Specific status of Pandalus gracilis (Decapoda, Caridea, Pandalidae).

Pandalus gracilis Stimpson, which has been synonymized with P. hypsinotus Brandt, is revived as a good species. Both species occur in the Japanese fauna. It is more closely related to P. prensor Stimpson than to P. hypsinotus. The three species show a number of morphological differences; furthermore P. prensor is the smallest of the three, and P. hypsinotus the largest. The life span of P. hypsinotus is longer than that of P. gracilis. P. gracilis is known to occur rathe abundantly in the southern part of the Sea of Japan, but the commercial value is not high, because of the small size.