Description: This well known bivalve is solid and thick, with a broadly oval outline which reaches up to 5 cm, although much more commonly up to 2.5 cm. Colour can range from off-white to yellow or even brown and the outer surface of the shell may be covered in the yellow-greenish periostracum. Each valve as 22-28 radiating ribs, each of which has scale-like spines and some very fine concentric lines. These ridges are partially visible on the inside of the shell. Growth stages are clearly visible. Right valve has two anterior and two posterior lateral teeth. The inside of the shell is white, with some brown to purple staining at the posterior adductor scar.

Habitat: Sand, muddy sand, mud or muddy gravel from mid intertidal zone just just below the low water mark. Also found in estuaries.

Distribution: Widespread all around Britain and Ireland.

Similar Species: Could be confused with some other cockles, especially Cerastoderma glaucum although it is found in saline lagoons, and less commonly in estuaries. Careful inspection of lateral teeth and the number of ribs should help distinguish from other species of cockle.

Key Identification Features:

• Well-known bivalve with 22-28 radiating ribs.
• Growth stages clearly visible.
• Right valve has 2 posterior and 2 anterior lateral teeth.
• Brown staining on inside of shell at posterior adductor scar.

Distribution Map from NBN: Cerastoderma edule at National Biodiversity Network mapping facility, data for UK.

iNaturalist: Cerastoderma edule at iNaturalist World Species Observations database.

GBIF data for Cerastoderma edule

WoRMS: Cerastoderma edule at World Register of Marine Species. Accepted name: Cerastoderma edule (Linnaeus, 1758). AphiaID: 138998.

Classification: Biota; Animalia; Mollusca; Bivalvia; Autobranchia; Heteroconchia; Euheterodonta; Imparidentia; Cardiida; Cardioidea; Cardiidae; Lymnocardiinae; Cerastodermatini; Cerastoderma