The genetic structure of the whiteleg shrimp, Penaeus vannamei, in the Eastern Pacific is not fully understood, but the information available suggests that this species forms several genetically differentiated populations along the Central American coastline, one of which is in the Gulf of California (Valles-Jimenez et al. 2004). However, the geographic limits of this stock are not clear and more research is needed to delineate the distribution of that stock, so an Assessment Unit top node has been defined for this profile. Within the Gulf of California, the whiteleg shrimp is only commercially important in the Sinaloa-Nayarit area which is one of the assessment areas defined by INAPESCA. (INAPESCA 2016). Another assessment area is defined in the Gulf of Tehuantepec (INAPESCA 2016).