Habitat

Most freshwater habitats.

Key ID features

• Lobster-like appearance similar to the native white-clawed crayfish, but adult is much larger (up to 16cm). 

• It is red/brown with a small turquoise/white blotch on the ‘hinge’ of the claw. 

• The underside of the adult’s claws are bright red.

Distribution

Wide spread throughout England. More sparsely distributed in Wales.

Impacts

Huge impact on native crayfish as they spread disease, outcompete and predate. Undermines riverbanks through burrowing and eats native fish eggs and aquatic invertebrates.

Do’s & Don’ts

• DON’T break the law - Do not keep, transport, sell, release, exchange or use live signal crayfish, it’s illegal under the Invasive Alien Species (Enforcement & Permitting) Order 2019, unless you have a licence from NRW or a permit from the Animal and Plant Health Agency.

• DO dispatch any signal crayfish you catch at the place where they were caught. If you are not able to dispatch them, put them back where they were caught.

• DO be a responsible water user follow the Clean-Check-Dry guidance. Signal crayfish can carry ‘crayfish plague’, a fungus like disease that is lethal to the endangered native crayfish. This can be introduced on wet boots and other equipment.

• 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.