Meeting Abstract
The evolution of morphological traits in reef fish can provide insight into their ecology and biomechanics. The Acanthuridae display strong morphological diversity, and are a useful group for morphometric analysis in a phylogenetic context. Due to pronounced differences among acanthurids in locomotor behavior, we predict strong patterns of shape association with locomotor mode across the phylogeny, and we focus on caudal and pectoral fin shapes. We propose a new multi-locus phylogeny for the Acanthuridae, incorporating 90% of species diversity within the family. Morphometric landmarks were used to examine whole body shapes and detailed curves were used to examine fin shapes. Phylomorphospace analyses show that pectoral and caudal fin aspect ratios are strongly associated with locomotor mode across the tree. Ecological data relating to the dietary habits of each fish were also charted on the phylogeny, and trends between diet and fin aspect ratio were examined. Finally, integration tests show a strong relationship between body, tail, and pectoral fin anatomy in two alternative patterns. Some clades exhibit shallow bodies, high-aspect-ratio tails, and paddle-shaped pectoral fins, and others display deep bodies, low-aspect-ratio tails, and wing-like pectoral fins. There is a repeated pattern of convergence on these two morphotypes, which also correlates with dietary and lifestyle patterns. Species of the first morphotype are more likely to be pelagic and planktivorous than their reef-associated counterparts. The evolution of morphology and ecology in the Acanthuridae is a story of two alternative patterns determined by locomotor strategies, each with its own strong morphometric signal. Funded by NSF IOS 1425049 and DEB 1541547
