Cytogenetic studies in North American minnows (Cyprinidae): Chromosomal NOR phenotypes of 12 species, with comments on cytosystematic relationships among 50 species

Abstract

Chromosomal NOR phenotypes are documented for twelve species of North American cyprinid fishes whose NOR karyotypes have not been previously reported. Patterns of interspecific chromosomal NOR variation are then summarized for the fifty species of North American cyprinids surveyed to date. The degree of interspecific NOR variation among North American cyprinids suggests that the rate of chromosomal evolution within the group may have been higher than previously believed. The interspecific variants in chromosomal NORs are used as taxonomic and systematic characters in order to infer phylogenetic hypotheses of species relationships. The phylogenetic inferences drawn from the chromosomal NOR data provide a framework upon which future cytosystematic studies in North American cyprinids can be based.