The White-clawed crayfish (Austropotamobius pallipes) is one of the UK’s largest freshwater invertebrates and is our only native crayfish.
The White-clawed crayfish was once a widespread and common species in English and Welsh rivers, but has suffered a decline of 50 – 80% across its European range in the last ten years and is classified as ‘endangered’ on the IUCN red list of threatened species and is at risk of global extinction.
Many populations of White-clawed crayfish have already been lost and most of those remaining in streams and rivers are at risk of extinction in the future. The decline has been caused by invasive, non-native crayfish species such as the American Signal crayfish (Pacifastacus leniusculus), which spread of a disease known as crayfish plague, habitat degradation and pollution.
Invasive crayfish are a particular problem for White-clawed crayfish and for the health and ecology of the UK’s river habitats. You can learn more on both invasive invertebrate species and the non-native invaders here in the UK.