Systematics of Etheostoma tippecanoe and Etheostoma denoncourti (Perciformes : Percidae)

Recently, populations of Etheostoma tippecanoe from the Tennessee River dra inage were described as a new species, Etheostoma denoncourti. Although pop ulations of E. tippecanoe from the lower Tennessee River (Duck and Buffalo Rivers) were assigned to the new taxon, the species description did not con tain an analysis of specimens from these rivers. To evaluate the phylogenet ic placement of these unanalyzed populations with respect to all other popu lations of E. tippecanoe and E. denoncourti, we assembled a dataset compose d of DNA sequences (complete cytochrome b) from 32 individuals representing all known populations of these species. Parsimony analysis of these popula tions, 11 other darter taxa, and five outgroup taxa resulted in 3868 equall y most-parsimonous trees at 1687 steps. Populations from the Duck and Buffa lo Rivers were always resolved as members of the newly described taxon, E. denoncourti, consistent with the original description. Further, E, tippecan oe and E. denoncourti were resolved as monophyletic sister taxa in all most -parsimonious trees. The amount of cytochrome b sequence divergence separat ing these two taxa (5.63%) is within the range observed for cytochrome b va riation between other species of darters.