Biogeographic perspective on the phylogeny of Mexican Cyprinids (Actinopterygii, Cyprinidae)

" A molecular phylogeny, based on complete Cytochrome b gene of Mexican cyprinids of the genera Dionda, Notropis, Algansea, Cyprinella, Codoma, Agosia and Campostoma, was used to reconstruct their relationships and evolutionary history. These taxa occupy most of Mexico, including both the Atlantic and Pacific drainages, and represent the southern distributional limit for the order Cypriniformes in North America. Six primary clades were resolved with strong support; the genus Dionda was never recovered as a monophyletic group. One clade includes Mexican Notropis (plus Yuriria), occurring in central and south Mexican drainages. A second clade includes Southern species of the genus Dionda plus Codoma. One highly divergent undescribed species of Dionda is sister to this clade. All species of the Southern “Dionda” clade inhabit headwaters of the Pánuco-Tamesí drainage and coastal Nautla River and are proposed as a new genus endemic to central-east Mexico (Atlantic slope). A third clade includes species of the genus Cyprinella, resolved as sister to the Southern “Dionda” + Codoma group. A fourth clade includes species of the genus Algansea closely related to the western monotypic genus Agosia. The fifth clade includes Northern species of Dionda. All these species inhabit present or past tributaries of the Rio Grande basin. Campostoma is resolved as a monophyletic group and as the basal clade. A repeated pattern within clades clustering northern with southern taxa is apparent when relationships are evaluated in a geographical context. Phylogenetic relationships indicate strong agreement with previous biogeographical hypothesis and revealed more diversity than has been traditionally recognized "