Description: This bivalve is up to 6 cm in length and is roundly triangular in shape. It has a robust, thick shell that has prominent radiating ribs and grooves. It is usually cream, light fawn or light brown in colour with distinctive white and brown markings in the form of zig-zags or blotches. The pallial sinus is more shallow than in Ruditapes decussatus, and there is usually deep purple marking in this area. Body tissue is orange.

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

Distribution: Introduced to various sites through aquaculture and now spreading around Britain and Ireland, especially in the south of Britain. Known from Strangford Lough in Northern Ireland.

Similar Species: Could be confused with the native Ruditapes decussatus but the pallial sinus in that species is deeper and there are subtle differences in the shape of the shell, and the tissue is white is R. decussatus and orange in R. philippinarum. May also be confused with Venerupis corrugata.

Key Identification Features:

• Robust, thick shell with white and brown markings.
• Relatively shallow pallial sinus.
• Orange body tissue.
• Often has deep purple markings around pallial sinus and outer edge of shell.

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

iNaturalist: Ruditapes philippinarum at iNaturalist World Species Observations database.

GBIF data for Ruditapes philippinarum

WoRMS: Ruditapes philippinarum at World Register of Marine Species. Accepted name: Ruditapes philippinarum (A. Adams & Reeve, 1850). AphiaID: 231750.

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