DIVERSITY OF MARINE BIVALVIA IN GREEK WATERS - EFFECTS OF GEOGRAPHY AND ENVIRONMENT

The diversity and distribution of the Bivalvia fauna is examined in th e various seas of Creek territorial waters. There is a statistically s ignificant correlation between the bibliographical sources and the rec orded variety of Bivalvia at any given area, with the deeper areas con taining fewer species. Attention is given to some species 'introduced' into the area. Cluster analysis, based on the species present at 30 r egions which represent distinct geographical and ecological units, do not show any differentiation that corresponds to a geographical patter n. However, a distinct group is associated with the deeper open areas, which suggests that ecological parameters, such as depth and degree o f enclosure, play an important role in the distribution of species.