Flat periwinkles
(2 specie in Swedish waters)

Distribution in scandinavian waters

Maximum length: 1,8 cm.
Appearance: The shell can vary greatly in colour, shape and pattern, but the spire is very flat and usually has a yellow, olive-green or brown colour. The soft parts are uncoloured to black. Coloured bands on the tentacles are rare.
Depth: 0-5 m.
Environment: One of the specie creeps and feeds mainly on knotted wrack. The other specie is found mainly on bladder and toothed wrack, but primarily eats microalgae that grows on the surface of the seaweed. Empty flat periwinkle shells are often found on the beaches.
Misc: In its most northern areas of distribution, certain individuals of one specie have long spires and bear a certain resemblence to the rough periwinkle.
Classification: The flat periwinkle belongs to the periwinkle group (mesogastropoda) under the molluscs.

Flat periwinkle     More facts     Other names

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Bo Johannesson | Martin Larsvik | Lars-Ove Loo | Helena Samuelsson