African Arowana

About

The African Arowana (Heterotis niloticus) is a genuinely unusual member of the ancient bonytongue family, and it breaks just about every expectation you might bring from experience with its Asian or South American cousins. In the wild it ranges across an enormous swath of West and Central Africa, turning up in major river systems from the Senegal and Niger all the way east to the Nile and Lake Turkana. Juveniles hide among dense vegetation in shallow swamps, while adults move into open water, roaming both mid-water and near-shore zones of rivers and lakes. What really sets this species apart from other osteoglossids is its feeding strategy: rather than ambushing fish or insects at the surface, it filters phytoplankton and fine organic particles using a specialized suprabranchial organ. It is the only plankton-feeder in its entire family. In the aquarium it will also accept small invertebrates and prepared foods. It is an obligate air-breather, capable of getting by in poorly oxygenated water, which contributes to a reputation for hardiness that makes it more forgiving than most large oddballs. That said, the sheer adult size means you need to plan seriously for space before committing. Breeding pairs build circular nests in swampy areas, with the male guarding the fry after they leave the nest.