Description: This bivalve has a solid, broadly oval shell which can reach up to 8 cm in mature individuals. It can be white, light yellow or light brown in colour. There are 18-22 radiating ribs on each valve, these are prominent and each has a line of sharp spines down the centre, which are connected to each other by a low ridge, although this can be worn and therefore difficult to make out. Growth stages are clear in this species and there are a number of concentric grooves visible, although these may be irregular, especially on ribs. 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 a similar size.

Habitat: Fine sand, muddy sand, gravel or mud in a range of depths from 3 m onwards.

Distribution: Widespread 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 18-22 radiating ribs. Each rib has a line of sharp spines down their centre. Growth stages visible. Concentric grooves may be visible but irregular, especially over ribs. On left hand valve the cardinal teeth are of similar size.

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

iNaturalist: Acanthocardia echinata at iNaturalist World Species Observations database.

GBIF data for Acanthocardia echinata

WoRMS: Acanthocardia echinata at World Register of Marine Species. Accepted name: Acanthocardia echinata (Linnaeus, 1758). AphiaID: 138992.

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