On Monday, Detroit's WXYZ reported a red-bellied pacu had been caught in nearby Lake St. Clair, renewing fears from last summer that the weirdly toothy piranha relative was coming for our junk. As described by Vocativ, KMGH Denver and others, the pacu is "known for consuming human testicles" earning it the nickname "the ball cutter." But America's testicle-havers will be happy to learn the chiefly vegetarian fish's reputation for ball consumption is unfounded, the result of a decade-long game of telephone.

Pacu hysteria first made the news last August when Denmark's Natural History Museum jokingly advised swimmers to "keep their swimsuits well tied" after a specimen was found in Scandinavian waters. As museum expert Henrik Karl told a Swedish newspaper:

"The pacu is not normally dangerous to people but it has quite a serious bite, there have been incidents in other countries, such as Papua New Guinea where some men have had their testicles bitten off."

However, the earliest and only report of pacu-on-testicle violence comes from a 2011 episode of Animal Planet's somewhat less than scholarly River Monsters. That account, in turn, appears to be based on a dubious story from 2001 of two Papua New Guinea fisherman bleeding to death after having their penises bitten bitten off by unidentified fish. Even then, a marine biologist explicitly believed the responsible party to be a species other than the pacu.


A popular aquarium fish, red-bellied pacus have been found in the waters of more than 40 states since 1988. In that time America has had 0 reports of pacu-related dick and/or ball attacks.

[Image via Henrik Carl/Natural History Museum of Denmark]