Relevant Synonyms Planaxis savignyi Deshayes, 1844 Misidentification Planaxis sulcatus (Born, 1880) [Vaillant, 1865] Planaxis punctostriatus Smith, 1871 [Giannuzzi-Savelli et al., 1997]  photo: S. Gofas

SHORT DESCRIPTION Shell globose, solid, with stout conical spire. Sculpture of broad, flat spiral cords with narrow interspaces. Aperture ovate, with outer lip somewhat thickened inside, hardly denticulated. A shallow, small siphonal notch at the anterior end of the aperture. color : dark brown, nearly black, showing through as bands inside the aperture. common size : 10-15 mm. DISTINGUISHING CHARACTERISTICS The related species Planaxis sulcatus (Born, 1780) is larger (up to 35 mm) with more separated and higher cords, and a more variable color pattern of flames. This species differs from P. punctostriatus in having heavier cords, a stouter profile, and in lacking the distinct tooth bordering the siphonal notch. BIOLOGY / ECOLOGY This species differs from the related P. sulcatus in lacking planktotrophic larvae. habitat : on rocks of the shore.

1st Mediterranean record Egypt, 1905 [no collecting date]. DISTRIBUTION Worldwide: this is the Red Sea representative of a species complex represented in the Indo-Pacific by P. sulcatus (Born, 1780). Common in the Suez Canal (Tillier and Bavay, 1905). Mediterranean: recorded as common in Port Said, Egypt by Tillier and Bavay (1905) but this occurrence was disputed by Moazzo (1939). The next record from Haifa, Israel (Giannuzzi-Savelli et al., 1997, misidentified as P. punctostriatus), is doubtful. ESTABLISHMENT SUCCESS Very rare, only one record in recent years. 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., 1987. Anatomy, reproductive biology and phylogeny of the Planaxidae (Cerithiacea: Prosobranchia). Smithsonian contributions to Zoology, 445: 1-57. 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

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