Meeting Abstract

8.2  Saturday, Jan. 4 08:08  Tongue projection in aquatic and terrestrial environments: The effect of drag on a high-powered ballistic movement ANDERSON, C.V.*; HUDSON, D.S.; DEBAN, S.M.; Brown University, Providence, Rhode Island; University of South Florida, Tampa; University of South Florida, Tampa; University of South Florida, Tampa Christopher_V_Anderson@brown.edu

Adult plethodontid salamanders can inhabit both terrestrial and aquatic environments, and while most taxa typically use jaw prehension while feeding underwater, some will use tongue projection, which is generally more typical of terrestrial feeding strategies. Performance of tongue projection during underwater feeding events, however, is likely to be heavily affected by increased drag. To better understand how the environment affects tongue projection performance in adult salamanders inhabiting both terrestrial and aquatic habitats, we examined feeding performance in four plethodontid taxa feeding in and out of water: Desmognathus marmoratus (aquatic; low-powered tongue), D. quadromaculatus (amphibious; low-powered tongue), Psuedotriton ruber (amphibious to terrestrial, high-powered tongue), and Eurycea guttolineata (largely terrestrial; high-powered tongue). We found that taxa with a high-powered tongue projection mechanism showed greater relative performance declines in the aquatic environment than those with a low-powered tongue projection mechanism. The performance decline of the high-powered tongue projection suggests that a more significant impact of drag from water on the high-powered mechanism, which is likely due to the increased velocity of their movements, could be a reason why a low-powered tongue projection mechanism seems to be favored among the more aquatic taxa. This trade-off between high performance and reduced performance loss due to drag could possibly show that the transition from water to land played a significant role in the evolution of the high-powered tongue projection mechanisms within the Plethodontidae.