Relevant Synonyms Gourmya (Gladiocerithium) argutum barashi Nordsieck, 1972 [Haifa bay, Israel] Cerithium scabridum var. hispida Pallary, 1938 [Syria] Cerithium yerburyi Smith, 1891 Misidentification -  photo: S. Gofas

SHORT DESCRIPTION Shell high-spired, about three times as long as wide, of 9-10 whorls. Sculpture on spire whorls of 3 strong, raised spiral cords with interspaces as broad as the cords, and weak axial folds which determine strong knobs at their intersection with the cords. Some weak varixes on the spire. Body whorl slightly expanded with respect to the spire whorls, externally with 7-8 cords, internally with a smooth outer lip and a short, small siphonal canal. color : brownish, with a contrasting pattern of white and dark brown mottles on the cords. common size : 12-20 mm. DISTINGUISHING CHARACTERISTICS C. scabridum is distinguished from any other native or introduced species of Cerithium by the markedly raised shape of the spiral cords, separated by rather broad interspaces. BIOLOGY / ECOLOGY Egg masses in the form of coiled gelatinous, transparent strings packed with small eggs (Barash and Danin, 1973). This species has been taken as a possible model for the genetics of invasive marine species, and as such has been investigated by Lavie and Nevo (1986) who found a high level of genetic variability, not less considerable in Mediterranean than in Red Sea populations. This species has been shown to have a quite long planktotrophic larval phase, which lasts 45 to 60 days, and has been calculated to have a life span of two years (Ayal and Safriel, 1982). habitat : intertidal or shallow water zone, on a variety of substrates including sandy mud with Cymodocea nodosa or Zostera nana, rock pools in sheltered places, and lagoons.

1st Mediterranean record Port Said, Egypt, 1883 [no collecting date]. DISTRIBUTION Worldwide: Red Sea, Persian Gulf, western and southern India (Houbrick, 1992); found in the Suez Canal (Keller, 1883). Mediterranean: recorded first from Port Said, Egypt (Keller, 1883); successively from Israel (Haas, 1937); Syria (Pallary, 1938); Lebanon (Pallary, 1938); Italy: Sicily (Di Natale, 1978a), Naples (Mienis, 1985); southern Turkey (Enzenross et al., 1990); north Cyprus (Cecalupo and Quadri, 1996), southern Tunisia (Enzenross and Enzenross, 2001); Imbros Island, NE Aegean (Albayrak, 2001). The species from Cyprus illustrated as C. scabridum by Tornaritis (1987) is however the native C. lividulum Risso, 1826. ESTABLISHMENT SUCCESS This is one of the earliest recorded and most successful of the Lessepsian migrants, which now constitutes large, stable populations. It is locally invasive, for example in the Gulf of Gabès. speculated reasons for success : the larval dispersal via a planktonic stage, the unspecialized feeding habits and unusually high levels of genetic vairability may be key characters for success. MODE OF INTRODUCTION Via the Suez Canal into the Levantine Sea; probably by shipping from there to Porto Megarese, Sicily, where it spread along the Sicilian east coast and later to Tunisia. IMPORTANCE TO HUMANS None.

KEY REFERENCES Albayrak S., 2001. Prosobranch gastropods of the Imbros Island (NE Aegean Sea). Acta. Adriatica, 42(2): 35-42. Di Natale A., 1978a. Note sur la présence et la répartition de Cerithium scabridum Philippi, 1849 (Mollusca, Gastropoda) sur les côtes siciliennes. Bulletin de l'Office National des pêches de Tunisie, 2(1-2): 193-198. Enzenross L., R. Enzenross and H.J. Niederhöfer, 1990. Wissenschaflich interssante Funde aus der Sammlung Enzenross (marine Invertebraten). Jahreshefte der Gesellschaftten fuer Naturkunde in Wuerttemberg, 145: 283-294. Enzenross L. and Enzenross R., 2001. Untersuchungen über das Vorkommen mariner Mollusken in tunesichen Gewässern. Schriften für Malakozoologie, 17: 45-62.   Houbrick R.S., 1992. Monograph of the genus Cerithium Bruguière in the Indo-Pacific (Cerithiidae: Prosobranchia). Smithsonian contributions to Zoology, 510: 1-211 [C. scabridum pp. 172-177]. Keller C., 1883. Die Fauna im Suez Kanal.und dieDiffusion dermediterranen und erythraischen Thierwelt. Eine thiergeographische Untersuchung. Neue Denkschriften der allgemeinen Schweizerischen Gesellschaft für die gesammten Naturwissenschaften, Zürich, 28(3): 1-39, pl. 1-2. Basel. Lavie B. and Nevo E., 1986. Genetic diversity of marine Gastropods: contrasting strategies of Cerithium rupestre and C. scabridum in the Mediterranean Sea. Marine Ecology Progress series, 28: 99-103. FEEDBACK / COMMENTS TO AUTHORS

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