Bivalves · Cardiida · Cardiidae

Common Cockle

Cerastoderma edule

Not Evaluated

It has not yet been assessed against the IUCN criteria. See full glossary

The common cockle — known in Spanish as berberecho común or verdigón — is a bivalve mollusc of the family Cardiidae. No subspecies are recognised.

Size

2 cm – 5 cm

Lifespan

4 years

Diet

Omnivore

Combines animal and plant food depending on availability.

Social structure

Colony

Lives in large concentrations, often for breeding reasons.

Sighting difficulty

Unknown

Fun facts

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 mortalities of between 30 and 90 %, depending on size.
The Burry Inlet fishery in Wales is certified as sustainable by the Marine Stewardship Council.