Meeting Abstract
Tongue projection is often used by salamanders to feed on land. Many plethodontid salamanders are known for high-powered, thermally robust, ballistic tongue-projection; however, examples of similar feeding mechanisms in salamanders outside of the group are limited. Previously, we found that a distantly-related salamandrid, Chioglossa lusitanica, possesses a high-powered feeding mechanism with two distinct, ballistic movements. Here we continue our investigation into this highly specialized feeding mode by testing the thermal robustness of tongue projection in the salamandrids Chioglossa and Salamandra salamandra. High-speed imaging (3000 Hz) was used to capture feeding events over a 20-degree temperature range for both species. During both tongue projection and radial rotation (i.e. tongue pad flipping), Chioglossa continued to show evidence of an elastic mechanism, with tongue projection power exceeding 4000 W/kg, while radial rotation often reached over 2000 W/kg. High-powered projections were observed over the entire temperature range for Chioglossa. Projection performance decreased as temperature decreased, but was more thermally robust than retraction performance across all temperature ranges. Conversely, feeding performance in Salamandra was more strongly affected by low temperatures; tongue projection and retraction velocity, acceleration, and power were lower than those at higher temperature ranges. These results further support the hypothesis of convergent evolution elastically powered feeding mechanism in Chioglossa and plethodontid salamanders.
