GENETIC-VARIATION WITHIN AND BETWEEN 2 TYRRHENIAN POPULATIONS OF THE MEDITERRANEAN ALCYONARIAN CORALLIUM-RUBRUM

Allozymic variation of 13 gene loci was investigated in 2 samples of C orallium 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 P gi showed the highest level of heterozygosity. In the Elba sample all polymorphic loci were in Hardy-Weinberg equilibrium, whereas in the Ca lafuria sample, Pgm and Pgi were not. Mixing of individuals from genet ically different subpopulations (Wahlund effect) may cause this disequ ilibrium. Nei's indices together with F-statistics show that the sampl es investigated can be considered as 2 distinct local populations. The results suggest that limited larval dispersal may be more important i n promoting C. rubrum population differentiation than differential sel ection on the migrating larvae.