Description: This species can have two forms depending on habitat, in lagoons it is finer with a thin shell, whereas in estuaries it is more solid with a thicker shell. Each valve as 20-24 radiating ribs which are also visible from the inside of the shell.

Habitat: Saline lagoons or occasionally in estuaries.

Distribution: Scattered records from around Britain and Ireland, where there is suitable habitat.

Similar Species: Could be confused with other cockles, especially Cerastoderma edule. C. edule is symmetrical if a line is drawn from the umbo, whilst C. glaucum appears more stretched out on one side.

Key Identification Features:

• Thin or solid form depending on location.
• Asymmetric shell which appears more stretched out on one side.
• 20-24 radiating ribs.
• Ribs are very visible from inside of shell.
• Found in saline lagoons.

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

iNaturalist: Cerastoderma glaucum at iNaturalist World Species Observations database.

WoRMS: Cerastoderma glaucum at World Register of Marine Species.