REVISION OF JAPANESE CUBOMEDUSAE

要旨

In 1929 the writer reported two Cubomedusae, Charybdea rastonii and Tamoya alata from Japan. Concerning these species, the identification of the former species is correct, but while studying on the Carybdeidae, it has been revealed that the young medusae described as the young forms of Tamoya alata seem to be nothing but the small Carbdeid medusa Carybdea sivickisi STIASNY. Moreover, thanks to BIGELow's report (1938), it has been clear that Carybdea alata is a distinct species and does not belong to the genus Tamoya. Therefore, the Japanese Tamoya was identified by the present writer ( 194 7) with T. burs aria which is widely distributed in the Pacific. But the Pacific species belongs possibly to the Atlantic species T. haplonema as KRAMP (1968) pointed out, thence reduction of two species of Tamoya to the single tropical cosmopolitan species, T. haplonema. Recently many immature medusae of this species were collected in the vicinity of the Aitsu Marine Biological Station attached to the Kumamoto University in Ariake Bay and the writer was able to study the metamorphosis of T. haplonema and made out that Tamoya-stage is gradually formed from the Carybdea-stage. Furthermore, Tripedalia cystophora CoNANT hitherto found in Jamaica and the Philippines was found for the first time at the same locality. Then, Japanese Cubomedusae are listed as below. They all belong to the family Carybdeidae. I. Carybdea rastonii HAACKE 2. Carybdea sivickisi STIASNY 3. Tamoya haplonema F. MuLLER 4. Tripedalia cystophora CoNANT In comparision with medusae of Tamoya the writer could examine through the kindness of Dr. T. TOKIOKA a good preserved specimen of the gigantic species, Carybdea alata REYNAUD obtained off Cape Town and preserved in the Seto Marine Biological Station.

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