Serrasalmidae is a family of freshwater fish commonly known as piranhas and pacus. They are primarily found in the rivers and lakes of South America, particularly in the Amazon Basin. These fish are known for their sharp teeth and strong jaws, which they use to feed on a variety of foods, including plants, insects, and smaller fish. Members of the Serrasalmidae family vary in size and behavior. While some species, like the red-bellied piranha, are famous for their aggressive feeding habits, others, such as the pacu, are more herbivorous and have a diet that consists mainly of fruits and seeds.