Giant stingray caught in the Mekong, the “largest freshwater fish ever documented”

Scientists have touted a colossal stingray caught in the Mekong River as the largest freshwater fish ever documented.

The 300kg (661lb) female stingray has usurped a 646lb (293kg) giant catfish caught in Thailand in 2005 from its place as record holder, scientists say.

The Mekong River is the 12th longest river in the world and the third longest in Asia, flowing from the Tibetan Plateau through China, Myanmar, Laos, Thailand, Cambodia and Vietnam.

Its boundless biodiversity has made the Mekong account for a quarter of the world’s freshwater fish catch, according to the WWF. But overfishing has caused fish stocks and catches to decline, threatening to inflict irreparable damage on its vulnerable ecosystem.

Zeb Hogan, a biologist who runs Wonders of the Mekong, a USAID-funded conservation project, said: “In 20 years of researching giant fish in rivers and lakes on six continents, this is the largest freshwater fish we’ve ever found. or that it has been documented anywhere in the world.”

“Finding and documenting this fish is remarkable, and a rare positive sign of hope, all the more so because it occurred in the Mekong, a river currently facing many challenges,” added Dr. Hogan, who is also a professor at the University of Nevada. , Reno.

Wonders of the Mekong works with the Cambodian Fisheries Administration to establish a network of fishermen who alert researchers if they catch giant or endangered fish.

And on June 13, in the middle of the night, scientists received a call from a local Koh Preah fisherman, telling them he had caught a “very large” ray. He later took home a $600 (£490) reward for the remarkable find.

The 3.98m long and 2.2m wide fish was given an acoustic tag to track its future movement, before being released back into the river.

The stingray disappeared under the murky waters of the Mekong at dusk when the moon was already high in the sky, Dr. Hogan said.

The fish is called “Boramy”, which means full moon in the local Khmer language.

“The ray finding is evidence that the natural world can still produce new and extraordinary discoveries, and that many of the largest aquatic creatures remain woefully understudied,” said Dr. Hogan.

The giant freshwater stingray is an endangered species and this discovery is the second of its kind that the team has examined since May, as the first weighed in at 181kg.

“When record fish are found, it means the aquatic environment is still relatively healthy. This contrasts with what we have seen in places like the Yantzé River, where scientists reported the extinction of the Chinese paddlefish,” said Dr. Hogan.

“The deep pools of the Mekong harbor life far beyond these impressive giants. Spawning in this critical habitat produces billions of fish each year, ensuring food security and livelihoods for millions of people in Cambodia and Vietnam.”