Local experts said the fish might have died from exhaustion after its repeated struggles to escape.
On July 5, a fisherman in southern An Giang Province netted the catfish, which was believed to be the world’s largest single freshwater fish.
He later sold it to Hong, police chief of Quoc Thai commune, for more than VND11 million ($550), according to Dan Tri newswire.
Hong released the fish into his pond, which also boasts pet giant barbs, but the catfish died a few days later.
It came from a species that holds the Guinness Book of World Records title as the largest kind of freshwater fish on the planet.
Both the International Union for Conservation of Nature’s Red List and Vietnam’s Red Book label the Mekong giant catfish as critically endangered. Over-fishing and a decrease in water quality because of development and upstream damming threaten to wipe out the fish. Laos, Thailand, and Cambodia have made catching the catfish illegal.
The fish is believed to exist only in small, isolated populations in the central Mekong region.
The giant catfish caught in Hau River on July 5, 2012.
...and dies a few day later.