9306672 Wainwright This research will investigate the evolution of anatomical and physiological design of the feeding mechanism in fishes of the order Tetraodontiformes (puffer fishes, trigger fishes, and their relatives). The primary goal of this work is to provide several specific tests of the general hypothesis that features of design limit or direct subsequent evolutionary changes. During feeding behavior, patterns of muscular contraction will be documented by recording the electrical signals associated with muscle contraction through fine-wire electrodes, and movements of the structural components of the head will be assessed by comparing the ability of species to alter muscle activation patterns and movements while feeding on prey that vary in the challenges they present to the fish. Data collected from several species will be used to examine the correlation between evolutionary duplication of jaw closing muscles may enhance subsequent diversification and flexibility of feeding behavior. Second, the effect of incorporating a major evolutionary novelty into the head on the feeding system will be explored using the puffer fish body-inflation mechanism as a model system. This research will contribute to our understanding of how complex muscle-skeleton systems evolve. The work will provide rare tests of the influence of specific features of functional design on the subsequent evolution of those systems. In addition, this research will broaden our base of comparative knowledge of the diverse feeding systems in vertebrates. ***
