Description: A solid shell that reaches around 2.5 cm. It is broadly rounded in outline, but slightly pointed at one end. Colour can vary and can range from white or pale yellow to pink or purple, which is often arranged in concentric bands of stronger colour. Periostracum is brown and is usually visible at the shell margins. The surface of the shell is smooth aside from some very fine concentric lines. Inside of shell white or purple, or a shade matching the exterior colour. 2 cardinal teeth in each valve, no lateral teeth. Pallial sinus is deep, irregular in shape and fused in places with the pallial line.

Habitat: Thick mud, muddy sand or muddy gravel from the intertidal zone to the lower shore. Can tolerate lower salinities so sometimes found in estuaries.

Distribution: Recorded all around Britain and Ireland.

Similar Species: Could be confused with other tellins such as Arcopagia crassa or Serratina serrata.

Key Identification Features:

• Cardinal teeth only, no lateral teeth.
• Broadly circular outline, but slightly pointed at one end.

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

iNaturalist: Macoma balthica at iNaturalist World Species Observations database.

GBIF data for Macoma balthica

WoRMS: Macoma balthica at World Register of Marine Species. Accepted name: Macoma balthica (Linnaeus, 1758). AphiaID: 141579.

Classification: Biota; Animalia; Mollusca; Bivalvia; Autobranchia; Heteroconchia; Euheterodonta; Imparidentia; Cardiida; Tellinoidea; Tellinidae; Macominae; Macoma