Austropotamobius pallipes
The White-clawed crayfish is the UK’s only native crayfish species—and one of the River Eden’s more elusive residents.
These shy crustaceans spend their days tucked away beneath rocks or tree roots, emerging at night to forage.
Lives for 8-12 years,
At 12cm it’s the largest invertebrate in the UK,
Typical weight of about 0.09kg.
They can shed a limb to escape or distract predators. This ability is called automoty.
However, unlike humans and other mammals, a crayfish can regrow its missing limb!
The Eden catchment is one of the last strongholds for White-clawed crayfish in England.
White-clawed crayfish are omnivores, feeding on a mix of aquatic plants, decaying matter, insect larvae, small fish, and other invertebrates. From above, they appear brown or olive, but their pale pinkish-white underside gives them their name.
Like crabs and lobsters, they are crustaceans and rely on mineral-rich water to build and maintain their protective outer shell, or exoskeleton. As they grow, they must shed this shell—a process called moulting. During this time, before their new shell hardens, they are especially vulnerable to predators like otters, herons, and large fish.
Female crayfish carry their eggs for up to nine months. Once hatched, the tiny young cling to their mother’s back for several weeks, gaining protection and strength before venturing out on their own.
The Eden catchment is one of the last strongholds for White-clawed crayfish in England—but their survival is under serious threat from:
Protecting the White-clawed crayfish starts with simple actions:
Avoid pouring chemicals or oils down the sink
Only flush the 3 Ps – pee, poo, and (toilet) paper
Respect their habitat – They are a protected species, so never disturb or relocate them without the proper licence.
Every summer, we run crayfish monitoring sessions with volunteers to track the health of the population in the Eden. If you’d like to get involved, keep an eye on our website for training opportunities in spring and summer.
