Seasonal Dynamics of the Density of the Crab Larvae (Decapoda: Brachyura et Anomura) in Minonosok Bay of Pos'eta Bay (Peter the Great Bay, Sea of Japan)

摘要

As the materials for this project, we used data on the distribution of the larvae of the Asian paddle crab Charybdisjaponicus (A. Milne-Edwards, 1861); the spider crabs Hyas coarctatus ursinus (=Hyas ursinus) (Rathbun, 1924), Pugettia quadridens (de Haan, 1839), and Pisoides bidentatus (H. Milne-Edwards, 1873); the samurai crab Paradorippe granulata {=Dorippe granulata) (de Haan, 1841); the pea crab Pinnixa rathbuni (Sakai, 1934); and the porcelain crab Pachycheles stevensii (Stimpson, 1858) in Minonosok Bay of Pos'eta Bay obtained during 2000—2002 and in 2004. The planktonic samples were collected from the last third of May to September. The greatest density of the larvae was observed in May, mid-June, late June—early July, and late July—early August. The greatest densities of the crab larvae and the decapod larvae ranged from 20.4 to 48.2 and from 88.4 to 245.3 specimens/m3. The schedule of the crab larvae's occurrence in the plankton is provided for the first time. The distribution of the density showed pronounced patchiness.