About 2,500 fish species have been found within the Amazon system, but many more remain unidentified. Among the more important commercial species are the pirarucu, one of the world’s largest freshwater fish, and various giant catfish. The small flesh-eating piranha generally feeds on other fish but may attack any animal or human that enters the water. Other animals include caiman, river turtles, river dolphins, and manatees. The Amazon is also home to the semiaquatic capybara, the largest rodent in the world, and the nutria (or coypu).
