On the Mean Value of Latitude in the Distribution of Marine Mollusca from Hokkaido

Abstract

This paper deals with the latitudinal mean value of the distribution of 190 spec es of marine mollusca from Hokkaido. Results (Table 1) show that Hakodate, Otaru and Yagishiri Island are most strongly affected by the Warm Tsushima Current among the localities. On the other hand, such localities as Monbetsu, Utoro and Akkeshi are more influenced by the Cold Oyashio Current compared with the other places in this study.