Common Cockle

• GeneralIt buries itself a few centimetres down in the sand and filters the water through two short siphons.
• Its muscular, sickle-shaped foot lets it leap across the sediment to escape starfish and crabs.
• Cockle beds are the main food of thousands of wintering waders, which depend on them during migration.
• The rings on the shell mark the winters and make it possible to tell the animal's age.
• It lives very close to the surface, with short siphons, and that is why it can leap: it folds its muscular foot and pushes off to escape a predator or reposition itself.
• How deep it buries depends on fear: in the presence of the green crab it buries less, because it changes its vertical orientation and performs a water-expulsion response.
• Its growth bands tell its story: the annual winter ones allow its age to be dated, and the internal ones are laid down to the rhythm of the semidiurnal tides.
• It is essential prey for waders and crabs. On one Welsh beach green crabs were estimated to consume 236,000 cockles a year for every linear metre of shore.
• It suffers normal winter mortality of between 30 and 90%, depending on size.
• The Burry Inlet fishery in Wales is certified as sustainable by the Marine Stewardship Council.

Habitat and environment

Intertidal sand and mud of rias and estuaries

Sexual maturity

1 year

Sources consulted: https://es.wikipedia.org/wiki/Cerastoderma_edule