Clam
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 Edible clams in the family Veneridae
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Clam is a word which can be used for all, some, or only a few species of bivalve mollusks; the word is a common name which has no real taxonomic significance in biology. It is however quite widely used as part of the common names of bivalves, and also has significance in fisheries and cuisine.
In the USA, the word "clam" can be used in several different ways: one, is as a general term covering all bivalve mollusks. The word can also be used in a more limited sense, to mean bivalves which burrow in sediment, as opposed to ones which attach themselves to the substrate (for example oysters and mussels), or ones which can swim and are migratory, like scallops. In addition the word "clam" can be used in an even more limited sense, to mean one or more species of commonly consumed marine bivalves, as in the phrase clam chowder, meaning a thick shellfish soup usually made using the hard clam. Many edible bivalves have a roughly oval shape, however, the edible razor clam has an elongated, parallel-sided shell, whose shape suggests that of an old-fashioned straight razor.
In the UK, the word clam is not as widely used: it forms part of the common names of various species of bivalve mollusk, but it is not used as a general term to cover edible clams that burrow, and it is not used as a general term for all bivalves.
The word "clam" can be applied to freshwater mussels, and other freshwater bivalves, as well as marine bivalves.[1]
Numerous edible marine bivalve species live buried in sand or mud, and respire by means of siphons which reach to the surface. In the USA, these clams are collected by "digging for clams" or clam digging. Again, in the USA, clam diggers is a term that can mean people who are searching for clams, or it can also mean one variety of three-quarter length pants or trousers.
In October 2007 an Arctica islandica clam, caught off the coast of Iceland, was discovered to be at least 405 years old, and was declared the world's oldest living animal by researchers from Bangor University, see Ming (clam).
In regard to the concept of edible clams, most species of bivalves are at least potentially edible, but some are too small to be useful, and not all species are considered palatable.
The word "clam" has given rise to the metaphor "clamming up", meaning refusing to speak, at least on a certain topic. A "clam shell" is the name given to a plastic container which is hinged, and which consists of two equal halves that lock together.
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A clam's shell consists of two (usually equal) valves, which are connected by a hinge joint and a ligament which can be external or internal.
In most clams, two adductor muscles contract to close the shells. The clam has no head, and usually has no eyes, (scallops are a notable exception), but a clam does have kidneys, a heart, a mouth, and an anus. For more information see bivalve and pseudofeces.
Clams, like most mollusks, also have open circulatory systems, which means that their organs are surrounded by watery blood that contains nutrients and oxygen.
Clams eat plankton by filter feeding, and they themselves are eaten by small sharks and squid.
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| mollusks |
| abalone |
| clams |
| cockles |
| escargot |
| geoduck |
| periwinkles |
| mussels |
| oysters |
| scallops |
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| cephalopods |
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| fishing industry |
| fisheries |
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| I N D E X |
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[edit] In North America
In culinary use, within the USA, the term "clam" most often refers to the hard clam Mercenaria mercenaria. It may also refer to several other common edible species, such as the soft-shell clam Mya arenaria, and the ocean quahog, Arctica islandica. Another species which is commercially exploited on the Atlantic Coast of the US is the surf clam Spisula solidissima.
Clams can be eaten raw, steamed, boiled, baked or fried; the method of preparation depends partly on the size and species. They can also be made into clam chowder (a popular soup in the U.S. and Canada) or they can be cooked using hot rocks and seaweed in a New England clam bake.
[edit] In Italy
In Italy, clams are often an ingredient of mixed seafood dishes, or are eaten together with pasta.
The Maxima clam Tridacna maxima, a species of giant clam, is a popular species with saltwater aquarium hobbyists.
The Moche people of ancient Peru worshiped the sea and its animals. They often depicted clams in their art.[2]
Edible:
- Grooved carpet shell: Ruditapes decussatus
- Hard clam or Northern Quahog: Mercenaria mercenaria
- Soft clam: Mya arenaria
- Atlantic surf clam: Spisula solidissima
- Ocean quahog: Arctica islandica
- Pacific razor clam: Siliqua patula
- Pismo clam: Tivela stultorum (8 inch shell on display at the Pismo Beach Chamber of Commerce)
- Geoduck clam: Panopea abrupta or Panope generosa (largest burrowing clam in the world)
- Atlantic jackknife clam: Ensis directus
Not usually considered edible:
- Ark clams, family Arcidae
- Nut clams or pointed nut clams, family Nuculidae
- Duck clams or trough shells, family Mactridae
- Marsh clams, family Corbiculidae
- File clams, family Limidae
- Giant clam: Tridacna gigas
- Asian or Asiatic clam: genus Corbicula
- Peppery furrow shell: Scrobicularia plana
- ^ "Merriam-Webster Dictionary".
- ^ Berrin, Katherine & Larco Museum. The Spirit of Ancient Peru:Treasures from the Museo Arqueológico Rafael Larco Herrera. New York: Thames and Hudson, 1997.
- Nutrition Facts for Clams
- Deep In The Ocean A Clam That Acts Like A Plant Science Daily March 2, 2007
- How to Shuck Hard Shell Clams
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