giant clam


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giant clam,

common name for the largest bivalve mollusk in the world, Tridacna gigas, also known as the bear's paw clam. The giant clam may weigh over 500 lb (225 kg) and attain a length of over 4 ft (120 cm). The heavy shell is coarsely fluted and toothed. Giant clams are found in the South Pacific and Indian oceans, especially in the Great Barrier Reef. They lie with the hinge downward in the coral reefs, usually in shallow water. The adductor muscles, which cause the shell to close, are a source of food for people of the South Pacific. The shell closes very slowly; stories of human beings trapped within giant clams have never been substantiated. Small giant clam shells have been used as birdbaths and baptismal fonts. An interesting symbiosis occurs between a unicellular green alga (Zooanthella) and the clam. The algae live in the tissues of the clam's siphon and mantle; they are able to obtain the sunlight needed for photosynthesis because the clam lies with its valves opening upward and part of the thick, purple mantle extruding over the shell. In addition, there are crystalloid vesicles on the mantle surface that let in sunlight, thus allowing the algae to live deep within the tissues. The clam uses the algae as a supplementary or perhaps even a major source of food. Tridacna gigas is classified in the phylum MolluscaMollusca
, taxonomic name for the one of the largest phyla of invertebrate animals (Arthropoda is the largest) comprising more than 50,000 living mollusk species and about 35,000 fossil species dating back to the Cambrian period.
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, class Pelecypoda or Bivalvia, order Eulamellibranchia, family Tridacnidae.
References in periodicals archive ?
Once matured, the native giant clams will be deployed to MFI's marine protected areas in the north of Palawan.
We thank Shigeaki Sone for spawning clam larvae obtained from BMR and for invaluable advice on giant clam aquaculture.
On the validity of Noah's giant clam Tridacna noae (Roding, 1798) and its synonymy with Ningaloo giant clam Tridacna ningaloo Penny & Willan, 2014.
The current title holder for the largest natural giant clam pearl is the 14-pound Pearl of Lao Tzu, which was discovered in Palawan waters.
The southern giant clams, which can grow up to 60cm in length, were part of a large consignment intercepted and confiscated after being illegally imported into the country.
The southern giant clams, which can grow up to 60cm in length, were part of a large consignment which was intercepted and confiscated after they were illegally imported in to the country.
The Thai government released 299 giant clams into the Andaman Sea on Feb.
After returning from the USA, I was approached by Dr Ken Menz, who was now with ACIAR, about the possibility of my doing more research on the "Economics of giant clam mariculture".
"The Palauans have giant clam breeding down to a fine art," says biologist Chuck Cook, director of The Nature Conservancy's Micronesian programs.
Serchuk; hydraulic dredging of clam resources in the Adriatic Sea; Mutsu Bay scallop culture, stock enhancement, and resource management; giant clam fisheries and stock enhancement; management of the Saharan trawl fishery for cephalopods; population assessment, management, and fishery forecasting for Todarodes pacificus; Pacific and Mediterranean precious coral fisheries, and world echinoderm fisheries.
He is particularly proud of their giant clam adoption program, a sanctuary for the endangered Taklobo (scientific name: Tridacna Gigas) species, said to be the largest living bivalve mollusk on earth.