Low genetic variability in the fifth introduction of Litopenaeus vannamei in Cuba, as

The present work estimated the genetic variability and relatedness index of the fifth stock of Pacific white shrimp, Litopenaeus vannamei, imported into Cuba for farming purposes from the US Shrimp Improvement System (SIS). Genetic variability was estimated by genotyping 33 samples for four microsatellite loci: M1, Pvan 1815, Pvan 0040 and Pvan 1758. This stock had average expected and observed heterozygosities of 0.37 and 0.27 respectively; the lowest of all stocks previously introduced in Cuba. The above, together with the low amount of allelic variants detected for each microsatellite, was suggestive of low genetic variability. In addition, pairwise relatedness coefficients clustered around unity, indicating a high degree of consanguinity. Taken as a whole, the data suggests that this breeding stock should be crossed first with other individuals from a different source or with higher genetic variability.