Crayfish
There are two types of crayfish in Britain’s rivers, the native White-Clawed Crayfish (Austropotamobius pallipes) and the American Signal Crayfish (Pacifastacus leniusculus), an invasive non-native species. There are no natural populations of native White-Clawed Crayfish in West Cumbria’s rivers as our waters do not contain the right levels of natural minerals for them.
American red Signal Crayfish are much larger than our native crayfish, with red undersides to their claws, whilst white clawed have much paler claws. Signal Crayfish are having a dramatic impact on our biodiversity, eating fish eggs and burrowing into riverbanks causing erosion and damage to riverbanks. They also carry crayfish plague which does not harm them, but has led to the rapid decline of native crayfish . White Clawed crayfish are protected in the UK and categorised as being Endangered on the global IUCN Red list of Threatened Species.
Did you know?
The White-Clawed Crayfish needs mineral-rich water to strengthen its exoskeleton, the same way we need calcium for our bones.
White-Clawed Crayfish
American Signal Crayfish
