The headline in Live Science sounds like the premise for a bad SyFi channel made-for-cable movie – Testicle-Biting Fish Invading Denmark. It turns out that a Danish fisherman caught, what is believed to be, a red-bellied pacu, an omnivorous South American freshwater fish related to the piranha, in the Oresund, the strait between Denmark and Sweden. The fish have what are described as “uncannily human-looking teeth.” The fish caught in Denmark was quite small at less than 8 inches (20 cenitmenters) long, but can grow much larger. Some pacu can reach three feet long and weigh as much as 55 pounds.
The fish are also rumoured to bite human testicles, earning it the nickname “ball-cutter.” Whether there is any truth to this rumor is unclear. Though widely repeated, at least one expert has dismissed the claim as a myth. The claim seems to be traceable only as far back as December 2011, when two fisherman in Papua New Guinea are reported to have died from loss of blood after being castrated by something in the water. The report came from Jeremy Wade, a British “extreme” angler, who featured the story on his reality TV show River Monsters, on the Animal Planet cable channel, owned by the Discovery Channel.