Brycon falcatus is a large, commercially important South American characin distributed across the Paraguay basin and parts of the lower Amazon drainage in Brazil and Bolivia. Its streamlined, laterally compressed body and characteristic sickle-shaped — falcate — caudal and dorsal fins make it one of the more elegantly built large characins. In the wild it is an omnivore feeding on fruits, seeds, invertebrates, and smaller fish during seasonal floods.
In the aquarium, Brycon falcatus requires very large, well-oxygenated conditions — 1500 litres minimum — with excellent filtration and strong circulation. It is an exceptionally fast, powerful swimmer that needs extensive open water space and a robust lid to prevent jumping. Water should be soft to moderately hard and warm to warm-subtropical.
Like other Brycon species, B. falcatus can be semi-aggressive and is best kept with other very large, robust fish or as a solo display specimen. Its impressive size and sickle-fin profile make it a spectacular, if demanding, display animal for specialist aquarists and public aquariums. Diet should include large pellets, fresh fruit and vegetables, and meaty supplements.