The pacu is a vegetarian relative of the piranha native to the Amazon. They have very human-like teeth used for breaking open the cases of nuts that fall in the water. However, it seems that under the right conditions (i.e. limited food supply and the presence of human testicles) these typically shy fish have a tendency to turn into vicious genitalia manglers.
The fish were introduced into the Sepik river in Papua New Guinea in 1994 as a food source. There the pacu is known as “the ball cutter,” where it has been blamed for the painful mutilations and death of two men due to blood loss after fish-induced castrations.
“Extreme angler” Jeremy Wade traveled to Papua New Guinea to investigated these claims in a third season episode of River Monsters. While his testicles presumably remained intact, he did manage to catch a large and elusive red-bellied pacu to confirm their presence in the river.
Whether pacu just get their nuts confused or have a tendency to resort to carnage in the face of slim pickings, the most frightening thing to keep in mind is the high number of these fish found frequently in lakes and rivers all over the world. This includes a majority of the states in the US.
In recent months reports of pacu have come from Denmark, France, Illinois and now New Jersey.
The fish are commonly sold as “vegetarian piranhas.” However, pacu grow much larger than piranha, up to 3 or 4 feet long and weighing in at up to 55 pounds. When they outgrow their tanks, they get dumped in the nearest body of water. This has earned them the nickname “tank busters.”
When pacu are found in local water it is usually recommended to avoid skinny dipping. Unless castration sounds like a good time, you just might want to wear a cup next time you go swimming.