A cockle is an edible, marine bivalve mollusk. Although many small edible bivalves are loosely called cockles, true cockles are species in the family Cardiidae. True cockles live on sandy, sheltered beaches throughout the world. The distinctive rounded shells are bilaterally symmetrical and are heart-shaped when viewed from the end. Numerous radial, evenly spaced ribs are a feature of the shell in most but not all genera (for an exception, see the genus Laevicardium, the egg cockles, which have very smooth shells).
The word "cockle" is also applied to some other edible bivalves which are not in the family Cardiidae. Those most frequently called cockles include species in the genus Donax, sometimes called "thumb shells", and in several marine clams of the family Canidae (previously known as Psammobiidae), some of which are also called "razor clams." Species in the genus Ensis also bear the common name "razor clam", but are in a different family, Enidae. The more general term "clam" is used technically to mean any member of the molluscan class Bivalvia that is not a squid, snail, or mussel.
The cockleshell is rounded and symmetrical with a deep, pronounced waist in the outer edge (visible when looking at the shell from the end). The shell of most cockles is smooth, but many have growth lines and there are prominent ridges across the surface of the shell in some genera such as Clinocardium and Acrosterigma. In others, such as Glycymeris the shell is sculpted with a rounded "keel" in relief at the midpoint of each valve, which gives a sloped appearance to its profile. Cockles have a large muscular foot and a pair of strong siphons which flow straight out from the mantle cavity.
The visible part of the soft body of a cockle is generally black or dark brown, and this distinguishes most cockles from the similar Venusshells, which may be very colorful. The shell is composed mostly of calcium carbonate, and is somewhat brittle; brittleness increases with water erosion.
Cockles are capable of 'jumping' by bending and straightening the foot. This action appears to reduce the risk of being dislodged by a passing fish or crab, an ability that is also shared by several other bivalve species including the venus shells. The jumping action has earned them the name "noodle clam" among Chinese cooks.
They are sensitive to the slightest changes in water salinity and temperature, and when these change beyond their limits they can no longer remain in equilibrium with that environment. If conditions become unfavorable in one area, however, adult cockles
Global cockle production
Cockles are a type of shellfish that are often found in coastal areas around the world. They are a popular seafood item and are harvested for both their meat and their shells. Cockle's global production is estimated to be around 9,000 metric tons annually. The vast majority of cockles are harvested in China, which accounts for over 80% of the world's total production. Other major producers include Vietnam, Indonesia, and the Philippines.
Cockles are typically harvested using hand-held rakes or dredges. The shellfish are then sorted by size and either sold fresh or processed for export. Cockle meat is often used in soups and stews, while shells are used for decoration or to make jewelry.
Cockles are a nutritious seafood item that is high in protein and low in fat. They also contain several essential minerals, including iron and calcium. Cockles are a good source of omega-3 fatty acids, which are beneficial for maintaining heart health.
While cockles are generally safe to eat, there is a risk of contamination from harmful bacteria. It is important to cook cockles thoroughly to reduce the risk of food poisoning. Cockles should also be avoided by people with allergies to shellfish.
The global production of cockles has remained relatively stable in recent years. However, there has been a slight decrease in production in China, due to overfishing and environmental degradation. It is important to sustainable manage cockle populations to ensure that they remain a valuable resource for future generations.