Relevant Synonyms ? Diplodonta subrotundata Issel, 1869 Diplodonta sp. Misidentification Diplodonta rotundata [Sabelli et al., 1992] * sensu Bogi and Galil, 1999  photo: C. Bogi / Coll. B. Galil

SHORT DESCRIPTION Shell thin, fragile, equivalve, inequilateral, moderately inflated. Outline, subovate, with beaks in front of the midline. Posterior area more expanded than anterior. Sculpture of fine concentric lines giving the shell a smooth texture. Hinge with two prominent teeth in each valve, median tooth bifid. Ligament on a shallow nymph (resilium) which is steeply inclined posteriorly. Internal margin smooth. Juvenile specimens are difficult to identify because of the complexity of the genus that is confusing. color : white. common size : up to 10 mm, Israel findings 7-10 mm. DISTINGUISHING CHARACTERISTICS Similar to the Mediterranean species Diplodonta rotundata with which it has been erroneously confused (Sabelli et al., 1990-92) and from which it differs by its smaller size, its more rounded profile, and the globose shape in adult specimens (Bogi and Galil, 1999). According to Oliver (1992), the Red Sea specimens assigned as Diplodonta sp. may be juveniles of D. subrotundata, but their even sculpture, moderate tumidity, steeply inclined resilium and thickness suggest that this is not so. BIOLOGY / ECOLOGY Infaunal siphonate, actively mobile, unattached animals known as suspension feeders (Todd, 2002). Another species of the family Diplodonta punctata was observed in aquaria to build a "nest" of sand grains cemented by mucus (Domaneschi, 1979). habitat : sands, offshore; the Mediterranean records from depths 9-30 m.

1st Mediterranean record Israel, 1999 [no collecting date]. DISTRIBUTION Worldwide: throughout Red Sea; common in the Suez Gulf, frequent in the Suez Canal as a variety of D. rotundata (Moazzo, 1939). Mediterranean: recorded only from Israel coasts (Bogi and Galil, 1999). ESTABLISHMENT SUCCESS Known only from two recent records along the Israeli coasts, but at least one of them is based on numerous juvenile and adult specimens. speculated reasons for success : - MODE OF INTRODUCTION Via the Suez Canal. IMPORTANCE TO HUMANS None.

KEY REFERENCES Bogi C. and Galil S.B., 1999. Nuovi ritrovamenti di immigranti lessepsiani lungo le coste israeliane. La Conchiglia, 292: 22-29, 63. Domaneschi O., 1979. Biological aspects of Diplodonta punctata (Say, 1822) (Bivalvia, Lucinacea, Ungulinidae). Revista nordestina de biologia, Paraiba, 2(1-2): 21-25. Moazzo P.G., 1939. Mollusques testacés marins du Canal de Suez. Mémoires de l'Institut d'Egypte, 38: 1-283, Cairo [Diplodonta rotundata Montagu et var. subrotunda Issel, p. 93].   Oliver P.G., 1992. Bivalved seashells of the Red Sea. Christa Hemmen, Wiesbaden and National Museum of Wales, Cardiff, 330 p. van Aartsen J.J., 2000. European marine Mollusca: Notes on less well-known species. XVI. Diplodonta eddystonia (Marshall, 1895), with notes on the European Diplodonta species. La Conchiglia, 297: 46-51. FEEDBACK / COMMENTS TO AUTHORS

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