Description: This bivalve has a solid, broadly oval shell which can reach up to 9 cm in mature individuals. It is brown or red-brown in colour, occasionally with some irregular dark brown bands. There are 21-22 radiating ribs on each valve, these are prominent and each has a row of broad, blunt spines towards the edge of the shell and sharper spines towards the top of the shell. These are not connected by a ridge. Growth stages are clear in this species and there are a number of (mostly irregular) concentric grooves visible. The margins of the shell are deeply scalloped and have prominent grooves which extend to the inside of the shell. In the left hand valve, the cardinal teeth are similar in size.

Habitat: Muddy sand and gravel.

Distribution: Scattered records from around Britain and Ireland.

Similar Species: Could be confused with other species of Acanthocardia, however in this species the spines on the shell are not joined by ridges.

Key Identification Features:

• Broadly oval shell with 21-22 radiating ribs.
• Each rib has a line of spines down their centre.
• Spines are blunt towards the outer edge of the shell and sharper towards the top.
• Spines are not connected by ridges.
• Growth stages clear, irregular, concentric grooves visible on valves.

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

iNaturalist: Acanthocardia tuberculata at iNaturalist World Species Observations database.

GBIF data for Acanthocardia tuberculata

WoRMS: Acanthocardia tuberculata at World Register of Marine Species. Accepted name: Acanthocardia tuberculata (Linnaeus, 1758). AphiaID: 381057.

Classification: Biota; Animalia; Mollusca; Bivalvia; Autobranchia; Heteroconchia; Euheterodonta; Imparidentia; Cardiida; Cardioidea; Cardiidae; Lymnocardiinae; Acanthocardiini; Acanthocardia