micklemi sound recordings were made and combined with behavioural observations, linking vocal communication to behaviour. An extensive vocal repertoire was revealed for Fukomys micklemi. Sixteen Lecture Abstracts different adult specific calls and four juvenile specific calls were distinguished, based on their physical characteristics derived from the spectrograms and the associated behaviours. The adult specific calls were further subdivided into five call-categories: contact calls, mating calls, distress calls, agonistic calls and submissive calls. Certain call-types served multiple functions. As expected for subterranean animals, the vocalizations were situated in the low to middle frequency range. In general, the extensive vocal repertoire of F. micklemi is quite comparable to that of Fukomys anselli and Heterocephalus glaber, two other social species. The large number of call-types contrasts with the limited vocal repertoire of solitary species.

Keywords: African mole-rats, behaviour, vocal communication E-mail: [email protected]

Session 4.3 Characterization of the putative epithelial stem cells involved in continuous tooth replacement in Salmo salar

Vandenplas S.1, Willems M.1, Soenens, M.1, Witten P.E.1, Hansen T.2, Fjelldal P.G.2, Huysseune A.1

1 Biology Department, Ghent University, K. L. Ledeganckstraat 35, B-9000 Ghent, Belgium 2 Havforskningsinstituttet (IMR), Matre 5, 5984 Matredal, Norway

With the exception of mammals, tooth-possessing vertebrates have the ability

Lecture Abstracts Lecture to replace their teeth throughout life. It has been suggested that adult epithelial stem cells are required for continuous tooth replacement (Huysseune & Thesleff 2004). The dentition of Atlantic salmon (Salmo salar), a teleost fish and member of the salmonid family, has been well characterized (Huysseune et al. 2007). Similar to other salmonids, replacement teeth develop without the involvement of a successional dental lamina. Presumably epithelial stem cells reside in a cell layer between the inner (IDE) and outer dental epithelium (ODE), termed middle dental epithelium (MDE) (Huysseune & Witten 2008).

Their progeny is assumed to translocate to the ODE to form a replacement tooth (Huysseune & Witten, 2008). We test this hypothesis by studying cell proliferation dynamics and the presence of label retaining cells (LRC). 3D reconstructions based on histological sections were made to visualize immunostaining patterns and the spatial relationship between the potential stem cell niche and the developing replacement tooth. Different stages of tooth replacement were labelled for proliferating cells in late G1-phase and S- phase of the cell cycle by means of PCNA (Proliferating Cell Nuclear Antigen) immunostaining. A BrdU (Bromodeoxyuridine) pulse-chase experiment was performed to quantify BrdU positive cells in IDE, ODE and MDE during different chase times. The detection of LRC in long chase times could be a first indication of stem cells. To distinguish these from terminally differentiated cells we will set up a double PCNA-BrdU immunostaining protocol in the future.

Keywords: tooth replacement; epithelial stem cells; BrdU E-mail: [email protected]

Session 9.1 Population genetic differences along a latitudinal cline between original and recently colonized habitat in a butterfly

Vandewoestijne S., Van Dyck H.

Behavioral Ecology and Conservation Group, Biodiversity Research Centre, Earth and Life Institute, Université catholique de Louvain (UCL), Croix du Sud 4, B-1348 Louvain-la-Neuve, Belgium

Background: Past and current range or spatial expansions have important consequences on population genetic structure. Habitat expansion, i.e. changing habitat associations, may also influence genetic population parameters, but has been less studied. Here we examined the genetic population structure of a Palaearctic woodland butterfly Pararge aegeria (Nymphalidae). In NW-Europe, it has recently colonized agricultural landscapes with hedgerows. Butterflies from woodland and agricultural landscapes differ in several phenotypic traits (including morphology, behavior and life history). We investigated whether phenotypic divergence is accompanied by genetic divergence between landscape populations along a 700 km latitudinal gradient. Methodology/Principal Findings: Populations (23) along the gradient in both landscape types were sampled and analyzed using microsatellite and allozyme markers. A general decrease in genetic diversity with latitude was detected, likely due to post-glacial Lecture Abstracts colonization effects. Contrary to expectations, agricultural landscapes were not less diverse and no significant bottlenecks were detected. Nonetheless, a genetic signature of recent colonization is reflected in the absence of clinal genetic differentiation within the agricultural landscape, significantly lower gene flow between agricultural populations (3.494) than between woodland populations (4.183), and significantly higher genetic differentiation between agricultural (0.050) than woodland (0.034) pairwise comparisons, likely due to multiple founder events. Globally, genetic data suggest multiple long distance dispersal/colonization events and subsequent high intra- and inter-landscape gene flow in this species. PGM (phosphoglucomutase) deviated from other enzymes and microsatellite markers, and hence may be under selection along the latitudinal but not the landscape gradient. Phenotypic divergence was greater than genetic divergence, indicating directional selection on some flight morphology related traits. Main Conclusions/Significance: Clinal differentiation characterizes the population structure within the original woodland habitat. Genetic signatures of recent habitat expansion remain, notwithstanding high gene flow in this range- and habitat expanding butterfly species. After differentiation through drift was excluded, both latitude and landscape were significant factors inducing spatially variable phenotypic variation. Further reciprocal transplant experiments will determine to what extent phenotypic plasticity and/or adaptation influence phenotypic variation.

Keywords: genetic population structure, range/habitat expansion, butterfly E-mail: [email protected]

Session 10.2 Wolbachia-induced sex-ratio distortion in the solitary spider Oedothorax gibbosus and its potential implications on sexual selection

Vanthournout B.1, Hendrickx F.2

1 Terrestrial Ecology Unit, Department of Biology, Ghent University, Ledeganckstraat 35, 9000 Ghent, Belgium 2 Royal Belgian Institute of Natural Sciences, Vautierstraat 29, 1000 Brussels, Belgium

Lecture Abstracts Lecture According to the sex-allocation theory of Fisher, a 50:50 sex ratio is considered to be an evolutionary stable strategy. In a population with uneven numbers of males and females, the underrepresented sex will have a fitness advantage at the time of mating, hence increasing in the population. This ultimately leads to the evolution of a stable 50:50 sex ratio.Despite this theory, many examples of distorted sex ratios can be found in nature. This is also the case in the male dimorphic and solitary dwarf spider (Oedothorax gibbosus), for which populations are female biased. Specific breeding designs show that the sex

ratio distortion is primarily maternally inherited and correlated with the presence of the endosymbiotic bacteria (Wolbachia).This first direct evidence of a female biasing effect of this bacterium in spiders was further confirmed by antibiotic curing of females, which restored the sex ratio to an equal proportion of males and females. Endosymbiotic bacteria can potentially have profound effects on its host ecology and evolution by altering sexual selection pressures. Therefore, the potential interaction of maternally inherited bacteria on the effect of the morph specific reproductive strategies are discussed within the framework of the apparently stable dimorphism observed in this spider species.

Keywords: sex ratio, endosymbionts, sexual selection E-mail: [email protected]

Session 7.3 Does non-random segregation of DNA-strands occur during stem cell division in the flatworm Macrostomum lignano?

Verdoodt F.1, Willems M.1, Mouton S.1, Houthoofd W.1, Ladurner P.2

1 Nematology Section, Ghent University, Belgium 2 Institute of Zoology, University of Innsbruck, Austria

The ‘immortal strand hypothesis’ was proposed by Cairns (1975) as a means by which stem cells might limit acquiring mutations during DNA-replication. According to this hypothesis, there is a non-random segregation of DNA strands during stem cell division: the sister chromatids containing the older template DNA, are selectively retained in the daughter cell, destined to be the renewed stem cell. Labelling these template strands during development, results in ‘label retaining cells’ (LRC’s), cells which retain label through an indefinite number of cell divisions. The younger DNA-strands (with any mutations acquired during replication) are passed on to the tissue committed cell. In Macrostomum lignano (Platyhelminthes), the ‘immortal strand hypothesis’ can be studied in vivo, performing sequential pulses with DNA-analogues, such as chlorodeoxyuridine and iododeoxyuridine. Exposure to the first DNA-analogue Lecture Abstracts at different stages of embryonic and post-embryonic development, followed by chase times of several weeks or months, resulted in a relatively small population of LRC’s. Mitotic activity of these cells was tested, by means of a second continuous pulse with a different DNA-analogue, which allowed us to determine whether random or non-random segregation of DNA-strands occurs in these cells.

Keywords: immortal strand hypothesis AND stem cells AND flatworms E-mail: [email protected]

Session 11.1 The effect of sheep grazing on the breeding success of the Woodlark (Lullula arborea)

Vermeersch G., Strubbe D., De Bruyn L.

Species diversity, Research Institute for Nature and Forest (INBO), Kliniekstraat 25, B-1070 Brussels, Belgium

The Woodlark (Lullula arborea) is a multi-brooded ground-breeding insectivorous passerine of high conservation concern (listed on Annex I of the European Birds Directive). In Flanders it occurs mainly in large heathland areas, Lecture Abstracts Lecture many of which are grazed by large herbivores for nature management purposes. The aim of our research was to study whether there is an impact of grazing on breeding success. Our study area is a large (>1500ha) heathland nature reserve in the northern part of the Antwerp province and across the border in the Netherlands, called ‘Grenspark De Zoom-Kalmthoutse Heide’. Sheep grazing within fixed plots is only implemented in the Belgian part of the nature reserve, the Dutch part remains ungrazed. During the breeding season (march-june) we searched and found 75 nests (40 grazed / 35 ungrazed). We focused on the first two broods of each pair that we located. In most cases, both clutches of individual pairs could be located, most of them in the egg- phase. Breeding success was significantly higher during the first brood and we found no difference in breeding success between grazed and ungrazed plots while sheep were still absent (only present during the second brood). However, we found that there is a significant negative impact of the presence of sheep on breeding success of the second brood. This suggests that nests are lost either directly by trampling or indirectly by predation made possible by females leaving the nest being disturbed by the sheep herd.

Keywords: grazing, breeding success, ground breeder E-mail: [email protected]

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Session 7.4 The cadherin-catenin complex during zebrafish tooth development

Verstraeten B.1, Sanders E.1,2,3, D’Heuvaert T.1, van Hengel J.2,3, Huysseune A.1

1 Evolutionary Developmental Biology, Ghent University, Belgium 2 Molecular Cell Biology Unit, Department for Molecular Biomedical Research, VIB Ghent, Belgium 3 Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium

The development of teeth is the result of interactions between competent mesenchyme and epithelium, both of which undergo extensive morphogenesis. The importance of cell adhesion molecules in morphogenesis has long been acknowledged but remarkably few studies have focused on the distribution and function of these molecules in tooth development. We analyzed the expression pattern of an important epithelial cadherin, E-cadherin, during the formation of first-generation teeth as well as replacement teeth in the zebrafish, using in

situ hybridization and whole mount immunostaining to reveal mRNA Lecture Abstracts expression and protein distribution. The uninterrupted expression of E- cadherin in the epithelial-derived part of the tooth indicates that downregulation of E-cadherin is not required for formation of an epithelial tooth bud.In order to identify the intracellular partners in the adhesion complex, we are now embarking on a study of the expression pattern and distribution of several cadherin-associated molecules like p120catenin, β- catenin and plakoglobin and their role during the renewal of teeth.

Keywords: tooth development, cell adhesion molecules, morphogenesis E-mail: [email protected]

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Session 8.4 Do colour traits signal individual quality in the lizard Podarcis siculus?

Vroonen J.1, Fulgione D.2, Maselli V.2, Van Damme R.1.

1 Department of Biology, University of Antwerp, Universiteitsplein 1, B-2610 Wilrijk, Belgium 2 Department of Structural and Functional Biology, University of Naples, “Frederico II”, via Cinthia Monte Sant’Angelo bld 7, I-80126 Naples, Italy

Colour variation is widespread among lizard species and has been interpreted as an adaptive compromise between conflicting selective pressures arising Lecture Abstracts Lecture from antipredatory and thermoregulatory requirements and sexual selection. In many species colour is used in social signalling and may serve as an honest signal of individual quality. Studies on several species have shown that characteristics of colour may be related to dominance status, aggression and immune response. We studied aspects of colour (e.g. UV and blue chroma of the blue lateral spot and throat colour) in two populations of Podarcis siculus in Italy and investigated if they were correlated to other individual traits that are related to fitness. To this end we measured the SVL, body mass, body condition and the immune response with the delayed cutaneous hypersensitivity (DCH) test. We also assessed the level of sexual dichromatism of the two populations. Preliminary results suggest that certain colour traits, like UV chroma, may signal aspects of individual quality in Podarcis siculus.

Keywords: colour, signal, individual quality E-mail: [email protected]

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Session 11.5 Use of physiologically based pharmacokinetic models in marine mammal toxicology

Weijs L.1,2, Yang R.S.H.3, van Elk N.4, Jauniaux T.5, Das K.6, Covaci A.1,2, Blust R.1

1 Laboratory of Ecophysiology, Biochemistry and Toxicology, Department of Biology, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium 2 Toxicological Centre, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk, Belgium 3 Quantitative and Computational Toxicology Group, Department of Environmental and

Radiological Health Sciences, Colorado State University, 1680 Campus Delivery, Fort Collins, CO 80523, USA 4 Dolfinarium Harderwijk, Strandboulevard 1, 3841 AB Harderwijk, The Netherlands 5 Department of Veterinary Pathology, University of Liège, 4000 Liège, Belgium 6 Laboratory for Oceanology-MARE Center, University of Liège, 4000 Liège, Belgium

Physiologically based pharmacokinetic (PBPK) models are mathematical models

which are largely based upon the physiological characteristics of the species Lecture Abstracts and upon the biochemical properties of the selected chemical. They give important information about the kinetics and bioaccumulation of pollutants inside the body. As such, they can have a great predictive value and they can be of major importance for risk assessment of chemicals in marine mammals. PBPK models were made for some selected polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) in order to find out more about the bioaccumulation of these compounds in tissues of harbour porpoises. Harbour porpoises (Phocoena phocoena) have relatively long life spans, are common cetaceans in the European North Sea, a heavily polluted area, and are known to be very sensitive to pollution. Models consist of 5 compartments, namely liver (metabolism), blubber (storage), kidney (excretion), brain (neurotoxicity) and the rest of the body and were developed using Berkeley Madonna software and parameters found in the literature. All models were evaluated using existing datasets from the literature and data from own analyses performed with gas chromatography – mass spectrometry (GC-MS). Data were from stranded or dead porpoises and covered different locations in the distribution range of this species (Black Sea, North Sea) and different years to assess spatial and temporal trends. Results show that PBPK models are a good approach of reality and that they can be used as a non-destructive tool for predicting pollution in harbour porpoises or possibly in marine mammals in general.

Keywords: PBPK, harbour porpoises, pollution E-mail: [email protected]

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Session 9.4 Spatiotemporal variation in the diversity of orb weaving spiders in a fragmented Afrotropical forest

Wiersma E.1,2, Bonte D.1, Lens L.1

1 Terrestrial Ecology Unit, Ghent University, K.L. Ledeganckstraat 35, B-9000 Ghent, Belgium. 2 Invertebrate Zoology Section, The National Museums of Kenya, PO Box 40658, 00100 Nairobi, Kenya.

Understanding the causes of variation in species assemblages requires analyses at multiple spatial and temporal scales. Factors related to geographical Lecture Abstracts Lecture configuration of habitats and local environmental conditions simultaneously govern species diversity distribution. However, where fragmentation and disturbance occur, these factors change. We used Afrotropical orb weaving spiders within a complex of forest fragments to study how species assemblages are affected by local environmental variables and spatial configuration along spatiotemporal scales. To describe patterns in species composition, total spider richness was decomposed into independent alpha and beta diversity components. Variation partitioning was applied to assess the unique and shared contribution of microclimate variables, prey abundance and vegetation structure in explaining variation in species richness, seasonal and spatial turnover. We found that the influences of habitat-related factors and spatial configuration on spatiotemporal turnover are scale dependent. Even at a small spatial scale, geographical position is fundamental in explaining variation in seasonal species turnover whereas at a larger scale local environmental variables are more important. Most of the explained variation in yearly spatial turnover was related to the environmental factors. The variability in space increased (i) with a harsher climate, (ii) with higher but more variable prey biomass abundance and (iii) with higher leaf area index. We conclude that examining both spatial and temporal beta diversity is important because geographical and environmental changes caused by forest fragmentation are expected to cause shifts in spatial species distribution as well as temporal turnover in species assemblages.

Keywords: species diversity, spatiotemporal scale, variation partitioning E-mail: [email protected]

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Session 10.3 Clusters formation in Eisenia fetida (Oligochaeta, Lumbricidae)

Zirbes L.1, Deneubourg J.-L.2, Brostaux Y.3, Haubruge E.1

1 Unity of Functional and Evolutionary Entomology, University of Liege Gembloux Agro-Bio Tech, Gembloux, Belgium 2 Unity of Social Ecology, University of Brussels, Brussels, Belgium 3 Unity of Applied Statistics, Computer Science and Mathematics, University of Liege Gembloux Agro-Bio Tech, Gembloux, Belgium

Earthworms represent up to 70 per cent of soil biomass and are the major representatives of the drilosphere and the detritusphere. More particularly, Eisenia fetida is an important ecological earthworm species that is commonly used in industrial vermiculture and vermicomposting and is the model specie for all scientist ecotoxicological researches. Moreover, like some other lumbricids, Eisenia fetida lives in patchy distribution and in rearing conditions some earthworms group are observed. These earthworms groups are often maintained by contact between individuals and some earthworms balls can be formed out of soil or in rearing substrates. However, chemical ecology and behaviour of this earthworm are poorly studied. Therefore this information Lecture Abstracts could have an important impact on soil ecology’s and on fundamental earthworm biology’s knowledge. As a first step to achieve such understanding, we have focused our study on intra-specific interactions in E. fetida to explain earthworms group formation. We have explored two mechanisms of earthworms groups formation: retention of individuals and earthworms attraction by conspecifics in circular arena and in two-arm olfactometer. We have proved that retention between individuals maintains group formation and that one earthworm is attracted by an earthworms group.

Keywords: Earthworms, Behaviour E-mail: [email protected]

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Lecture Abstracts Lecture

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POSTER ABSTRACTS

P.36 The acute toxicity of ZnO and SiO2 nanoparticles to aquatic organisms

Adam Nathalie, Knapen Dries, Blust Ronny

University of Antwerp, Antwerp

The production of metal oxide nanoparticles recently has increased and in the future nanoparticle based products will become commercially relevant. This increasing production will inevitably lead to a run-off to the aquatic environment. However, the knowledge of the potential risk of metal oxide nanoparticles to aquatic organisms is still limited. Therefore, our research focuses on the toxicity of these types of nanoparticles, more specifically on ZnO and SiO2. We tested the acute toxicity of ZnO and SiO2 nanoparticles.

Poster Abstracts Poster Crustaceans (Artemia salina and Daphnia magna), algae (Pseudokirchneriella subcapitata) and fish (Danio rerio) were exposed to both the powder as well as the dispersion form of SiO2 and ZnO nanoparticles. After 48h to 96h (depending on the type of species) endpoints were determined (mortality for A. salina, D. magna, D. rerio and growth inhibition for P. subcapitata). Additionally, the toxicity of nanoparticles was compared to that of standard ZnO and SiO2 salts. Our results showed no toxic effect of any of the 3 tested forms of ZnO to A. salina, D. rerio, nor of SiO2 to A. salina, D. magna, D. rerio. However, ZnO

nanoparticles and salt appeared to be toxic to D. magna (EC50 dispersion: 2.401mg/L, EC50 nanopowder: 3.104mg/L, EC50 bulk: 4.216mg/L) and P. subcapitata (EC50 nanodispersion: 0.027mg/L, EC50 nanopowder: 0.045mg/L, EC50 bulk: 0.044mg/L). P. subcapitata did experience an inhibition of growth when exposed to the SiO2 nanodispersion (EC50: 23.14mg/L), nanopowder (EC50: 48.59mg/L) and salt (EC50: 27.99mg/L). In the future chronic toxicity tests will be performed to gain more insight in nanoparticle toxicity.

Keywords: nanoparticles, aquatic, toxicity E-mail: [email protected]

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P.44 Movements, habitat choice and breeding success of the marsh harrier, Circus aeruginosus in fragmented landscapes

Anselin Anny, De Bruyn Luc

Research Institute for Nature and Forest (INBO), Kliniekstraat 25, B-1070 Brussels, Belgium

The marsh harrier, Circus aeruginosus, a marshland species of the Annex I of the EU Birds’ Directive, occurs in a range of open habitats, mainly wetlands. These are rare in the highly fragmented landscape of Flanders (Belgium). During the last decade there is a decline of breeding numbers in its NW-Europe range. The causes can be multiple. Changes in marshland breeding habitat quality and landuse in the feeding home ranges could cause local changes in breeding success that might lead to sink populations. Locally, the species

started to shift to intensive farmland (cereal fields) as a nesting habitat. Little is known about the long-term effect of this behaviour on population demography. INBO is currently preparing a research project on the species (together with other partners). We will include populations from Belgium and The Netherlands at sites of different fragmentation levels. The first objective is to collect data on dispersal and other movements (home-ranges) using ringing and radiotagging. The second aim is to assess breeding success in habitats of different sizes and habitat types. The data should give us insights in the magnitude of interchange of birds among populations and sites, and on habitat Poster Abstracts use, and answer questions as: (1) are there differences between wetland and farmland, (2) does this depend on the fragmentation level, (3) does birds (adults/offspring) that bred successfully in farmland show habitat fidelity, (4) can this be linked to bird performance? This knowledge is important to evaluate the overall population status and to provide conservation policy advice.

Keywords: marsh harrier, movements, breeding success E-mail: [email protected]

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P.37 Short-term effects of an organochloride pesticide (endosulfan) on amphibian tadpoles

D’hooghe B.1, Brasseur C.2, Kestemont P.3 Denoël M.1

1 Behavioural Biology Unit, University of Liege, Quai Van Beneden 22, 4020 Liège, Belgium 2 Laboratory of Mass Spectrometry, University of Liege, Allée de la Chimie 3, 4000 Liège, Belgiu 3 URBO, University of Namur, 5000 Namur, Belgium

Many studies have shown the harmful effect of endosulfan on amphibian tadpoles. It affects survival after long or high exposition and acts on the nervous system. However, little is known on behavioural effects on the short term after exposition to environmental concentrations. Our aim was then to stick particularly on this point in using tadpoles of the common frog, Rana Poster Abstracts Poster temporaria. The tadpoles were placed in a replicated design with five treatments, including controls and different pesticide concentrations during eight days, but only the first four days with pesticide. Ten behavioural patterns were recorded in the 20 aquaria three times a day during eight days. Morphology and survival were also studied. Endosulfan affected survival, growth and behaviour. The most outstanding results are the immobility and “spirling” behaviours. In correlation with the immobility, we observed a strong reduction in breathing and movements up to water surface. Feeding was negatively affected. Body mass and length of contaminated tadpoles were lower than those in control conditions. To conclude, these results show that endosulfan is a harmful substance on the very short term as it deeply affects behaviour, growth and survival at environmental concentrations. Even before survival is affected, their altered behaviour could make tadpoles easy prey and thus affect indirectly survival. The present results show that endosulfan could cause amphibian declines in area where there are used and that much caution much be taken for the use of this chemical at proximity of water bodies.

Keywords: ecotoxicology, behaviour, amphibian E-mail: [email protected]

110

P.32 Developing an acoustic map of the north coast of Moorea, French Polynesia: a roadmap for settling larvae

Berten L.1, Lecchini D.2, Simpson S.D.3, Parmentier E.1

1 Functional and Evolutionary Morphology Laboratory, Liège University, Liège, Belgium 2 Centre IRD Nouméa, Institut de Recherche pour le Développement, UR 227 CoReUs, Noumea, New Caledonia 3 School of Biological Sciences, University of Bristol, Bristol, UK

Contrary to Cousteau, the underwater realm is not a silent world. Abiotic (waves, wind and rain) and biotic (crustacean, fishes, cetaceans, etc) components combine to produce complex sounds which provide a valuable cue for orientation for the larvae of fish and invertebrates as they settle from the plankton to benthic habitat. The marine environment is loudest in shallow habitat near land, and sound intensity decreases with distance into the open ocean. In this study from French Polynesia the propagation of sound with respect to distance from habitat was studied intensively for the first time. During February and March 2010, we recorded sounds on the North Coast of Moorea Island. A library of one-minute recordings was made using a recorder and hand-held hydrophone from a kayak along transects heading into the open

ocean, at 20, 100, 250, 500, 750, 1000, 1500 and 2000m from the reef crest, at Poster Abstracts day, dusk and night, and in different weather conditions. The recordings were cleaned and analysed with Avisoft SasLab Pro to explore and characterise the propagation of sound from the reef crest to the ocean. This analysis is valuable in developing theory to estimate the distance from the coast from which fish larvae are able to detect and orientate to habitat, and provides a ground- truthed soundscape model that allows the conflicting effects of anthropogenic noise to be investigated.move toward them.

Keywords: sound propagation, French Polynesia E-mail: [email protected]

111

P.52 A study of the genomic integrity and the gene expression pattern of an asexual bdelloid rotifer species submitted to desiccation

Hespeels Boris, Li Xiang, Van Doninck Karine (contributed equally)

Unit of Research in Organism Biology (URBO), University of Namur (FUNDP)

Asexual organisms are usually short-lived in evolutionary time. However, one of the most notorious exceptions is the group of bdelloid rotifers, persisting asexually for more than 40 myr. Another prominent feature of bdelloid rotifers is their tolerance to desiccation at any stage in their life-cycle. Moreover, they are extraordinary resistant to ionizing radiation, being able to resume reproduction after a dose of radiation that causes hundreds of DNA double strand breaks (DSBs). As in Deinococcus radiodurans, it is speculated that

Poster Abstracts Poster desiccation and radiation in bdelloid rotifers induces DNA DSBs. However, it is not yet demonstrated whether desiccation indeed induces this DNA damage in bdelloids and which genes are expressed to recover from desiccation. Our first study desiccated bdelloid rotifers for different lengths of time (1 to 42 days) and at each time point we checked the survival and the genomic integrity of desiccated bdelloids by pulsed field gel electrophoresis (PFGE). This experiment determines whether desiccation induces DNA DSBs in bdelloids and at which time point DNA breaks appear. Second, we investigated the gene expression pattern of bdelloids experiencing desiccation. More specifically, cDNA was prepared from bdelloid rotifers experiencing different stresses related to desiccation and submitted for Solexa sequencing. Currently, the complete genome and the cDNA of the bdelloid species Adineta vaga are being sequenced at Genoscope (Evry). Finally, the same PFGE and cDNA sequencing analyses are conducted on A. vaga after exposure to ionizing radiation. These studies should provide insights into the genetic features of desiccation and radiation resistance in this asexual lineage.

Keywords: asexual, bdelloid rotifer, desiccation E-mail: [email protected]

112

P.42 The impact of social hierarchy on the parasitic burden in Soay sheep in Belgium

Brakel I.1,2, Levecke B.1,2, Stevens J.2

Although it has been hypothesized that dominant animals harbor fewer parasites compared to submissive animals, studies assessing the relationship between the rank of animals within a social hierarchy and their parasite burden are scarce. Therefore, the objective of the present study was to assess the impact of social hierarchy on the parasitic burden in Soay sheep. To this end, the social hierarchy within a flock of 18 animals (15 ewes) housed at Planckendael Animal Park (Belgium) was determined by all occurrences sampling method (53.5 hours of observation). Fecal samples were examined using the McMaster technique to detect and quantify parasite infections of the gastro-intestinal tract by means of number of eggs excreted. Nonparametric tests were used to test for differences in parasite burden across ranks. Within

the flock there was a linear hierarchy (Landau's linearity index = 0.68 and Poster Abstracts steepness = 0.49), revealing the presence of three ranks. 10 out of 18 animals were excreting eggs, varying from 200 to 1200 eggs per gram feces. Overall, there was a significant difference in parasite burden across the three defined ranks (χ2 = 10, p = 0.007). However, the difference in parasite burden between the two lowest ranks was marginal (z = 1.37, p = 0.11) and this in contrast with the other pair-wise comparisons (z = 2.45-2.56, p = 0.012-0.006). These results confirm the correlation between social hierarchy effect and parasite burden in Soay sheep, which merits further attention in both the field of animal behavior and veterinary medicine.

Keywords: social hierarchy, parasite burden, Soay sheep E-mail: [email protected]

113

P.48 Hydrodynamics of prey capture in the semi-aquatic snakes: a broad taxonomical study

Brecko Jonathan1, Van Wassenbergh Sam1, Herrel Anthony2, Aerts Peter1,3, Van Damme Raoul1

1 Antwerp University, Antwerp 2 Natural History Museum Paris, Paris 3 Ghent University, Ghent

Semi-aquatic snakes are interesting study animals as there is a large divergence in morphology, performance, habitat preferences, diet etc. A lot already is known of these fascinating creatures. Huge differences between specialist and generalist predators can be found in strike speed under water, head Poster Abstracts Poster morphology, dietary preference, predation strategies and more. The general line is that the specialist species feeding on fish have more streamlined heads, strike faster under water and spend more time in the water than their generalist or specialist congeners feeding on a wide array of amphibian and terrestrial prey. However there are still some parts of the story that remain unclear. Why do some snake species strike sideways? Why are others faster while catching prey under water? Are generalists in fact able to successfully

capture elusive prey under water and just prefer slower amphibians? What about those species, we only know they are semi-aquatic and nothing more. Therefore in this study we look at a large array of snake species by laser scan based computational fluid dynamics and look at the effects of the head morphology during strike and swimming. First results will indicate the differences between the several species and their ability to prey on elusive prey respectively. Preliminary results show major differences in drag force. Secondly, we aim to predict strike strategies for those snake species we only know their dietary preference.

Keywords: CFD, snakes, functional morphology E-mail: [email protected]

114

P.1 Biodiversity informatics give wings to your research

Brosens Dimitri, Gonzalez Barbara

INBO, Brussels ULB, Brussels

The mission of the Global Biodiversity Information Facility (GBIF) is to facilitate free and open access to biodiversity data worldwide via the Internet to underpin sustainable development. Priorities, with an emphasis on promoting participation and working through partners, include mobilizing biodiversity data, developing protocols and standards to ensure scientific integrity and interoperability, building an informatics architecture to allow the interlinking of diverse data types from disparate sources, promoting capacity building and catalysing development of analytical tools for improved decision-making.

Keywords: biodiversity informatics, GBIF, BioBel E-mail: [email protected]

Poster Abstracts

115

P.17 Genotype-genotype interactions between the cyanobacterium Microcystis and its grazer, the waterflea Daphnia

Brusciotti S.1, Lemaire V.1, van Gremberghe I.2, Vanoverbeke J.1, De Meester L.1

1 Department of Aquatic Ecology and Evolutionary Biology, K.U.Leuven, Ch. Deberiotstraat 32, 3000 Leuven, Belgium 2 Laboratory of Protistology and Aquatic Ecology, Ghent University, Krijgslaan 281 – S8, 9000 Gent, Belgiu

Microcystis are cyanobacteria inhabiting many of the freshwater systems we use for recreation, drinking water, or fisheries worldwide. Microcystis blooms

Poster Abstracts Poster have a pervasive impact on their abiotic (e.g. low light levels, hypoxia) and also impact their biotic environment by producing secondary metabolites (e.g. microcystin-LR, protease inhibitors), which can poison or kill organisms spanning the entire foodweb, including humans and livestock. Large-bodied Daphnia are capable of ingesting cyanobacteria, but can Daphnia control Microcystis blooms or, is it rather Microcystis that suppresses Daphnia? Recent studies report Daphnia physiologically acclimatizing and genetically adapting to cyanotoxins. We hypothesized that interactions between Daphnia and

Microcystis are genotype-genotype specific, the outcome of the interaction depending on the genetic identity of both. To test this, we exposed two-day old juveniles of ten Daphnia clones for 48 hours to increasing concentrations of ten Microcystis strains (supplemented with Scenedesmus to 1 mgC/l). We observed a significant Microcystis strain effect on Daphnia mortality. These differences could only partly be attributed to differences in microcystine-LR content between the strains. We also observed a significant effect of Daphnia genotype on mortality caused by Microcystis. Finally, we confirm our hypothesis: there are genotype-genotype dependent interactions between Microcystis and Daphnia, indicating that there is scope for local co-adaptation of Microcystis and Daphnia, suggestive of a geographic mosaic of co-evolution. Microcystis evolved a portfolio of anti-grazer defenses, and in response Daphnia acquired different resistance mechanisms to circumvent defenses of Microcystis strains. We conclude that locally adapted Daphnia may be able to control cyanobacteria and prevent blooms.

Keywords: Daphnia, microcystis, genotype-genotype interaction E-mail: [email protected]

116

P.21 Spatial variability of the Siphonophorae along the radial Calvi- Nice (Corsican side)

Collignon A.1,2, Hecq J.-H.1,2, Goffart A.1,2

1 Oceanology, MARE Center, University of Liège, Belgium 2 STARESO SA, Calvi, Corsica

The spatial distribution of the Siphonophorae has been examined, in Occidental Mediterranean, along the radial Calvi-Nice, from Calvi up to 30 miles offshore in September 2009. The variation of the abundance of the plankton and of the Siphonophorae was put in relation with the hydrological structures of the Liguro-Provençal front. This structure separates the coastal waters of Atlantic origin from the offshore central Mediterranean waters of deep origin. Globally, the larger abundances of Siphonophorae were present in inshore waters between the front and the coast. Both nectophores (asexual stage) and gonophores and bracts (reproductive stage) of Lensia subtilis occured only in the inshore waters. The nectophores of Chelophyes appendiculata occurred at all sampling stations with no significative variation. However, the abundance of the bracts and the gonophores increases when we get closer to the coast. This allows us to hypothesize that the maximum of reproduction is located in waters close to the coast. On the other hand, the larvae abundance of calycophoran siphonophores, in the plankton samples, increase from the Poster Abstracts coastal waters to the offshore waters with a maximum of abundance at the station located at 25 miles offshore. That contradiction could be explained by plankton net avoidance of small larvae, by current transport or by variable hatching success at the various stations. The larvae of physonect siphonophores are more often found offshore.

E-mail: [email protected]

117

P.43 Behavioural analysis of leaders during group recruitment in the ant Tetramorium caespitum

Collignon Bertrand, Cervantes Luz, Detrain Claire

Université Libre de Bruxelles

The ant Tetramorium caespitum uses leader-based group-mass recruitment towards food sources. An ant having discovered food come back to the nest, recruits workers and behaves as a leader by guiding a group of recruits to the food location. However, every successful forager will not become leader and among the leaders, there is a high variability in the number of recruited ants. We studied the behaviour of leader ants during the recruitment and compared it to non-leader ants. Particularly, we investigate the time spent inside the nest

Poster Abstracts Poster by individuals, the proportion of nest that they explored and the number of contacts that they performed with nestmates. Our results show that leaders are individuals that stay a shorter time in the nest, focus their activity into the nest entrance, and have a high contact rate with nestmates. On the other hand, non leaders stay longer in the nest and are more often engaged in food exchange. In addition, the contact rate of leaders with congeners is correlated with the size of the group they recruit. Finally, we observe that the loss of recruits on their journey towards the food source does not result in any behavioural changes by the leader ants, contrasting with the tandem-running recruitment also based on leader individuals but displaying a high level of attention to the followers. These results provide a new understanding of the recruitment mechanisms and highlight quantitative differences of leaders’ behaviour within the nest.

E-mail: [email protected]

118

P.45 The effect of zoo visitor numbers on the behaviour of Congo peafowl (Afropavo congensis) at Antwerp Zoo

Dams Jan R.M.1, Galbusera Peter1,2, Stevens Jeroen M.G.1,2

1 University of Antwerp, Universiteitsplein 1, B-2610 Wilrijk, Belgium 2 Centre for Research and Conservation, Royal Zoological Society of Antwerp, K. Astridplein 26, B-2018 Antwerp, Belgium

Congo peafowl (Afropavo congensis) are strongly threatened in their natural habitat. An ex situ population of this poorly know species has been maintained in zoos since the 1960s. However, the breeding program faces difficulties, including a relatively high mortality, possibly as a consequence of inbreeding and/or stress. For this reason we investigated the effect of zoo visitors as a possible stressor on the behaviour of Congo peafowl in Zoo Antwerp. The visitor effect is studied on three levels: does Congo peafowl behaviour change (1) with the presence or the absence of visitors, (2) on days with many visitors in the zoo (indirect visitor effect) and (3) on days when there are many people in front of the exhibit (direct visitor effect)? Furthermore, we also investigated the effects of the presence of other Congo peafowl, other bird species and caretakers on Congo peafowl behaviour. These results will give insights on how wellbeing, and breeding success, can be enhanced. We found no differences in the behaviour of the Congo peafowl in the absence or presence of visitors. Poster Abstracts However, the indirect and direct visitor effect showed that there was an increase in movement, preening behaviour, display behaviour and a decrease in resting behaviour and foraging behaviour which implies the existence of a negative visitor effect. Noise from the other Congo peafowl induced a decrease in foraging behaviour, caretakers induced an increase in movement and display behaviour what also implies a negative effect. Noise from the other birds had a neutral effect.

Keywords: Congo peafowl, visitor effect, behaviour E-mail: [email protected]

119

P.22 Selection of Perciforms: functional genomic potential of natural and cultured populations

Daneels Dorien, Raeymaekers J., Volckaert F.A.M.

Katholieke Universiteit Leuven, Labo voor Diversiteit en Systematiek van Dieren, Charles Debériotstraat 32, B-3000 Leuven, Belgium

With a growing world population and recurrent problems of hunger and malnutrition, food security is of major societal and international concern. The growing need for nutritious and healthy food will increase the demand for fishery resources. Unfortunately, the production of marine captureﬁsheries is close to the maximum ecosystem productivity and cannot be increased substantially in the future. Therefore, the interest in aquaculture has grown

Poster Abstracts Poster substantially the last 40 years. To ensure a sustainable development of aquaculture, the selection criteria have to lead to an improvement in production efficiency and a greater adaptability of the selected animals. The rapid advances of genomic technologies that lead to large amounts of genomic information will show the way for a selection procedure solely based on the genotype. In this project we exploit the large amount of available genomic data of fish species to identify, both between and within species, functionally important regions and selection-sensitive areas. Our main objective is the study of functional genomic regions susceptible to positive selection in sea bass. The project has four major objectives: i) identification of potential selection- sensitive areas by an in silico comparison of three fully sequenced Perciform genomes (stickleback, Nile tilapia and sea bass); ii) Development of genetic markers for a genome scan of natural and cultured populations of sea bass; iii) Genome scan and candidate gene analysis in natural populations of sea bass and iv) Genome scan and candidate gene analysis in cultured sea bass populations.

Keywords: comparative genomics, marker-assisted selection, population genomics E-mail: [email protected]

120

P.55 Evaluation of host immune responses to envenomation by the ectoparasitic wasp Nasonia vitripennis with antibacterial assays

Danneels Ellen L.1, Formesyn Ellen1, Jacobs Frans J.1, de Graaf Dirk C.1

Ghent University, Department of Physiology, Ghent

Nasonia vitripennis is an ectoparasitic wasp that lays its eggs in fly pupae after injecting a venomous mixture into its host organisms. This causes an enormous impact on host physiology and is crucial to create a good environment for its offspring. One of the major effects caused by this venom, is the suppression of host immunity, this to prevent the wasp eggs to be rejected by the host. But on the other hand, the host cannot become highly susceptible to external microbial threats, so immune systems cannot be shut down completely. This

balance of suppression and stimulation of host immunity probably situates on the Toll and the Imd pathways which represent the host defence against respectively Gram-positive and Gram-negative bacteria. Antibacterial assays, either in plate growth or in liquid growth can be applied to measure the impact of N. vitripennis venom on immune reactions in the haemolymph of its host organism. Escherichia coli as Gram-negative bacteria and Bacillus subtilis as Gram-positive bacteria were used to target both pathways.

Keywords: Nasonia, venom, immunity Poster Abstracts E-mail: [email protected]

121

P.9 Collembola assemblages under the invasive Senecio inaequidens and the native S. jacobaea

De Bruyn Luc1,2, Janssens Frans2, Vanparys Valérie3

1 Research Institute for nature and Forest (INBO), 1070 Brussel, Belgium 2 Evolutionary Ecology, University of Antwerp, 2020 Antwerpen, Belgium 3 Genetics, Reproduction & Populations, Université Catholique de Louvain, 1348 Louvain, Belgium

In the present study we assessed the effects of the invasive Senecio inaequidens (Asteraceae), one the most invasive species in Europe, on the soil fauna. As a control we used the related native S. jacobaea. Both species can occur in the same open habitats and share quite similar life history traits Poster Abstracts Poster (height, perennial habit,…). The invasive S. inaequidens is a perennial pioneer of dry habitats. The native S. jacobaea is a common biennial (to perennial) of various types of grassland. The aim of the study was to assess whether the invasive S. inaequidens alters the faunal composition of the Collembola communities. At the sample locality (Antwerpen, Belgium) three sample sites were selected: (1) dominated by S. inaequidens, (2) dominated by S. jacobaea and (3) both species equidominant. In each site, four pairs (one S. inaequidens

and one S. jacobaea, maximum 1.5m apart) of plants were selected. The soil fauna was sampled in the rootzone of the plants in the autumn of 2006 with core samplers (5 cm deep, 8 cm Ø) and extracted with berlese-Tullgren. Overall, we collected 1423 specimen belonging to 20 taxa. 9 species were found in significantly higher numbers under the native S. jacobaea while 1 species had higher numbers under S. inaequidens.

Keywords: invasive species, Collembola, soil community E-mail: [email protected]

122

P.49 Head morphology of the pelican eel, Eurypharynx pelecanoides (Saccopharyngoidei: Eurypharyngidae)

Eagderi Soheil1,2, Dierick Manuel3, Van Hoorebeke Luc3, Adriaens Dominique1

1 Ghent University, Evolutionary Morphology of Vertebrates, K.L. Ledeganckstraat 35, 9000 Ghent, Belgium 2 Tehran University, Department of Fisheries, Faculty of Natural Resources, Karaj, Iran 3 Ghent University, UGCT – Dept. of Physics and Astronomy, Proeftuinstraat 86, 9000 Gent, Belgium

The pelican eel, Eurypharynx pelecanoides, as the only member of the

Eurypharyngidae, is found in the bathyal zone of the tropical and temperate areas of all oceans. It is characterized by the reduction and loss of many structural elements of the head and by an extreme modification of many of the remaining elements. The study was aimed to understand to what degree the ancestral anguilliform cranial musculoskeletal system has become modified into a highly specialized ‘gulping’ feeding system found in E. pelecanoides. Hence, a detailed description of the cranial musculoskeletal system is added to the current knowledge. In relation to these extensive modifications, possible implications for the functioning of feeding apparatus were described based on Poster Abstracts its cephalic musculoskeletal system and a broadcasted short footage (sixty-five seconds) of a feeding pelican eel in the BBC documentary series (Blue planet: Eposide2 - The Deep, 2001). The result revealed that many extreme modifications of head structures of E. pelecanoides are to be seen in relation to functional shifts compared to those of other Anguilliformes. Also, it shows two novel cephalic muscles that have no equivalent in other fishes, as far as we know.

Keywords: Anguilliformes, deep sea fish, feeding E-mail: [email protected]

123

P.11 Corbicula invasion in European rivers : three mitochondrial lineages and an unique mode of reproduction

Etoundi Emilie, Marescaux Jonathan, Pigneur Lise-Marie, Van Doninck Karine

Unit of Research in Organism Biology (URBO), University of Namur (FUNDP)

Native to Asia, Middle East, Africa and Australia, the genus Corbicula is one of the main pest bivalves in European freshwater ecosystems since the 1980s. Presently, very few data are available on which Corbicula species did invade Europe, their entry point and their colonization routes. Moreover, the taxonomy of the genus Corbicula is very controversial, mainly due to a high phenotypic plasticity and a very unique asexual reproductive mode in the Poster Abstracts Poster invasive lineages, androgenesis. Androgenesis is a form of unisexual reproduction corresponding to a strictly paternal inheritance. After the fertilization of an egg by an unreduced and biflagellate sperm, the female pronucleus is expulsed as two polar bodies but the mitochondria are retained. Androgenetic sperm can also parasitize oocytes from different Corbicula lineages, a kind of egg parasitism, resulting in a disjunction between nuclear and mitochondrial lineages as well as between morphology and mitochondrial

haplotype. The aim of this study, the first to focus globally on the genus in Europe, is to determine which Corbicula lineages invaded Europe and if those invasive lineages are reproducing sexually or through androgenesis. We combined morphological analyses with the sequencing of the mitochondrial genes COI, Cyt b and 16S. In addition, we investigated the sperm morphology of Corbicula individuals from different European populations in order to determine their reproductive mode since androgenesis is characterized by biflagellate sperm. Finally, we started karyotyping Corbicula individuals from River Meuse (Belgium), polyploidy being another indication of the unisexual mode of reproduction of the invasive lineages.

Keywords: invasion, Corbicula, phylogeny E-mail: [email protected]

124

P.28 Impacts of an invasive species: Corbicula spp. in the River Meuse

Falisse Elodie, Pigneur Lise-Marie, Leporcq Bruno, Viroux Laurent, Van Doninck Karine, Descy Jean-Pierre

Unit of Research in Organism Biology (URBO), University of Namur (FUNDP)

In the last decade, an unprecedented pattern of phytoplankton biomass decrease was observed 2004 up to now, in the French and Belgian parts of the River Meuse. From Ham-sur-Meuse to Andenne, the mean chlorophyll a concentration has decreased regularly and phytoplankton blooms have disappeared. This substantial decrease of the phytoplankton in River Meuse seems unrelated to the factors that normally influence their development such as discharge, temperature, nutrients and zooplankton. Indeed, nutrient concentration (like phosphorus and nitrogen) studied over the past years remained high and the others factors did not undergo significant change during the last decade. The origin of this dramatic decrease, which influences the upper food chain, seems to be related to the presence of the filter-feeding invasive clam, Corbicula spp. This clam was first recorded in the 1980s in the lower River Meuse and since then it has expanded upstream. Moreover, in some parts of the river Corbicula reaches densities of approximately 800 ind/m². This study will highlight and quantify the impacts of Corbicula on the Meuse ecosystem. First, we continue the monitoring of the biotic and abiotic Poster Abstracts factors in the river. Second, we investigate the clam densities along the river. Third, laboratory experiments are conducted to estimate the filtration rates, which will allow estimates in situ filtration impact.

Keywords: Meuse, Corbicula E-mail: [email protected]

125

P.50 An increased mechanical loading accelerates growth and osteogenesis in zebrafish (Danio rerio)

Fiaz A.W.1, Schulte-Merker S.2, van Leeuwen J.L.1, Kranenbarg S.1

1 Wageningen University, Wageningen 2 Hubrecht Institute, Utrecht

The interaction between muscle and bone is essential for a proper growth and maintenance of the bones. Muscles impose mechanical loads on bones leading to adaptations in the bone structure and mass. Mechanical loading by muscle forces does not only affect bones in adult animals, but also during embryonic development (osteogenesis). Although much is known about the effect of a decreased mechanical loading on in vivo osteogenesis, the effect of an

Poster Abstracts Poster increased mechanical loading on in vivo osteogenesis has not yet been investigated. To investigate the effect of an increased mechanical loading on in vivo osteogenesis, wildtype zebrafish were swim-trained 9 hours daily during the osteogenesis of the axial skeleton (5-14 dpf). Control fish were kept in the same set-up but without endurance training. At the end of each day, 5 trained and 5 control fish were sampled and standard length measurements were taken. Subsequently, at the end of the experiment, fish were stained in one batch for the presence of bone. Although both trained and control fish swam intermittently (short bursts alternated with coasting), trained fish showed a higher rate of burst activity than control fish. Endurance training lead to an increased growth and accelerated the onset of osteogenesis in trained fish compared to control fish. These results suggests that an increased mechanical loading accelerates growth and overall development.

Keywords: osteogenesis, zebrafish, mechanical load E-mail: [email protected]

126

P.54 Twenty-three unique venom proteins of Nasonia vitripennis recombinant expressed for functional analysis

Formesyn Ellen, Danneels Ellen, Jacobs Frans, de Graaf Dirk

Laboratory of Zoophysiology, Ghent University, K.L. Ledeganckstraat 35, B-9000 Gent, Belgium

Nasonia vitripennis is an ectoparasitoid that uses host flies as a food source for its progeny. The venom of adult females is used to subdue the host and affects the immune responses, physiology and biochemical profile of parasitized fleshflies. Recently the genome of this wasp was sequenced and an in depth investigation of the venom composition was able to identify 79 venom proteins. The possible functions and interactions of these 79 venom proteins with host pathways remain largely speculative. The main challenge now is to

discover the functions of a subset of 23 venom compounds that do not display similarities to any known protein. Both the acid gland and the reservoir produce the toxic proteins. Due to the small size of the wasps (1.0 to 3.5 mm for females), little venom is present in the reservoir. To obtain sufficient amounts of the venom compounds, they are produced by the recombinant technology and provided with an N-terminal His-tag using the pET 100/D-TOPO expression vector and the prokaryotic E.coli BL21 (DE3) strain. This expression system is T7-regulated to control the expression of heterologous genes in E. coli. In order to discover their function, the purified recombinant venom Poster Abstracts proteins will be used in different bioassays.

Keywords: recombinant expression, venom E-mail: [email protected]

127

P.29 Increased mitosis in the bleached gastrodermis of the sea anemone Aiptasia pallida

Fransolet D., Roberty S., Plumier J.-C.

Université de Liège, Liège

Today, the upsurge of coral bleaching events (massive loss of symbiotic algae) around the world is getting alarming. Bleached corals, deprived of most of their energy incomes, may show a partial or total mortality, which ultimately lead to shifts in reef communities. Studies focusing on cellular bleaching mechanisms have shown different ways by which Symbiodinium may be expelled from gastrodermal host cells. Among those mechanisms, major emphasis has been put on host cells death, most probably due to both apoptosis and necrosis.

Poster Abstracts Poster Recovering gastrodermis is then expected to undergo regeneration process in order to be reinfected by new Symbiodinium. Here we describe this regeneration process in bleached Aiptasia pallida. Samples have been bleached before incubation with EdU, a thymidine analog, which is then incorporated into DNA strands during their replication. Histological analyses show an increase in EdU-positive cells in the gastrodermis of tentacles but also surprisingly in their ectoderm 24h after the bleaching treatment. One week after the bleaching treatment, an increase of EdU-positive cells is still significant in the gastrodermis but not in the ectoderm. These results highlight a critical period for the survival of the host during which it regenerates its symbiotic tissues. Increased mitosis in ectoderm could be explained by a higher production of cnidocysts in an effort to acquire more energy from heterotrophic sources but this hypothesis still needs to be investigated.

Keyword: coral bleaching histology E-mail: [email protected]

128

P.12 Histology and ultrastructure of the midgut of germ-free Artemia franciscana nauplii

Gunasekara R.A.Y.S.A.1, Rekecki Anamaria1, Casteleyn Christophe1, Cornelissen Maria2, Bossier Peter3, Van den Broeck Wim1

The morphology of the midgut of Artemia nauplii was studied using histology and transmission electron microscopy (TEM). Germ-free Artemia nauplii were fed with Baker’s yeast and dead Aeromonas hydrophila. For histology, two live nauplii were fixed at 2, 4 and 6 days of age in 100% ethyl alcohol, 40% formaldehyde and acetic acid for 5 min, dehydrated in graded alcohols and embedded in paraffin. Five µm thick sections were stained with haematoxylin and eosin and subsequently examined by light microscopy. For TEM, nauplii were fixed overnight in Karnovsky’s fixative, post-fixed overnight in 1% osmium tetroxyde and embedded in SPURR’s resin. Blocks were sectioned at 60 nm, Poster Abstracts sections were mounted on formvar coated grids and post-stained with uranyl acetate and lead citrate. They were examined using a Jeol 1200 EXII TEM at 80kV accelerating voltage. The entire midgut epithelium was composed of columnar to cuboidal cells. A clear brush border was visible in the apical part of the midgut cells. Large, central nuclei were characteristic. The cytoplasm contained numerous mitochondria and an abundant rough endoplasmic reticulum. Golgi complexes were seen in some cells. A basement membrane separates the epithelium from the underlying circular muscle layer. Future studies investigating the influence of microorganisms on germ-free Artemia will exploit the knowledge gathered in the present morphological study. It will allow the identification of potential morphological differences occurring in the midgut of Artemia nauplii when microorganisms are present in the culture compared to germ-free animals.

Keywords: germ-free, morphology, midgut E-mail: [email protected]

129

P.41 Foraging bats in a dynamically changing harbour area: can creation of new artificial lakes be a mitigation measure?

Gyselings R., Spanoghe G., Van den Bergh E.

Research Institute for Nature and Forest, Brussels

Landscape modification is often considered as the principal cause of population decline in many bat species. Expanding harbours and associated industries cause a severe change in the landscape structure. A previous study indicated that bat activity and bat species diversity in the Antwerp harbour area are low in the central part, but the outskirts are intensively used by foraging bats due to the presence of canals and artificial lakes. Harbour expansion might change the local situation in the near future. A big part of the Antwerp harbour is lying

Poster Abstracts Poster in Natura 2000 area, and new lakes have been created as a compensation for bird habitats. We examined to which extent these new lakes are used by foraging bats. We found that artificial lakes are used, even if they are recently created. Pipistrelle bats (P. pipistrellus and P. nathusii) showed higher activity at an older lake with a better developped bank side vegetation, but (Myotis daubentonii and (M. dascycneme used younger sites as well. However, for these species the embedding of the lakes in the landscape seems to be very important. We concluded that creation of artificial lakes in a dynamically changing landscape like a harbour can act as a mitigation measure for foraging bats, but the landscape structure around them must also be taken into account in the planning process. The lakes must be part of a coherent network of foraging sites, well connected with canals and trees.

Keywords: bats, artificial lakes, mitigation E-mail: [email protected]

130

P.7 Molar shape differentiation between subspecies of the edible dormouse Glis glis in the North of Anatolia and Turkish Thrace (Mammalia: Rodentia)

Helvacı Zeycan1,2, Renaud Sabrina3, Ledevin R.3, Adriaens D.4, Çolak Dominique2, Kankiliç Teoman5, Kandemir Irfan2, Çolak Ercüment2

1 Aksaray University, Aksaray 2 Ankara University, Ankara 3 CNRS University Lyon 1, Lyon 4 Ghent University, Ghent 5 Niğde University, Niğde

The use of morphometric methods allows a very accurate quantification of a broad range of phenotypic traits, such as teeth. Beyond their value as taxonomic characters for species identification, intra-specific patterns of differentiation in tooth shape can thus be addressed. The present study illustrates the potential of a fine-scale analysis of tooth shape variation in the edible dormouse Glis glis (Gliridae, Rodentia, Mammalia). The size and shape of the first upper molar was analysed in populations of Thrace and Anatolia, using an outline analysis (elliptic Fourier transform). Our study evidenced an important differentiation between the two subspecies that had been described Poster Abstracts from the Balkan Peninsula and southwest of Asia, confirming the role of the Marmara straits as a major biogeographic barrier. Yet, our results also suggest recent events of migration between the two areas, pointing towards more complex biogeographic dynamics than previously recognised.

Keywords: Glis glis, geometric morphometrics, elliptic Fourier analysis E-mail: [email protected]

131

P.2 DNA barcoding as identification tool in fruitfly interception and surveying activities

Jordaens K.1,2, Breman F.1,2, De Meyer M.1,2, Virgilio M.2,3

1 Joint Experimental Molecular Unit (JEMU), Leuvensesteenweg 13, B-1000 Brussels & B-3080 Tervuren, Belgium 2 Royal Museum for Central Africa, Leuvensesteenweg 13, B-Tervuren, Belgium 3 Royal Belgian Institute of Natural Sciences, Vautierstraat B-1000 Brussels, Belgium

DNA barcoding uses the sequences of a particular part of the mitochondrial gene COI as a unique identifier for all zoological species. DNA barcodes can provide a valuable alternative to morphological identification in cases where morphological characters do not provide diagnostic features. Our study focuses Poster Abstracts Poster on the African fauna of the main fruit fly genera of economic importance (EI): Ceratitis, Dacus, Bactrocera and to a lesser extent Capparimyia and Trirhithrum. Currently, a DNA library has been compiled for more than 120 African taxa. This includes all major EI species belonging to the target taxa, several congeneric species, and outliers of related genera. For widespread species, representatives of different geographical regions were included in order to cover for intraspecific variability. The library also includes more than

75% of all taxa regularly trapped in para pheromone traps in the last 20 years. As test material, samples were obtained from French and UK NPPO’s, resulting from fruit fly interception in fruit consignments from the last five years. In addition, recent material from survey programs in western and southern Africa was also obtained. Preliminary results show that DNA barcodes can provide an alternative as identification tool, especially with regard to juvenile stages like larvae found in intercepted fruit consignments. Difficulties in species differentiation are mainly encountered in recognized species complexes such as the Ceratitis FAR complex (C. fasciventris, C. anonae, C. rosa).

Keywords: DNA barcoding, taxonomy, Africa E-mail: [email protected]

132

P.34 Genetic and morphological differentiation of the crab Dissodactylus primitivus, ectoparasite of two sympatric echinoids

Jossart Quentin, De Ridder Chantal, De Bruyn Colin

Laboratoire de Biologie Marine (CP 160/15), Université Libre de Bruxelles, 50 avenue F. D. Roosevelt, 1050 Brussels, Belgium

At Discovery Bay (Jamaica), Dissodactylus primitivus is a parasitic crab of two urchin species, Meoma ventricosa and Plagiobrissus grandis. D. primitivus uses asymmetrically its sympatric hosts. Indeed, all post-metamorphic stages (juveniles, adults) are present on M. ventricosa but only adults are found on P. grandis. Furthermore, the fecundity of female crabs varies between occupied hosts: it is greater on P. grandis than on M. ventricosa. These urchins present also great differences in morphology and behavior.These characteristics raise the question of the specialization of crabs suiting a particular host species. The aim of this work is to test the genetic differentiation (microsatellite analysis) and the morphological differentiation (shape analysis) between crabs originating from different hosts. Our results indicate the lack of genetic differentiation between crabs parasitizing M. ventricosa and P. grandis. In

addition, genetic homogeneity between infra-populations (occupying one Poster Abstracts individual host) of crabs has also been detected, and is probably explained by the mobility of adults (“host-switching behaviour”). A morphological differentiation linked to host species and sampling year has been detected. This phenotypic plasticity is presumably related to differences in environmental pressures met by the crabs on their two host-species. In this context (no genetic differentiation), P. grandis could appear as an alternate host.

Keywords: microsatellite, morphometry, symbiosis E-mail: [email protected]

133

P.31 Sound production and sexual dimorphism in sonic apparatus of Ophidion rochei (Teleostei)

Kéver L., Parmentier E.

Universty of Liège

As in many Ophidiidae, Ophidion rochei has an unusual sound-producing system with sexually dimorphic sets of characters. This work highlights in details the morphological dimorphism of the sonic apparatus in Ophidion rochei and establishes the relationships between each morphological structure and the sound characters. The differences between sexes are found in the anterior vertebrae and ribs, the swimbladder configuration, and the size of the three pairs of associated muscles. Sounds were recorded in the field from the sunset

Poster Abstracts Poster to the sunrise. These recordings show that the mean sound duration is almost a hundred time longer in males (4.8 ± 1.5 s, n = 21) than in females (0.06 ± 0.05 s, n = 21). This is due to the number of pulses (38 in males vs 8 in females) and to the pulse period that is approximately 20 times longer in males (126 ± 36ms, n=775) than in females (6 ± 0,5ms, n=165). According to the sex, each pulse shows also a different waveform. In males, sounds could be made by a tension release mechanism involving slow sound producing muscles. In females, swimbladder sound production seems to be forced response by contraction of fast sonic or drumming muscles.

Keyword: ophidiiform sound dimorphism E-mail: [email protected]

134

P.15 Daphnia-symbiont community structure under different productivity regimes

Lange Benjamin, Muylaert Koenraad, Decaestecker Ellen

K.U.Leuven, Kortrijk

The freshwater crustacean Daphnia magna inhabits ponds and lakes which differ substantially in productivity levels. This is a consequence of agricultural fertilisation and major differences between habitat structures. A taxonomically diverse group of symbionts lives in and on Daphnia magna. We tested in an experimental approach if productivity can influence the symbiont communitiy within a short period of two months. It was found that epibionts were strongly affected by productivity changes while parasites were not. Our results show

that productivity changes have an instant effect on the symbiont community of Daphnia magna. Thus, agricultural fertilisation leads to secondary effects on biodiversity which can easily be overlooked.

Keywords: productivity, symbiont, Daphnia E-mail: [email protected]

Poster Abstracts

135

P.38 Toxicity of endosulfan on the tadpole stage of an amphibian (Rana temporaria): a video-tracking analysis

Lavorato Manuela1, Libon Sylvie1, De Pauw Edwin2, Kestemont Patrick3, Denoël Mathieu1

1 Behavioural Biology Unit, University of Liège, Quai Van Beneden 22, 4020 Liège, Belgium 2 Laboratory of Mass Spectrometry, University of Liège, Allée de la Chimie 3, 4000 Liège, Belgium 3 URBO, University of Namur, 5000 Namur, Belgium

Endosulfan is a persistent chemical that has been demonstrated to bioaccumulate in exposed organisms. This organochlorine compound is used in

Poster Abstracts Poster agriculture as an insecticide and acaricide with neurotoxic effects in mammal and aquatic animals. An automated video-tracking and motion analysis system (Ethovision) was used to examine behavioural effects on 140 amphibian tadpoles Rana temporaria exposed to a high, but environmental concentration of endosulfan (0.05 mg/L) and to two control conditions (with and without solvent). Ethovision offers a wide range of video tracking options, and an extensive analysis of locomotor tracks. The exposure to the contaminant had significant effects on varied behavioural traits. Endosulfan induced a significant

decrease in distance moved, velocity and mobility of tadpoles at the 10th and 20th day. Space use was also significantly affected, but only at the 10th day: contaminated tadpoles used a more open area than the controls. Behavioural effects may indicate the neurotoxic action of endosulfan. Although 96h-LC50 tests did not show any mortality effect at the studied concentration on Rana temporaria, the present results evidenced more subtle effects at the behavioural level. They may have detrimental consequences in term of resource use and predator avoidance, i.e. traits which can also affect fitness. Our study thus confirms and extends the results of previous studies on the toxicity of this organochlorine pesticide in showing its possible role in amphibian decline.

Keywords: amphibian, behaviour, pesticide E-mail: [email protected]

136

P.33 Essential and non-essential elements in the eggs of sea turtles from Lesser Antilles

Leroy Céline, Dyc Christelle, Bouquegneau Jean-Marie, Das Krishn

Laboratoire d'Océanologie,Institut de Chimie, Université de Liège, Allée de la Chimie n°3 - B- 4000 Sart-Tilman (Liège), Belgique

In sea turtles, the survival of the embryo requires energy and nutrients provided by maternal transfer during egg formation. A concomitant transfer of pollutants from maternal tissues to eggs has been shown in these species. These pollutants are potentially harmful to the growth of the embryo and to the future adult turtle. Concentrations of essential elements (Cu, Zn, Ca, Fe, Se) and non-essential elements (ΣHg, Cd, Pb) were determined in 16 eggs of 6

green turtles (Chelonia mydas) and 2 hawksbill turtles (Eretmochelys imbricata) collected in Guadeloupe in 2008. All these elements were detectable in egg albumen, yolk and eggshell. Concentrations of toxic metals such as Hg, Cd, Pb were low compared to other turtle species. It appeared that element concentrations in eggs depended on the diet, and on the co-transfer of some metals through the formation of eggs (e.g. Zn-Fe). Inter-specific comparison revealed that Se concentrations in eggs can be high in hawksbill turtles (mean ± sd) compared to green turtles (mean ± sd). Specific diet of hawksbill turtles including Demospongea might explain this discrepancy. Essential elements Poster Abstracts needed for egg formation and embryo development are regulated by various homeostatic mechanisms which require the presence of metalloproteins (such as ovotransferrin and vitellogenin). Despite low levels of non-essential metals measured in eggs of these turtles, there is a blatant lack of reference values in Chelonians. Further investigation is needed before drawing any definite conclusion on the toxicological status of these endangered species.

Keywords: sea turtle eggs; essential and non-essential elements; maternal transfer E-mail: [email protected]

137

P.4 Towards a revision of Western Australian Bennelongia (Crustacea, Ostracoda, Cyprididae)

Martens K.1, Halse S.2, Schön I.1

1 Royal Belgian Institute of Natural Sciences, Freshwater Biology, Vautierstraat 29, B-1000 Brussels, Belgium 2 Bennelongia Pty Ltd, 5 Bishop Street, Jolimont WA 6014, Perth, Australia

The genus Bennelongia is enigmatic, as some species have antero-ventral beak- like expansions, which are very reminiscent of some Mesozoic (fossil) Cypridea species. Here, we revise 10 species of this genus in Western Australian: we redefine B. australis (Brady, 1886) De Deckker & McKenzie, 1981 and describe nine new taxa, seven of which from sexual populations. It is found that Poster Abstracts Poster especially the anteroventral part of the right valve and the male copulatory appendages (including the prehensile palps) allow identification. We have observed that at least B. australis is a filter feeder and that the beak-like structure is an adaptation to this way of feeding. The structure in the left valve is similar in most species, but the counter part in the right valve, completing the filter apparatus, has different morphologies thus indicating that either different solutions have been found to the same problem, or that a gradual increase in beak complexity has occurred in evolution. These alternative hypotheses are tested with a molecular phylogeny of a subset of the species.

Keywords: Ostracods, temporary pools, cryptic species E-mail: [email protected]

138

P.20 The role of meiofauna in energy transfer in a Mediterranean seagrass bed (Calvi, Corsica)

Mascart T.1, Lepoint G.2, Borges A.V.3, Darchambeau F.3, Dauby P.2, De Troch M.1

1 Marine Biology, Ghent University, Krijgslaan 281-S8, B-9000 Gent, Belgium 2 Laboratory of Oceanology, University of Liège, Allée du 6 août B6, B-4000 Liège, Belgium 3 Chemical Oceanography Unit, University of Liège, Allée du 6 août B5, B-4000 Liège, Belgium

Meiofaunal communities of the endemic Mediterranean seagrass, Posidonia oceanica, were sampled in five different habitats characterised by different degradation level of macrophytodetritus. In term of abundance, harpacticoid copepods represent half of the community followed by nematodes and polychaetes. Two meiofauna communities were distinguished: (1) a benthic community of meiofauna, living in the sediment or on highly fragmented macrophytodetritus, and (2) a foliar, epiphytal community associated with seagrass leaves and low fragmented macrophytodetritus leaves. They differed significantly in their harpacticoid copepod family composition. The benthic community consisted mainly of families like Tisbidae and Miraciidae, while the epiphytal community was dominated by families like Thalestridae and

Laophontidae. These differences in composition may also imply a differential Poster Abstracts functional diversity. Trophic biomarkers (stable isotopes, fatty acids) were used to identify the major sources of organic matter contributing to the copepods diet and hence to gain insight in the overall carbon flux. Harpacticoid copepods showed preferences to feed upon the epiphytal biofilm community composed of bacteria, diatoms, fungi and microalgae. Copepods used the seagrass and detritus material merely as substrate, but were attracted to the biofilm rather than the plant material which is rich in structural carbohydrates difficult to assimilate by animals (i.e. lignin, cellulose, ...). Since harpacticoid copepods showed to use different sources of carbon, unravelling the contribution of each of them and the role of the degradation level of the detritus for food selectivity is the next step forward.

Keywords: trophic biomarkers, community composition, Copepoda E-mail: [email protected]

139

P.19 Impact of grazing by amphipods on the epiphytic cover of the Posidonia oceanica leaves: an in situ experiment

Michel Loïc1, Dupont Alessandra1, Gobert Sylvie2, Dauby Patrick1, Lepoint Gilles2

1 Laboratory of Systematics and animal Diversity, University of Liège, Allée du VI Août n°13, 4000 Liège, Belgium 2 Laboratory of Oceanology, University of Liège, Allée du VI Août n°13, 4000 Liège, Belgium

It is now established that several species of amphipods associated to Mediterranean Posidonia oceanica meadows consume the macro-epiphytes present on the leaves of the seagrass. Moreover, under controlled in vitro conditions, three amphipod taxa (Apherusa chiereghinii, Dexamine spiniventris Poster Abstracts Poster and Gammarus spp.) are able to drastically deplete the biomass of erected algae, thus influencing the epiphytic cover in both a quantitative and a qualitative way. Here, we tried to assess whether this strong and complex trophic interaction was realized in the field. We designed an in situ experiment that used microcosms placed directly in the meadow, at a depth of 10m, to estimate the impact of grazing by the aforementioned amphipod taxa on the dynamics of the epiphytic cover. Both Gammarus spp. and Dexamine

spiniventris caused a significant decrease of the biomass of erected algae and erected animals (bryozoans and hydrozoans). Impact of grazing by Apherusa chiereghinii on these two epiphytic groups was less important, although strong but marginally non-significant (0,1>p>0,05) trends to lower biomasses were present. None of the considered taxa seemed to consume encrusting macro- epiphytes. In addition, assimilation of epiphyte-derived carbon and nitrogen by grazers was monitored using stable isotopes (13C and 15N), and epiphyte elemental content (C & N) was measured. Our results shed light on trophic interactions between the amphipods from Posidonia oceanica meadows and the seagrass epiphytic cover, and thus enhance our understanding of the role of these grazers in the functioning of the meadow as an ecosystem.

Keywords: amphipod, grazing, seagrass E-mail: [email protected]

140

P.25 The effects of land use on soil food webs and ecosystem functioning

Middelveld R.1, Hemerik L.1, Mulder C.2, de Ruiter P.C.1

1 Wageningen University, Wageningen 2 Institute for Public Health and the Environment, Bilthoven

In nature an enormous diversity of biological species is present and the abundance of these species varies in space and time. All these organisms may affect each other e.g. by predator-prey interactions, competition, symbiosis or social behaviour. What do all these interactions imply for the functioning of an ecosystem? In our project we are especially interested in the role of trophic interactions, those between predators and prey, for soil ecosystem functions that are of importance to humans, the so-called ecosystem services. Understanding how such ecosystem functions relate to soil biodiversity is important in order to develop, for instance, more efficient, more sustainable agricultural practices. In this project we study the two soil ecosystem services of the soil, that are the direct consequences of trophic interactions, that is “nutrient mineralisation” and “carbon storage-respiration balance”. The RIVM in cooperation with ALTERRA has collected a unique dataset on the composition of the soil community food web in 170 sites throughout the Netherlands. In the first step we try to determine the carbon and nitrogen Poster Abstracts mineralisation by each food web. This is done by applying a food web model that is in essence based on the assumption that all trophic species in the food webs are at equilibrium on a time-scale of years. In a next step we will use these model calculations to construct a carbon and nitrogen salization map for the Dutch soils, given the environmental conditions. This map will provide information on how land use influences carbon and nitrogen mineralisation rates in soil, which is important in assessing the role of soil biodiversity in processes of nutrient cycling and global warming.

Keywords: food web, ecosystem function E-mail: [email protected]

141

P.5 Soil mite diversity from Ivory Coast

N’Dri Julien K.1, André Henri M.2, Hance Thierry1

1 Université Catholique de Louvain, Biodiversity Research Center, Earth and Life Institute, Place Croix du Sud 4, B-1348 Louvain-la-Neuve, Belgium 2 Musée royal de l’Afrique centrale, Leuvensesteenweg 13, B-3080 Tervuren, Belgium

Lamto savannah (LAS), Oumé primary forest (OPF), teak plantation (OTK) situated in (Sudanese domain) and the Tai primary forest (TPF) (Guinean domain) were sampled twice in ivory Coast. After a 1-week extraction in Berlese-Tullgren funnels, and description, 177 species was recorded, respectivelly (LAS: 85 species, OPF: 98, OTK: 51 and TPF: 66). Shannon index estimated for mites was highest in TPF (5.13) and lowest in OTK (4.63).

Poster Abstracts Poster Evenness values were close in the 4 sites: LAS (0.745), OPF (0.742), OTK (0.816), TPF (0.849). OTK and TPF were the most different sites, with only 23 mite species in common (Jaccard distance = 76). Many mite species (100/177) were exclusive and were collected in a single site. The species richness was maximum in the upper layer and decrease with the depth. Beta diversity measured along the depth is greater than that measured along the transect. rapp, Ctot,Ntot, Depth and CORG were correlated to the species richness.

Keywords: Acari, forest, species richness E-mail: [email protected]

142

P.10 EAG response of Helicoverpa armigera Hubn. and its predator Chrysoperla carnea Steph. to volatiles of different varieties of cotton and sunflower

Pandey Ashish

Dept. of Zoology, D.A.V. College, Kanpur (U.P.) India

Electro-antennogram (EAG) response of male and female adults pest Helicoverpa armigera Hubn. and predator Chrysoperla carnea was recorded for leaf and bolls extract of different varieties of cotton and sunflower. Among the sexes females showed more response than males. Among the varieties AK-235 and Adonicum recorded higher EAG response but least response was recorded in the variety Ak-227. in case of C. carnea the varieties tested Goarani-6, Indore-1, Badnawar and Andrews showed better response than other. Boll varieties extracts like K-6 recorded more response. Among the sunflower varieties KBSH-1 recorded more response. Least response was noted in the variety KBHH-1. In case of C. carnea males showed higher response than females. Sungen-85 variety showed more response.

Keywords: Helicoverpa armigera, Chrysoperla carnea, electro-antennogram

E-mail: [email protected] Poster Abstracts

143

P.26 Experimental study of metapopulation dynamics and viability in Tetrahymena thermophila microcosms

Pennekamp F., Schtickzelle N.

Université Catholique de Louvain, Louvain-la-Neuve

Understanding what makes some species at risk of extinction is of prime interest to conservation biology. The project uses artificial microcosms of Tetrahymena thermophila, a unicellular organism, to improve our understanding of how species/population features interplay with landscape configuration and environmental factors in determining viability of metapopulation systems. The metapopulation concept was firmly grasped and applied to the field of conservation biology even if its effective value for

Poster Abstracts Poster practical conservation biology is still debated. Indeed, not all its basic principles have been validated,and many studies were either theoretical or field-based and focussed on patterns. We propose (1) an experimental approach focussed on processes more than on patterns, (2) the massive advantages of microcosms to control landscape and environment, and replicate experiments, and (3) the availability of genetically distinct T. thermophila clonal lineages that display different life styles (combinations of life history traits) representing several of the major life history strategies found in a wide range of taxonomic groups. Artificial metapopulation systems will be constructed as sets of test tubes connected by pipes, representing patches and matrix respectively. We study the relative importance of (1) landscape configuration, local habitat quality and (3) life styles as well as their interactions for metapopulation dynamics and viability.

Keywords: metapopulation microcosm E-mail: [email protected]

144

P.14 Shading and alterations of the sediment: in situ experiments to mimic impacts of fish farms on a Mediterranean coastal ecosystem

Pête Dorothée1, Velimirov Branko2, Lepoint Gilles1, Gobert Sylvie1

1 Laboratory of Oceanology, University of Liege, Liege, Belgium 2 Center of Anatomy & Cell Biology, Microbiology, Molecular Biology and Virology, Medicine University of Vienna, Vienna, Austria

In the Mediterranean coastal zone, the seagrass Posidonia oceanica forms underwater meadows which sustain a high biodiversity and has many important roles (production of oxygen, protection of coasts, …). Unfortunately, they are more and more threaten, notably by the increasing development of aquaculture. Indeed, fish farms increase the biomass of phytoplankton organisms in the water column (leading to a shading effect) and modify the sediment, which entail the disappearance of the seagrass. To understand the impact of those troubles on P. oceanica and the ecosystem, in situ experiments were led during three months, in STARESO (STAtion de Recherches Sous- marines et Océanographiques; Calvi, Corsica), at a depth of 10 meters. The shading was mimicked by shading frames, which stopped around 50 % of the

incident light. To modify the sedimentary compartment, sediment was taken Poster Abstracts from under the aquaculture of Calvi and added once a week on marked zones in the meadow. Those sites were compared with a control site, situated near them. Measured parameters are: the concentration of nutrients in pore water, grain size, redox potential discontinuity, biomasses of bacteria, organic matter, meiofauna and microphytobenthos within the sediment, the length, width, biomass and chlorophyll a content of P. oceanica leaves and the biomass of epiphytes. During those experiments, P. oceanica was not very affected although some parameters of the sedimentary compartment were modified. These results show that the sedimentary compartment reacts more rapidly to threats then the seagrass itself. So, it could be an interesting tool in quality assessments.

Keywords: fish farm, sediment, ecology E-mail: [email protected]

145

P.13 GFP-labelled Listonella anguillarum HI610 visualized within the gut of gnotobiotic sea bass larva

Rekecki Anamaria1, Gunasekara R.A.Y.S.A.1, Dierckens Kristof2, Boon Nico3, Favoreel Herman4, Cornelissen Maria5, Bossier Peter2, Van den Broeck Wim1

1 Department of Morphology, Faculty of Veterinary Medicine, Ghent University, Belgium 2 Laboratory of Aquaculture and Artemia Reference Center, Ghent University, Belgium 3 Laboratory of Microbial Ecology and Technology, Faculty of Bioscience Engineering, Ghent University, Belgium 4 Department of Virology, Parasitology, and Immunology, Faculty of Veterinary Medicine, Ghent University, Belgium

Poster Abstracts Poster 5 Department of Anatomy, Embryology and Histology, Ghent University, Belgium

A gnotobiotic sea bass (Dicentrarchus labrax L.) model was used to investigate i interactions in early stages of fish larvae. In this study, germ-free sea bass larvae exposed to a purposely-constructed GFP-labelled Listonella anguillarum HI610 pathogen (GFP-HI610), the causative agent of vibriosis, were examined using light, fluorescence and confocal microscopy and transmission electron

microscopy (TEM). DAH4 larvae were exposed to 108CFU ml-1 GFP HI610 and sampled at 2-6-12-24-48-72-120-168 hrs post exposure (p.e). Colonisation of gut enterocytes was observed from 2 hrs and 48 hrs p.e. by light microscopy and fluorescence microscopy, respectively, whereas presence of bacteria within the swim bladder was visualized from 48 hrs p.e onwards. Ultrastructural findings, concentrating on bacterial localization within the gut lumen, demonstrated direct contact with oesophagic and gastric mucosa, putative attachment to microvilli in mid- and hindgut, indications for endocytosis and for luminal antigen sampling by macrophages. Intercellular translocation of bacteria was not shown. A detailed examination of adhesion strategies of the wild type L. anguillarum within the gut of gnotobiotic sea bass larva is the next step. The presented results suggest further investigation of swim bladder infection in early stages of fish larvae and plausible relevance of treatment with probiotics in this infection process.

Keywords: gfp pathogen, gnotobiotic system, microscopy E-mail: [email protected]

146

P.30 Photoacclimation responses of a symbiotic sea anemone reveal an important host cellular plasticity

Roberty S.1, Fransolet D.2, Ladrière O.1, Poulicek M.1, Plumier J.-C.2, Franck F.3

1 Université de Liège - Lab. Ecologie Animale & Ecotoxicologie, Liège, Belgium 2 Université de Liège - Lab. Physiologie Animale & Ecophysiologie, Liège, Belgium 3 Université de Liège - Lab. Physiologie Végétale & Photobiologie, Liège, Belgium

The high productivity of coral reef ecosystems is largely attributed to the mutualistic symbiosis between reef-building corals and their intracellular dinoflagellate in the genus Symbiodinium commonly referred to as zooxanthellae. These photosynthetic algae translocate a majority of their photosynthetically fixed carbon to the host and contribute to their metabolic needs and the calcification process. Symbiodinium must maintain a balance between the energy derived from the light reactions in the chloroplast and the amount of energy used during dark reactions and other metabolic processes. Nevertheless, in the natural environment the holobiont have to cope with daily and seasonal changes in light intensity, upsetting that balance and creating a stress that induces a physiological response (photoacclimation) to optimize

growth rates. After a ten day exposition to high and very low light intensity, Poster Abstracts morphological and photophysiological analysis conducted on the symbiotic sea anemone, Anemonia manjano, reveal significant modifications of the host tissues ultrastructure and the Symbiodinium metabolic processes (photosynthesis, respiration). Those results highlight particularly important gastrodermal and ectodermal plasticity in which symbiotic cnidarians acclimate to the Symbiodinium physiological status (mainly photosynthesis) by varying the density of particular cellular types (e.g.: cnidocytes, gastrodermal cells) contained in their tissues.

Keywords: Cnidaria, symbiosis, photoacclimation E-mail: [email protected]

147

P.8 Bioindications of night moths for maintaining biodiversity in vineyards

Šafář J.

Mendel University Brno, Department of Zoology

Within the entire Czech Republic, the region of South Moravia (Czech Republic) is characterized by the highest biodiversity of moths occurring in predominantly agrarian landscape at refuges of very small area (protected areas). These ""islands"" of natural habitats in agricultural landscapes are isolated from each other, they are very small in size and small populations of many species of organisms are gradually dying out for genetic, environmental or demographic reasons. Therefore, in relation to efforts to reduce biodiversity

Poster Abstracts Poster loss, it is necessary to use alternative habitats within the agrarian landscape. In the vicinity of hills called Pavlovské vrchy (a protected area) there is an area of 522 ha of steppe reserves (23 sites) that are in most cases in neighbourhood of the vineyards, while here is the highest concentration of vineyards in the Czech Republic. Vineyards are managed in three ways, namely conventional (the most intense with so-called fallow ground with no vegetation in 50% of alleyway), integrated (with variously rich understory vegetation in alleyway) and bio- management. In 2010 and 2011 it is planned to discover what is the most appropriate method to manage a vineyard to avoid reduced economy of growing and to allow the species of prairie reserves to use these sites for migration between isolated natural habitats and to the environment.

Keywords: night moths, biodiversity E-mail: [email protected]

148

P.3 Changes in surface waters: a malacological analysis of a Late Glacial and early Holocene palaeolake in the Moervaartdepression (Belgium)

Serbruyns Lynn1, Van Damme Dirk1, Antrop Marc4, Bats Machteld2, Bourgeois Jean2, Court-Picon Mona1, Crombé Philippe2, De Maeyer Philippe4, De Reu Jeroen2, De Smedt Philippe3, Finke Peter1, Van Meirvenne Marc3, Werbrouck Ilke4, Zwertvaegher Ann1, Verniers Jacques1

1 Department of Geology and Soil Science, Ghent University, Ghent, Belgium 2 Department of Archaeology, Ghent University, Ghent, Belgium 3 Department of Soil management, Ghent University, Ghent, Belgium 4 Department of Geography, Ghent University, Ghent, Belgium

The Moervaartdepression is a key locality for the study of Latest Weichselian palaeoecology and archaeology. This lowland area, situated in NW Belgium, used to harbour a large and shallow palaeolake. The malacological survey presented here, which is part of the interdisciplinary project ’Prehistoric settlement and land-use systems in Sandy Flanders (NW Belgium): a diachronic and geoarchaeological approach’ (GOA project, UGent), represents the first extensive analysis of mollusc assemblages in this area and aimed at studying Poster Abstracts the local environment. Mollusc remains were recovered from a 80 m long trench through the deepest part of the former lake and were especially abundant in the lake marl. The molluscan fauna (32 species) is mainly dominated by freshwater taxa. Terrestrial molluscs (seven species) have also been recovered, but are rare. Changes in mollusc assemblages allow to identify five mollusc assemblage zones spanning approximately the Oldest Dryas to the Preboreal. Overall, shallow water with abundant vegetation and quiet conditions are indicated. Finally, the absolute lack of freshwater mussels (Mollusca: Unionoida) and fish remains -indicating a closed lake system- possibly shed new light on the formation history of the Moervaartdepression.

Keywords: molluscs, palaeoenvironment, Quaternary E-mail: [email protected]

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P.51 Expression of matrix metalloproteinase 9 in regenerating and ontogenetic scales of adult zebrafish

Sharif F1, de Vrieze E.2, Metz J.2, Flick G.2, Richardson M.K.1

1 Institute of Biology, Leiden University, The Netherlands 2 Department of Organismal animal Physiology, Radboud University, Nijmegen, The Netherlands

Matrix metalloproteinases (MMPs) are key enzymes in the turnover of extracellular matrix in health and disease, as well as in developmental and regenerative processes. We have studied zebrafish scale regeneration in order to ascertain the role of mmp-9 expressing cells in this process. Scales were plucked from the surface of anaesthetized adult male zebrafish, and the scales Poster Abstracts Poster that regenerated from the scale pocket were recovered at various times after plucking. Analysis consisted of (i) in situ hybridistaion with mmp-9 probe, followed by histological sectioning; (ii) qRT-PCR for mmp-2 and mmp-9, and (iii) zymography for gelatinase activity. We found that ontogenic scales, had multinucleated aggregates of mmp-9 expressing cells along their lateral margins, as well as mononucleated mmp-9 expressing cells along the radii. The multinuclear aggregates were not always in the same location in different scales and varied considerably in scales from different individuals. In 2 and 4d scale regenerates, aggregates along the lateral margins were not present, but mononucleated cells were abundant, particularly along the episquamal side of the matrix at 4d. The matrix at these timepoints remained thin. During this early phase of scale regeneration, mmp-2 and mmp-9 transcripts increased in abundance in the scale, and gelatinase activity increased. Later (up to 8d), all of these parameters returned to the basal values seen in the ontogenetic scales, as did the histological distribution and appearance of mmp-9 positive cells. These findings suggest that matrix metalloproteinases play an important role in remodelling of the scale during regeneration, and that this function may reside in mononuclear cells. The multinuclear mmp-9 positive aggregates on the margins of ontogenetic scales may be associated with normal scale growth during the animal’s lifetime. Our findings suggest that the fish scale regeneration model may be a useful system in which to study the cells and mechanisms responsible for regeneration, development and skeletal remodelling.

Keywords: zebrafish, scales E-mail: [email protected]

150

P.18 Top-down role of fish predators in structuring amphipod community associated to Posidonia oceanica seagrass meadows

Sturaro N.1, Lepoint G.1, Panzalis P.2, Navone A.2, Gobert, S.1

1 Laboratoire d’Océanologie, Département des Sciences et Gestion de l’Environnement, Faculté des Sciences, Université de Liège, Sart Tilman B6, 4000 Liège, Belgium 2 Corsorzio di Gestione Area Marina Protetta Tavolara-Punta Coda Cavallo, via Dante 1, 07026 Olbia, Italy

Despite the major ecological importance of Posidonia oceanica seagrass meadows in the Mediterranean Sea, little attention has been given to community structuring forces by predators in this ecosystem. To better understand the mechanisms by which fishes affect amphipod community structure associated to P. oceanica beds, experimental manipulations of predation intensity (enclosure and exclusion cages) were set up in the Tavolara-Punta Coda Cavallo Marine Protected Area (Sardinia, NW Mediterranean). In totally protected area, where high abundance of predatory fishes is recorded, we have performed exclusion experiment. Total amphipod abundance increased at the end of the experiment, but diversity and specific composition were unaffected. At the species taxonomic level, significant

increase in abundance between treatments appeared only for Caprella Poster Abstracts acanthifera. In partially protected area, where fish abundance is lower and amphipod abundance higher, individuals of the carnivorous fish Coris julis (Labridae) were enclosed in cages to provide an estimate of the potential for this species to impact on amphipod community. There was a small but measurable effect on amphipod abundance between enclosures and unmanipulated controls. A few dominant amphipod species responded to fish predation by significant decrease in abundance. These results suggest that fish predation may determine the relative abundances in the community of some amphipod species and to some degree, through an untested link with habitat complexity, determine the spatial distribution of amphipod abundance within P. oceanica beds. Moreover, patterns observed at the species level, suggest parallel complex interactions probably mainly related to ecological behaviour of amphipod species.

Keywords: Posidonia oceanica seagrass meadows, amphipods, fish predation E-mail: [email protected]

151

P.46 Cranial variation in the Persian jird (Meriones persicus, Rodentia, Gerbillinae): shape changes across geoclimatical ranges

Tabatabaei Yazdi F.1, Adriaens D.1, Darvish J.2

1 Evolutionary Morphology of Vertebrates, K.L. Ledeganckstraat 35, 9000 Gent, Belgium 2 Rodentology Research Department, Ferdowsi University of Mashhad, Azadi square, 91735 Mashhad, Iran

Intraspecific variation in the Persian jird (Blanford, 1875), an endemic species of the Iranian Plateau, is poorly studied. Considering the wide geographical range they span, thereby covering a wide variety of ecogeographical niches, a study focusing on their inter- and intraspecific morphological differences allows Poster Abstracts Poster testing the hypothesis of phenotypic variation being partially driven by the environment. For this study, cranial variation was studied in these Jirds across a wide geographical area. In this study morphological variation was investigated in order to test to what degree the geographical differences is reflected in their cranial shape and size. Using two-dimensional geometric morphometric approach, a total of 221 intact skulls of this species were analyzed, originating from more than 45 different localities along their distribution range, from Iraq

to the east of the Iranian Plateau. Cranial variation was also compared to patterns of variation in geoclimatical variables, such as elevation, temperature and rainfall. Our results show that the specimens from some localities (e.g. from Khuzestan, Kohkiluyeh and Boyer-Ahmad and Bamyan provinces) reveal cranial differences, that were interpreted by the level of rainfall and elevation.

Keywords: geoclimatical variables, cranium, geometric morphometrics, Muridae E-mail: [email protected]

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P.24 Habitat change in a network of ponds in an endangered newt species, Triturus cristatus

Timmermann Michaël, Hanoy Mylène, Denoël Mathieu

Behavioral Biology Unit, University of Liege, Quai Van Beneden 22, 4020 Liège, Belgium

The configuration of breeding patches is of primary importance for the maintenance of numerous species. The great crested newt (Triturus cristatus) is currently in decline in several countries, including Belgium. Previous studies analysed habitat use in relatively distant ponds and showed the importance of maintaining pond networks. More quantitative data are now needed to understand its complex population dynamics and to protect this species. Our aim was to study patterns of pond use across time during a reproductive

season in a dense network of ponds within a Natura 2000 area. Our work got support from SPW, FRS-FNRS, Life Natura2Mil, la Défense, and the military authorities of Camp Albert 1er. We individually marked more than 700 adults of crested newts with PIT-tags and analysed movements among breeding patches during one season. Our results are preliminary but indicate that the studied pond configuration allowed the establishment of a huge crested newt population. It can be considered as a priority target in terms of conservation at the regional (Wallonia) and country level. Our results also evidenced a higher than previously thought rate of pond change and the significant effects of Poster Abstracts several habitat traits (e.g. water depth) on pond use and movements. A second year of study would allow to determine the distribution of the marked newts and to better quantitatively assess the determinants of pond use. At term, we aim at defining the most optimal composition and configuration of habitats to sustain large newt populations.

Keywords: amphibian, passive integrated transponder, population dynamics E-mail: [email protected]

153

P.27 Gradual adaptation toward a range-expansion phenotype initiated the global radiation of toads

Van Bocxlaer Ines1, Loader Simon P.2, Roelants Kim1, Biju S. D.3, Menegon Michele4, Bossuyt Franky1

1 Vrije Universiteit Brussel, Brussels 2 University of Basel, Basel 3 University of Delhi, Delhi 4 Museo Tridentino di Scienze, Trento

Recent studies have identified range expansion as a potential driver of speciation. Yet it remains poorly understood how, under identical extrinsic

Poster Abstracts Poster settings, differential tendencies for geographic movement of taxa originate and subsequently affect diversification. We identified multiple traits that predict large distributional ranges in extant species of toads (Bufonidae) and used statistical methods to define and phylogenetically reconstruct an optimal range-expansion phenotype. Our results indicate that lineage-specific range- shifting abilities increased through an accumulation of adaptive traits that culminated in such a phenotype. This initiated the episode of global colonization and triggered the major radiation of toads. Evolution toward a

range-expansion phenotype might be crucial to understanding both ancient widespread radiations and the evolutionary background of contemporary invasive species such as the cane toad.

Keywords: adaptation, range-expansion, Bufonidae E-mail: [email protected]

154

P.35 A study of the underlying pathways of exposure to cadmium and hexavalent chromium on the cell proliferation in Schmidtea mediterranea

Van Roten A.

Hasselt University, Hasselt

Heavy metals are a serious ecological threat as they accumulate in the different compartments of the environment. Numerous studies already focused on different physiological and cellular aspects of metal toxicity, but information about underlying molecular pathways is rather scarce. We don’t know whether there is one single mechanism of action via which heavy metals exert their effects, or if metal-specific pathways exists. Therefore, it is essential to gain more knowledge concerning the impact of heavy metals, especially in a multipollution context. Cadmium (Cd) and hexavalent chromium (Cr(VI)) are two carcinogenic heavy metals of which the effects are studied at multiple levels in the flatworm, Schmidtea mediterranea. At the ultrastructural level and several physiological levels alterations due to Cd and Cr(VI) have already been observed. Also exposure to both these metals has shown to cause an increase in the cell proliferation rate in this organism. The aim of this study is to find the underlying mechanisms of this (malignant) cell proliferation, as well in a single as multipollution context. Therefore we are now screening both the Poster Abstracts transcriptional and enzymatic level in S. mediterranea for the effects caused by exposure to these metals.

Keywords: cell proliferation, multipollution E-mail: [email protected]

155

P.53 Identification of novel isoforms of PVF-1 and icarapin in honeybee venom glands using an RT-PCR-based approach

Van Vaerenbergh Matthias C.1, Devreese Bart2, de Graaf Dirk C.1

1 Laboratory of Zoophysiology, Ghent University, K.L. Ledeganckstraat 35, B-9000 Gent, Belgium 2 Laboratory for Protein Biochemistry and Biomolecular Engineering, K.L. Ledeganckstraat 35, B-9000 Gent, Belgium

Honeybee (Apis mellifera) stings have the potential to elicit a systemic allergic reaction, which can result in life-threatening anaphylaxis. This makes an efficient diagnosis and immunotherapy important. Nowadays, mostly complete venom extracts are used for this purpose. This has some major disadvantages Poster Abstracts Poster due to the high variability in venom composition and Hymenoptera venom homology. Recombinant technology may provide a solution for these drawbacks. However, good knowledge of the venom composition is required. Already 10 venom components have been recognized as allergens. Protein heterogeneity might broaden this allergen spectrum even further. Here, we report on an analysis of transcript heterogeneity of two venom components detected at the Laboratory of Zoophysiology: PVF-1 and icarapin. Using an RT-

PCR-based cloning approach, we revealed the existence of at least three alternative splice variants of PVF-1. Also, icarapin seems to contain at least 11 transcripts derived from the same genomic locus by complicated alternative splicing. Due to frameshifts and introduction of alternative stop codons, translation of multiple PVF-1 and icarapin transcript variants will produce C- terminally truncated isoforms. These findings are important for diagnosis of honeybee venom allergy and immunotherapy as different isoforms may differ in their allergenic potential. Several variants of PVF-1 and icarapin will be recombinant expressed using an insect cell expression system. The availability of several purified variants will allow us to do a comparative analysis of their allergenic potential. The allergenic potential of PVF-1 will be tested for the first time.

Keyword: honeybee venom allergy E-mail: [email protected]

156

P.23 Basin-linked population genetic structure of turbot

Vandamme S.G.1,2, Maes G.E.2, Moreau K.1, Robbens J.1, Volckaert F.A.M.2

1 Institute for Agricultural and Fisheries ResearchAnkerstraat 1, 8400 Oostende Belgium 2 Katholieke Universiteit LeuvenLaboratory of Animal Diversity and Systematics Ch. de Beriotstraat 32, 3000 Leuven, Belgium

Many marine species have the capacity to dispersing over vast geographical areas, either passively by drifting eggs and larvae following ocean currents, or actively by migration of juveniles and adults. The apparent lack of physical barriers in the sea, leads to the expectation of weak or absent population structure. However, in the last decade an increasing number of population genetic studies describe distinct genetic structures for several marine species,

even on small geographical scale. The presence of subpopulations might suggest that mechanisms other than physical barriers shape population differentiation such as oceanic currents, larval retention, dispersal constraints, philopatry and associated local adaptation do play a role. Turbot is a valuable commercial species in Europe, living in the NE Atlantic Ocean, Mediterranean and Black Sea. Previous genetic studies showed low or non-existing genetic differentiation. However, most of these studies were basin-specific, included relatively few samples/locations or used an incongruent set of markers. Here we analyze the population genetic structure of turbot on a pan-European scale Poster Abstracts with genetic fingerprints eighteen microsatellite markers. On a large scale we refute the hypothesis that turbot is a truly ‘panmictic’ marine species, although on a small geographical scale patterns are less distinct. Finally, we evaluate the biological significance for fisheries management.

Keywords: Psetta maxima, population structure, genetic stock identification E-mail: [email protected]

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P.6 Discovering marine biodiversity through integrative taxonomy 2 case studies: the Triphoridae, a family of micromolluscs and the Mediterranean sponge genus Hexadella

Vanmaele S.1, Allewaert C.2

1 Ghent University, Faculty of Bioscience Engineering, Department of Animal Production, Rozier 44, 9000 Ghent, Belgium 2 Ghent University, Faculty of Science, Department of Marine Biology, Krijgslaan 181/ S8, 9000 Gent, Belgium

The International Census of Marine Life (COML) has listed over 55000 marine molluscs and around 9000 estimated sponge species. Yet, these numbers represent only a small fraction of the likely total. Species are going extinct Poster Abstracts Poster faster than can be described due to a shortage of taxonomic expertise, sampling effort and lack of communication between scientists, also known as the ‘taxonomic impediment’ (Bouchet & Strong, 2010). Knowledge of species biodiversity is a prerequisite for further research and conservation purposes. However, traditional taxonomic characteristics (e.g. morphology) do not always identify species boundaries correctly due to environmental changes, plasticity and cryptic species. DNA barcoding is one of the new methods proposed to

help tackling these problems. DNA datasets can easily be obtained and taxonomists are not necessary for species identification (Hebert et al., 2003). However, DNA barcoding is not sufficient for taxa description because of the non visual communication of raw molecular data. DNA barcoding should therefore complement traditional taxonomy instead of replacing it. A new approach is being promoted recently, which aims to delimit species boundaries by combining various disciplines (e.g. molecular data, morphology and environmental data): integrative taxonomy. During the first case study DNA sequences were obtained for the first time from triphorids, a highly divers family of micromolluscs. Molecular evidence revealed that morphology can be used for species segregation in the case of the Triphoridae and that is a good proxy for diversity, unlike the majority of other marine molluscs. The second case study demonstrates the possibility of discriminating genetically revealed cryptic sponge species of the genus Hexadella through comparative integrative taxonomy combining morphological (cytological) and chemical data. To summarize, integrative taxonomy will greatly improve our knowledge of biodiversity, as shown in both case studies, by combining molecular methods (e.g. DNA barcoding) with morphological data and should be used more frequently in modern taxonomy.

E-mail: [email protected]

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P.16 The development of transgenic Daphnia in the Daphnia- Pasteuria interaction

Decaestecker Ellen1,2, Vanoverberghe Isabel1,2

1 Aquatic Biology, Science & Technology, IRF-Life Sciences, K.U.Leuven-Campus Kortrijk, Belgium 2 Aquatic Ecology and Evolutionary Biology, K.U.Leuven, Belgium

We aim to evolve a direct approach to detect the Daphnia genes involved in the interaction between Daphnia and its endoparasite Pasteuria ramosa by constructing transgenic Daphnia. In a first stage we aim to transfect or transduce GFP into primary embryonic Daphnia cells to obtain over-expression o knock-down of immune genes. We focus both on non-viral and viral techniques. We succeeded in the preparation of primary Daphnia cell cultures. Non-viral techniques such as CaF, Fugene, Lipofectamin and PEI were tested on these cell cultures but were not successful. Detection of GFP expression by fluorescence microscopy showed difficulties with background noise through autofluorescense. Therefore, expression will also be analyzed on protein level by western blot. Further approaches that are currently investigated are micro- injection of the Daphnia in order to be able to transduce or silence the genes in vivo in Daphnia. Poster Abstracts

E-mail: [email protected]

159

P.40 Entamoeba spp. infections in wild Barbary macaques (Macaca Sylvanus), Morocco

Verschave S.1,2, Stevens J.2, Majolo B.3, Dorny P.4, Vercammen F.2, Vercruysse J.1, Levecke B.1,2

1 Department of Virology, Parasitology and Immunology, Faculty of Veterinary Medicine, Salisburylaan 133, 9820 Merelbeke, Belgium 2 Centre for Research and Conservation, Royal Zoological Society of Antwerp, Koningin Astridplein 26, B-2018 Antwerp, Belgium 3 School of Psychology, University of Lincoln, Brayford Pool, Licoln LN6 7TS, United Kingdom 4 Department of Animal Health, Institute of Tropical Medicine, Nationalestraat 155, B-2000 Antwerp, Belgium Poster Abstracts Poster Entamoeba spp. are frequently detected in faecal samples of non-human primates (NHP). Although the majority of these Entamoeba spp. are considered to be harmless, care should be taken when E. histolytica is involved, which may cause hemorrhagic dysentery, liver abscesses and even death. Until now, the majority of the studies conducted on the prevalence of Entamoeba spp. in NHP are based on diagnosis by light microscopy. However, this method is inadequate for making a correct diagnosis, since E. histolytica cannot be distinguished from the nonpathogenic E. dispar and E. moshkovskii. Furthermore, recent molecular analysis of E. histolytica indicates genetic differences between human and NHP isolates, which may provide a discriminatory tool to demonstrate zoonotic transmission. Yet, the distribution of both variants in both humans and NHP remains unclear. In the present study we examined 48 faeces samples of wild Barbary macaques (Macaca sylvanus) collected in Morocco by using light microscopy for the presence of Entamoeba spp. In addition, a previously described PCR protocol was applied for the detection of the human and the NHP variant of E. histolytica. E. hartmanni was the most prevalent (68.8%), followed by E. coli (77.1%), E. histolytica/dispar/moskovskii (54.2%) and E. polecki (25.0%). The molecular analysis did not reveal the presence of E. histolytica. These results indicate that wild Barbary macaques are frequently infected with Entamoeba spp., but that they are no potential reservoir for zoonotic transmission of E. histolytica. This study received financial support of Centre for Research and Conservation, Royal Zoological Society of Antwerp.

Keywords: Entamoeba spp., Macaca sylvanus E-mail: [email protected]

160

P.39 Impact of pit-tagging on behaviour, growth and survival in Alpine newts, Mesotriton alpestris

Winandy Laurane, Denoël Mathieu

Behavioural Biology Unit, University of Liège, Liège, Belgium

Passive integrate transponder devices allow investigations into physiological, ecological and behavioural traits of many animals, included newts. This marking technique gives a more reliable assessment than the most usual other marking techniques because of its unique permanent code and inside insertion. Nevertheless, it is important to evaluate its potential invasive effects on several traits. Because most studies evaluated the impact on recovery, mortality and

growth, we aimed at measuring additional patterns at a more detailed scale, i.e. behaviour. We compared survival, growth and behaviour of 16 pit-tagged and 16 unmarked adult Alpine newts Mesotriton alpestris in the laboratory. The size of the newts was taken at the beginning and at the end of experiment. To quantify behaviour, we applied replicated visual observations in the aquaria and carried out video-tracking analyses in specific arenas. All the individuals survived to the implantation and recovered from tag injection. During the study, pit-tagged newts had a significant lower growth than unmarked newts. The visual observations showed no significant impact of tag on feeding and Poster Abstracts courtship behaviours. However, we noted a slight difference in shelter use in marked newts. The video-tracking analyses did not highlight any significant effects on movement, distance and speed. In conclusion, despite some slight differences between marked and unmarked newts, this technique is not destructive and has no major invasive effects. This study shows that more studies should integrate quantitative behavioural analyses to estimate the adequateness of methodologies and that further works are needed on the effects of pit-tagging.

Keywords: behaviour, amphibian, marking technique E-mail: [email protected]

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LIST OF PARTICIPANTS

Adam, Nathalie [email protected] Adriaens, Dominique [email protected] Aerts, Peter [email protected] Allewaert, Celine [email protected] Anselin, Anny [email protected] Attia, Sabrine [email protected] Baggerman, Annemieke [email protected] Bastien, D'hooghe [email protected] Benton, Tim [email protected] Bert, Wim [email protected] Berten, Laetitia [email protected] Biswas, Bhabananda [email protected] Bonte, Dries [email protected] Boone, Mieke [email protected] Borghgraef, Inge [email protected] Bosman, Davy [email protected] Bossuyt, Franky [email protected] List of Participants of List Braeckman, Bart [email protected] Brakel, Ilse [email protected] Brecko, Jonathan [email protected] Breine, Jan [email protected] Bright Imariable, Eguavon [email protected] Broly, Pierre [email protected] Brosens, Dimitri [email protected]

Callens, Tom [email protected] Caro, Samuel [email protected] Christiaens, Joachim [email protected] Collignon, Amandine [email protected] Collignon, Bertrand [email protected] Crucke, Jeroen [email protected] Dams, Jan [email protected] Daneels, Dorien [email protected] Danneels, Ellen [email protected] Dauby, Patrick [email protected] De Bruyn, Frederik [email protected] De Bruyn, Luc [email protected] De Busschere, Charlotte [email protected] De Coster, Greet [email protected] de Gelder, Stefan [email protected] de Graaf, Dirk [email protected] De Groot, Evelien [email protected] De Kegel, Barbara [email protected]

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De Meester, Nele [email protected] De Neve, Liesbeth [email protected] De Vrieze, Erik [email protected] de Waal, Frans [email protected] Decae, Arthur [email protected] Decaestecker, Ellen [email protected] Dekeirsschieter, Jessica [email protected] Descamps, Emilie [email protected] Desmet, Niels [email protected] Devigne, Cédric [email protected] Devreese, Lieven [email protected] Dewit, Jasper Dewit [email protected] Dhondt, Ineke [email protected] Duchateau, Marie José [email protected] Eagderi, Soheil [email protected] Etoundi, Emilie [email protected] Falisse, Elodie [email protected] Fiaz, Ansa [email protected]

Fienieg, Elmar [email protected] Fonderie, Pamela [email protected] Formesyn, Ellen [email protected] Fransolet, David [email protected] Geerinckx, Tom [email protected] Geerts, Lindsay [email protected] Genbrugge, Annelies [email protected]

Gunasekara, Rangalle [email protected] List of Participants Gyselings, Ralf [email protected] Hablützel, Pascal [email protected] Hallensleben, Nollie [email protected] Hanzen, Céline [email protected] Harke, sanjay [email protected] Hauquier, Freija [email protected] Hecq, Jean-Henri [email protected] Helvacı, Zeycan [email protected] Hemerik, Lia [email protected] Herman, Anne-Catherine [email protected] Herrel, Anthony [email protected] Hespeels, Boris [email protected] Heylen, Dieter [email protected] Huybrechts, Roger [email protected] Huyse, Tine [email protected] Ide, Celine [email protected] Janssenswillen, Sunita [email protected]

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Jordaens, Kurt [email protected] Jossart, Quentin [email protected] Kéver, Loïc [email protected] Klaren, Peter [email protected] Lange, Benjamin [email protected] Laurane, Winandy [email protected] Lavorato, Manuela [email protected] Lehouck, Valerie [email protected] Lemaire, Veerle [email protected] Lemmer, Louis-Joan [email protected] Lepoint, Gilles [email protected] Leroy, Céline [email protected] Leysen, Heleen [email protected] Li, Xiang [email protected] Ludivine, Fassotte [email protected] Marescaux, Jonathan [email protected] Martens, Koen [email protected] Mascart, Thibaud [email protected] List of Participants of List Matthijs, Severine [email protected] Mergen, Patricia [email protected] Metz, Juriaan [email protected] Michel, Loïc [email protected] Middelveld, Robert [email protected] Mikaili Akanbi, Lawal [email protected] Millot, Sandie [email protected]

Moens, Tom [email protected] Mouchette, Olivier [email protected] Musschenga, Maartje [email protected] Naert, Miranda [email protected] Nauwelaerts, Sandra [email protected] N'Dri, Kouadio Julien [email protected] Nikolakakis, Spyridon [email protected] Oluwatobiloba, Adesina [email protected] Pandey, Ashish [email protected] Parmentier, Eric [email protected] Pennekamp, Frank [email protected] Pereboom, Zjef [email protected] Pête, Dorothée [email protected] Peters, Hanneke [email protected] Pierre, Devos [email protected] Pigneur, Lise-Marie [email protected] Plumier, Jean-Christophe [email protected] Pollet, Marc [email protected]

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Praet, Tomas [email protected] Radstake, Yvonne [email protected] Raeymaekers, Joost [email protected] Raknuzzaman, MD. [email protected] Rekecki, Anamaria [email protected] Remy, François [email protected] Roberty, Stephane [email protected] Šafář, Jaroslav [email protected] Schaerlaeken, Vicky [email protected] Schiedon, Esther [email protected] Schnitzler, Joseph [email protected] Schön, Isa [email protected] Serbruyns, Lynn [email protected] severin, Dushimirimana [email protected] Sharif, Faiza [email protected] Simeon, Oseghale [email protected] Sodiq, Oyede [email protected] Staes, Nicky [email protected]

Steel, Hanne [email protected] Stevens, An-Sofie [email protected] Stevens, Jeroen [email protected] Stolwijk, Rowan [email protected] Sturaro, Nicolas [email protected] Tabatabaei Yazdi, Fatemeh [email protected] Thijssen, Michiel [email protected]

Timmermann, Michael [email protected] List of Participants tkint, Tim [email protected] Treer, Dag [email protected] Van Belleghem, Steven [email protected] Van Bocxlaer, Bert [email protected] Van Bocxlaer, Ines [email protected] Van Daele, Paul [email protected] Van den Broecke, Lynn [email protected] van der Meijden, Arie [email protected] Van Dyck, Hans [email protected] Van Hove, Arno [email protected] van Kessel, Anne [email protected] van Rijssel, Jacco [email protected] Van Roten, Andromeda [email protected] van Straalen, Nico M. [email protected] Van Vaerenbergh, Matthias [email protected] Van Wassenbergh, Sam [email protected] Van Wynsberge, Hilde [email protected]

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Vandamme, Sara [email protected] Vandebergh, Wim [email protected] Vanden Hole, Charlotte [email protected] Vandenplas, Sam [email protected] Vandewoestijne, Sofie [email protected] Vanhooydonck, Bieke [email protected] Vanmaele, Sofie [email protected] Vanoverberghe, Isabel [email protected] Vanreusel, Ann [email protected] Vanthournout, Bram [email protected] Verdoodt, Freija [email protected] Verheyen, Erik [email protected] Vermeersch, Glenn [email protected] Vernimmen, Tim [email protected] Verschave, Sien [email protected] Verschelde, Dominick [email protected] Verstraeten, Barbara [email protected] Vervloet, Athena [email protected] List of Participants of List Vidick, Nicolas [email protected] Visser, Marcel [email protected] Volckaert, Filip [email protected] Vroonen, Jessica [email protected] Waheed Alao, Adeosun [email protected] Weijs, Liesbeth [email protected] Wiersma, Liesbeth [email protected]

Willems, Maxime [email protected] Yakub Olamide, Adesina [email protected] Zirbes, Lara [email protected] Zuure, Wieteke [email protected]

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See you next year for the 18th Benelux Congress of Zoology Utrecht 2-4 November 2011

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Gent-Sint-Pieters Railway Station Railway To railwaystation ICC To center ATM P

ATM Underground Parking Sint-Pietersplein To center E17/E40 To/from FRIDAY OCTOBER 22nd 8h30 Registration & coffee (Peristilium) 9h15 Welcome and opening (A3) 9h30 PLENARY 1 - Tim Benton (A3) Physiology & Behaviour (A3) Functional Ecology & Morphology I (A5) 10h20 R. Huybrechts P. Aerts 10h50 S. de Gelder* N. Desmet° 11h10 Coffee (Peristilium) 11h40 J. Stevens V. Schaerlaeken° 12h00 S. Matthijs° B. Van Bocxlaer° 12h20 J. Schnitzler° S. Millot 12h40 S. Attia° T. Praet 13h00 Lunch (ICC) 14h00 KETS Award Presentations (A3) Behavioural Ecology (A3) Ontogeny & Regeneration (A4) Evolution (A5) 14h50 S. Caro J. Crucke* S. Janssenswillen° 15h10 L. De Neve I. Dhondt* W. Vandeberg° 15h30 Coffee (Peristilium) 16h00 P. Broly* S. Vandenplas° L.-M. Pigneur° 16h20 L. Devreese M. Boone° C. De Busschere° 16h40 G. De Coster° E. de Vrieze° S. Van Belleghem° 17h00 D. Treer° J. Dewit° L. Van den Broecke 17h20 POSTER SESSION 1 + RECEPTION (Peristilium) 19h00 SOCIAL + 'MEET THE EXPERT' (Peristilium) SATURDAY OCTOBER 23rd 9h00 PLENARY 2 - Frans de Waal (A3) Diversity & Distribution (A3) Molec. & Cell. Zool. (A4) Funct. Ecol. & Morph. II (A5) 9h50 J.-H. Hecq E. Decaestecker J. Raeymaekers 10h20 J. Breine A.-S. Stevens° S. Van Wassenbergh 10h40 F. Remy* F. Verdoodt° J. van Rijssel° 11h00 P.A.A.G. Vandaele° B. Verstraeten° J. Vroonen° 11h20 P. Hablützel° H. Peters* N. De Meester° 11h40 POSTER SESSION 2 + COFFEE (Peristilium) 12h30 Lunch (ICC) 13h30 PLENARY 3 - Anthony Herrel (A3) Spatial Ecology (A3) Evolutionary Ecology (A4) Ant. Effects & Human Use (A5) 14h20 S. Vandewoestijne J. Dekeirsschieter° G. Vermeersch 14h40 D. Bosman B. Vanthournout° H. Steel° 15h00 V. Lehouck L. Zirbes° P. Fonderie° 15h20 L. Wiersma I. Schön R. Gunasekara° 15h40 T. Callens° C. Vanden Hole* L. Weijs° 16h00 Coffee & Jury deliberations (Peristilium) 16h30 Awards and closing (A3) * MSc award competitor, ° PhD award competitor