Galaxea, Journal of Coral Reef Studies 12: 51（2010） Photogallery An unidentified species of acoel flatworm in the genusWaminoa associated with the coral Acropora from the field in Japan Kanae MATSUSHIMA1, Eiji FUJIWARA2, and Masayuki HATTA1, * 1 Graduate School of Humanities and Sciences, Ochanomizu University, Tokyo 112-8610, Japan 2 Documentary Channel Co., Ltd., Skip-City, Saitama 333-0844, Japan * Corresponding author: M. Hatta E-mail: [email protected] Communicated by Michio Hidaka (Editorial Board Member) Keywords Acoela, Acropora, coral, flatworm,Waminoa In May 2008, we found five individuals of an acoel flatworm species, which is not found in the literatures or webs, on a branch piece of the coral Acropora humilis off Maja Beach, Aka Island, Okinawa, Japan (2611N, 12717E). They were approximately 1 mm in length, and had white dots and brown symbiotic algae (Fig. 1A). Identical sequences of the 18SrDNA were obtained from two individuals so far analyzed (accession no. AB539806). DNA phylogenetic analyses assigned its position in the genus Waminoa (data not shown), and the highest BLAST match at present is W. brickneri (accession no. AJ875221, Ogunlana et al. 2005). But, large sequence differences (150 base substitutions and 14 gaps per 1464bp) and morphological differences (Ogunlana et al. 2005) suggest that the flatworm we found is distinct from W. brickneri. Detailed description is a subject remained. There are several reports on Waminoa being epizoic on hard and soft corals in the Red Sea and South-West Pacific (e.g. Ogunlana et al. 2005). In particular, the species in this study seems to be camouflagic on Acropora corals (Fig. 1B and Online Supplementary Material). Interests would be taken in their ecological aspects. Acknowledgments We thank Akajima Marine Science Laboratory for providing a field research base and for sample collection, and T. Katayama-Hikosaka for morphological identification. This work was supported by a grant from Fujiwara Natural History Foundation to KM and by the Grants-in-Aid for Scientific Research from the MEXT Japan to MH. Fig. 1 Representative pictures of the acoel flatworm found in this study. A A dorsal view of an individual kept in a watch glass. The anterior end is located at the upper right. B An individual on a corallite of Acropora humilis. Its position is indicated by an arrowhead Online Supplementary Material. A movie of the observations References Ogunlana MV, Hooge MD, Tekle YI, Benayahu Y, Barneah O, Tyler S (2005) Waminoa brickneri n. sp. (Acoela: Acoelomorpha) associated with corals in the Red Sea. Zootaxa 1008: 1-11 Received: 7 January 2010/Accepted: 24 April 2010 Ⓒ Japanese Coral Reef Society.