GEOGRAPHICAL VARIATION OF BODY-SIZE IN WESTERN MEDITERRANEAN STRIPED DOLPHINS (STENELLA-COERULEOALBA)

The variation in maximum, body size of striped dolphins, Stenella coer uleoalba, was studied in various areas of the Mediterranean Sea. Anima ls inhabiting the southern part of the Mediterranean are larger than t hose inhabiting the northern fringe. Although a number of ecological f actors affecting maximum body size in mammals has been identified, the ir role in causing the variation observed is difficult to determine be cause of the lack of appropriate data. However, the southern fringe is characterized by stronger seasonality and lower density of dolphins, both factors likely to favour larger maximum individual body sizes in a population. The variation observed may reflect population stratifica tion leading to a degree of genetic isolation within the western Medit erranean Sea.