Phylogenetic Systematics of Coral Reef Fishes

Epibulus insidiator, the sling-jaw wrasse. (Photo: J. E. Randall)

A major challenge in biology is the resolution of phylogenetic relationships among diverse clades of fishes, particularly in species-rich groups such as the Labridae (the wrasses and parrotfishes of coral reefs around the world). The family Labridae is the 2nd largest family of reef fishes in the world. Techniques include both molecular and structural approaches to the search for evidence of ancestry in this diverse group of animals. My early work included a phylogeny for the labrid subfamily Cheilinini (Westneat 1993), and analysis of evolutionary biomechanics in that group (Westneat, 1995).

Molecular phylogenetics of the Labridae is nearing completion- we have one of the largest molecular data sets for a large group of fishes ever compiled. To resolve phylogenetic questions within and among labrid genera, and to assess the molecular evolution of both mitochondrial and nuclear genes known to evolve at different rates, we sequenced the 12S, 16s, cytb (mitochondrial) RAG1, and TMO 4C4 (nuclear) genes for over 100 taxa. We are currently expanding our taxon sample for these 5 genes and beginning alignment and character analysis for these genetic data. This data set will give us extraordinary power to test hypotheses of relationship, rates of molecular evolution, biogeography, and the evolution of biomechanics and physiology in fishes.