The World’s Largest Freshwater Fish?


Scientists working in Thailand’s Mae Klong River made a big find, an enormous stingray that they think is a contender for the largest freshwater fish ever documented by researchers. The ray was caught and released in about 65 feet (20 metres) of water in the Amphawa District, about an hour outside Bangkok. Nantarika Chansue, a veterinarian and professor at Chulalongkorn University in Bangkok, helped catch and measure what she calls the “big one.”

The ray (Himantura polylepis or H. chaophraya) was 7.9 feet (2.4 metres) across and 14 feet (4.3 metres) long and weighed an estimated 700 to 800 pounds (318 to 363 kilograms), she said. The team was unable to get an exact weight because “it’s really hard to weigh these things without hurting them, because they are such big, awkward animals,” says Zeb Hogan, a National Geographic fellow and a professor of biology at the University of Nevada, Reno.

“Certainly [this] was a huge fish, even compared to other giant freshwater stingrays, and definitely ranks among the largest freshwater fish in the world,” he says. The Guinness Book of World Records lists the Mekong giant catfish, which also lives in Thailand, as the “world’s largest freshwater fish,” weighing up to 660 pounds (300 kilograms).

The 2015 edition of the book breaks out the largest saltwater ray as a separate category from bony fish, even though rays are technically a type of fish. Anthony Yodice, a spokesperson for Guinness World Records North America, said the organization would not comment on whether this catch constitutes a new record until a formal application had been submitted and reviewed.