Description: This periwinkle is up to 1 cm in height and colour can vary, ranging from yellow, red or brown to olive green and sometimes has a banded pattern. The spire is of the shell is flattened, and there is a large opening. The body whorl is slightly larger than the shell opening.

Habitat: Usually found on seaweeds, especially bladder wrack and egg wrack. Usually from mid to lower shore.

Distribution: Found on all coasts of Britain and Ireland.

Similar Species: Could be confused with Littorina fabalis, however in L. fabalis the shell opening is larger than the body whorl, and the spire is flatter. L. fabalis also usually found on Fucus serratus.

Key Identification Features:

• Shell opening slighly smaller than body whorl.
• Usually found on bladderwrack and egg wrack.

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

iNaturalist: Littorina obtusata at iNaturalist World Species Observations database.

GBIF data for Littorina obtusata

WoRMS: Littorina obtusata at World Register of Marine Species. Accepted name: Littorina obtusata (Linnaeus, 1758). AphiaID: 140263.

Classification: Biota; Animalia; Mollusca; Gastropoda; Caenogastropoda; Littorinimorpha; Littorinoidea; Littorinidae; Littorininae; Littorina