Genetic diversity and structure of largemouth bass (Micropterus spp.) populations in reservoirs of northeastern Mexico
The largemouth bass (belonging to the genus Micropterus) is one of the most important freshwater fish for sport fishing; the native range of Micropterus salmoides extends into the northeastern Mexican drainages, providing important economic benefits for communities with thriving bass populations. However, the genetic diversity of this species is progressively declining due to various factors, including direct human impacts and alteration of natural ecosystems. In this study, the genetic diversity and structure of largemouth bass from the main reservoirs of northeastern Mexico were assessed. A total of 350 Micropterus spp. dorsal fin samples collected from seven reservoirs were genotyped using a panel of 10 microsatellite markers. The individual samples were genotyped and the different genetic diversity parameters and population structure analysis were evaluated. The microsatellite markers used in this study were highly informative. All the populations exhibited Hardy Weinberg disequilibrium, with some degree of inbreeding within populations. The populations showed moderate genetic differentiation, allowing the establishment of three genetic clusters. Structure analysis indicated that four ancestral populations is most likely. The populations are characterized by low genetic diversity, reduced effective population sizes and a high probability of inbreeding. This study highlights the importance of genetic diversity studies to manage native largemouth bass in the main reservoirs of northeastern Mexico.