Tridacna gigas

Tridacna gigas
    n 1: a large clam inhabiting reefs in the southern Pacific and
         weighing up to 500 pounds [syn: {giant clam}, {Tridacna
         gigas}]
    

Tridacna \Tri*dac"na\, n. [L., pl., a kind of oysters, fr. Gr. ?
   eaten at three bites, ? tri- + ? to bite.] (Zool.)
   A genus of very large marine bivalve shells found on the
   coral reefs of the Indian and Pacific Oceans. One species
   ({Tridacna gigas}) often weighs four or five hundred pounds,
   and is sometimes used for baptismal fonts. Called also {paw
   shell}, and {fountain shell}.
   [1913 Webster] Tridactyl
    

Clam \Clam\ (kl[a^]m), n. [Cf. {Clamp}, {Clam}, v. t.,
   {Clammy}.]
   1. (Zool.) A bivalve mollusk of many kinds, especially those
      that are edible; as, the long clam ({Mya arenaria}), the
      quahog or round clam ({Venus mercenaria}), the sea clam or
      hen clam ({Spisula solidissima}), and other species of the
      United States. The name is said to have been given
      originally to the {Tridacna gigas}, a huge East Indian
      bivalve.
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            You shall scarce find any bay or shallow shore, or
            cove of sand, where you may not take many clampes,
            or lobsters, or both, at your pleasure. --Capt. John
                                                  Smith (1616).
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            Clams, or clamps, is a shellfish not much unlike a
            cockle; it lieth under the sand.      --Wood (1634).
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   2. (Ship Carp.) Strong pinchers or forceps.
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   3. pl. (Mech.) A kind of vise, usually of wood.
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   {Blood clam}. See under {Blood}.
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