RICE, Aaron N.; University of Chicago and Field Museum of Natural History: Evolution of Coordination in Fish Feeding: The Intersection of Functional Morphology and Ecology

Prey capture in fishes is a complex behavioral process. From initial sensory detection of a food item, to the final motor output of jaws and fins, these components have to be coordinated for successful feeding to occur. Despite traditionally being studied separately, recent studies of the interaction of three systems, fins, jaws, and eyes, have revealed components of feeding behavior previously overlooked. Comparing patterns of coordination between different species will elucidate conserved and diversified elements of functional morphological systems in fishes. A detailed molecular phylogeny of wrasses (Teleostei: Labridae) now permits testing of hypotheses of the function and timing of kinetic systems in this diverse group of reef fishes. The present analysis explores the effect of phylogenetic constraint and ecological adaptation in the diversification of coordination patterns during feeding wrasses. To investigate coordination patterns in a phylogenetic context, four species with different feeding ecologies (two piscivores and two molluscivores) from the wrasse tribe Cheilinini were studied. To find out how coordination patterns compare with other feeding strategies from across the Labridae, Cheiline coordination patterns were compared with six other wrasses, including two molluscivores, two herbivores, and two planktivores. Patterns of coordination were more similar for fishes of a particular feeding strategy than for a phylogenetic lineage, suggesting that coordination of these systems may represent adaptations to varying ecological selection pressures rather than evolutionary conservation. Diversity in feeding, locomotor, and visual mechanisms seen in wrasses may reflect broader trends in the interaction of feeding and locomotor systems in coral reef fishes as a whole.