Ron Rossi from Delran, Burlington County (New Jersey) was fishing with his son Frank on Sunday at Swedes Lake, in New Jersey when they made a rare catch. They initially thought that it was a piranha until they found out through the Internet that they caught something some say are capable of biting their testicles.

"We scoop this thing up and brought it up. We didn't know what kind of fish it was," said Ron to 6ABC.

The fishing buddies realized it wasn't a piranha because its teeth weren't sharp. "We did pull the bottom lip down to see what they looked like and they have almost human teeth. It's exactly what it looked like on the Internet," Ron added.

The Rossi's found a Pacu fish, a relative of the piranha that is commonly found in the Amazon region abd can grow bigger than a piranha, reaching up to 25 kg (55 pounds) in weight and 0.9 m (3 feet). 

Pacus normally feed on algae and tree nuts that fall into the water. But an urban legend that seems to have originated in Sweden says that every now and then Pacus are known to mistake male genitals for the tree nuts, attacking men who swim in the waters of South America, earning them the nickname "ball-cutter." However, there is no hard evidence of the species ever attacking in this way. 

So how did the Pacus end up swimming in New Jersey? The same way they did in Sweden. State officials said that people are buying them as pets for their aquariums. So it could be some owner who threw his pet in the lake.

Ron is now worried that the Pacus could attack people swimming in the lake. "A lot of residents swim and then there's the marathon people that swim the length of this lake just about every day," said Ron.

There were reported sightings of the Pacu fish in Russia and in Sweden as well. Fish experts in Sweden actually released a humorous warning to Swedish men not to take off their swimming trunks after a fisherman caught a Pacu in the southern coast in 2013.