The narrow-clawed crayfish (Astacus leptodactylus), also known as the Turkish crayfish, is a non-native species in the UK, introduced primarily via aquaculture. Native to Eastern Europe and Western Asia, it has established populations in some UK water bodies. This species is larger and more aggressive than the native white-clawed crayfish (Austropotamobius pallipes) and poses ecological risks by outcompeting natives and potentially spreading crayfish plague (Aphanomyces astaci), to which it is a carrier but resistant.
