Description: This bivalve has a solid, broadly oval shell which can reach up to 10 cm in mature individuals. It is yellow to light brown in colour, occasionally with dark brown blotching. There are 20-22 radiating ribs on each valve, these are prominent and each has a line of spines down the centre, which are connected to each other by a low ridge. Spines can be long, thin and sharp but become broad and bend backwards towards the margin. Growth stages are clear in this species and there are a number of 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 anterior cardinal tooth is larger than the posterior.

Habitat: Sublittoral muddy sand, down to around 50 m.

Distribution: Scattered records from around Britain and Ireland.

Similar Species: Could be confused with other species of Acanthocardia, careful inspection of cardinal teeth should allow these to be distinguished.

Key Identification Features:

• Broadly oval shell with 20-22 radiating ribs.
• Each rib has a line of spines down their centre.
• Growth stages clear, concentric grooves visible on valves.
• On left hand valve, the anterior cardinal tooth is larger than the posterior.

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

iNaturalist: Acanthocardia aculeata at iNaturalist World Species Observations database.

GBIF data for Acanthocardia aculeata

WoRMS: Acanthocardia aculeata at World Register of Marine Species. Accepted name: Acanthocardia aculeata (Linnaeus, 1758). AphiaID: 138990.

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