CHIANG KHONG, Thailand -- In this photo released by World Wildlife Fund-National Geographic, two Thai fishermen show a 646-pound giant catfish they caught from the Mekong River in Chiang Khong district of Chiang Rai province, northern Thailand Saturday, June 11, 2005. Thai fishermen caught this giant catfish, believed to be the world's heaviest living freshwater fish, but it died after environmentalists and officials negotiated for its release to allow it to spawn, and then was eaten. (06/30/05 AP photo)