Black arowana (Osteoglossum ferreirai) care guide

Group
Freshwater fish
Other names
Black arawana
Family
Osteoglossidae (bonytongues)
Origin
South America: Rio Negro basin (Brazil, Colombia and Venezuela), in soft, acidic blackwater
Water
freshwater
Maximum size
90 cm
Temperature
24–30°C
pH
5–7
Hardness
Soft, 1–10 dGH
Minimum tank
1500 litres
Care level
expert
Temperament
predatory
Lifespan
10–20 years years

Care

The black arowana is a close relative of the silver arowana from the soft, acidic blackwater of the Rio Negro. Adults reach 80–90 cm and need the same very large aquarium: ideally 2.4 m long or more (about 1,500 litres), and at least as wide as the adult fish is long. Juveniles are striking: dark brown to black, with a broad yellow-edged stripe from the gill cover to the tail. They turn silver-grey with age. Young fish under about 30 cm are skittish and delicate, and do best in a quiet species tank with soft, slightly acidic water. They become much hardier once they reach about 30 cm. Water: soft water, 1–10 dGH, pH 5.0–7.0, 24–30 °C. Peat or leaf litter in the filter helps match its natural water. Stable, clean water with strong filtration is essential. Cover: a heavy, tight-fitting lid is essential, as black arowanas jump. Not listed by CITES. Listed as Least Concern by the IUCN (assessed 2020). 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/Osteoglossum-ferreirai.html); Tropical Freshwater Fish (tropicalfreshwaterfish.com/species/Osteoglossumferreirai.html). Checked October 2026.

Diet

Surface predator. Young fish do best on live and frozen foods: bloodworm, small earthworms, insects and chopped prawn. Older fish move on to prawns, mussels, strips of white fish, earthworms, crickets and floating pellets, which many accept with patience. No mammal or poultry meat, and no live feeder fish.

Breeding

A mouthbrooder: the eggs and young are carried in the parent's mouth. Breeding has only been reported in very large aquariums with soft, peat-filtered water, and is not practical for most keepers.

Compatibility and tank mates

Keep juveniles on their own or with calm fish; they are easily stressed. Adults behave like silver arowanas: peaceful with fish too large to swallow, and they will eat anything smaller. Best kept as the only arowana, with large catfish or cichlids living lower in the water as tankmates.

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

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