Molecular phylogeny of the humbug damselfishes inferred from mtDNA sequences

The damselfish genus Dascyllus comprises nine species of both large- and small-bodied fishes distributed over the entire Indo-West Pacific. Most members of the genus have polygynous mating systems with protogynous sex change, while others are promiscuous with no sex change. Hypotheses linking presumed phylogenetic relationships with body size, sex change and mating structure have been proposed previously. However, lack of a strong phylogenetic hypothesis has prevented the careful testing of such hypotheses. In this study, the phylogenetic relationships between Dascyllus species based on mitochondrial DNA sequences (cytochrome b and 16SrRNA) have been established. The data also shed light on the relationship between mating structure and body size, as well as on the complex biogeographical patterns of the genus.