Meeting Abstract
Plethodontid salamanders have good clinging and climbing performance in their natural environments, enabling scansorial species to access food, shelter, or beneficial microclimatic conditions through adhesive and gripping attachments to inclined, elevated, and inverted surfaces. Our testing has shown that plethodontid species with different body sizes and morphologies have significantly different cling performance on smooth acrylic surfaces. While surface area of adhesion has been shown to affect performance, bolitoglossine salamanders with webbed feet have also been hypothesized to use foot suction to enhance attachment. We tested how a porous surface that eliminates suction affects cling performance in 14 species of salamanders. We found that porous surfaces had no effect on maximum cling performance, regardless of foot morphology, refuting the suction hypothesis. We also tested the effect of surface roughness on cling performance. Surface roughness had a significant effect on maximum cling angle, and the effect varied significantly among species depending on foot morphology and attachment mechanism. Surfaces of intermediate roughness (grit size 100 um to 350 um) resulted in the poorest attachment performance for all species. Webbed species performed best on smooth surfaces, while species with long, dexterous toes showed significant improvement on the roughest surfaces (grit size 1000 um to 4000 um), switching from adhesive attachment on a smooth surface to a gripping attachment mechanism on rough surfaces. Studies of climbing mechanisms and performance and their relationship to surface properties may cast light onto how these animals have radiated into the largest family of salamanders in the world that occupy diverse habitats across an enormous geographical range.
