PRELIMINARY ACCOUNT OF A NEW SPECIES OF OKENIA FROM OSAKA BAY, JAPAN (NUDIBRANCHIA-GONIODORIDIDAE)

Abstract

Six species of the genus Okenia (subg. Okenia s. s.) have been reported from our seas by BABA (1937-1960). While collecting on the rocky shore of Tannowa, Osaka Bay, on July 30 and August 12 of this year, I found specimens of a pretty nudibranch, 15 in total, which appeared to belong to the genus and subgenus mentioned above, probably forming a new species distinct from the previously recorded ones. Their eggs were also formed in the native habitat of the parent animals. My thanks are due to Dr. Kikutaro BABA of the Osaka Gakugei University who has encouraged me to study these specimens, and generously let me use his collection of reprints for identification.