Phylogenetic relationships of the suckermouth minnows, genus Phenacobius, inferred from parsimony analyses of nucleotide sequence, allozymic and morphological data (Cyprinidae : Cypriniformes)

We investigated the phylogenetic relationships among the five species of th e genus Phenacobius (Cyprinidae: Cypriniformes) using a combined analysis o f molecular and morphological characters. The nucleotide characters were co mprised of 208 potentially informative sites among a total 1773 aligned bas e pairs from several segments of mitochondrial genes that encode the large and small RNA subunits, the valine transfer RNA, and the NADH ubiquinone ox idoreductase subunit 2. Allelic data from 23 polymorphic allozyme loci and nine morphological characters taken from the literature were also included in the total evidence analysis. Third position codon characters were demons trated to be saturated for transitional changes and unsuitable for phylogen y estimation among the species studied here. The total evidence phylogeny i s isomorphic with Mayden's (1989) morphological hypothesis. Phenacobius mir abilis was found to be basal, followed in ascending order by P. teretulus, P. catostomus and a clade comprised of P. crassilabrum and P. uranops. (C) 1999 Elsevier Science Ltd. All rights reserved.