Blennies of the family Chaenopsidae number about 60 species of primarily tropical fishes and are particularly notable for their varied patterns of anatomical differences between males and females. This study will investigate the evolutionary relationships of 26 species within the family by analysis of these traits. This approach will address several taxonomic controversies within chaenopsids, provide a detailed study of the historical patterns of change in their sexually dimorphic traits, and, together with earlier studies on the ecology of chaenopsids, permit evaluation of alternative hypotheses for the evolution of conspicuous morphological differences between the sexes.
