Ключевые слова: amazon, america, american, animal, aquarium, brazil, characiformes, fauna, fish, lake, natural, nature, paraguay, parana, piranha, piranhas, pygocentrus, pygocentrus nattereri, red bellied piranha, red piranha, redbellied piranha, rio machado, rio negro, rio paraguay, rio parana, river, serrasalmus nattereri, south america, south american, swim, underwater, water, wild, wildlife,