Thanks to local fishers, a team of scientists on an expedition in Cambodia to tag Mekong River fish has discovered the largest freshwater fish ever documented–a 300-kilogram giant stingray that stretches nearly 4 meters from nose to tail.
“It’s almost inconceivable that a fish this large still occurs in a river as heavily fished and developed as the Mekong,” says Zeb Hogan, a fish biologist at the University of Nevada, Reno.
The team of scientists, part of an international collaboration called Wonders of the Mekong, tagged and released the record-breaking stingray (Urogymnus polylepis) thanks to having cooperative ties to local fishing communities and a bit of luck. The researchers were preparing to put acoustic tags on 200 fish and use arrays of receivers to track their movements through 300 kilometers along the heavily braided Mekong near the city of Stung Treng in northern Cambodia. The data could aid conservation efforts.