ALLOZYMIC CHARACTERIZATION OF SCOTTISH AND AEGEAN POPULATIONS OF NEPHROPS-NORVEGICUS

One Scottish and two Aegean samples of Nephrops norvegicus (Crustacea: Decapoda) were allozymically tested using a total of 110 individuals and compared with two already characterized Adriatic populations. Thre e main characteristics of their genetic structure emerge: a highly hom ogeneous allele pattern, a strong heterozygote deficiency at some loci and a significant genotypic variance among populations, mainly caused by the Pgm locus. Population subdivision, intraunit inbreeding, bottl enecks and selective constraints are taken into account to allow for t hese genetic features, although none of them proved decisive. The sear ch for straightforward characters differentiating Norway lobsters of g eographically different areas proved unsuccessful, although a signific ant genotypic differentiation was noticed among our samples. Observed D values among the geographically distant samples indicate a very low genetic divergence, so that no clear phyletic conclusions can be trace d on the sole allozyme-gene analysis.