ALLOZYME SIMILARITY IN 2 MORPHOLOGICALLY DISTINGUISHABLE POPULATIONS OF PARACENTROTUS-LIVIDUS (ECHINODERMATA) FROM DISTINCT AREAS OF THE MEDITERRANEAN COAST

Allozymes of Paracentrotus lividus from Palermo Gulf in the northern S icilian coast (Italy) and from a small body-size population in the wes tern Greek coast (Ionian Sea) were investigated by PAGE. Five of the t wenty examined loci were polymorphic (AAT, ADH*, ME*, PGI* and PGM*) over each population with a polymorphism value of 0.25. Average hetero zygosity was equal to 0.081 in the Sicilian sample and 0.084 in the Gr eek. Deviations from Hardy-Weinberg equilibrium were significant in ME and PGI* loci (as calculated by chi(2)). Nei's (1978) genetic distan ce (D=0.0025) index described a close identity between the two samples . F-ST value of polymorphic loci ranged from 0.001 to 0.029, its mean value (0.008) resulting low and appearing to be discriminate between t he samples with a significant difference (P < 0.05). The number of mig rants per generation was equal to 31.