In this photo provided by Wonders of the Mekong taken on June 14, 2022, a man touches a giant freshwater stingray before being released back into the Mekong River in the northeastern province of Stung Treng, Cambodia. A local fisherman caught the 661-pound (300-kilogram) stingray, which set the record for the world's largest known freshwater fish and earned him a $600 reward. (Chhut Chheana/Wonders of the Mekong via AP)

BANGKOK (AP) — The world’s largest recorded freshwater fish, a giant stingray, has been caught in the Mekong River in Cambodia, according to scientists from the Southeast Asian nation and the United States.

The stingray, captured on June 13, measured almost 13 feet from snout to tail and weighed slightly under 660 pounds, according to a statement June 20 by Wonders of the Mekong, a joint Cambodian-U.S. research project.

The previous record for a freshwater fish was a 646-pound Mekong giant catfish, discovered in Thailand in 2005, the group said.

The stingray was snagged by a local fisherman south of Stung Treng in northeastern Cambodia. The fisherman alerted a nearby team of scientists from the Wonders of the Mekong project, which has publicized its conservation work in communities along the river.

The scientists arrived within hours of getting a post-midnight call with the news, and were amazed at what they saw.

“Yeah, when you see a fish this size, especially in freshwater, it is hard to comprehend, so I think all of our team was stunned,” Wonders of the Mekong leader Zeb Hogan said in an online interview from the University of Nevada in Reno. The university is partnering with the Cambodian Fisheries Administration and USAID, the U.S. government’s international development agency.

Freshwater fish are defined as those that spend their entire lives in freshwater, as opposed to giant marine species such as bluefin tuna and marlin, or fish that migrate between fresh and saltwater like the huge beluga sturgeon.

The Mekong River runs through China, Myanmar, Laos, Thailand, Cambodia and Vietnam. It is home to several species of giant freshwater fish but environmental pressures are rising. In particular, scientists fear a major program of dam building in recent years may be seriously disrupting spawning grounds.

The team that rushed to the site inserted a tagging device near the tail of the mighty fish before releasing it. The device will send tracking information for the next year, providing unprecedented data on giant stingray behavior in Cambodia.

“The giant stingray is a very poorly understood fish,” Hogan said. “It’s found throughout Southeast Asia, but we have almost no information about it.”

In addition to the honor of having caught the record-breaker, the lucky fisherman was compensated at market rate, meaning he received a payment of about $600.