Asian arowana (Scleropages formosus) care guide

Group
Freshwater fish
Other names
Dragon fish, Asian bonytongue, Golden arowana, Red arowana, Green arowana
Family
Osteoglossidae (bonytongues)
Origin
Southeast Asia: southern Myanmar to the Malay Peninsula and Indonesia, and eastern Thailand to the Cardamom Mountains
Water
freshwater
Maximum size
90 cm
Temperature
24–30°C
pH
5–8
Hardness
Soft to medium, 2–15 dGH
Minimum tank
1500 litres
Care level
expert
Temperament
territorial
Lifespan
15–20+ years years

Care

The Asian arowana is a large, long-lived surface predator, reaching about 90 cm. It needs the biggest aquarium most keepers can provide: a tank at least as wide as the adult fish is long, so it can turn easily, and ideally 2.4 m long or more (about 1,500 litres for an adult). Water: soft to medium-hard water, 2–15 dGH, pH 5.0–8.0, 24–30 °C. In the wild it lives in slow, tannin-stained blackwater streams in forest and peat areas. Keep water quality very stable with strong, well-maintained filtration and large regular water changes. Gentle surface movement suits it best. Cover: arowanas are powerful jumpers. A heavy, tight-fitting lid with no gaps is essential, and sudden lights or movement near the tank can startle them into jumping. Behaviour: usually kept on its own. It is territorial and often intolerant of other arowanas and of other fish living near the surface. Conservation and the law: listed as Endangered by the IUCN (assessed 2019) and on CITES Appendix I since 1975. In Great Britain it is an Annex A species: you need an Article 10 certificate from the Animal and Plant Health Agency (APHA) to sell it, offer it for sale or advertise it. Legal fish come from registered captive-breeding farms (mainly in Indonesia, Malaysia and Singapore), are microchipped and come with a certificate. When selling, give the buyer a copy of the Article 10 certificate marked "copy for information only", or put its number on the invoice. Colour varieties include super red, red-tail golden, crossback golden and green. 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/Scleropages-formosus.html); Seriously Fish (seriouslyfish.com/species/scleropages-formosus/); GOV.UK: Commercial use of endangered species (gov.uk/guidance/endangered-species-certificates-for-commercial-use); Practical Fishkeeping. Checked October 2026.

Diet

Predator. In the wild, young fish take insects from the surface and adults eat fish, crustaceans and small vertebrates. In the aquarium: quality floating sticks or pellets, plus prawns, mussel, strips of white fish, earthworms and insects such as crickets and locusts. Do not feed mammal or poultry meat, and avoid live feeder fish (disease risk).

Breeding

A paternal mouthbrooder: the male carries the large orange-red eggs, which hatch in about a week. The larvae stay in his mouth for another 7–8 weeks, and the young are about 6 cm long when they leave. Fry take around three months to become free-swimming. Breeding is done commercially in large outdoor ponds and is not practical in home aquariums.

Compatibility and tank mates

Best kept alone. If you have tankmates, choose robust fish that live lower in the water and are too large to swallow, such as large catfish or large peaceful cichlids. Avoid other arowanas unless you have a very large group in a huge tank, and avoid other surface fish.

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

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