NRC Research Press (a division of Canadian Science Publishing)
Doi
Abstract
The longnose dace (Cyprinidae: Rhinichthys cataractae (Valenciennes 1842)) is one of the most widespread freshwater fishes in North America and across this range there have been several divergent forms described that are of uncertain taxonomic status. One of these forms, the Nooksack dace, is found in southwestern British Columbia and adjacent portions of western Washington State, and is distinguished from longnose dace by a lower number of lateral line scales. We sequenced a total of approximately 1,400 base pairs of mitochondrial DNA and found that the longnose dace found west of the continental divide and Nooksack dace constituted reciprocally-monophyletic clades that differed from each other by between 2 and 3% sequence divergence. Sequence analysis at two nuclear loci (the S7 ribosomal protein and recombination activation gene 1 introns, ~1,600 base pairs), however, showed no consistent difference between longnose dace and Nooksack dace and several alleles were shared between them. By contrast, consistent differences both at mitochondrial and nuclear DNA loci were resolved between R. cataractae samples from east and west of the Continental Divide. The Nooksack dace does not appear to warrant separate taxonomic status from the longnose dace, but the mitochondrial DNA differences support its recognition as an important component of the evolutionary and biogeographic legacy of R. cataractae.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author
