Molecular systematics of the cyprinid genus Campostoma (Actinopterygii: Cypriniformes):: Disassociation between morphological and mitrochondrial differentiation

Campostoma are ubiquitous across North America, yet relationships among members of the genus are poorly understood. Here we present phylogenetic hypotheses based on analyses of DNA sequence data from the mitochondrial cytochrome b gene. All analyses consistently recovered nine clades of comparable topological structure. Differentiation of the recovered clades did not follow currently accepted taxonomic boundaries, and was not consistent with previously hypothesized relationships among recognized species and subspecies. Rather, the recovered clades corresponded to broad geographic divides and to areas known either to have high rates of endemism or to represent discrete biogeographic provinces, indicating that clades not corresponding to recognized taxa represent additional diversity within the group. This result provides evidence of morphological similarity among genealogically divergent lineages, and supports several disputed descriptions of putative Campostoma taxa based on subtle variation in morphology. At least nine lineages could be recognized as distinct taxa to provisionally resolve differences among prior systematic accounts of Campostoma evolutionary diversity.