Morphological and Genetic Variation in Northwestern Longnose Suckers, Catostomus catostomus: The Salish Sucker Problem

Abstract

taries) or Columbia River systems. These drainages contain a mixture of North American haplotypes. In contrast, Salish suckers possess unique haplotypes that distinguish them from all other northwestern longnose suckers. Thus, both the morphometric and molecular data indicate that Salish suckers have diverged from northwestern longnose suckers. Our molecular data also hint at divergence between western and eastern North American longnose suckers; however, the sample sizes are too small to be certain. Although both typical longnose suckers and Salish suckers occur in the Fraser system, they are separated by about 60 km of unobstructed river, and there is no evidence of gene-flow between the two forms. Thus, we conclude that the Salish sucker constitutes an evolutionarily significant unit within the longnose sucker genome and as such warrants protection in both British Columbia and Washington State.