The Interaction of Fish Biology and Microbial Ecology

The main aim of this project is to investigate the feedbacks between organisms and the microbes that are in their environment. How does the environment influence the establishment of a microbial community within an organism, with particular focus on its gut microbial community, and how does the organism shape its microbial environment? We are using the three-spined stickleback, Gasterosteus aculeatus, to explore the interaction of microbial ecology and fish biology within lake mesocosms. Sticklebacks have adapted to stream and lake habitats in Switzerland, and stream phenotypes typically feed on benthic prey such as invertebrates while lake phenotypes consume planktonic prey. We are interested in seeing if these phenotypic differences cascade down to affect the microbes in their environment. If so, is this a plastic effect, and do these environmental effects subsequently shape the gut microbial community assembly in juveniles of the next generation? This experiment, which is conducted in two phases, will enable us to determine 1) if adult sticklebacks influence the microbes in their environment, 2) are these effects dependent on the rearing conditions of the fish or based on population differences and 3) the degree to which the environment structures the gut microbes of closely related, but divergent fish populations.

Karen Sullam is currently involved with this project while visiting on Fulbright-Swiss Government grant.
This project is in collaboration between Microbial Ecology and Ecology groups.