Meeting Abstract

18.1  Friday, Jan. 4  The morphological and kinematic basis of suction feeding performance evolution COLLAR, D.C.*; MEHTA, R.S.; HOLZMAN, R.; WAINWRIGHT, P.C.; Univ. of California, Santa Cruz; Univ. of California, Santa Cruz; Tel Aviv Univ.; Univ. of California, Davis dcollar@ucsc.edu

Organismal performance is a product of the size and shape of morphological structures and the way organisms use them (i.e., kinematics). Performance evolution, therefore, may result from change in morphology, kinematics, or both. Although performance has featured prominently in evolutionary studies, focus has generally been on performance as a link between morphology and ecology. Much less is known about the relative importance of the morphological and kinematic changes underlying performance evolution. In this study, we examine the basis of suction feeding performance evolution and fit evolutionary models to morphological, kinematic, and performance data for 17 centrarchid fish species and a robust, time-calibrated phylogenetic tree. We find that feeding performance has diverged toward separate adaptive optima in piscivores and insectivores, and this pattern is evident in morphology but not kinematics. Piscivorous centrarchids have enhanced success rates on evasive prey and evolved toward a morphological peak featuring large oral cavities, limited upper jaw protrusion, and shallow heads. Insectivores, on the other hand, have increased ability to feed on attached prey and have evolved small mouths, extensive upper jaw protrusion, and deep skulls. Despite their evolution toward separate optima for performance and morphology, piscivores and insectivores show no evidence of divergence in kinematics. These results suggest performance evolution has been a consequence of morphological but not kinematic changes. Even though both morphology and kinematics are important in determining performance, our results imply that different evolutionary processes have shaped these levels of design.