It turns out that the invasion of testicle-crunching fish that were said to have invaded the Oeresund Strait, the channel of water separating Denmark and Sweden, is a myth. The Telegraph reports that the claims are likely untrue.

Danish and Swedish swimmers were warned to stay out of the Oeresund Strait after a Danish angler caught the pacu fish in his nets.

“If they bite, they can bite hard … especially when they bite you where you really don’t want to be bitten,” said Peter Resk Moeller, of the Natural History Museum of Denmark, according to The Telegraph.

Speaking to National Geographic, however, Moeller admitted that he was joking about the fish’s weakness for male anatomy.

“All we said last week was that male swimmers should keep their pants on in case there are more pacus out there in our cold Baltic waters,” said Moeller in an email. “Its teeth and powerful bite can for sure be dangerous, but to meet one here and [have it bite your testicles] is highly unlikely, of course.”

The pacu fish is a relative of the piranha that is usually found in the Amazon region. The pacu is also vegetarian, unlike the piranha. Although capable of severing fingers and fishing lines, the fish’s teeth aren’t nearly as sharp as the piranha’s.

However, the pacu fish likes crunching on nuts with its strong jaws, which may be one of the reasons that a joke about its weakness for male anatomy worked so well.

Lars Skou Olsen, curator of Denmark’s Blue Planet Aquarium, said that Danish and Swedish swimmers are safe to reenter the water.

“I think it’s just a rumor,” Olsen said, according to National Geographic. “There’s no need for swimmers to worry at all. They will be lucky if they see [a pacu fish].”

Though its attraction to testicles was probably overblown, one question still remains: how did this non-native fish end up in the Oeresund Strait? According to Natural History Museum of Denmark, the pacu fish was probably placed in the water by someone who kept the fish as a pet or by someone who raises them at a fish farm. The Blue Planet quickly dispelled any idea that the fish had escaped from the aquarium’s tanks.

“Ours are a lot larger than the one caught,” Olsen said in a press release.

What else do scientists know about the pacu fish?

In an interview with National Geographic, Olsen said that the fact that the a pacu could reside in the wild in Denmark is a “mystery.” Not only is the water temperature too cold, but the pacu is a freshwater fish. A pacu fish can live for nearly 20 years and grow up to 44 pounds.

Interestingly, Olsen noted that pacu fish can make great pets. However, they quickly become too big for their tanks, which is why this pacu probably ended up in the Oeresund Strait.

Was this an appropriate joke? Would you feel safe swimming in the Oeresund Strait even though the likelihood of there being other pacu fish is very small? Sound off in the comments section.