CONTRIBUTIONS TO THE JAPANESE ASCIDIAN FAUNA XXXVI. -A NEW SPECIES OF ADAGNESIA (FAMILY AGNESIIDAE) FROM THE JAPAN SEA, WITH A NOTE ON ITS STRANGE STRUCTURE, "EPIDERMAL VESICLE"-

Abstract

More than 60 specimens of a strange stalked simple ascidian were submitted to the author for identification by Mr. Tsutomu Shin'ya of the Noto Marine Biological Laboratory, Kanazawa University. These specimens were collected in 1981 by Mr. Shin'ya by dredging at a depth of 20m in the northern part of Toyama Bay in the Japan Sea, far south off Noto-Ogi on the south coast of Noto Peninsula. Closer examinations on these led the author to the conclusion that they belong to a new species of the genus Adagnesia Kott that is represented here for the first time from the western North Pacific. Further, a strange structure, "the epidermal vesicle", was detected at the base of the stalk on all the specimens examined. Seemingly, this structure might be related to the asexual reproduction by budding of a manner of so far unknown type. Before going further, the author would like to express his cordial thanks to Mr. Shin'ya for this very interesting material and to Dr. Takasi Tokioka for his critical reading of the manuscript.