Fishermen in northern Thailand have caught the biggest catfish on record -- a 646-pound (293-kg) giant the size of a grizzly bear -- and eaten it, the WWF and the National Geographic Society said on Wednesday.

　　The giant catfish, believed to be the largest freshwater fish ever found, was caught along the Mekong River, home to more species of massive fish than any river on Earth.

　　The Mekong giant catfish is southeast Asia's largest and rarest fish and the focus of a National Geographic Society project headed by Hogan to study freshwater fish greater than 6.5 feet (2 metres) or 220 pounds (100 kg).