For as much as people think they know about the world’s rivers, the wildlife you can find there always manages to surprise us. Case in point: The world’s largest freshwater fish was found in the Mekong River in Cambodia. But scientists aren’t just excited about the find because of its massive size.
On Monday, Wonders of the Mekong, a joint Cambodia-U.S. research project, confirmed that a local fisherman south of Stung Treng in northeastern Cambodia caught a stingray weighing just under 660 pounds. To put that into perspective: The largest freshwater fish previously on record was a 646-pound Mekong catfish caught in Thailand in 2005.
The stingray isn’t only massive in terms of weight. The aforementioned catfish was about 8.9 feet long, but the stingray came in at nearly 13 feet from snout to tail. (And don’t worry: Scientists say that the stingray was safely released.)
Of course, scientists couldn’t help but marvel at the stingray’s size. Per NPR, Wonders of the Mekong leader Zeb Hogan said in an online interview from the University of Nevada at Reno that “when you see a fish this size, especially in freshwater, it is hard to comprehend, so I think all of our team was stunned.” Check out the video below if you want to see the stingray for yourself.
The Mekong is the third longest river in Asia, running through China, Myanmar, Laos, Thailand, Cambodia, and Vietnam. Perhaps most importantly, the Mekong is one of the most biodiverse regions on Earth, and, as Science reported, it’s also a vital food source for much of Southeast Asia due to its support of regional fisheries.
Unfortunately, the Mekong is also one of the most polluted rivers in the world. In 2021, the United Nations Environment Programme (UNEP), alongside several other partners, launched an in-depth study of plastic’s impact on the Mekong. And as a project, the Wonders of the Mekong is “working toward a sustainable future for the region [and to] increase awareness about the value of a healthy Mekong River, with a focus on Cambodia.”
Finding such a massive fish gives scientists hopes for the river’s health. Solomon David, an aquatic ecologist at Nicholls State University who is not associated with the project, told Science that the stingray’s capture “signals there is still time to safeguard these freshwater megafish.”
“Freshwaters are among the most imperiled ecosystems in the world,” he added. “We need to act quickly to conserve these habitats and their uniquely charismatic biodiversity.”
