The most impressive product of social evolution is the eusocial society: a group of animals with a division of labor and cooperative brood care. The classic examples are social insects (ants, bees, wasps, and termites) but this list has expanded to include aphids, shrimp colonies, naked mole rats, and most recently: trematodes. Trematodes are parasitic flatworms, common parasites of snails and humans, where some species form larval infrapopulations with a division of labor. “Reproductives” are large and asexually produce larvae, while “soldiers” are small and attack enemy trematodes trying to establish in the same snail. Virtually every question about trematode sociality is yet to be answered, and with my research I seek to answer one of the most fundamental questions about their sociality: how do these trematodes recognize friend from foe? How do they know who is part of their colony, and who is an invader they need to attack before it is too late?
The Tsutsui lab focuses on uncovering and understanding recognition systems in social insects, particularly invasive ant species. With this project we aim to establish a similar depth to the unknown recognition system of these newly discovered trematode societies. Using behavioral assays and thin layer chromatography, we can (1) analyze quantitative chemical differences of the “glycocalyx” on the skin (i.e. tegument) of trematodes from rival colonies, and (2) test if any of these compounds elicit aggression. While it may sound simple, these methods are very exploratory, and such discoveries would be extraordinary. We could show that similarities in social evolution across mammals and insects now also apply to flatworms. But a fascinating addition is that this same work also brings new insight into the function and evolution of the trematode glycocalyx, which holds the secrets of how trematodes bypass the immune systems of their hosts, whether they be the snails in which these colonies occur, or the estimated 218 million humans exposed to Schistosomiasis around the globe.
Field work = might travel to salt marshes across California once or twice, develop a search image for California horn snails, and collect them.
Lab work = dissect snails, identify trematodes, preserve trematodes in ethanol, set up behavioral assays, and help analyze video recordings of behavior.
These are the tasks both myself and the student will be doing, but once the project is underway, the student might get involved in thin layer chromatography preparation and analysis.
Independent, enthusiastic, and experienced. While good experiences include lab work for projects in the topic of chemical ecology and invertebrate behavior, this project is most beneficial for a student experienced and deeply interested in animal behavior generally; eager to learn the methodology of figuring out what an animal is doing, why it is doing it, and how it got that way.