Abstract
Some cultured shrimp populations have been domesticated from a very small number of founders, which likely limits their genetic variability and heightens inbreeding. The population of Pacific blue shrimp Litopenaeus stylirostris in New Caledonia is one such case. It has undergone domestication since 1980 (36 generations at the time of this study) but was based on only four initial founders. Polymorphic SNPs for pedigree assignment and assessment of genetic variability were identified by partial RAD sequencing. The low genetic variability of this domesticated population compared with a wild Mexican population of reference was confirmed with 820 SNP markers. To estimate genetic parameters, full-sib and half-sib families (n = 148) were bred from 74 dams and 92 sires using a double-sire insemination of each dam with spermatophores from two sires, the first time that this method has been used in shrimp genetics. At 6 months of age (14.5 g), 1200 progenies were then phenotyped for body weight and external color by digital vision, before and after cooking, using the CIE L*a*b* color space international reference system. This allowed 99.4 % of the progenies were to be successfully assigned to parents with 171 SNP markers. Heritability was high for body weight and color traits before and after cooking (h2 = 0.41-0.59). Correlations between the blue color (b*) of uncooked shrimps and uncooked body weight was negative but did not differ from zero (rg =-0.25 +/- 0.24). The blue (b*) value of uncooked shrimps was positively correlated with the red (a*) value of cooked shrimps (rg = 0.48 +/- 0.14). All results are favorable to pursuing a selective breeding program for blue shrimp in New Caledonia using this population despite its limited number of initial founders and more than 36 generations of domestication. Genetic factors potentially contributing to the results are discussed.