A fisherman at a New Jersey lake got a surprise when he hooked an exotic fish that's been rumored to feast on testicles.

His 10-inch catch turned out to be a pacu, which is a gentler cousin of piranhas found in South America's Amazon River.

The fish Tom Boylan landed Saturday in Passaic's Third Ward Veterans Memorial Park had rounded teeth and an orange belly and fins.

Boylan, a retired bus driver, was "shocked, surprised, amazed" by his catch, especially by the "human-like teeth."

A regular fisher at the pond, Boylan says he knew it wasn't a carp when he caught it. This one was orange and jumped straight out of the water.

He turned to an aquarium supply store for answers.

Absolutely Fish manager Pat Egan told The Record newspaper someone most likely had the pacu in a fish tank and dumped it when it became too big.

“We call them ‘tank busters.’ We don’t even sell them because they grow so big,” Egan told the paper.

Egan says the fish can grow up to 4 feet long. The pacu Boylan caught was most likely a pet that someone decided to set free this summer.

While pacus feed on vegetation and nuts, unlike flesh-eating piranhas, the species has developed a reputation as a potentially dangerous foe for men in the water. Reports that the fish feasted on testicles of fisherman in Papua New Guinea prompted researchers in Denmark to warn the public to "keep their swimsuits well tied" after a pacu was discovered in Copenhagen waters.

Rob Schmitt contributed to this report.