Meeting Abstract

25.4  Monday, Jan. 4  Jumping in the salamander Desmognathus ocoee RYERSON, WG; University of Connecticut william.ryerson@uconn.edu

Jumping in plethodontid salamanders has been noted anecdotally as a defense mechanism, but there is currently no description of how this movement is performed. Contrary to most terrestrial examples, where this behavior is powered by hind limb activity, these salamanders jump using body bending. I investigated the mechanics of jumping in the plethodontid salamander D. ocoee using high speed imaging at 1000 fps. Kinematic analyses of twenty individuals in an ontogenetic series (SVL 2.0 – 4.8 cm) showed jumping in these salamanders is performed by: (1) bending the body laterally, (2) rapidly straightening the body, (3) the individual becomes airborne. Durations, velocities and angles were measured for bending and straightening, only duration was measured for jumping. The duration of the three stages is less than half of a second (250 ± 77 ms). Initial bending of the body had a higher duration (135 ± 64 ms) than both straightening (43 ± 16 ms, p < 0.001) and jump duration (72 ± 19 ms, p < 0.001). None of the kinematic variables could be used to predict jump duration. In addition to quantifying the kinematics of jumping, I also investigated the effect on size on this behavior. Only duration of bending increased with SVL (p = 0.03). Although the axial musculature is primarily responsible for this behavior, the role of the limbs during jumping in these salamanders remains to be seen.