Population genetics of whiteleg shrimp Litopenaeus vannamei in Sinaloa, Mexico

Whiteleg shrimp Litopenaeus vannamei is an important fishery species in Sinaloa, Mexico, which production has declined in recent years. For its recovery, the release of cultivated larvae has been suggested as an alternative. This strategy requires to include information about the genetic characteristics of the wild populations to warrant that these programs do not negatively impact their long-term biological fitness. In this work, the genetic structure of Whiteleg shrimp in Sinaloa, Mexico was studied through the genetic profile of 6 microsatellites of samples from 10 sites located in 5 coastal lagoons. High levels of genetic diversity (15.6 number of alleles per locus and 0.87 expected heterozygosity), and deviation from the Hardy-Weinberg equilibrium (HWE) in most sites were registered. In spite of the significant genetic differences observed among locations (Fst = 0.012; p < 0.001), the lack of a specific geographical pattern and a low differentiation among estuaries (Fst = 0.005; p = 0.062) indicated regional genetic homogeneity. The departures from HWE and the differences among locations are explained by the Wahlund effect. Also, recommendations for the management of restocking activities under genetic criteria are discussed.