P3-20 Sunday, Jan. 6 15:30 - 17:30 Comparative kinematics of the forelimb during terrestrial locomotion in semi-aquatic versus terrestrial salamanders VALENCIA, M/M*; KAWANO, S/M; Long Beach State Univ.; Long Beach State Univ. MrMilesValencia@Gmail.com
Locomotion is affected by the physical features of the environment that may affect loads applied to the bones, such as buoyancy in water versus greater effects gravity on land. Salamanders live in aquatic and terrestrial habitats and must accommodate the contrasting demands of both environments, but do those that primarily live underwater exhibit decreased locomotor performance on land? To evaluate differences in salamander forelimb function, we compared how semi-aquatic adult Spanish ribbed newts (Pleurodeles waltl) and predominantly terrestrial adult tiger salamanders (Ambystoma tigrinum) overcome a similar challenge: terrestrial locomotion. We quantified the 3D kinematics of the forelimbs on level ground in P. waltl and then compared these data to those published on A. tigrinum. Preliminary analyses suggested that P. waltl and A. tigrinum exhibited similarities about the elbow and wrist, with a few distinct differences. The kinematic profile of the elbow in P. waltl generally followed the same pattern as A. tigrinum, except with slightly more extension throughout stance. The timing of maximum flexion about the wrist in P. waltl occurred later in stance compared to A. tigrinum, and the duty factor of P. waltl was lower than A. tigrinum. These preliminary results suggested that the degree of terrestriality in salamanders may not affect these kinematic variables during terrestrial locomotion, but ongoing analyses of locomotor function along the entire forelimb will provide a more comprehensive evaluation of whether semi-aquatic salamanders employ different strategies than terrestrial salamanders for moving on land. Findings from this research may provide new insights into the many-to-mapping of forelimb function for terrestrial locomotion.