Meeting Abstract

P1-93   -   Performance trade-offs in the locomotion of Cyprinodontiform fishes Luther, J*; Kamrath, S; Axlid, E; Minicozzi, M; Minnesota State University, Mankato ie6141by@go.minnstate.edu

Many fishes voluntarily leave the water and are capable of an overland movement termed a tail-flip jump. The physical demands of living in both water and land should lead to performance tradeoffs between the two environments. Much like a penguin lost the ability to fly to maximize swimming performance, we investigated the potential tradeoffs in fishes that engage in both terrestrial and aquatic locomotion. Fishes that spend a considerable time in a terrestrial environment tend to be anterior-posteriorly elongated and more uniform mass distribution and fishes that rarely leave the water have a fusiform body plan with an anteriorized mass. Because of these differences, we hypothesized that fishes that spend more time out of water will jump farther but will have a slower swimming speed compared to fishes that rarely leave the water. To test terrestrial movement, we used then individuals from three Cyprinodontiform species (Gambusia affinis, Poecilia reticulata, and Kryptolebias marmoratus), representing a broad range of ability to perform the tail-flip jump. Each fish performed a tail-flip jump, recorded at 600hz, and analyzed for jump distance, takeoff angle, and duration of the movement. The same fish were also placed in a fish flume, acclimated for one hour, and subjected to a standard U_crit test. Post acclimation, flow was incrementally increased until the fish could no longer resist the flowing water and was swept into a mesh trap. These data indicate that more amphibious fishes (K. marmoratus) cannot resist as fast of flows as the more the aquatic fishes indicating functional constraints when fishes evolve to live in both environments. Future work on this project will include collecting data on more fishes from aquatic and amphibious groups to better understand what morphological or physiological features are diving these tradeoffs.