Meeting Abstract

P3.96  Friday, Jan. 6  Feeding at the Air-water Interface: Biomechanics and Functional Morphology of Feeding in Funnel-mouthed Tadpoles (Megophryidae: Megophrys) ZENG, Yu; Univ. of California, Berkeley

Larval anurans occupy a great variety of ecological niches, and accordingly they have evolved tremendous diversity of feeding mechanisms. The feeding apparatus of the funnel-mouthed tadpoles is among the most intriguing, but the mechanism of feeding with such apparatus is not well understood. Here the feeding biomechanics and relevant morphology are investigated in details through a combination of lab and field experiments using tadpoles of the genus Megophrys, a group native to Eastern and Southeastern Asia. The morphologies of oral discs and branchial skeletons were quantitatively studied multiple species, and a series of high-speed filming and fluid experiments were conducted to examine the hydrodynamic function of this apparatus. Funnel-mouthed Megophrys tadpoles filter a thin film of water collected from the surrounding water surface. The film flow is primarily driven by shearing effects generated by the branchial skeleton movements. Moreover, the spatial arrangement and wetting properties of papillae on the oral disc play important roles in channeling and filtering the film flow. Results of these studies suggest Megophrys tadpoles use an efficient mechanism to collect the surface film. This work illuminates how functional novelties evolve homologous modules, and contributes to our understanding of the ecology and evolution of adaptive radiation in larval anurans.