Phylogenetic relationships of the western North American phoxinins (Actinopterygii: Cyprinidae) as inferred from mitochondrial 12S and 16S ribosomal RNA sequences

Parsimony analysis of the mitochondrial 12S and 16S rRNA sequences of North American phoxinin taxa indicated the existence of three major clades, the Western Clade, the Creek Chub Clade, and the Open Posterior Myodome Clade. The monophyletic Western Clade identified in this paper contained fewer taxa than that identified by previous authors. This clade contained species restricted to drainages west of the Continental Divide, such as Gila, Acrocheilus, Relictus, Eremichthys, Siphateles, Ptychocheilus, Lavinia, and Orthodon, and the wide-ranging genus Phoxinus found in eastern North America and Eurasia Within this Western Clade Phoxinus was the basal sister group. Gila was recognized as a monophyletic group exclusive of Siphateles and Snyderichthys, clades traditionally recognized as subgenera of Gila. The genus Gila was most closely related to the genus Acrocheilus and together these formed the sister group to the genus Relictus. These relationships mere supported independent of weighting schemes used in analyses. Identification of Phoxinus as the basal sister taxon of the Western clade implies that other major clades of North American Phoxinins likely have Asian or European relatives. (C) 1998 Academic Press.