Abstract
The starfish Asterias amurensis that is a common species in Japanese waters shows the remarkable morphological variation in several characters such as colour pattern of body between local populations. The genetic differentiation and relationships among seven local Japanese populations were investigated by allozyme analysis. From the allozyme variation observed in 25 genetic loci coding for 14 enzymes, Nei's genetic distances between seven local populations were calculated and a biochemical dendrogram for seven populations was constructed. The dendrogram indicated that the Akkeshi (Hokkaido), Ushimado (Inland Sea), and Ise (Ise Bay) populations are much genetically differentiated from the other four populations, and that the degree of genetic differentiation between them was much higher than that between conspecific local populations. Judging from allozyme and morphological data, we conclude that the starfish A. amurensis from Japanese waters consists of at least three groups that are largely genetically divergent at subspecies or sibling species level.
