Genetic variation within and between two Tyrrhenian populations of the Mediterranean alcyonarian Corallium rubrum

Abstract

Allozymic variation of 13 gene loci was investigated in 2 samples ofCorallium rubrum (L.) collected in the Tyrrhenian Sea (Tuscany, Italy),at the coastal Calafuria cliff (south of Leghorn) and at Elba Island(Tuscan Archipelago) respectively. Among 5 polymorphic loci, Pgm and Pgishowed the highest level of heterozygosity. In the Elba sample allpolymorphic loci were in Hardy-Weinberg equilibrium, whereas in theCalafuria sample, Pgm and Pgi were not. Mixing of individuals fromgenetically different subpopulations (Wahlund effect) may cause thisdisequilibrium. Nei's indices together with F-statistics show that thesamples investigated can be considered as 2 distinct local populations.The results suggest that limited larval dispersal may be more importantin promoting C. rubrum population differentiation than differentialselection on the migrating larvae.