pacifastacus leniusculus

The North American signal cray?sh (Pacifastacus leniusculus) has been present in Scotland since at least 1995 and the species is now known to be present in a number of catchments. Once established, few opportunities for containment exist and eradication can often be impossible to achieve. However, in small, isolated water bodies, the application of a non-cray?sh-speci?c biocide has provided the opportunity to remove this species permanently. In July 2011, signal cray?sh were discovered in a ?ooded quarry pond at Ballachulish in the Scottish Highlands.