Cottus specus, a new troglomorphic species of sculpin (Cottidae) from southeastern Missouri.

Cottus specus, a new species, is described from the karst regions of the Bois Brule drainage in eastern Missouri, USA. Cottus specus is distinguishable from all members of the genus Cottus using both genetic and morphological characters, including eye size and cephalic pore size. Cottus specus represents the first description of a cave species within Cottus. The addition of C. specus brings the total number of recognized species of Cottus to 33 in North American fresh waters.

A molecular phylogeny of the Percidae (Teleostei, Perciformes) based on mitochondrial DNA sequence.

The family Percidae is among the most speciose families of northern hemisphere fishes with > 178 178 North American species and 14 Eurasian species. Previous phylogenetic studies have been hampered by a lack of informative characters, inadequate taxonomic sampling, and conflicting data. We estimated phylogenetic relationships among 54 percid species (9 of 10 genera and all but one subgenus of darters) and four outgroup taxa using mitochondrial DNA data from the 12S rRNA and cytochrome b genes. Four primary evolutionary lineages were consistently recovered: Etheostomatinae (Ammocrypta, Crystallaria, Etheostoma, and Percina), Perca, Luciopercinae (Romanichthys, Sander, and Zingel), and Gymnocephalus. Except Etheostoma and Zingel, all polytypic genera were monophyletic. The Etheostoma subgenus Nothonotus failed to resolve with other members of the genus resulting in a paraphyletic Etheostoma. The subfamily Percinae (Gymnocephalus and Perca) was not recovered in phylogenetic analyses with Gymnocephalus sister to Luciopercinae. Etheostomatinae and Romanichthyini were never resolved as sister groups supporting convergent evolution as the cause of small, benthic, stream-inhabiting percids in North American and Eurasian waters.

INTRASPECIFIC PHYLOGEOGRAPHY OF NORTH AMERICAN HIGHLAND FISHES: A TEST OF THE PLEISTOCENE VICARIANCE HYPOTHESIS.

The highland fish fauna of eastern North America consists of Appalachian and Ozark centers of endemism separated by the intervening Glacial Till Plains. Clades within these areas are more closely related phylogenetically to each other than to clades occurring in the intervening formerly glaciated region, suggesting that the Pleistocene glaciations fragmented a widespread highland region and its associated fauna. Alternatively, it is possible that these faunal assemblages predate the glaciations or that recent dispersals may have been more important than vicariance in determining faunal compositions. We examined the relationships among mitochondrial DNA (mtDNA) haplotypes within five clades of highland fishes, each with a distribution suggestive of a Pleistocene vicariance event. Darters of the subgenera Litocara and Odontopholis have distributions and mtDNA relationships that are consistent with the Pleistocene integration and burial of the Teays-Mahomet valley, a major drainage of the early Pleistocene. The distribution and mtDNA relationships among subspecies of Erimystax dissimilis are not consistent with Pleistocene vicariance, but relationships among Appalachian haplotypes are consistent with the late Pleistocene integration of the modern Ohio River system. Both Cottus carolinae and the Fundulus catenatus species group have representatives in the Mobile basin consistent with pre-Pleistocene divergences. Three haplotype clusters were found in C. carolinae, corresponding to the Appalachian, Ozark, and upper Kanawha River populations. However, Appalachian and Ozark F. catenatus populations are paraphyletic with respect to each other. This, coupled with a relatively low degree of sequence divergence, suggests that no long-term barriers to gene flow exist for C. carolinae and F. catenatus. These three distinct phylogeographic patterns indicate that Pleistocene vicariance is not the only explanation for the Appalachian-Ozark distribution of highland fish communities.