Allozymic analysis of some Mediterranean Veneridae (Mollusca : Bivalvia): preliminary notes on taxonomy and systematics of the family

An allozyme analysis on three species of Mediterranean Veneridae (Mollusca. Bivalvia): Callista chione (subfamily Pitarinae), Venus verrucosa (Venerin ae) and Chamelea gallina (Chioninae) is presented. The results were compare d with the previously obtained allozyme data on Tapes philippinarum, T. dec ussatus, Venerupis aurea and Paphia undulata (all pertaining to the subfami ly Tapetinae). The newly analysed species showed remarkable departures from the Hardy-Weinberg proportions, as commonly observed in several population s of Bivalvia. The present analysis revealed a high level of relationship b etween C. gallina and Venus verrucosa and suggested that the genus Tapes, a s presently defined, should he regarded as an unnatural taxon. The allozyme results are consistent with mitochondrial 16s ribosomal DNA and satellite DNAs analyses on the same species, with the only exception of Callista chio ne which seems to be basal to (UPGMA method) or even included (Neighbor-Joi ning method) in the Tapetinae cluster.