White-clawed crayfish

The White-clawed crayfish is a freshwater, bronze-coloured crustacean with pale undersides to its claws - hence the name. It is under threat from an invasive and introduced species of crayfish.

Species information

Statistics

Length: 6-12cm
Weight: up to 90g
Average Lifespan: 8-12 years

Conservation status

Protected in the UK under the Wildlife and Countryside Act, 1981. Listed as Endangered on the global IUCN Red List of Threatened Species.

When to see

January to December

About

As the UK's only native freshwater crayfish, the White-clawed crayfish is in decline due to the introduction of the non-native North American signal crayfish. This invasive species has brought disease to which our indigenous crayfish has no natural resistance. An omnivorous crustacean, the White-clawed crayfish eats invertebrates, carrion, water plants and dead organic matter. It inhabits small freshwater streams of a depth less than 1 metre, hiding underneath stones and rocks and in small crevices where they forage for food.

How to identify

The White-clawed crayfish is small and bronze-coloured, with pale cream or rose undersides on its claws.

In our area

As well as competition from American Crayfish, White-clawed Crayfish are also under threat from river pollution and reduction in habitat quality. In Shropshire, populations have declined dramatically, the River Corve in South Shropshire did once have strong numbers of Crayfish, but we are unsure how many can now be found here.

Shropshire Wildlife Trust is working alongside partners to deliver a project which aims to survey waterways for the species, improve habitats and try and maintain populations. We are also aware that there is very low knowledge of Crayfish in Shropshire and would like to involve the community in survey work along stretches of their local river, helping us to raise awareness of the importance of keeping waterways clean for wildlife and securing the presence of Crayfish in our rivers.

Without action for conservation, White-clawed Crayfish will continue to be lost from sites and whole rivers.

Distribution

Widespread in England and Wales, but rare.

Habitats

Did you know?

The White-clawed Crayfish needs mineral-rich water to fortify its exoskeleton, the same way we need calcium to enrich our bones.

How people can help

The Wildlife Trusts work with planners, water companies, landowners, statutory bodies and anglers to help make our waterways and waterbodies as good for wildlife as they are for people. By working together, we can create Living Landscapes: networks of habitats stretching across town and country that allow wildlife to move about freely and people to enjoy the benefits of nature. Support this greener vision for the future by joining your local Wildlife Trust.