Testicle-biting fish discovered in US lake

Swimmers in a popular Michigan lake are being warned to watch out for a fish with human-like teeth and reportedly has a taste for biting on men's testicles.

The pacu fish, which can grow up to three feet in length and is closely related to piranhas, has been spotted recently in the lake.

See also: Testicle-biting fish caught in River Seine

See also: Fish with human teeth found in New Jersey

The fish have a set of teeth that look alarmingly like those found inside the human mouth and they have been found recently in a lake in Michigan, USA, Metro reports.

They are native to South America but are believed to have appeared in Michigan after people have dumped them there after they became too big to keep as pets, the Detroit Free Press reports.

Paige Filice of Michigan State University said: "If your pacu has outgrown its tank or begun to feed on your other fish, rather than releasing it into a pond or stream, consider donating or trading it with another hobbyist, an environmental learning center, an aquarium or zoo."

This latest discovery is not the first time the fish has been found outside its usual environment.

In 2013, men in Sweden were warned to make sure they held on to their trunks in the Øresund channel between Denmark and Sweden after a so-called 'ball cutter' fish was found by a local fisherman.

Henrik Carl, fish expert at the museum, told The Local: "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."

The fish was also found in the River Seine in Paris in 2013, a fisherman caught the fish and reported it to the river police.

Speaking in 2013, Professor Peter Rask Moller of Copenhagen's Museum of Natural History, warned men against the dangers of the pacu fish.

He told CNN: "We did say that we recommend men to keep their swimsuits tied up until we know if there are more pacus out there in our waters."

He admitted this was 'half a joke' as it was unlikely that you would come across one of the fish.

National Geographic later confirmed that the warnings had been blown out of proportion.

Moller said: "Its teeth and powerful bite can for sure be dangerous, but to meet one here and (have it bite you) is highly unlikely, of course."