The rusty crayfish (Faxonius rusticus) is an invasive crayfish species native to North America, with limited presence in the UK but considered a potential ecological threat. Known for its aggressive behaviour and high reproductive rate, the rusty crayfish can outcompete native crayfish species, disrupt aquatic vegatation, and alter ecosystem dynamics. It is also a carrier of crayfish plague (Aphanomyces astaci), further threatening native populations.
