Invertebrates
Common Periwinkle
Littorina littorea · also called winkle
On a rocky shore at low tide, hundreds of common periwinkles sit sealed in their dark shells, waiting for the sea to return so they can graze again.
Overview
The common periwinkle, Littorina littorea, is a Not Evaluated sea snail of rocky shores and mudflats in the northeast Atlantic, introduced along the east coast of North America. Its toughness, its tight-sealing lid, and its place on the seaside menu make it one of the most familiar snails of the shore.
A snail built for the tide
By sealing its shell with a horny lid, the periwinkle keeps its body moist for the hours or days between tides, a trick that lets it live high on the shore.
Status
Not Evaluated globally, though widespread and abundant.
Common Periwinkle: common questions
How does a periwinkle survive out of water?
It seals its shell with a tough, horny lid called an operculum, which keeps moisture in until the tide returns.
What does the common periwinkle eat?
It grazes on algae, seaweed, and the films of microscopic plants that grow on rocks and mud.
Do people eat periwinkles?
Yes, they are boiled and picked from their shells with a pin, as a traditional seaside food known as winkles.
Where is the common periwinkle found?
It lives on rocky shores and mudflats of the northeast Atlantic, and has been introduced along the east coast of North America.