Relevant Synonyms Hipponix conicus (Schumacher, 1817) Misidentification -  drawing: Tuvia Kurz

SHORT DESCRIPTION Shell thick, cap-shaped, low conical with the apex closer to the posterior margin or overhanging it. Edge of aperture of irregular shape, matching the surface of the substrate. Sculpture of broad, irregular radiating ribs with narrow interspaces. color : exterior of shells white, with reddish brown stains or rays, the interior white with or without brown stains, the edge of the aperture conspicuously tinged with brown. common size : up to 20 mm in the Indo-Pacific; the Mediterranean specimen only 3 mm (Barash and Danin, 1992). DISTINGUISHING CHARACTERISTICS The only native species which could create confusion is the pulmonate Trimusculus mamillaris (Linnaeus, 1758), which rarely has the apex overhanging so much and is pure white in color. BIOLOGY / ECOLOGY Lives as a commensal attached on shells of larger molluscs, without being host-specific. It is a protandric hermaphrodite (so, large specimens are females) and has long-lived planktotrophic larvae. habitat : shallow subtidal rocky bottoms.

1st Mediterranean record Israel, 1986 [1980]. DISTRIBUTION Worldwide: Red Sea, Indian Ocean, and throughout the Tropical Pacific. Mediterranean: recorded in 1980 from Dor, Israel as Hipponyx conicus, record based on a single shell (Barash and Danin, 1986); later one spurious locality in Sicily (Giannuzzi-Savelli et al., 1997). ESTABLISHMENT SUCCESS The occurrence of this species in the Mediterranean is questionable, with several records but all very doubtful. The specimen from Israel (Mienis, pers. comm.) is a tiny juvenile (3 mm) and the Italian specimens seem so much out of context that the locality data can be questioned. speculated reasons for success : - MODE OF INTRODUCTION Possibly via the Suez Canal. IMPORTANCE TO HUMANS None.

KEY REFERENCES Barash A. and Danin Z., 1986. Further additions to the knowledge of Indo-Pacific mollusca in the Mediterranean Sea. Spixiana, 9(2): 117-141 [Hipponix conicus p. 120]. Cernohorsky W.O., 1968. Observations on Hipponix conicus (Schumacher, 1817). The Veliger, 10(3): 275-280. Giannuzzi-Savelli R., Pusateri F., Palmeri A. and Ebreo C., 1997. Atlante delle conchiglie marine del mediterraneo. Vol. 2: Caenogastropoda. La Conchiglia, Roma, 258 p.   Vermeij G.J., 1998. Sabia on shells: a specialized pacific-type commensalism in the Caribbean Neogene. Journal of Paleontology, 72(3): 465-472. FEEDBACK / COMMENTS TO AUTHORS

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