646-Pound Catfish Netted in Thailand

Fishermen in northern Thailand have netted a fish as big as a grizzly bear, a 646-pound Mekong giant catfish, the heaviest recorded since Thai officials started keeping records in 1981. The behemoth was caught in the Mekong River and may be the largest freshwater fish ever found.

"It's amazing to think that giants like this still swim in some of the world's rivers," said Dr. Zeb Hogan, a WWF Conservation Science fellow and leader of a new World Wildlife Fund (WWF) and National Geographic Society project to identify and study all freshwater fish over 6 feet long or 200 pounds. "We've now confirmed now that this catfish is the current record holder, an astonishing find."

The fish was caught and eaten in a remote village in Thailand along the Mekong River, home to more species of giant fish than any other river. Local environmentalists and government officials negotiated to release the record-breaking animal so it could continue its spawning migration in the far north of Thailand, near the borders of Thailand, Laos, Myanmar and China - also known as the "Golden Triangle"). But the fish, an adult male, later died. The species is declining, which fishermen in the region blame on upstream dams and environmental deterioration. The specimen is the largest giant catfish ever recorded; it is listed by the Guinness Book of World Records as the largest freshwater fish.

The Mekong giant catfish is Southeast Asia's largest and rarest fish and the focus of Dr. Hogan's project along with about two-dozen other species around the world such as the giant freshwater stingray, the infamous dog-eating catfish, the dinosaur-like arapaima, and the Chinese paddlefish - all of which remain contenders for the title of the world's largest fish. Long shots for the title include caviar-producing sturgeon, goliath Amazon catfish, giant lungfish, razor-toothed gars, massive cods, and Mongolian salmon.

"I'm thrilled that we've set a new record, but we need to put this discovery in context: these giant fish are uniformly poorly studied and some are critically endangered. Some, like the Mekong giant catfish, face extinction," continued Dr. Hogan. "My study of giant freshwater fish is showing a clear and global pattern: the largest fish species are disappearing. The challenge is clear: we must find methods to protect these species and their habitats. By acting now, we can save animals like the Mekong giant catfish from extinction."

The Mekong River Basin is home to more species of massive fish than any river on Earth. It is also the most productive fishery in the world, generating $1.7 billion each year. Fish from the Mekong are the primary source of protein for the 73 million people that live along the river.