www.cassiopeabase.org [email protected] 4th International Cassiopea Workshop May 20-23, 2021 The Fourth International Cassiopea Workshop will be held online across four sessions, from 10:00 AM to 3:00 PM Eastern Standard Time (USA). This year, the workshop will be held virtually, but similar to previous workshops, our goal is to grow our community, generate collaborations, and encourage sharing of knowledge and ideas. In order to offer an experience beyond Zoom presentations, we are planning virtual ‘mini-workshops’ centered around tutorials on topics such anatomical identification of Cassiopea, spawning/husbandry, embryo injections, computational fluid dynamics, etc. We will also organize a virtual space for attendees to converse with others, participate in trivia, and make new colleagues. This meeting is for those working on Cassiopea and those interested in working in Cassiopea! Past attendees have diverse research backgrounds and questions, but we all come away with much to gain. Social hours will be held over Gather Town (gather.town). Gather.town is a virtual networking service which allows attendees to move their avatar from room to room, in and out of conversations, and interact with colleagues in a virtual space. You do not need an account to participate, and a demo is available on the website if you would like to explore before the workshop. Links to access the workshop gather.town space will be released to attendees during the week of the workshop. Thursday, May 20 EST (USA) Title Presenter 10:00 Welcoming Remarks Mónica Medina (Pennsylvania State University 10:15 History of Cassiopea (Dedication to Hugo Freudenthal) Dietrich Hoffman William Fitt University of Georgia 10:30 Cassiopea sp. Life Cycle Dietrich Hoffman William Fitt University of Georgia 10:45 Tutorial: Spawning and Husbandry of Cassiopea Aki Ohdera Caltech Victoria Sharp Pennsylvania State University 11:30 BREAK 12:00 Tutorial: JGI Genome Browser Sajeet Haridas Joint Genome Institute 12:45 BREAK 13:00 Tutorial: Embryo Micro-injections DeGennaro Lab Florida International University 14:00 SOCIAL (gather.town) 2 Friday, May 21 EST (USA) Title Presenter 10:00 Ramifications of viewing symbiosis as a loop of context Tamar Goulet dependent states U. of Mississippi 10:15 Conserved symbiotic mechanisms in invertebrate-algal Angus Thies symbioses Scripps Inst. of Oceanography 10:30 Amoebocytes facilitate efficient nutrient transfer in Cassiopea Niclas Lyndby Swiss Federal Inst. for Technology in Lausanne 10:45 Quo vadis, Symbiodiniaceae miRNA evolution? Viridiana Avila- Magaña U. of Colorado Boulder 11:00 BREAK 11:15 The relationship between diverse Symbiodiniaceae species, Victoria Sharp strobilation, and resulting host phenotypes in Cassiopea Pennsylvania. St. U. xamachana 11:30 A deep dive into Cassiopea sleep: complementary behavioral, Michael Abrams RNAseq, and pharmacology experiments implicate UC Berkeley homeostasis as a key function of sleep 11:45 Behavioral differentiation among Mastigias papua Karly Higgins-Poling subpopulations in an isolated marine lake (Lightning Talk) UC Merced 11:53 TBA (Lightning Talk) 12:00 Feeding Behavior of Cassiopea xamachana Kendra Pfeil Pennsylvania. St. U. 12:15 Cassiopea care and culture at the Maritime Aquarium Rachel Stein Maritime Aquarium 12:30 BREAK 13:15 Laura Miller Plenary Talk: The fluid dynamics of Cassiopea sp. U. of Arizona 13:30 BREAK 14:00 Hydrodynamic studies of Cassiopea feeding and exchange Arvind currents Santhanakrishnan Oklahoma St. U. 14:15 Hopscotching Jellyfish: combining different duty cycles can Nicholas Battista lead to enhanced swimming performance College of New Jersey 14:30 Exploring the Benthic Fluid Dynamics of Cassiopea with 3D Alexander Hoover Computational Models U. of Akron 14:45 Introducing Planktos: an agent-based modeling framework for Christopher Strickland small organisms in fluid flow U. of Tennessee, Knoxville 15:00 SOCIAL (gather.town) 3 Saturday, May 22 EST (USA) Title Presenter 10:00 Using Cassiopea cf. xamachana as a model to study the Gloria Lorena effects of temperature and pH on symbiotic interactions Velazquez Mejia Universidad del Mar 10:15 In vivo evaluation of bioenergetic parameters in heat- Edmée Royen stressed Cassiopea U. of Liège 10:30 Influence of Salinity, Temperature, and Light Intensity on the Marcela Prado- Rate of Strobilation of Cassiopea xamachana Zapata, Raian Counsman, Caroline Link New College of Florida 10:45 Mitochondrial dysfunction and reductions in symbiont Bradford Dimos colonization occur in tandem during thermal stress in U. of Texas at Cassiopea xamachana Arlington 11:00 BREAK 11:15 Symbiont Genotype Influences Host Response to Jennica Moffat Temperature in a Model Cnidarian-Dinoflagellate Mutualism California St. U., Northridge 11:30 Untangling genetic tentacles: Characterizing population Megan Maloney diversity in a model jellyfish Auburn U. 11:45 Symbioses in 3D: diversity and dynamics in pelagic Michael Dawson photosymbioses UC Merced 12:00 A chemist in the ocean - exploration of the microbial Sandra Loesgen community and chemistry of Cassiopea U. of Florida 12:15 The bacterial community of Cassiopea xamachana Natalia Carabantes Universidad Nacional Autónoma de México 12:30 BREAK 13:00 Plenary Talk: Adaptation to the environment by Annika Guse endosymbiosis - a model systems' approach Heidelberg U. 13:30 BREAK 14:00 High photosynthetic plasticity may reinforce invasiveness of Marta Mammone upside-down zooxanthellate jellyfish in Mediterranean Università del coastal waters Salento 14:15 Upside-down jellyfish (Cassiopea) as a model organism for Madeline McKenzie biomonitoring environmental variability James Cook U. 14:30 Cassiopea as a biomonitoring tool Shelley Templeman TropWATER, James Cook U. 14:45 Upside-down down under: identification, distribution, and Claire Rowe population dynamics of the invasive Cassiopea jellyfish in U. of Sydney Lake Macquarie, Australia 15:00 SOCIAL (gather.town) 4 Sunday, May 23 EST (USA) Title Presenter 10:00 Laura Miller Tutorial: A quick tutorial on numerically simulating University of Arizona mathematical models relevant to Cassiopea Christina Hamelt Bucknell University 11:00 BREAK 11:30 Todd LaJeunesse Pennsylvania State University Tutorial: Symbiodinium Culturing William Fitt University of Georgia 12:00 BREAK 12:30 Andre Morandini University of São Paolo Tutorial: Cassiopea Morphology Edgar Gamero University of São Paolo 13:30 Winner of best talk Mónica Medina Pennsylvania State University 13:45 Closing Remarks Mónica Medina Pennsylvania State University 14:00 SOCIAL (gather.town) 5 Abstracts Plenary Adaptation to the environment by endosymbiosis - a model systems' approach Annika Guse / Heidelberg University Symbiotic interactions between organisms occur in all domains of life. A prime example is the symbiosis between corals and eukaryotic, photosynthetic dinoflagellates. Each generation, initially symbiont-free coral larvae take up dinoflagellates from the environment and a new, stable symbiotic interaction is established. Symbionts provide essential nutrients such as sugars, amino acids and lipids to their host powering the productivity of reefs ecosystems. This ‘photo-symbiosis’ is evolutionary ancient and considered a key adaptation to shallow, sunlit tropical oceans where food is scarce, and likely the main driver for coral diversification as well as onset of reef formation in the Triassic. Despite of its importance, key aspects about coral symbiosis establishment, maintenance, its evolution and ecosystem functions are still largely unknown. Here I will present our advances in developing Aiptasia, a marine sea anemone, as a tractable model to dissect fundamental aspects of symbiosis establishment at the mechanistic level. I will summarize our currently available resources and experimental toolkit for Aiptasia. Based on our findings combining Aiptasia work at the bench and comparative work with corals collected in the field, I will give an overview over our current understanding of the mechanisms underlying symbiont uptake via phagocytosis, how the symbionts escape the hosts’ defensive strategies to persist intracellularly and conversely, how hosts prevent invasion by non-symbiotic organisms, how symbionts integrate into host cell metabolism and transfer nutrients such as sterols to the host. We provide fundamental insight into how two very distinct cells, an animal host and a dinoflagellate symbiont cell, coordinate their cellular functions to adapt to nutrient-poor environments and drive the productivity and biodiversity of the ecosystem. Presentations 1. Ramifications of viewinG symbiosis as a loop of context dependent states Tamar Goulet / University of Mississippi In 1878, de Bary defined symbiosis as the “living together of differently named organisms.” de Bary’s definition of symbiosis described a phenomenon, not its ramifications. Subsequently, attributes were assigned to symbioses based on benefits and costs, from mutualism (both partners benefit), commensalism (one partner benefits while the other is neither harmed nor gains a benefit), parasitism (one partner benefits while the other is harmed), to the recently added amensalism (one partner is harmed while the other is neither harmed nor gains a benefit). Although the symbiotic states may appear as discrete boxes, or a sliding continuum, neither portrayal captures the complexities of symbioses, since the former assumes that a symbiosis is constrained into one category while the latter implies that a mutualism needs to transition