PHYLOGENETIC STUDIES OF NORTH AMERICAN MINNOWS, WITH EMPHASIS ON THE GENUS CYPRINELLA (TELEOSTEI: CYPRINIFORMES) (MORPHOLOGY, PISCES, PHYLOGENETICS, OSTEOLOGY, NOTROPIC).

摘要

The primary intent of this study was to resolve species relationships of the traditionally recognized subgenus Cyprinella of Notropis. Through comparisons with other cyprinids, the genus "Notropis", as traditionally used is not a monophyletic group (sensu Hennig) and can no longer be considered as such. Thus, some of the subgenera are elevated to generic status.;Variation in osteology and secondary sexual characteristics of North American cyprinids suggests that many eastern North American species form a monophyletic group. Included in this group are species traditionally placed in the genus Notropis (except Aztecula sallei). and the genera Cyprinella, Luxilus, Lythrurus, Pteronotropis, Oregonichthys, Clinostomus, Richardsonius, Yuriria, Hybopsis, Pimephales, and a clade inclusive of Hybognathus, Exoglossum, Dionda, Campostoma, Nocomis, Platygobio, Macrhybopsis, Extrarius, Phenacobius, and Erimystax. Relationships of all of these species were not fully resolved and polytomys were obtained. Basally, a mutichotomy exists between a clade inclusive of the genera Pteronotropis, Cyprinella, Luxilus, Lythrurus, plus a restricted Notropis and each of the remaining clades above. The genus Pteronotropis forms the basal sister group of the first clade and the Lythrurus-Luxilus-Cyprinella clade is the sister to the restricted Notropis clade. The genus Lythrurus is hypothesized as the sister group to Luxilus plus Cyprinella. Within the restricted Notropis clade, the subgenus Notropis is the sister to the more inclusive Notropis texanus species group. This clade forms a polytomy with the Notropis volucellus species group and the subgenera Hydrophlox and Alburnops.;Monophyly of the genus Cyprinella is supported by 38 characters. Species relationships based on 205 character transformations produced a fully resolved phylogeny of the genus. Within the genus, two major clades are recognized: the primarily southwestern United States and Mexico lutrensis clade and the eastcentral United States whipplei clade. Species of the lutrensis clade include ornata, lutrensis, garmani, formosa, bocagrande, lepida, rutila, and xanthicara. Species of the whipplei clade include spiloptera, camura, whipplei, analostana, chloristia, venusta, galactura, pyrromelas, xaenura, caerulea, trichroistia, gibbsi, callistia, nivea, leedsi, callisema, and callitaenia. A detailed account for each species is presented, as well as an analysis of osteological variation.