Cockle (bivalve)

Cockle (bivalve)

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.