Allozymic variation in Mediterranean hake, Merluccius merluccius (Gadidae)

Four hundred and twenty individual hake from 10 sample sites in the Mediterranean Sea were analysed in order to study genetic variability and identify genetic stock structure. Twenty loci were identified, four of which were polymorphic at the 95% level: ADH*, PGI‐1*, PGI‐2* and SOD‐1*. Average observed and expected heterozygosity were 0.084 and 0.090, respectively. PG1–1* deviated from Hardy‐Weinberg expectations due to an excess of heterozygotes and F‐statistic analysis showed also a significant excess of heterozygosity at SOD‐1*. FST was not significant for each locus except for PGI‐2*, where a single sample from the Channel of Sicily (C5) showed a different pattern in allelic frequencies, probably caused by a stochastic event. The samples analyzed seemed to be homogeneous, but future analyses may be necessary using other complementary molecular markers.