Procambarus clarkii, commonly known as the red swamp crayfish, is a freshwater crustacean native to the southeastern United States. It typically inhabits swamps, marshes, and rivers, where it prefers muddy substrates. This species is known for its bright red coloration, especially during mating season, and can grow up to 15 cm in length. The red swamp crayfish is an important species in aquatic ecosystems, serving as both predator and prey. It is also widely farmed for food and is a popular bait in fishing. Due to its adaptability, Procambarus clarkii has been introduced to various regions worldwide, sometimes becoming invasive.