P2.46 Thursday, Jan. 5 Heads or tails? Two different ways for fish to jump ASHLEY-ROSS, MA*; PERLMAN, BM; CARPENTER-CARTER, S; GIBB, AC; EARLEY, RL; Wake Forest University; Wake Forest University; Wake Forest University; Northern Arizona University; University of Alabama firstname.lastname@example.org
Multiple species of small littoral fish have been described to move on land by executing a “tail-flip” behavior in which the fish forcefully pushes the tail against the substrate and launches into the air. We hypothesized that possibly all teleost fish below a threshold mass, and with a fusiform body shape, would be capable of tail-flipping. We tested this idea by comparing terrestrial movements of a species known for coordinated tail-flipping, Kryptolebias marmoratus, with those of largemouth bass (Micropterus salmoides), which as adults are known to flop ineffectually on land, and are only distantly related to K. marmoratus. We recorded movements of juvenile largemouth bass that were sized similarly to adult K. marmoratus using high-speed video (500 fps) and compared movement patterns of the two species. K. marmoratus always jumps via the tail-flip mechanism, in which the animal lifts its head from the substrate and curls it up and over the caudal peduncle, then straightens its body, pushing the tail against the ground to spring into a ballistic trajectory that moves the animal several body lengths from its starting point. We expected that juvenile bass would use tail-flipping as well, but surprisingly found that while bass can jump, it was most often accomplished by a completely different movement pattern, in which the fish would rapidly bend its entire body toward the substrate, bringing head and tail toward one another, and launching into the air by the forceful displacement of the center of mass. Kinematics of the M. salmoides jumps suggest that the animal is attempting to execute stage 1 of a C-start on land, which results in minimally directed, uncoordinated terrestrial movement.