African arowana (Heterotis niloticus) care guide

Group
Freshwater fish
Other names
African bonytongue, Bony tongue
Family
Arapaimidae (sometimes placed in Osteoglossidae)
Origin
West and north-east Africa: Senegal, Gambia, Volta, Niger, Chad and Nile basins and Lake Turkana. Introduced to the Congo basin and Madagascar.
Water
freshwater
Maximum size
100 cm
Temperature
25–30°C
pH
6.5–7.5
Hardness
Medium, 4–12 dGH
Minimum tank
1500 litres
Care level
expert
Temperament
peaceful_with_caution
Lifespan
10+ years years

Care

The African arowana grows to about 1 m and over 10 kg in the wild, so it is only for very large aquariums or indoor pools: plan for 1,500 litres or more for an adult, with a long, wide footprint and plenty of open swimming space. Unlike the other arowanas, it is the only plankton feeder in the family, sifting food from the water and the bottom. Give it a soft sandy substrate and plenty of space at the bottom of the tank. Water: 25–30 °C, pH about 6.5–7.5, 4–12 dGH. It lives in the open water of rivers and lakes. Keep the water clean and stable with strong filtration, especially as it stirs up the substrate. Cover: use a tight-fitting lid, as it can jump. It is an important food fish across Africa and is farmed. Not listed by CITES. Listed as Least Concern by the IUCN (assessed 2019). Selling: our policies require the adult size and long-term tank needs to be stated clearly in the listing. Large fish must travel by a specialist live-animal courier (see the Livestock shipping guide). Sources: FishBase (fishbase.se/summary/Heterotis-niloticus.html); Tropical Freshwater Fish (tropicalfreshwaterfish.com/species/Heterotisniloticus.html). Checked October 2026.

Diet

Unlike other arowanas, it is mainly a filter and bottom feeder: in the wild it eats mud, plankton, plant debris and small invertebrates. In aquariums it takes sinking pellets, earthworms, bloodworm, brine shrimp, chopped prawn and mussel. Some are hard to wean onto prepared foods. Feed small amounts several times a day.

Breeding

Not bred in aquariums because of its size. In the wild, the pair builds a circular nest about 1 m across and 20–60 cm deep in swampy, plant-filled shallows. The female lays amber eggs, both parents guard the nest, and the male guards the young after they leave the nest a few days after hatching.

Compatibility and tank mates

Generally calm with fish it cannot swallow, but small fish may be eaten. Fights with its own kind, so keep one per tank. Suits large, peaceful tankmates such as big catfish and large cichlids.

Last updated 2 October 2026. Community-edited care guide on Aquatic-Auctions.

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