Description: This bivalve reaches up to 7.5 cm and has a strong, thick shell which is broadly oval to square in shape. There are a number of concentric grooves and light ridges intersected with radiating ridges on the outer side of the shell, becoming more pronounced posteriorly. It is cream to yellow in colour occasionally with some darker markings. The pallial sinus forms a deep wedge, and this helps distinguish from Ruditapes philippinarum. Body tissue of the animal is white.

Habitat: Lower shore and shallow sublittoral, in sand, muddy sand or clay.

Distribution: Recorded from most coasts of Britain and Ireland. Seems to be mostly absent from NE Scotland.

Similar Species: Could be confused with the non-native Ruditapes philippinarum, which has a more shallow pallial sinus and orange flesh, as well as some differences in overall shape of shell.

Key Identification Features:

• Thick, robust shell up to 7.5 cm.
• Deep wedge formed by pallial sinus.
• Body tissue white.

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

iNaturalist: Ruditapes decussatus at iNaturalist World Species Observations database.

GBIF data for Ruditapes decussatus

WoRMS: Ruditapes decussatus at World Register of Marine Species. Accepted name: Ruditapes decussatus (Linnaeus, 1758). AphiaID: 231749.

Classification: Biota; Animalia; Mollusca; Bivalvia; Autobranchia; Heteroconchia; Euheterodonta; Imparidentia; Venerida; Veneroidea; Veneridae; Tapetinae; Ruditapes