外洋における沿岸動物の浮泳性幼体の分布

抄録

Pelagic larvae of littoral animals are studied in the present paper, by using the samples which were collected from the sea areas east of Japan by the ship Ryof ?? -maru in her two voyages of August-September and November, 1955. Larvae identified are cyphonautes of Bryozoa, actinotrocha of Phoronidea, trochophora of Annelida, zoëa and megalopa of Brachyura, nauplius and cypris of Cirripedia, and ophiopluteus, a certain pluteus and post-larvae of Echinodermata. We can know the extent and strength of the influconce of coastal waters to the open sea by tracing the distribution of these larvae, for they may be considered as tiny drift bottles in view of the fact that they have hatched out in littoral areas. Main patterns of their distribution exist along the Kuroshio main current in August-September, being transferred somewhat northwards in November. Additionally referring to the observational results obtained by the Ryof ?? -maru in February-March and May-June, 1955, it may be concluded that pelagic larvae in the sea east of Japan are principally originated in coastal areas covered by the Kuroshio water.