Slipper limpet

When is a limpet not actually a limpet? When it’s an invasive snail

Author: Pat
2nd April 2015

This profile is a little different. The slipper limpet (Crepidula fornicata) is known as an invasive or non-native species.

This means this is a species that is not naturally found in a country but has turned up there through accidental introduction. Finding the new environment desirable they then spread, reproduce and potentially cause damage to native species or human health. Slipper limpets are not harmful to humans but they do modify the seabed environment, restricting the development of other species.

live in chains of up to 15 individuals

The introduction of the slipper limpet is believed to date between 1887 and 1890. Although of no commercial value in the UK, they tagged along with imported oysters, which are of commercial importance. Once introduced, they spread quickly around the south coast of the UK, Bristol Channel and a few places around southern Ireland. However, the colder waters further north have prevented the spread completely around the UK coastline.

Even though they are called a limpet they are actually a filter-feeding sea snail. They have a pale, kidney shape shell and are up to 5 cm in length. They won’t be found alone as they live in chains of up to 15 individuals, and can be found no deeper than 10 metres. The larger shelled individuals will be found at the bottom of the chain with shell size decreasing upwards. All slipper limpets start off their lives as males, and the largest shelled individual converts to female. When the female passes away or gets lost off the shack the first male will change his sex in a process known as protandrous hermaphroditism.


  • Invasive species in a few locations around the UK such as the south coast, East Anglia and south of Wales.
  • Found down to a depth of around 10 metres
  • Chains are commonly washed up on shore in storms or high tides

Key Identifying Features

  • Kidney-shaped shell
  • Curved chains with up to 15 animals, usually less
  • Pale cream in colour

Conservation Status

  • Not evaluated
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