Description: This bivalve is solid, and the right valve is considerably larger and more convex than the left, which fits easily inside it, with the gap filled by the periostracum. The shape is swollen and broadly triangular and it reaches around 12-13 mm in length. The outside of the shell is white to cream with a dark grey to brown periostracum. Triangular pit in left valve into which fits a tooth-like projection in the right valve. On the hinge line of the right valve there are numerous small teeth which fit into indentations on the left valve. Inside of the shell is white with a blue or pink tinge, occasionally there are some yellow blotches. The pallial line is very faint.

Habitat: Silty sand or muddy gravel from low intertidal to around 150 m.

Distribution: Found all around Britain and Ireland.

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

Key Identification Features:

• Left valve fits easily inside right valve.
• Swollen, broadly triangular shape.
• Faint pallial line

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

iNaturalist: Varicorbula gibba at iNaturalist World Species Observations database.

GBIF data for Varicorbula gibba

WoRMS: Varicorbula gibba at World Register of Marine Species. Accepted name: Varicorbula gibba (Olivi, 1792). AphiaID: 378492.

Classification: Biota; Animalia; Mollusca; Bivalvia; Autobranchia; Heteroconchia; Euheterodonta; Imparidentia; Myida; Myoidea; Corbulidae; Varicorbula