Flat Periwinkle

Littorina obtusata


Found amongst the seaweeds on which it feeds, the Flat Periwinkle inhabits the lower parts of the shore. It is most commonly associated with Egg Wrack and Bladder Wrack seaweeds, and is often mistaken for the air floats of these species.

How to identify

The Flat Periwinkle has a flattened whorled shell, which is variable in colour but often bright yellow, orange or green. It is distinguished from similar, snail-like periwinkles and topshells by the flattened shape and shiny, smooth shell.

Where to find it

Found on rocky shores all around our coasts, but absent from most of Lincolnshire and East Anglia.


When to find it

  • January
  • February
  • March
  • April
  • May
  • June
  • July
  • August
  • September
  • October
  • November
  • December

How can people help

Molluscs provide a vital link in the food chain for many of our rarer species. Our seas and coastline are in need of protection if we are to keep our marine wildlife healthy. The Wildlife Trusts are working with fishermen, researchers, politicians and local people towards a vision of 'Living Seas', where marine wildlife thrives. This work has recently had a massive boost with the passing of the Marine Bill, promising sustainable development of the UK's marine environment. Do your bit for our Living Seas by supporting your local Wildlife Trust.

Species information

Common name
Flat Periwinkle
Latin name
Littorina obtusata
Aquatic gastropods (e.g. sea snails)
Diameter: 1cm Lifespan: 3 years
Conservation status