Allozyme and mitochondrial DNA variation in Cuban populations of the shrimp Farfantepenaeus notialis (Crustacea : Decapoda)

We investigated the genetic diversity among populations of the shrimp Farfa ntepenaeus notialis, the most abundant penaeid species around Cuba. A total of 25 allozyme loci were analyzed in samples of shrimps from seven localit ies at the south central platform of the island (Ana Maria Gulf). Samples f rom three of these localities and from Batabano Gulf and Guacanayabo Gulf a t the south west and south east platforms of the island, respectively, were also characterized at the mtDNA level through sequence variation of a 2027 bp segment including part of the COI and COIII genes. Of the 25 allozyme l oci studied 9 were polymorphic: Akp2, Akp3, AmyB, Est3, Gdh, GP7, and Per1, 2 and 3. In contrast to mtDNA, the pattern of allozyme variation among loc alities revealed strong population structuring at Ana Maria Gulf, with sign ificant F-st in all pairwise comparisons. The magnitude of F-st estimates a s well as the grouping pattern obtained by a UPGMA analysis based on a dist ance matrix indicated that the level of differentiation was concordant with the geographical position of the localities and the hydrographic regime. H omogeneity of mtDNA suggested that differentiation of allozyme loci might b e due to more recent events rather than historical isolation of the sampled populations. Ana Maria and Guacanayabo Gulf populations were differentiate d by mtDNA from Batabano Gulf, at the southwestern end of the island. The a nalysis showed three restriction site differences among them, suggesting ge netic isolation of the two regions. The present results also suggest that a n artificial introduction of larvae from Tunas de Zaza into Batabano Gulf, in an effort to repopulate this fishing region, may have been ineffective.