Meeting Abstract
49.4 Saturday, Jan. 5 Terrestrial jumping in the mangrove killifish Kryptolebias marmoratus PACE, C.; GIBB, A.C.*; ECKEL, J.; Northern Arizona University; Northern Arizona University; Northern Arizona University alice.gibb@nau.edu
The amphibious mangrove killifish (Kryptolebias marmoratus) exhibits terrestrial jumping (or leaping); however, the mechanism that generates this behavior is undescribed. We address two questions about this behavior: (1) how does K. marmoratus jump on land? and (2) how does jumping in K. marmoratus compare with jumping in other amphibious fishes? Terrestrial jumping events in K. marmoratus were recorded from lateral and dorsal views using high-speed digital-video imaging. A kinematic profile of jumping was generated using X, Y, and Z coordinates that were tracked over time with a custom digitizing program. K. marmoratus can leap over 18 cm (>500% TL) and perform a series of sequential jumps in the same direction. K. marmoratus begins each leap lying on its side; that is, the lateral aspect of one side of the body (right or left) is in direct contact with the substrate. In preparation for the leap, the fish generates axial bending by �peeling� the anterior region of its body off of the substrate and curling it vertically (perpendicular to the substrate) towards the tail. During the propulsive phase, K. marmoratus launches its body into the air by pushing off the substrate with the tail. This behavior is in contrast to that described for other terrestrial jumpers, such as mudskippers. Mudskippers are ventrally flattened; thus, before the leap, the ventral surface rests on the substrate. During the preparatory phase, mudskippers generate axial bending by moving the tail toward the head of the fish; during this movement the body remains parallel to the substrate. However, both mudskippers and K. marmoratus ultimately launch the center of mass by the tail pushing against the substrate. In this manner, similar ballistic movements are produced in two divergent amphibious taxa via markedly different kinematic patterns.
