Meeting Abstract
The role of ecological specialization and the impacts it has on diversification is a necessity to better understand biological patterns associated with diversity. Coral reefs are some of the most complex and nutrient rich habitats in the world and harbor one of the most diverse communities of fishes. Here we investigate if trophic specialization drives rates morphological evolution in coral reef fishes. We gathered volumetric diet data from the literature and measured seven functional traits from lateral photographs of 318 species of coral reef acanthomorph fishes from the West Indies, Okinawa Island, Japan, and Kona, Hawaii. Dietary items were categorized into five different prey functional groups: evasive prey, planktonic prey, durophagous prey, attached prey, and plant matter. To determine if certain dietary specialists had faster rates of morphological evolution than others, we used the r package geomorph to calculate the multivariate rate of morphological evolution across the phylogeny. We performed three different versions of this analysis using different prey volume cutoffs for consideration of dietary specialization at 50%, 66%, and 75% consumption of a functional prey type. The main axis of morphological variation of the coral reef fishes in our data set is head elongation and depth, accounting for 49.8% of the variation. The extensiveness of the fork in the caudal fin and caudal peduncle length accounted for 14.5% and 11.1% respectively. When comparing rates of multivariate morphological evolution we find that fishes that specialize on evasive prey items have significantly higher rates of morphological evolution than other specialists and non-specialists across all three volumetric dietary cutoffs. Our results indicate that dietary specialization can be a major driver of morphological evolution in coral reef fishes.
