Population structure of Litopenaeus schmitti (Decapoda: Penaeidae) from the Brazilian coast identified using six polymorphic microsatellite loci.

The population structure of the only Litopenaeus species occurring in Brazilian waters, the white shrimp L. schmitti, was surveyed by screening six microsatellite loci. High diversity (HE = 0.863; average number of alleles per locus = 37.8) was found across eight geographical locations (2 degrees S to 27 degrees S). Estimates of overall FST(0.0060) were low but significantly different from zero (P < 0.05). FST pairwise estimates and amova revealed a significant discontinuity around a major biogeographical boundary, near Cabo Frio, at 23 degrees S. This separation may have been caused either by historical or on-going hydrogeographical and/or selective factors.