抄録
Geographic variation in the skull morphology of the finless porpoise was studiedwith special reference to identifying local populations in Japanese waters. Twenty-five skull characters were measured for 146 specimens. These specimens were divided into five samples on the basis of available distributional information: 1) from Sendai Bay to Tokyo Bay, 2) Ise Bay and Mikawa Bay. 3) Inland Sea and theadjacent waters, 4) Omura Bay, 5) Ariake Sound and Tachibana Bay. Morphological differences were examined by the analysis of covariance and canonical discriminant analysis. The skull morphology varied among the samples. The porpoises in IseBay and Mikawa Bay possessed rather narrow skulls. There was no evidence that skull morphology was more similar between geographically close areas. Such geographic variation suggests that porpoises in each area rarely intermingle. We considered that there are at least five local populations in Japanese waters.
