Tridacna squamosa   Lamarck,  1819 (Clam)
Organism information awaits expert curation
Class: Bivalvia

Image copyright: Jan Sevcik

Size: 408 mm in length

Color: The main ground color of the mantle is dark grayish purple. Along the outer mantle margin is a row of rhomboidal spots which are very light bluish green. The larger irregularly-circular spots towards the center of the mantle are multicolored, their outer periphery being pale yellow, inside of which is a band of dark yellow, and entire center is nearest to light blue.

The shell is semicircular in outline. The angle formed at the umbos by the hinge line and ventral margin is usually greater than 150ยบ. The shell is strongly inflated and having medium-sized to small byssal orifice. Valves moderately heavy and thick, encrusted with vermetids, annelid tubes, coral, coralline algae, other organisms and debris. Surface of valves dull. Dorsal shell margins broadly fan-shaped in outline, and undulate. Hinge line usually about half the length of shell. A single, oblong cardinal tooth present in each valve. 2 elongate posterior lateral teeth present in right valve and 1 in left. Ligament secondarily prosodetic. Umbos directed postero-medially. Ventral margin slightly concave in region of byssal orifice, convex posteriorly. Pallial line is entire, moderately wide.

Tridacna squamosa derives its nutrition mainly through photosynthesis which is performed by zooxanthellae, a photosynthetic algae living symbiotically within the mantle of clam.

Synonym (s)
Tridacna scapha (Meuschen, 1787)
Tridacna (Chametrachea) squamosa Lamarck, 1819

Common Name (s)
• Scaly Clam (English)
• Fluted Giant Clam (English)
• Fluted Clam (English)
• Giant Clam (English)
Economic Importance and Threats
Importance:  Commercial
(Fisheries, aquarium. Collected for food and the shell trade.)

Habitat:  Reef Associated,Demersal
Trophic Level:  Consumer
Prey:  Plankton


• Andaman and Nicobar Islands, Andaman Islands INDIA
• Lakshadweep, Agatti INDIA (Record: 01/1987-03/1987)
• Lakshadweep, Bangaram INDIA (Record: 01/1987-03/1987)
• Lakshadweep, Kadamatt INDIA (Record: 01/1987-03/1987)
• Lakshadweep, Bitra INDIA (Record: 01/1987-03/1987)
• Lakshadweep, Chettalatt INDIA (Record: 01/1987-03/1987)
• Andaman and Nicobar Islands INDIA

Literature Source(s)
  • Tikadar, BK; Daniel, A and Subbarao, NV (1986) Sea shore animals of Andaman and Nicobar Islands The Director, ZSI, Kolkatta 188 Available at - ZSI, Pune
  • 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
  • UNEP World Conservation Monitoring Centre Available at -
  • Checklist of fish and invertebrates listed in the CITES appendices and in EC regulation no. 338/97 Available at -
  • Chantrapornsyl, S; Kittiwattanawong, K and Adulyanukosol, K (1996) Distribution and abundance of giant clam around Lee-Pae island, the Andaman sea, Thailand Phuket Marine Biological Center Special Publication 16 195-200 Available at - NCL, Pune
  • Saad, MAH (1984) Proceedings of the Symposium on Coral Reef environment of the Red Sea King Abdulaziz University, Saudi Arabia 1-681 Available at - NIO, RC Kochi
  • Allen, GR (2005) Reef fishes of northwestern Madagascar RAP Bulletin of Biological Assessment 31 39-48
  • Sealifebase Available at -
  • Fresh marine Available at -
  • Rosewater, J (1965) The family Tridacnidae in the Indo Pacific Indo-Pacific Mollusca Academy of Natural Sciences of Philadelphia, Pennsylvania 1(6) 347-408 Available at - NIO, Goa
  • Society for the Management of European Biodiversity Data (2009) World Register of Marine Species (WoRMS) Available at -
  • 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 -
  • Sundaram, KS; Sarvesan, R; Mohamed, KH and Shanbhogue, SL (1969) Catalogue of molluscs, prawns, stomatopods and marine algae in the reference collections of the central marine fisheries research institute Bulletin Of Central Marine Fisheries Research Institute CMFRI, Cochin 9 1-52 Available at -
  • Appukuttan, KK; Chellam, A; Ramadoss, K; Victor, ACC and Meiyappan, MM (1989) Molluscan resources Bulletin Of Central Marine Fisheries Research Institute CMFRI, Cochin 43 77-92 Available at -
  • Rao, GC (1991) Distribution of plants and animals on the rocky sea shores of Andaman and Nicobar Islands Journal of the Andaman Science Association Andaman Science Association, Port Blair 7(2) 30-42 Available at - NIO, Goa

Page last updated on:2011-08-30

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