Habitat

Tidal streams, rivers and estuaries. Adults migrate to estuaries and the sea to breed. 

Key ID features

• Pincers covered in a mat of fine hair, giving the appearance of mittens.

• Body is olive green-brown, up to 8 cm wide.

• Legs long and hairy. 

Distribution

Scattered across England and North Wales. Only one South Wales record to date (2020).

Impacts

They can travel large distances from the sea, including river systems and across dry land. This means that all waterbodies in Britain, including the Gwent Levels reen and ditch network, have the potential to be invaded. They damage banks/flood defences by burrowing into them, silt up gravel beds used for fish spawning and outcompete the native white-clawed crayfish.

Do’s & Don’ts

• DON’T buy from any outlets for aquariums and water gardens.  It is against the law to sell, exchange, use or keep live specimens.

• DON’T break the law. If you catch any mitten crabs they must be dispatched at the place where they were trapped/caught. If you are not able to dispatch them, put them back where they were caught. 

• DO report any sightings, with a photo, using the LERC Wales app.

More Information

For more information visit the GB Non-Native Species Secretariat website.