| Cockle | |
|---|---|
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| Live specimens ofCerastoderma edule fromFrance | |
Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Mollusca |
| Class: | Bivalvia |
| Order: | Cardiida |
| Superfamily: | Cardioidea |
| Family: | Cardiidae Lamarck, 1809 |
| Subfamilies | |
| Synonyms | |
Lymnocardiidae | |
Acockle is a marinebivalve mollusc. Although many small edible bivalves are loosely called cockles,true cockles are species in the familyCardiidae.[2]
True cockles live in sandy, sheltered beaches throughout the world. The distinctive rounded shells are bilaterally symmetrical, and areheart-shaped when viewed from the end. Numerous radial, evenly spaced ribs are a feature of the shell in most but not allgenera (for an exception, see the genusLaevicardium, the egg cockles, which have very smooth shells).
The shell of a cockle is able to close completely (i.e., there is no "gap" at any point around the edge). Though the shell of a cockle may superficially resemble that of ascallop because of the ribs, cockles can be distinguished from scallops morphologically in that cockle shells lack "auricles" (triangular ear-shaped protrusions near the hinge line) and scallop shells lack apallial sinus. Behaviorally, cockles live buried in sediment, whereas scallops either are free-living and will swim into the water column to avoid a predator, or in some cases live attached by abyssus to asubstrate.
Themantle has three apertures (inhalant, exhalant, and pedal) for siphoning water and for the foot to protrude. Cockles typically burrow using the foot, and feed by filteringplankton from the surrounding water. Cockles are capable of "jumping" by bending and straightening the foot. As is the case in many bivalves, cockles displaygonochorism (the sex of an individual varies according to conditions),[3] and some species reach maturity rapidly.
The common name "cockle" is also given by seafood sellers to a number of other small, edible marine bivalves which have a somewhat similar shape and sculpture, but are in other families such as theVeneridae (Venus clams) and theArcidae (ark clams). Cockles in the family Cardiidae are sometimes referred to as "true cockles" to distinguish them from these other species.
There are more than 205 living species of cockles, with many more fossil forms.[4]
Thecommon cockle (Cerastoderma edule) is widely distributed around the coastlines ofNorthern Europe, with a range extending west toIreland, theBarents Sea in the north,Norway in the east, and as far south asSenegal.
Thedog cockle,Glycymeris glycymeris, has a similar range and habitat to the common cockle, but is not at all closely related, being in the familyGlycymerididae. The dog cockle is edible, but due to its toughness when cooked it is generally not eaten, although a process is being developed to solve this problem.[5]
The blood cockle,Tegillarca granosa (not related to the true cockles, instead in the ark clam family,Arcidae), is extensively cultured from southernKorea toMalaysia.[6]
Living genera within the family Cardiidae include:
Cockles are a popular type of edibleshellfish in both Eastern and Westerncooking. They are collected by raking them from the sands at low tide, known as cockle-picking. Collecting cockles is hard work and can be dangerous if local tidal conditions are not carefully watched, as seen from theMorecambe Bay disaster, in which 23 cockle-pickers drowned after being caught in high tides.
Boiled cockles (sometimes grilled) are sold at manyhawker centres in Southeast Asia, and are used inlaksa,char kway teow andsteamboat. They are calledleas hal (លៀសហាល) inKhmer,kerang inMalay andsee hum inCantonese.
Cockles are astreet food in Cambodia, where they are usually steamed or boiled and served with a dipping sauce consisting of crushed peppercorns, salt andlime juice.[7]
In Japan, the Japanese egg cockle (Laevicardium laevigatum) is used to createtorigai sushi.
Cockles are sold freshly cooked as a snack in theUnited Kingdom, particularly in those parts of the British coastline where cockles are abundant. Boiled, then seasoned withmalt vinegar and whitepepper, they can be bought from seafood stalls, which also often have for salemussels,whelks,jellied eels,crabs andshrimp. Cockles are also available pickled in jars, and more recently, have been sold in sealed packets (with vinegar) containing a plastic two-pronged fork. A meal of cockles fried withbacon, served withlaverbread, is known as a traditionalWelsh breakfast.[8][9]
In England and Wales, as of 2011[update], people are permitted to collect 8 pounds of cockles for personal use. Those wishing to collect more than this are deemed to be engaging in commercial fishing and are required to obtain a permit from the Inshore Fisheries and Conservation Authority.[10]
A study conducted in England in the early 1980s showed a correlation between the consumption of cockles, presumed to be incorrectly processed, and an elevated local occurrence ofhepatitis.[11]
Cockles are an effective bait for a wide variety of sea fishes. The folk song "Molly Malone" is also known as "Cockles and Mussels" because the title character's sale of the two foods is referred to in the song's refrain. The shells of cockles are mentioned in the English nursery rhyme "Mary, Mary, Quite Contrary". Cockles are also eaten by the indigenous peoples of North America.[12]
The commonEnglish phrase "it warms the cockles of my heart" is used to mean that a feeling of deep-seated contentment has been generated.
Differing derivations of this phrase have been proposed, either directly from the perceived heart-shape of a cockleshell, or indirectly (thescientific name for the type genus of the family isCardium, from the Latin for heart), or from the Latin diminutive of the word heart, corculum. Another proposed derivation is from the Latin for the ventricles of the heart,cochleae cordis, where the second word is an inflected form ofcor, heart, whilecochlea is the Latin for snail.[citation needed]
Laverbread, not actually bread at all but seaweed, is rolled in oatmeal, fried into crisp patties and served with eggs, bacon and fresh cockles for a traditional Welsh breakfast.
Swansea breakfast recipe - a treat with the taste of the coast: There's nothing like the smell of cockles and laverbread sizzling away in a pan to bring the essence of the Welsh coast directly to you, wherever you might be.
Commercialmollusks | ||
|---|---|---|
| Marinegastropods |  | |
| Land and freshwater gastropods | ||
| Free-swimming marinebivalves | ||
| Infaunal bivalves | ||
| Sessile bivalves | ||
| Freshwater bivalves | ||
| Cephalopods | ||
| Techniques | ||
