Meeting Abstract
Anuran jumping is a single discrete movement that requires substantial power. Previous studies have shown that whole-organism muscle-mass specific power in frog jumping differs substantially between three diverse species. However, these differences in whole organism muscle-mass specific power are not explained by the organisms’ maximum muscle power output. Power output during in vitro muscle stimulation for all three species falls within the muscle physiological limit of approximately 300 W/kg. The disparity between whole-organism power and maximal muscle power output has been attributed to the utilization of elastic mechanisms to amplify power output, yet the general importance of these mechanisms in explaining species differences is unclear. We test the hypothesis that variation in the mechanical properties of tendons underlies interspecific variation in whole-organism power output and explains the disparity between muscle performance and whole-organism performance. Using 18 Oklahoman frog species that cover both advanced (Neobatrachia) and basal (Archaeobatrachia) frogs, we first recorded frogs jumping with high-speed video to calculate muscle-mass specific power output and test for differences across species. Next, we used materials testing to determine whether such differences are due to differences in the stiffness and elastic modulus of the aponeurosis surrounding the plantaris longus muscle. Our preliminary results highlight variation in jumping abilities between different species of frogs. Additionally, disparities in elastic modulus between a subset of families suggest that changes in aponeurosis material properties may be in part responsible for differences in jumping performance. By investigating the material properties of the aponeurosis, we aim to understand how structural changes drive variation in diverse locomotor strategies of frogs.
