Meeting Abstract
Emersion from an aquatic to a terrestrial environment is a tactic used by many fish species for a variety of reasons. With Kryptolebias marmoratus, emersion occurs due to stranding, to escape predators, and to capture prey. Once on land, K. marmoratus can employ a tail-flip behavior in order to move across the substrate. The performance of this tail-flip behavior can depend on a variety of factors such as age, size, and time spent acclimating to air. In this experiment, forty K. marmoratus individuals were exposed to one of four different fasted acclimation treatments: 28 days in water, 14 days in air followed by 14 days in water, 14 days in air, and 14 days in water. Fish were then put on moist paper and prompted to jump. Number of jumps and distance moved during jumps were analyzed. Preliminary results show that the individuals who acclimated in air only jumped more frequently and moved further with each jump, indicating that plastic changes may occur during air acclimation that improve locomotor performance on land. To test if one of these plastic changes could be a change in mass distribution from the anterior to the posterior, where most of the force needed to jump is generated, lateral and dorsal photos were taken of fish before and after treatment. These photos were then analyzed to track changes in mass along the body. Preliminary results indicate that while most individuals lost weight, mass distribution of individuals in the 14 days in air treatment shifted towards the posterior, while mass distribution did not appear to change appreciably in the other treatment groups. Plastic shifts in mass may thus be the mechanism that allows K. marmoratus to perform better when jumping in a terrestrial environment after air exposure.
