Meet the world's largest 300kg freshwater fish ever found!

Rivers have always been lifelines, as sources of food, stories, and surprises that remind us how little we truly know about the wild. Recently, fishermen caught the world’s largest freshwater fish from a lively waterway in Southeast Asia, and it has people talking worldwide.

Meet the world's largest freshwater fish

In June 2022, fishers near Koh Preah island in Cambodia's Mekong River caught a monster that took a dozen people to handle. This giant freshwater stingray, named Urogymnus polylepis, weighed 300 kilograms and measured 3.98 meters long, snout to tail. According to Guinness World Records, it shattered the prior record of 293 kg, which was held by a Mekong giant catfish from Thailand in 2005.

Researchers from the Wonders of the Mekong project, backed by the University of Nevada, Reno, rushed in to measure and tag it before releasing it alive. Guinness World Records soon certified it as the largest freshwater fish ever documented. Unlike ocean behemoths, river dwellers rarely hit such scales due to cramped habitats, making this find extra special.

Where do such giant stingrays live?

These rays hug muddy riverbeds, camouflaging while feeding on small fish and critters. Researcher Jack Eschenroeder called the catch “surreal,” according to a Wonders of the Mekong report. Listed as endangered by the IUCN, they face threats from dams, sand mining, and overfishing in the 4,350-km Mekong basin, which spans Tibet to Vietnam and feeds millions.

Experts guess this ray was decades old, growing slowly in stable spots. Seasonal floods boost feeding, while deep pools shelter them in dry times. Acoustic tags now track its moves to map habits and migration, according to Wonders of the Mekong.

Why the Mekong is home to such massive monsters

The river's nutrient-packed waters and floodplains fuel mega-fish like the now-critically endangered giant catfish. This stingray's survival signals some areas still work for long-lived giants, yet dams and fishing shrink their world fast.