Assessment of genetic variability in two lots of white shrimp, Litopenaeus vannamei (Boone, 1931) introduced to Cuba

Abstract

To monitor the genetic variability of L.vannamei shrimp-specie as founder stock and their correspondent first generation (F1), four microsatellite DNA loci species-specific for these animals were used. Data from allelic diversity (size, number and frequency of alleles) and levels of hetrozygozity were obtained as measures of genetic diversity. The protocol used is belonging to the lab, from the Norwegian College of Fishery science (NFH) of the University of Tromsø (Uitø). The results indicated a decrease in some of measures for genetic diversity. The number of allele (Na) ranged from 1-9 and their effectives number of alleles (ne) from 1.1 to 6.72. The mean value observed heterozygosity (Ho) by populations range from 0.29 to 0.63, which were lower than the expected one. Loss of genetic diversity may have originated from the selection of better performing individuals for a number of traits of interest. There is gap concerning to pedigree information from these animals, due to their origin place (USA). Artificial breeding practices may result in a decrease of genetic variability in terms of allelic diversity but which is not necessarily detectable from the levels of heterozygosity. Thus, should be taking into account at moment to start a genetic breeding program with the animals tested. This study highlights the importance of constantly assessing the genetic variability in the cultured shrimp populations in Cuba. Considering the low variability observed, it is suggested that the development of a sustainable selective breeding program in Cuba should be conducted only after application of measures aimed at enhancing the genetic variation (through exchange of broodstocks with others producers or sampling of wild specimens) and that the genetic information be constantly used to reduce the risks of further inbreeding.