Procambarus clarkii is a crustacean species native to American freshwater bodies. Brought to Japan in the 1920s as a feed for frogs, this crustacean has slowly taken over the Japanese freshwaters by predation and propagation. In fact, in 2023, the red-swamp crayfish was designated as an invasive alien species by the Japanese Ministry of the Environment and of the Agriculture, Forestry and Fisheries.