Meeting Abstract

P1.117  Saturday, Jan. 4 15:30  Conflicts between locomotor modes: terrestrial and aquatic locomotion in the Senegal running frog, Kassina senegalensis REYNAGA, CM*; DANOS, N; AZIZI, E; Univ. of California, Irvine; Univ. of California, Irvine; Univ. of California, Irvine cmmreynaga@gmail.com

Most frog species specialize in either jumping or swimming as a primary mode of locomotion. However, Kassina senegalensis (Senegal running frog) primarily uses a unique quadrupedal gait, which is characterized by limbs moving in diagonal pairs. A number of previous studies have focused on the mechanics of frog swimming and jumping, but little is known about the walking and running abilities of frogs. While these frogs are specialized for a quadrupedal gait and utilize it at all speeds on land, they can also swim and jump. We used the diverse locomotor repertoire of K. senegalensis to understand how locomotor specialization affects an organism’s performance during other modes of locomotion. In this study, we characterize limb morphology and quantify limb kinematics in K. senegalensis during walking, running, jumping and swimming. We use 3D high-speed videography to measure the angle and timing of joint extensions in the fore- and hindlimb during all modes of locomotion. We also compare the kinematics and performance of K. senegalensis to other anurans specialized for either swimming or jumping. Our preliminary results suggest that the evolution of a quadrupedal gait is correlated with changes in the relative lengths of the forelimb and hindlimb and that such shifts in limb dimensions may limit performance during jumping and swimming. By investigating conflicts among diverse modes of locomotion, we aim to understand how the evolution of novel gaits shapes variation in limb morphology, muscle properties, and motor control strategies. Supported by NSF grant 1051691.