Red swamp crayfish
The Red Swamp crayfish (Louisiana crayfish) Procambarus clarkii is native to south central United States. The Red Swamp crayfish has been categorised as an invasive species in Europe. Like its North American counterpart the Signal crayfish, the Red Swamp crayfish has been earmarked as a potent invasive species, whose introduction to Irish waterways would herald the destruction of the native White-clawed crayfish stock.
The ecological plasticity of the Red Swamp crayfish renders the species the most dangerous of all potential invasive species. The Red Swamp crayfish has all the traits of a detrimental invasive species as it is: able to withstand environmental change, utilise a wide range of food sources, reach maturity quickly, highly fecund and resistance to disease. The species ability to adapt to and tolerate slightly saline waters and polluted waters mean the Red Clawed crayfish is quite resilient to harsh environments.
Red Swamp crayfish grow to approximately 12cm. The species is dark red in colour with raised bright red spots covering the claws and body. Black wedged stripes are on the abdomen.
Like the Signal Crayfish the Red Swamp crayfish is a known vector of ‘crayfish plague’, with the species itself being impervious to the plague. Introduction of the species to watercourses has resulted in the decimation of the native species. The species ability to walk on dry land enables it to infiltrate and colonise waterways without direct introduction; this elevates the severity of the consequences for introducing Red Swamp crayfish to a regional watercourse. The Red Swamp crayfish is also known to burrow aggressively; this severely damages the integrity of river banks.
Red Swamp crayfish breed in August. Females typically produce approximately 600 young. The species is capable of reaching maturity three months after hatching. This allows the species to produce 2 generations per year in warm climates. This means that the species is capable of rapidly colonising a region and render it extremely difficult to remove.