Resumen de Genetic structure of Nephrops norvegicus (L.), (Decapoda: Nephropidae), from the Mediterranean Sea
Ferruccio Maltagliati, Laura Camilli, Franco Biagi, M. Abbiati
The population genetic structure of the Mediterranean Norway lobster was studied by means of cellulose acetate allozyme electrophoresis. Populations from one Atlantic and eight Mediterranean localities were sampled. The 15 enzyme systems analysed gave 23 presumptive gene loci, 11 of which were polymorphic. The analysis of genotypic and allelic frequencies revealed levels of genetic polymorphism comparable with those of studied decapods: mean heterozygosities ranged from 0.052 (se 0.025) to 0.142 (se 0.040). The values of Nei's genetic distance index showed moderate genetic differentiation between geographical regions and no geographical pattern of genetic differentiation was detected by UPGMA cluster analysis. Moreover no clear clines in allelic frequencies were detected, thus genetic variability seems to be randomly distributed among populations and Nephrops norvegicus seems to follow the island model of genetic structure. The degree of genetic subdivision of the species is confirmed by the mean value of the standardised variance in allelic frequencies (FST = 0.122), giving an estimate of gene flow, Nm = 1.80.
