At 661 pounds, this giant stingray may be the largest freshwater fish ever caught

A giant stingray snagged on a fisherman's line in Southeast Asia may be the largest freshwater fish ever caught.

A fisherman accidently caught the female stingray from the Mekong River in the northern province of Stung Treng, Cambodia, Zeb Hogan, a fish biologist at theUniversity of Nevada, Reno, told USA TODAY on Monday.

The 13-foot-long, 661-pound stingray was caught June 13 by a 42-year-old fisherman, according to Hogan, who is also host of Monster Fish on National Geographic Wild.

"Wonders of the Mekong research team tagged and released the giant stingray back into the Mekong River," Hogan said. "We will be able to track its movements over the next year."

“It proves these underwater leviathans, which are in critical danger, still exist,” Hogan told National Geographic.

The catch “highlights how little we know about a lot of these giant freshwater fish.

You have a fish that’s now the record holder for the world’s largest freshwater fish, and we know little about it.”

Previously, a 9-foot Mekong giant catfish caught in northern Thailand in 2005 had been the heaviest freshwater fish caught. According to Guinness World Records, the catfish weighed 646 pounds.

A team of Cambodian and American scientists and researchers, along with officials from the Fisheries Administration, measured the length of the stingray from snout to tail before they released it back into the river on June 14.