Allozyme variation in European lobster (Homarus gammarus) throughout its distribution range

The European lobster, Homarus gammarus, is a high value species, which is widely distributed from the northern part of Norway to Morocco in North Africa. It is also found throughout the Mediterranean including the Aegean Sea. Knowledge of the genetic structure is necessary for rational management of exploited species. As part of a comprehensive genetic investigation of European lobster (EU-project “Genetics of European Lobster”), 1514 lobsters from 14 locations were analysed for six polymorphic allozyme loci. Despite generally low levels of genetic differentiation (overall FST = 0.016), the tests for population differentiation revealed highly significant values for all loci investigated. In particular, the lobsters from three areas including northern Norway, the Netherlands, and Aegean Sea in the Mediterranean were genetically different from lobsters from other regions. Lobsters from northern Norway have 30% of the genetic diversity observed in the samples from other areas, and polymorphism was only detected at the IDHP-1* locus. A new slow-moving allele at the GPI-1* locus was found in the samples from the Aegean Sea. Pairwise FST comparisons, as well as a UPGMA dendrogram based on Nei’s genetic distance (calculated from allele frequencies across the six loci investigated), confirm the separate main groupings.