Genetic diversity of mitochondrial DNA from Litopenaeus vannamei broodstock used in northwestern Mexico

Abstract

Shrimp cultivation in Mexico is based on the whiteleg shrimp, Litopenaeus vannamei, with a production of about 100,320 t in 2012. Postlarvae are produced in hatcheries, where the selection process is geared towards producing lineages with better productive parameters and resistance to some diseases; however, the crossing of related organisms may reduce genetic variability, resulting in inbreeding depression. In this study we analyzed the sequences of the mitochondrial DNA control region of 425 shrimp from five hatcheries and of 29 wild whiteleg shrimp. The results suggest the presence of two dominant haplotypes in a monophyletic group of organisms used as broodstock and in wild whiteleg shrimp; this finding suggests a common origin. Low levels of genetic variability in some hatcheries highlight the importance of monitoring genetic diversity and supervising breeding programs to prevent loss of haplotypes.