The North American fish fauna provides an informative, natural laboratory useful in investigations of comparative, evolutionary, and -- phylogenetic relationships. Without these data the fauna is rendered inaccessible for direct estimates of community formation, evolutionary ecology, and modes and rates of speciation. Fishes of the family Percidae represent one of the most diverse groups in North America, yet relationships among many of the species are poorly known. The objectives of this study are to test previous biogeographic and evolutionary relationships hypothesis for several darter species, using starch gel electrophoresis and phylogenetic analyses. Relationships within and between the target species are extremely useful in resolving recently constructed area (river) cladograms for many drainages in eastern North America that dated the origin of the fauna well before the Pleistocene. The study will focus on two wide-spread species of the percid genus Etheostoma, the relationships of species within the subgenus Etheostoma (genus Etheostoma), and the phyletic affinities of this clade to the subgenus Ulocentra (or Nanostoma). The potential gains of the study are not restricted to revised taxonomy and relationships of traditionally confusing group. The analysis will supply both a framework for future systematic studies in percid fishes and improve our understanding of evolutionary biology.
