国立科博専報,(47): 39–50,2011年4月15日 Mem. Natl. Mus. Nat. Sci., Tokyo, (47): 39–50, April 15, 2011 Review of the Japanese Species of Alatotrochus and Sphenotrochus (Cnidaria: Anthozoa: Scleractinia: Turbinoliidae), with Description of a New Species, A. japonicus. Hiroyuki Tachikawa Natural History Museum and Institute, Chiba, 955–2 Aoba-cho, Chuo-ku, Chiba-shi, Chiba 260–8682, Japan E-mail:
[email protected] Abstract. Japanese species of the two genera of the azooxanthellate scleractinian family Turbinoliidae, Alatotrochus Cairns, 1994 and Sphenotrochus Milne Edwards and Haime, 1848, are reviewed. Two species are recognized in Alatotrochus: A. rubescens (Moseley, 1876) and A. japonicus n. sp. The new species, collected from the Ogasawara Islands, Izu Islands, and Satsu- nan Islands, is distinguished from A. rubescens by its smaller, flattened and taller corallum, few- er number of the septa, and lamellar columella. Although this new species is assigned to Ala- totrochus because it shares with A. rubescens two apomorphic characters, it is also superficially similar to Sphenotrochus wellsi Cairns, 1997 in the calicular and costal morphology. One species of Sphenotrochus, S. hancocki Durham and Barnard, 1952, is recorded for the first time from Ja- pan. Key words: Scleractinia, Turbinoliidae, Alatotrochus, Sphenotrochus, new species. new species, A. japonicus. In addition, Sphenotro- Introduction chus hancocki Durham and Barnard, 1952, previ- Alatotrochus Cairns, 1994 is a monotypic ge- ously known from the eastern Pacific and the nus of the scleractinian family Turbinoliidae that tropical western Pacific, is reported for the first is characterized by having alate thecal edge time from Japan. crests, costal number being twice as many as that of septa, linearly aligned papillose columella, and Materials and methods lacking pali and paliform lobes (Cairns, 1994, 1997).