Meeting Abstract
Thiaminase is a relatively understudied protein that is present in a variety of plant and animal tissues including some ferns, bivalves, and fish. While there has been a growing body of work examining the mechanisms of how this enzyme degrades thiamine (vitamin B1) or makes it biologically unavailable, less attention has been payed to its ecological significance. We are interested in understanding how animals containing thiaminase fit into the trophic systems within their habitats. Previous work has demonstrated that predatory fish populations in the Great Lakes have declined as a result of feeding extensively on introduced prey fish that are rich in thiaminase. Because of thiamine’s central role as a cofactor in the citric acid cycle, thiamine deficiency can lead to severe metabolic and neurological issues and eventual death. Theoretically, the risk of thiamine deficiency should shape natural trophic systems of predators feeding on prey containing thiaminase. To test this idea, we identified fish species in the gut contents of diamond-backed watersnakes (Nerodia rhombifer) to examine if snake prey items contained thiaminase. Simultaneously, we measured the thiaminase activity in fresh fish tissue of all species that co-occur with this population of watersnakes. Lastly, we collected historical data on the relative abundances of each fish species within the same watershed. While data collection and analysis are still underway, preliminary data suggest that diamond-backed watersnakes within the Lake Columbia watershed preferentially forage on fish species low in thiaminase activity despite other fish species containing thiaminase being relatively abundant within the habitat.
