The Virile Crayfish Orconectes virilis is native to Canada however it is widely dispersed throughout North America. The species is present in the River Lee catchment in London. Whilst the Virile crayfish is not as aggressive as its North American counterparts the Signal crayfish and the Red Swamp crayfish, it is a potential vector of ‘crayfish plague’ and therefore poses a significant threat to the native White-clawed crayfish population.

Little is known about how the non-native Virile crayfish will impact the River Lee region, and states that further monitoring and studies will have to be conducted on how the species interacts with the local environment.
The Virile crayfish is red/brown in colour often with blue claws. The species also has black paired black markings on its abdomen.

Virile crayfish have been identified as a biological control for zebra mussels, however trout eggs are preferred if available