The black arowana (Osteoglossum ferreirai) is a South American freshwater bony fish of the family Osteoglossidae.

[5] The black arowana is native to tropical South America where restricted to the Rio Negro basin, including the Branco River.

[3][6][7] Black arowanas were discovered in the 1970s in the Orinoco basins, but whether this is a natural population or the result of introductions by humans is disputed.

Once it reaches about 15 cm (0.5 ft), the markings disappear and the fish will develop a dark iridescent steel grey to blue coloration, hence its common name.

[8] Some Asian aquarists occasionally refer to arowana as dragonfish due to their unique appearance and believe they bring good luck.