25 years ago, a mutant American crayfish turned to asexual reproduction, and all of Europe's lakes are filling up with its clones

The marbled crayfish (Procambarus virginalis) is a mutant slough crayfish (Procambarus fallax) an American species; the mutation that allowed slough crayfish to reproduce asexually by cloning itself occurred a mere 25 years ago, and it came to Germany as an aquarium pet in 1995, sold as "Texas crayfish." (more")