Longest freshwater fish migration (return journey)

The longest freshwater fish migration (return journey) on record is that of the South American dorado catfish (Brachyplatystoma rousseauxii), which travels 11,600 km (7,200 miles) up and down the Amazon River, from the Andes to the Amazon's mouth and back. Also known as the gilded catfish, it is a species of goliath catfish, growing up to 2.8 m (9 ft 2 in), and inhabiting Amazon and Orinoco River basins and major rivers of French Guiana. Spawning occurs in the headwaters of the Andes, in Peru's Marañon River, and after hatching, the juvenile fish are carried downstream, growing and feeding during a 5,800-km (3,600-mi) journey taking them to the Brazilian Amazon estuary. Here they live for two to three years, feeding on prey such as crustaceans and fishes, before beginning the return journey, heading back upriver to breed, spawning in the Andes and thereby completing their cyclical marathon migration.

Three other species of Amazonian goliath catfishes, namely the zebra catfish (Brachyplatystoma juruense), the slobbering catfish (B. platynemum) and the Laulao catfish, aka piramuta (B. vaillantii) also perform long migrations, but none as far as the dorado catfish. This was determined by the scientific study that investigated the migrations of all four species, and whose findings were published on 6 February 2017 in the journal Nature.