Holley Luft, living in Michigan, was fishing last week when she captured a pacu - a foot-long relative of piranhas, with human-like teeth.

Pacus are native to the Amazon, where they can grow to weigh as much as 55 pounds, and stretch up to three feet in length. The fish have been known to nibble on fingers and toes of swimmers. They have a reputation for eating testicles of male swimmers, but the stories are likely exaggerated.

Lake St. Clair, located near Detroit, was the site of the unusual marine catch. The 52-year-old was fishing with her husband, Tom, about 15 feet off shore on 9 July when she caught the rare animal.

The fish Luft caught was around two feet in length and weighed 15 pounds.

Wildlife biologists believe the red-bellied Pacu was likely released into the water source from a pet owner. It is uncertain why the animal was released into the wild,  but it may have grown too large, or become too dangerous to keep at home.

"It's a popular fish in the pet industry. And this was rather large, so it's possible there are other fish out there. There may be more out there, but they'd be at very low levels," Jim Francis, spokesman for the Department of Natural Resources in Michigan, said.

Luft baited her hook with a nightcrawler and catfish. It is uncertain whether the captured fish was a male or female pacu.

"When it first came up, I'm like, 'Holy crap.' And just as I was ready to get it out of the net, my husband said 'I think it's a piranha.' So I dropped the fish and when I did, the hook came out of his mouth. At first we couldn't believe it - we were flabbergasted," Luft told Fox News.

According to Francis, an average of one of the fish are caught every two years in local waters.

Wildlife officials say the fish likely would not have lived through the harsh winter of Michigan. Given its significant size, they believe other members of the species likely exist in the same body of water.

Pacus are differentiated from piranhas by their teeth. While piranhas possess a single row of incisor-like teeth, pacus have two rows of teeth much like molars. They are largely vegetarians, consume nuts and fruits. The animals have been found in 43 states, and are a popular food source in South America.

The large piranha-like fish is now sitting in a freezer at Luft's house, waiting to become dinner.