Slipper Limpet ©Paul Naylor

Slipper limpet

These non-native limpets arrived from America in the 19th century and are now widespread in the UK. They form stacks and have a specially adapted shell which, when flipped upside down, looks like a slipper!

Scientific name

Crepidula fornicata

When to see

January to December

Species information

Statistics

Length: 5cm

Conservation status

Common, but a non-native species.

Habitats

About

The slipper limpet normally lives in stacks of up to 12 individuals, with the largest at the bottom and increasingly smaller animals on each other's backs. They live on the seabed out beyond the low tide mark, but empty shells can often be found washed up on beaches. Accidentally introduced from North America in a shipment of oysters, it is now a serious pest of oyster and mussel beds.

How to identify

Unmistakeable, slipper-shaped, oval shell. Normally pale creamy in colour with blotches of orangey-red.

Distribution

Found around the coasts Southern England and Wales as far north as Anglesey on the west coast and Spurn Point on the east coast.

Did you know?

At the base of the stack, the largest and oldest slipper limpets are female, with the younger and smaller males on top. However, if the females die, the largest male will turn into a female.

How people can help

It is important to monitor the spread of non-native species around UK shores. Slipper limpets are currently well established around southern England and Wales and have been recorded as far north as Anglesey on the West Coast and Spurn Point in on the East. Patchy records exist for Scotland and Northern Irish Sea. Report any slipper limpet sightings (e.g. whilst diving or shells found on the shore) to your local Wildlife Trust.