Relevant Synonyms - Misidentification -  photo: S. Gofas

SHORT DESCRIPTION Shell elongated-ovate, steeply conical, with an apical hole at approximately 1/3 of the way from anterior end. Outer surface with 20-25 major radiating ribs and some smaller ribs interpersed; comarginal ridges less developed than the ribs and forming knobs at their intersection. Margin of the aperture with conspicuous crenulations where the ribs terminate, the notches between crenulations somewhat continued towards the inside of the shell. color : shell whitish with radial sectors bearing dark blotches, inside white with external patterns showing through. common size : up to 20 mm long, 10 mm high in the Red Sea; more commonly 15 mm long. DISTINGUISHING CHARACTERISTICS This species resembles the native D. graeca (Linnaeus, 1758) but has a steeper profile, coarser sculpture, and different appearance of the edge of the aperture with notches distinctly continued towards inside. Some morphs of D. graeca found in deeper water of the Western Mediterranean may be misleading, but these are usually larger and have more continuous dark sectors on the shell (not blotches). BIOLOGY / ECOLOGY Species of Diodora feed on sponges lining the underpart of rocks. habitat : on rocky intertidal zone; also on gravel bottoms dredged 20-70 m (Barash and Danin, 1992).

1st Mediterranean Record Palestine, 1948 [no collecting date]. DISTRIBUTION Worldwide: Red Sea, Aden, Persian Gulf, Somalia, Madagascar, Natal, Seychelles, Mauritius; Pacific: Hawaii. Common in the Suez Canal (Tillier and Bavay, 1905). Mediterranean: recorded first in Palestine (Haas, 1948); later on the southeast coast of Turkey, from Gulf of Iskenderun to Alanya (Engl, 1995). ESTABLISHMENT SUCCESS Now quite frequent on Levantine shores. speculated reasons for success : - MODE OF INTRODUCTION Via the Suez Canal. IMPORTANCE TO HUMANS None.

KEY REFERENCES Barash A. and Danin Z., 1973. The Indo-Pacific species of Mollusca in the Mediterranean and notes on a collection from the Suez Canal. Israel Journal of Zoology, 21(3-4): 301-374 [Diodora rueppelli, p. 303, Fig. 2]. Barash A. and Danin Z., 1977a. Additions to the knowledge of Indo-Pacific Mollusca in the Mediterranean. Conchiglie, 13(5-6): 85-116. Engl W., 1995. Specie prevalentemente Lessepsiane attestate lungo le coste Turche. Bollettino Malacologico, 31(1-4): 43-50.   Haas, 1948. Sur l'immigration de mollusques de l'Indo-Pacifique dans les eaux côtières de la Palestine. Journal de Conchyliologie, 88: 141-144. Tillier L. and Bavay A., 1905. Les mollusques testacés du Canal de Suez. Bulletin de la Société Zoologique de France, 30: 170-181. FEEDBACK / COMMENTS TO AUTHORS

Last update : December 2003 ©ciesm 2002