本邦産Puerulusの2型、特にゴシキエビのPuerulusについて

Abstract

As to the puerulus of Panulirus japonicus (v. SIEBOLD), detailed morphological and some ecological descriptions have been made by the present writer. Wherefore some informations mostly on the puerulus of Panulirus versicola (LAIR.) ?=P. fasciatus, DE HAAN, 1850? will be given in this article. Nine pueruli and 2 first-young-forms were dealt with. Of these pueruli, 5 obtained from Japan (Izu, Shizuoka Pref. and Misaki, Kanagawa Pref.) in September and October, and the rest from Palau Islands. The fact that the puerulus of P. versicola has been found from Japanese waters is new to science. The body-lengths run from 19.0-22.6mm in the puerulus, from 20.7-21.0mm in the first-young-form (Table 1). The puerulus is greatly characterized by having vestigial exopodite of the third maxilliped, much longer (2.1-2.2 times as long as body-length in P. versicola, about 1.3 times in P. japonicus) antennae with spatulate tip stained with rather deep brown colour (in alcoholic specimens) in distal 6-8 segments (Fig. 3.), and eighth thoracic sternite armed with a large acute spine on ventral side of each lateral edge. The puerulus of P. versicola differs from that of P. japonicus by the following traits besides those given above, viz., the carapace has more elevated median carina, and largely has the spine-f (Fig. 1), and the endopodite of the maxillae is provided with 2 lobes on inner distal margin (Fig. 4, I). Some descriptions in regard to the puerulus of P. versicola have been given by ORTMANN (1894), CALMAN (1909), and DE MAN (1916). But no one has given description on the signal feature of the antennae.