Meeting Abstract

P3.168  Monday, Jan. 6 15:30  A comparison of aquatic and terrestrial landing in leiopelmatid and lalagobatrachian frogs MICHAEL, J. L.*; ESSNER, JR., R. L.; Southern Illinois University Edwardsville; Southern Illinois University Edwardsville ressner@siue.edu

Terrestrial jumping in frogs generally involves rapid hindlimb extension and loss of forelimb contact followed by mid-flight limb recovery. During landing, forelimbs make initial contact with the substrate, forming a pivot that helps with stabilization and support. Simultaneously, hindlimbs are rotated under the body so that the frog is in position to initiate another jump. Frogs of the family Leiopelmatidae (Tailed Frogs and New Zealand Frogs) differ from this general terrestrial condition by their exclusive use of “bellyflop” landings, with delayed hindlimb recovery. These frogs diverged from all other extant frogs (Lalagobatrachia) as long ago as 200 mybp. Anuran jumping is hypothesized to have evolved in a riparian context, with the earliest frogs leaping into water to flee terrestrial predators. Thus, the bellyflop landing of leiopelmatids, which appears to be an aquatic diving behavior, may provide insight into the ancestral condition. We compared aquatic and terrestrial landing in a leiopelmatid, the Rocky Mountain Tailed Frog, Ascaphus montanus, and a basal lalagobatrachian, the Fire-bellied Toad, Bombina orientalis. Frogs were filmed with high-speed video at 250 fps (n=6 individuals per species) jumping from a platform into water. Three-dimensional kinematic analysis indicated that aquatic landing behavior was generally similar to terrestrial landing behavior for both species, with A. montanus exhibiting delayed limb recovery and B. orientalis exhibiting mid-flight limb recovery regardless of context.