cockle

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cockle,

common name applied to the heart-shaped, jumping or leaping marine bivalvebivalve,
aquatic mollusk of the class Pelecypoda ("hatchet-foot") or Bivalvia, with a laterally compressed body and a shell consisting of two valves, or movable pieces, hinged by an elastic ligament.
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 mollusks, belonging to the order Eulamellibranchia. The brittle shells are of uniform size, are obliquely spherical, and possess distinct radiating ridges, or ribs, which aid the animal in gripping the sand. The mantle has three distinct apertures (inhalant, exhalant, and pedal) through which the inhalant and exhalant siphons and the foot protrude. The cockle lives in sand and mud in shallow water, often in brackish inlets. It burrows until only the siphons project, pulling in water from which the animal strains the minute planktonic organisms on which it feeds. All cockles are hermaphroditic. In order to accomplish the characteristic jumping form of forward locomotion, the large, powerful, muscular foot is bent backward beneath the shell and then straightened. In most adults, the foot is about as long as the greatest length of the shell.

Several species of cockles are considered to be good, edible clams. In the British Isles, great numbers of cockles are taken annually for food from densely populated beds. These beds have been known to migrate in units, probably in response to changes in currents. Protothaca staminea, the rock cockle, is among the best known and most widely used for food. It usually does not exceed 3 in. (7.5 cm) in length. Rock cockles are poor diggers and inhabit packed mud, or gravel mixed with sand, usually 8 in. (20 cm) below the surface. They are found on the Pacific Coast near the rocky shores of bays and estuaries. Those inhabiting the open coast during the summer months should not be eaten because they may be infected with toxin-producing organisms. P. semidecussata, the Japanese littleneck clam, is smaller but considered to be better-flavored than the rock cockle. The shell is more elongated, with a brownish to bluish banding on one end. It inhabits an environment similar to that of P. staminea and is widespread in Puget Sound, Wash.; British Columbia; and San Francisco and Tomales Bay, Calif.

Unlike the genus Protothaca, the basket cockles (Clinocardium nuttalli, or Cardium corbis) are good diggers and have a large foot. Lacking siphon tubes, basket cockles burrow only slightly beneath the surface and inhabit sand flats, particularly along the Pacific Coast. They are considered good eating clams but are too few in number to be widely marketed. They are most abundant in British Columbia and in Puget Sound, Wash., with fewer found south as far as Baja California and north as far as the Bering Sea.

The hard shell cockles, genus Chione, are found from San Pedro, Calif., S into Mexico. The giant Atlantic cockle, Dinocardium robustum (Cardium magnum), reaches 5 in. (12.5 cm) in diameter and is found along the Atlantic Coast from Virginia to Brazil. It has shells with toothed margins, strikingly colored in yellowish brown with spots and transverse stripes of chestnut or purple. Cockles are 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.

cockle

[′käk·əl]
(invertebrate zoology)
The common name for a number of species of marine mollusks in the class Bivalvia characterized by a shell having convex radial ribs.

cockle

2
1. any sand-burrowing bivalve mollusc of the family Cardiidae, esp Cardium edule (edible cockle) of Europe, typically having a rounded shell with radiating ribs
2. any of certain similar or related molluscs
3. short for cockleshell
4. a small furnace or stove

cockle

2
any of several plants, esp the corn cockle, that grow as weeds in cornfields
References in periodicals archive ?
Five of the two-man canoes cast off for the coast on a mission that would earn them the nickname the Cockleshell Heroes - the forerunners of today's Special Boat Service.
The men were immortalised in the 1955 film the Cockleshell Heroes.
Buy crushed cockleshells in natural shades or coloured wpink, purple and ocean shades of blue and green from www.
GUERNSEY: The cockleshell motifs are interesting and seem to play into that regenerative idea as well.
Sergeant Ewart was one of the famous Cockleshell Heroes, whose mission was so daring that it was made into a 1955 film starring Anthony Newley and Christopher Lee.
To entice the birds, the islands have been covered in cockleshells which cost only pounds 500 and have attracted more than 100 new birds.
Path surfaces are laid with what is easily acquired locally: bricks in clay areas, flints in chalky regions, quarry waste in the mountains and shingle or cockleshells on the coast.
Lieutenant Colonel Steve Richards, responsible for Royal Marines recruiting, said: "This commemorative event is widely supported by the serving corps of Royal Marines, as the courage of the Cockleshell Heroes in 1942 demonstrates all the commando qualities we still strive for today.