Cajun Crayfish Invading Africa, Eating Native Species

Without any native predators to keep it in check, the Louisiana crayfish, also known as the red swamp crayfish, is gobbling up small freshwater fish, fish eggs, mollusks, crustaceans, and aquatic plants.

The 6-inch-long (15-centimeter-long) invader is already widely distributed in lakes and other bodies of water throughout Kenya, as well as in Rwanda, Uganda, Egypt, Zambia, the Seychelles, Mauritius, and South Africa.
Conservationists are now concerned the crayfish will reach the East African lakes of Malawi, Tanganyika, and Victoria, which are home to hundreds—and probably thousands—of species found nowhere else.

Previously,by burrowing into the edges of dams, rivers, and lakes to make their nests, the crayfish have damaged local infrastructure and landscapes. For instance, their burrowing has caused water canals to leak, earth dams to collapse, and banks of rivers and lakes to erode.

National Geographic