Description: A thin, fragile bivalve that reaches up to 1.3 cm, but it usually smaller. The outline is broadly triangular. Outside the shell is white to grey but often covered by the glossy periostracum which can be yellow, green or brown. Growth stages are clear in this species and there are thin ribs and concentric lines on the outer shell surface. The inside of the shell is iridescent. There are 16-18 anterior teeth and 6-10 posterior teeth on the hinge line.

Habitat: Mud, sandy mud or muddy gravel from around 10 m to around 200 m.

Distribution: Found around most coasts of Britain and Ireland, but rare on south and west coasts of Ireland.

Similar Species: Unlikely to be confused with any other species.

Key Identification Features:

• Small broadly triangular bivalve.
• Inside shell is iridescent.
• Outside of shell often well covered by periostracum (green, yellow or brown).
• 16-18 posterior teeth, 6-10 posterior teeth on hinge line.

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

iNaturalist: Ennucula tenuis at iNaturalist World Species Observations database.

GBIF data for Ennucula tenuis

WoRMS: Ennucula tenuis at World Register of Marine Species. Accepted name: Ennucula tenuis (Montagu, 1808). AphiaID: 140584.

Classification: Biota; Animalia; Mollusca; Bivalvia; Protobranchia; Nuculida; Nuculoidea; Nuculidae; Ennucula