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

Image copyrights: Guido T. Poppe & Philippe Poppe - Conchology, Inc.

Size: Maximum shell height 4 cm, commonly to 3 cm.

Color: Outside white, often with pale pink to fawn blotches towards the umbones, scales on ribs light yellow. Interior is white, usually with some pale orange to pink radial flares in the umbonal cavity.

Shell solid, inequilateral, trapezoidal in outline, with rounded anterior and almost straight, high posterior margins. Posterior slope markedly set off from the rest of the shell by a sharp radial angulation. Anterodorsal margin is longer than posterodorsal margin. Posterior and ventral margins meet at an angle distinctly less than 90°. About 32 low and flat radial ribs (27 to 37) at each valve, with close-set transverse scales that become coarser on the anterior part of shell. Interstices of ribs are narrow and smooth. Hinge stout, strongly bent under the umbones. Cardinal teeth of right valve connected dorsally. Posterior lateral teeth are much closer to cardinals than anterior laterals. Internal margins are crenulated, the posterior one with sharp points.

Synonym (s)
Fragum flavum Roding, 1798
Corculum fragum (Linnaeus, 1758)
Cardium imbricatum Born, 1778
Cardium flavum Roding, 1798
Cardium fragum Linnaeus, 1758
Cardium imbricatum Born, 1780
Hemicardium (Fragum) fragum (Linnaeus, 1758)

Common Name (s)
Economic Importance and Threats
Importance:  Commercial
(Mainly collected for decorative purposes.)
Threats:  Natural threats
(Predated upon by gastropods)

Habitat:  Sandy


• Andaman and Nicobar Islands, Andamans INDIA
• Red Sea

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 -
  • Poppe, GT and Poppe, P (1996) Conchology, Inc. Conchology, Inc. Available at -

Page last updated on:2010-05-24

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