Meeting Abstract
Body and fin shape are considered chief determinants of fish swimming performance. Specific lateral profiles in conjunction with particular median fin shapes may enhance different aspects of locomotion. These body and fin shape combinations have been highlighted in extremely specialized taxa, such as tuna, where the deep anterior profile, narrow caudal peduncle and semi-lunate tail interact to reduce drag while maintaining thrust. Despite the importance of the interaction among the median fins and the body in swimming, there are few data indicating whether or not different body and fin shapes co-occur, or whether they vary independently. The cichlid fishes are a morphologically diverse family, whose well-studied phylogenetic relationships make them ideal candidates for a broad-scale study of morphological evolution and covariation. I studied the body, caudal fin, dorsal fin, and anal fin morphology from x-ray radiographs of over 150 cichlid genera, including all major tribes, using a combination of geometric and traditional morphometrics with phylogenetic comparative methods. Morphological variation of each structure was examined using principle components analysis. Covariation among structures was assessed using partial least squares canonical analysis. Interestingly, body shape, caudal fin shape, dorsal fin shape and anal fin shape all exhibited some degree of covariation with each other. Future research will address if and how the patterns of morphological covariation affect swimming performance, and whether or not covariation in fin shape is driven by developmental constraint.
