Relevant Synonyms Cerithium bifasciatum Sowerby, 1855 Clypeomorus clypeomorus Jousseaume, 1888 Misidentification Cerithium caeruleum Sowerby, 1855 [Giannuzzi-Savelli et al., 1997]  drawing: Tuvia Kurz

SHORT DESCRIPTION Shell thick, stout, about twice as high as broad, of 7-8 rather flat whorls. Sculpture on spire whorls of three equally spaced beaded cords; beads prominent and aligned axially so as to form ribs. Body whorl with a blunt varix opposite the outer lip. Aperture ovate, with a short, rather constricted siphonal canal, and opposite to it a well-defined anal canal delimited by a denticle on the columella. color : variable, with a whitish background and usually dark beads or series of dark spots on the cords; occasionally with dark spiral lines, bands, or interspaces of cords. common size : 15-20 mm. DISTINGUISHING CHARACTERISTICS The general appearance of this species resembles Cerithium caeruleum Sowerby, 1855, but it is distinguished by having three rows of beads instead of a poorly defined knobbed keel on the spire whorls. BIOLOGY / ECOLOGY Egg masses are deposited as long ribbon-like masses containing thousands of eggs, and the larvae are planktotrophic. habitat : in the Red Sea, this species usually occurs in large numbers on high rocky intertidal platforms (Houbrick, 1985) and partially buries in the patches of sand during low tide.

1st Mediterranean record Israel, 1985 [1983]. DISTRIBUTION Worldwide: Red Sea, Indian Ocean, and throughout the Tropical Western Pacific; occurring in the Suez Canal (Tillier and Bavay, 1905, as Cerithium clypeomorus). Mediterranean: recorded first in 1983 in Akhziv, Israel (Mienis, 1985a); later in Port Said, Egypt (Giannuzzi-Savelli et al., 1997); and Tobruk, Libya (ibid., as Cerithium caeruleum, fig. 63). ESTABLISHMENT SUCCESS Several records, but none of them convincing; therefore, considered as questionable occurrence until further notice of established populations. speculated reasons for success : - MODE OF INTRODUCTION Via the Suez Canal. IMPORTANCE TO HUMANS None.

KEY REFERENCES 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. Houbrick R.S., 1985. Genus Clypeomorus Jousseaume (Cerithiidae: Prosobranchia). Smithsonian Contributions to Zoology, 403: 1-131 [C. bifasciatus pp. 23-43]. Mienis H.K., 1985a. First record of the Indo-Pacific species Clypeomorus bifasciata from the Mediterranean coast of Israel. Levantina, 57: 638.   Tillier L. and Bavay A., 1905. Les mollusques testacés du Canal de Suez. Bulletin de la Société Zoologique de France, 30: 170-181. Yaron I., 1979. Zonation of Cerithiid species in the Gulf of Aquaba (Red Sea). Levantina, 21: 231-235. FEEDBACK / COMMENTS TO AUTHORS

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