The Black Arowana or Osteoglossum Ferreirai is a South American freshwater bony fish of the family Osteoglossidae. They are native to both black and white water floodplains of the Amazon drainage basin (Rio Negro) in South America and aren't overly aggressive, although they will hold their own and occasionally chase off other larger fish species.
It is critical that the aquarium has a tight fitting and secured lid that is extremely strong. Arownas are avid jumpers and can easily knock a heavy glass lid onto the floor! Many an Arowana has been lost this way. They do not tolerate poor water quality, so excellent filtration along with frequent partial water changes of 25% or more is required to keep nitrates low.