Cockle is the common name for a group of (mostly) small, edible, saltwater clams, marine bivalve molluscs in the family Cardiidae.
Various species of cockles live in sandy, sheltered beaches throughout the world.
The distinctive rounded shells of cockles are symmetrical, and are heart-shaped when viewed from the end. Numerous radial ribs occur in most but not all genera. For an exception, see the genus Laevicardium, the egg cockles, which have very smooth shells.
The mantle 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 filtering plankton from the surrounding water.
Cockles are capable of "jumping" by bending and straightening the foot.
Like many bivalves, cockles display gonochorism (the sex of an individual varies according to conditions), and some species reach maturity quickly. Confusingly, the common name "cockle" is also given (by seafood sellers) to a number of other small, edible bivalves which have a somewhat similar shape, but these bivalves are in other families such as the Veneridae (Venus clams) and the Arcidae (ark clams). Cockles in the family Cardiidae are sometimes known as "true cockles" to distinguish them from these other species.
In Cuisine and Culture
Cockles are a popular type of edible shellfish in both Eastern and Western cooking. They are collected by raking them from the sands at low tide. However, collecting cockles is hard work and, as seen from the Morecambe Bay disaster, in which 23 illegal immigrants died, can be dangerous if local tidal conditions are not carefully watched. In England and Wales, the Magna Carta grants every citizen the right to collect up to eight pounds of cockles from the foreshore. However, pickers wishing to collect more than eight pounds are deemed to be engaging in commercial fishing and are required to obtain a permit from the Inshore Fisheries and Conservation Authority.
Cockles are sold freshly cooked as a snack in the United Kingdom, particularly in those parts of the British coastline where cockles are abundant. Boiled, then seasoned with malt vinegar and white pepper, they can be bought from seafood stalls, which also often have for sale mussels, whelks, jellied eels, crabs and shrimps. 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 with bacon, served with laver bread, is known as a traditional Welsh breakfast.
Boiled cockles (sometimes grilled) are sold at many hawker centers in Southeast Asia, and are used in laksa, char kway teow and steamboat. They are called kerang in Malay and see hum in Hokkien.
