Clam is acommon name for several species ofbivalvemollusc. The word is often applied only to those that are deemededible and live asinfauna, spending most of theirlives halfway buried in thesand of thesea floor orriverbeds. Clams have two shells of equal size connected by two adductor muscles and have a powerful burrowing foot.[1] They live in both freshwater and marine environments; insalt water they prefer to burrow down into the mud and theturbidity of the water required varies withspecies and location; the greatest diversity of these is inNorth America.[2]
Clams in the culinary sense do not live attached to a substrate (whereasoysters andmussels do) and do not live near the bottom (whereasscallops do). In culinary usage, clams are commonly eaten marine bivalves, as inclam digging and the resulting soup,clam chowder. Many edible clams such aspalourde clams are ovoid or triangular;[3] however,razor clams have an elongated parallel-sided shell, suggesting an old-fashioned straight razor.[4]
Some clams have life cycles of only one year, whilst at leastone reached an age of more than 500 years.[5] All clams have two calcareous shells orvalves joined near a hinge with a flexible ligament and all arefilter feeders.
A clam's shell consists of two (usually equal) valves, which are connected by a hinge joint and a ligament that can be internal or external.[6] The ligament provides tension to bring the valves apart, whilst one or two adductor muscles can contract to close the valves. Clams also have kidneys, a heart, a mouth, a stomach, and a nervous system. Many have asiphon.[1]
Clams are shellfish that make up an important part of the web of life that keeps the seas functioning, both as filter feeders and as a food source for many different animals.[7] Extant mammals that eat clams include both the Pacific and Atlantic species ofwalrus, all known subspecies ofharbour seals in both the Atlantic and Pacific, most species ofsea lions, including theCalifornia sea lion,bearded seals and even species of river otters that will consume the freshwater species found in Asia and North America.[8] Birds of all kinds will also eat clams if they can catch them in thelittoral zone:roseate spoonbills of North and South America,[9] theEurasian oystercatcher,whooping crane[10] andcommon crane, theAmerican flamingo of Florida and the Caribbean Sea,[11] and thecommon sandpiper are just a handful of the numerous birds that feast on clams all over the world. Most species ofoctopus have clams as a staple of their diet, up to and including the giants like theGiant Pacific octopus.
In culinary use, within the eastern coast of the United States and large swathes ofthe Maritimes of Canada, the term "clam" most often refers to thehard clam,Mercenaria mercenaria. It may also refer to a few other common edible species, such as thesoft-shell clam,Mya arenaria, and the ocean quahog,Arctica islandica. Another species commercially exploited on theAtlantic Coast of the United States is the surf clam,Spisula solidissima.Scallops are also used for food nationwide, but notcockles: they are more difficult to get than in Europe because of their habit of being further out in the tide than European species on the West Coast, and on the East Coast they are often found in salt marshes and mudflats where mosquitoes are abundant.[12] There are several edible species in the Eastern United States:Americardia media, also known as the strawberry cockle, is found from Cape Hatteras down into the Caribbean Sea and all of Florida;Trachycardium muricatum has a similar range to the strawberry cockle; andDinocardium robustum, which grows to be many times the size of the European cockle.[13] Historically, they were caught on a small scale on theOuter Banks, barrier islands off North Carolina, and put in soups, steamed or pickled.[14]
Up and down the coast of the Eastern U.S., thebamboo clam,Ensis directus, is prized by Americans for makingclam strips, although because of its nature of burrowing into the sand very close to the beach, it cannot be harvested by mechanical means without damaging the beaches.[15] The bamboo clam is also notorious for having a very sharp edge of its shell, and when harvested by hand must be handled with great care.
InKerala, clams are used to make curries and fried with coconut. In theMalabar region it is known as "elambakka" and in middle kerala it is known as "kakka". Clam curry made with coconut is a dish from Malabar especially in theThalassery region. On the southwestern coast ofIndia, also known as theKonkan region ofMaharashtra, clams are used in curries and side dishes, like Tisaryachi Ekshipi, which is clams with one shell on.Beary Muslim households in theMangalore region prepare a main dish with clams called Kowldo Pinde. InUdupi andMangalore regions, it is calledmarvai in the localTulu language. It is used to prepare many dishes likemarvai sukka,marvai gassi, andmarvai pundi.[citation needed]
The rocky terrain and pebbly shores of the seacoast that surroundsGreat Britain provide ample habitat for shellfish including clams. Historically, British cuisine has been more heavily based on beef and dairy products than seafood, although there is evidence going back to before most recorded history of coastal shell middens near Weymouth and present day York.[24] 70% of the seafood cultivated for aquaculture or commercial harvesting is exported to the continent,[25] though present-day younger populations are eating more of the catch than a generation ago.[citation needed]
Staple favourites of the British public and local scavengers include the razorfish,Ensis siliqua, a slightly smaller cousin of thebamboo clam of eastern North America.[26] These can be found for sale in open-air markets like Billingsgate Market in London; they have a similar taste to their North American cousin.[27] Cockles, specifically thecommon cockle, are a staple find on beaches in western Wales and further north in theDee Estuary. The accidentally introduced hard-shell quahog is also found in British waters, mainly those near England, and does see some use in British cuisine. ThePalourde clam by far is the most common native clam and it is both commercially harvested as well as locally collected, andSpisula solida, a relative of the Atlantic surf clam on the other side of the Atlantic, is seeing increased interest as a food source and aquaculture candidate; it is mainly found in the British Isles in Europe.[28]
In Islam, clams are consideredhalal in three Sunnisects, but not in Hanafi, as onlyfish are considered halal inHanafi jurisprudence, not other aquatic animals. In Judaism, clams are notkosher.
^"Clams".Fishing & Shellfishing. Washington Department of Fish & Wildlife. Archived fromthe original on 16 March 2018. Retrieved8 November 2021. -"Cockle".SeafoodSource. Diversified Communications. 23 January 2014.