Abstract
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 ( H E = 0.863; average number of alleles per locus = 37.8) was found across eight geographical locations (2°S to 27°S). Estimates of overall F ST ( 0.0060) were low but significantly different from zero ( P F ST pairwise estimates and amova revealed a significant discontinuity around a major biogeographical boundary, near Cabo Frio, at 23°S. This separation may have been caused either by historical or on‐going hydrogeographical and/or selective factors.