The payara, Hydrolycus scomberoides, is a species of dogtooth tetra. This predatory fish is found in the Amazon Basin, where the Tapajós River appears to the eastern limits of its range.12 It was the first of four species to be described in the genus Hydrolycus. The payara's most noticeable feature is the two long fangs protruding from its lower jaw. These fangs can be 4 to 6 inches long and are kept in pockets in the skull.