Genetic structure of an endangered endemic fish (Gobiocypris rarus) in the upper Yangtze River

The goal of this study was to examine the genetic diversity and structure of wild populations of rare minnow (Gobiocypris rarus) in the upper Yangtze River. Individuals from nine locations were sampled and genotyped at eight microsatellite markers. Populations differed from each other on allelic frequency, although there were no significant differences on other genetic diversity indices. Our results further suggested low to moderate levels of population differentiation (FST: 0.0130–0.1537). Specifically, two distinct genetic clusters (C1 and C2) were found, which may be highly correlated with the evolution of water systems. In addition, a weak but significant isolation-by-distance pattern was best explained by riparian distance through man-made channels. It suggested that fish might use man-made channels for gene flow in history, although no significant recent migration event was found. Therefore, this study highlights the need to consider the genetic specificities of G. rarus for sustaining long-term survival of this species. 2012 Elsevier Ltd. All rights reserved.