Fragum unedo   (Linnaeus,  1758) (Clam)
Organism information awaits expert curation
Class: Bivalvia
Order:Euheterodonta incertae sedis

Image copyrights: Schooner specimen shells

Size: Maximum shell height 6.5 cm, commonly to 4 cm.

Color: Outside of shell white or cream, with bright pink to dark red scales. Interior white.

Shell solid, inequilateral, subquadrate in outline, with rounded anterior and almost straight posterior margins. Posterior slope set off from the rest of the shell by a rounded radial angulation. Anterodorsal and posterodorsal margins approximately equal in length. Posterior and ventral margins meeting almost at right angle. About 27 broad, low and flat radial ribs (23 to 31) at each valve, with distantly spaced transverse scales that become coarser and more numerous on the anterior part of shell. Interstices of ribs narrow and smooth. Hinge stout, strongly bent under the umbones. Cardinal teeth of right valve connected dorsally. Posterior lateral teeth slightly closer to cardinals than anterior laterals. Internal margins crenulated, the posterior one with sharp points.

Synonym (s)
Corculum unedo (Linnaeus, 1758)
Cardium cruentum Perry, 1811
Cardium unedo Linnaeus, 1758
Hemicardium tegulatum Dautzenberg, 1900

Common Name (s)
Economic Importance and Threats
Importance:  Commercial
(Exploited at subsistence level. The shell is commonly used in the shellcraft industry for decorative items.)

Habitat:  Sandy


• Andaman and Nicobar Islands INDIA

Literature Source(s)
  • Subba Rao, NV and Dey, A (2000) Catalogue of marine molluscs of Andaman and Nicobar Islands Occasional paper no 187 Records of the Zoological Survey of India ZSI 1-323 Available at - NCL, Pune
  • Poutiers, JM (1998) Bivalves FAO species identification guide for fishery purposes. The living marine resources of the western central Pacific. Volume 1: Seaweeds, corals, bivalves and gastropods FAO, Rome 1 686 pp Available at -
  • Society for the Management of European Biodiversity Data (2009) World Register of Marine Species (WoRMS) Available at -
  • Mayhew, R Schooner specimen shells Available at -

Page last updated on:2010-05-25

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