Cuban Experience in Genetics of White Shrimp Litopenaeus Schmitti (Burkenroad, 1936)

Shrimp farming is a priority economic activity in Cuba. Genetic characterization of natural and culture populations are essential for the sustainable exploitation of shrimp. We have conducted studies in white shrimp, Litopenaeus schmitti, for the last 10 years. Variation in the electrophoretic patterns of enzymes and total proteins throughout the ontogeny was first characterized. Different specific protein patterns were observed in each of the stages studied, the complexity increased with ontogeny, with the exception of mysis 3 were the number of allozyme bands significantly decreased. The population structure of wild and cultured populations were studied using both protein (21 electrophoretic loci from 9 protein systems) and 5 microsatellites markers. DNA was isolated from wild L. schmitti populations from 4 South Cuban coast locations (Batabanó Gulf, Cienfuegos Bay, Tunas de Zaza, and two areas of Guacanayabo Gulf). The protein systems revealed that Tunas de Zaza population was the most variable (He:0.132), whereas the two areas from Guacanayabo showed the lowest variability values (He:0.082). Microsatellite results showed no significant differences among Cienfuegos and Tunas de Zaza (Ho=0.653 and Ho=0.605, respectively) or in the mean number of alleles per locus (11.0-11.6). Genetic variation of cultured populations was lower than in wild populations. The heritability and genetic correlations among the growing characters in different developing stages were also estimated and served as the basis for the implementation of a genetic improvement program for L. schmitti. Future research will focus on sequencing the L. schmitti genome in order to develop SNP-based linkage and QTL maps.