41.2 Thursday, Jan. 5 Flipping out: jumping performance of mangrove rivulus (Kryptolebias marmoratus) from different geographic locations PERLMAN, B.M.*; ASHLEY-ROSS, M.A.; GIBB, A.C.; EARLEY, R.L.; Wake Forest University; Wake Forest University; Northern Arizona University; University of Alabama firstname.lastname@example.org
Mangrove rivulus (Kryptolebias marmoratus) inhabit brackish water habitats of often poor water quality, and perhaps as a result are found in crab burrows, hollowed out logs, or among wet leaf litter in mangrove swamps. K. marmoratus is capable of directed terrestrial movement via a tail-flip behavior that moves the fish several body lengths in a single jump. As the precise mechanisms underlying their terrestrial locomotion have not been described, our goal was to quantify the movements these fish make when on land. Fish representing isogenic lineages from multiple populations across their geographic range were tested, including Florida and Belize. Individual fish were placed in a wading pool covered in damp bench liner paper, and allowed to voluntarily jump for two minutes, followed immediately by a 30 second chasing trial to elicit maximal jump performance. A camera (60 fps) was placed above the wading pool to record all trials. Body movements and the following variables were quantified: number of jumps, jump trajectory, average and maximum jump distance. In a typical jump, the fish faces the stimulus, resting on its ventral side, and rotates the posterior half of its body 90°, splaying its caudal fin flat against the substrate. During the tail-flip, the fish curls its head over its tail, and pushes the tail against the substrate to spring into the air. Upon jump completion, the fish may reorient its body to face the stimulus via a squiggle, and execute another jump. Number and average and maximum jump distance decreased with increasing body length and mass. Populations varied in jump performance, suggesting habitat and morphological differences drive the observed kinematics.