Objectives: We are exploring the phylogenetic relationships of several major lineages of coral reef fishes in order to understand their molecular evolution, and the evolution of structure and function in these diverse groups. We use the phylogenies generated from both morphology and molecules to look at the evolution of characters such as biomechanics of the jaws for feeding, and functional morphology of locomotor structures.

Labridae. The largest group we are studying are the bright and colorful wrasses of the family Labridae. Wrasses are a diverse group of over 600 fish species in 66 genera that vary in body shape, size, coloration, and habitat (Westneat 1997). In addition to a large data set generated using comparative morphology, we are using 2 mitochondrial regions (12s and 16s) and 2 nuclear genes (Tmo4C4 and RAG2) to assess phylogenetic relationships among the lineages of labrids, including 45 genera and 120 species (including 10 outgroups). Preliminary results with these genetic data show good resolving power among higher taxa in the family. The data set, when complete, will be a character-by-taxon matrix of approximately 120 species by about 4000 bp.

Phylogenetic patterns generated from this data will provide an evolutionary framework for research on the biology of labroids ranging from rates of genetic change to the evolution of feeding mechanisms and breeding behavior. Resolution of higher level hypotheses of relationships among major labroid clades (Westneat, 1993) will provide an evolutionary framework for over 10% of living fishes. Interesting labrid subgroups are being examined in the Mediterranean Sea (Hanel et al., in review) and the New Zealand Odacid lineage of wrasses (in collaboration with Kendall Clements).

The need for incorporating phylogenetic patterns in evolutionary hypotheses is a message being heard throughout biology (Westneat 1995a, b). This project contributes to a deeper understanding of functional evolution by testing specific hypotheses regarding evolutionary associations among structure, function, and performance in feeding (Westneat, 1990, 1994, 1995a) and locomotion (Westneat, 1996, Westneat and Walker, 1997).

Scaridae. The parrotfishes are lovely beaked fishes that browse on algae and coral on reefs throughout the world. Thought to be a sub-group of the Labridae, the 88 species of scarids have received considerable attention due to their significant ecological role in algal herbivory and sand production during digestion. Two studies of parrotfish phylogeny and evolution at the genus level are now ready for publication (Alfaro et al, in review; Streelman et al, in review), and research continues by Jennifer Fessler and Lydia Smith that is focused on species-level phyloghenetics, rates of change in nuclear dna, and the biogeography of the most species-rich genus Scarus.

Chaetodontidae and Pomacanthidae. The butterflyfishes and marine angelfishes are some of the most beautiful animals found on Earth. We are beginning an analysis of the relationships among the these two related families with tissue samples collected from the world’s oceans, including Caribbean, Pacific, Indian Ocean, and Red Sea species. Molecular phylogenies will provide an assessment of evolutionary patterns in these colorful animals, and enable us to examine the evolution of color patterns and pair-bonding during breeding.


Alfaro, M. E., J. T. Streelman, S. A. Karl, and M. W. Westneat. Comparing the performance of Bayesian MCMC sampling and bootstrapping in assessing confidence in phylogenies: an example using the Scaridae. In Review Systematic Biology.

Hanel, R. M. W. Westneat, and C. Sturmbauer. 2002. Phylogenetics and evolution of breeding behavior in the labrid tribe Labrini. In Review, Systematic Biology.

Streelman, J. T. M. E. Alfaro, M. W. Westneat, D. R. Bellwood, and S. A. Karl. Evolutionary history of the parrotfishes: biogeography, ecomorphology, and comparative diversity. In Review Evolution.

Walker, J. A., and M. W. Westneat. 1997. Labriform propulsion in fishes: Kinematics of flapping aquatic flight in the bird wrasse Gomphosus varius (Labridae). Journal of Experimental Biology. 200: 1549-1569.

Westneat, M. W. 1990. Feeding mechanics of teleost fishes (Labridae: Perciformes): A test of four-bar linkage models. J. Morphol. 205:269-295.

Westneat, M. W. 1991. Linkage biomechanics and evolution of the jaw protrusion mechanism of the sling-jaw wrasse, Epibulus insidiator. J. Exp. Biol. 159:165-184.

Westneat, M. W. 1993. A phylogenetic hypothesis for the tribe Cheilinini (Labridae: Perciformes. Bull. Mar. Sci. 52:351-394.

Westneat, M. W. 1994. Transmission of force and velocity in the feeding mechanisms of labrid fishes. Zoomorphology 114:103-118.

Westneat, M. W. 1996. Functional morphology of aquatic flight in fishes: mechanical modeling, kinematics, and electromyography of labriform locomotion. American Zoologist.36:582-598.

Westneat, M. W. 1997. Family Labridae. The Western Central Pacific: FAO species identification sheets for fishery purposes. Food and Agriculture Organization of the United Nations.

Westneat, M. W. and J. A. Walker. 1997. Motor patterns of underwater flight: an electromyographic study of the pectoral muscles in the bird wrasse, Gomphosus varius. J. Exp. Biol. 200, 1881-1893.

Westneat, M. W. and M. E. Alfaro. ms. Mechanical modeling of parrotfish jaws: the function of the intramandibular joint. J. Morph. In manuscript.

Westneat, M.W. 1995a. Feeding, function, and phylogeny: Analysis of historical biomechanics and ecology in labrid fishes using comparative methods. Systematic Biology 44: 361-383.

Westneat, M.W. 1995b. Systematics and biomechanics in ecomorphology. Env. Biol. Fish 44:263-83.