Principal component analysis on the morphology of ten Eriocheir japonica populations and E.sinensis

Morphological metrical characters of ten Japanese mitten crab (Eriocheir japonica) populations collected from Japan and one Chinese mitten crab (E.sinensis) from Shanghai were described and compared using morphological method. The principal component analysis results indicated that there were great similarities among the Japanese mitten crab populations except in two Okinawa populations, which supported the standpoint that there was only small genetic differentiation among the Japanese mitten crab populations. Okinawa populations were different from others due to the geographic and water temperature isolation. The significant differences between Japanese and Chinese mitten crabs resulted in two large groups.