A young boy in Oklahoma has caught a bizarre, piranha-like fish with eerily human-like teeth hidden behind its fishy lips.
Pacu is a name given to several species of fish in the Serrasalmidae family. They are native to South America and are closely related to piranhas, with a similar body shape to their razor-toothed cousins. Pacus enter freshwater ecosystems in the U.S. when people keep them as pets but irresponsibly release them into nearby ponds and rivers when they grow too big for their tanks, ODWC officials wrote.
Pacu poop also helps to fertilize freshwater plants and disperse their seeds, which makes them a keystone species in their native ecosystems, according to AMNH. However, like most other invasive species, pacus can have a negative impact on ecosystems they are introduced to.