Silver arowana (Osteoglossum bicirrhosum) care guide

Group
Freshwater fish
Other names
Arawana, Silver arawana
Family
Osteoglossidae (bonytongues)
Origin
South America: Amazon River basin, plus the Rupununi and Oyapock rivers (Guyana and French Guiana)
Water
freshwater
Maximum size
90 cm
Temperature
24–30°C
pH
5–7.5
Hardness
Soft to medium, 2–15 dGH
Minimum tank
1500 litres
Care level
expert
Temperament
predatory
Lifespan
10–20 years years

Care

The silver arowana is very common in shops as a 10–15 cm juvenile, but it grows fast, to 80–90 cm and up to 6 kg. Very few home aquariums can house an adult. Plan for the adult size before you buy: a tank at least as wide as the fish is long, ideally 2.4 m long or more (about 1,500 litres). Water: soft to medium water, 2–15 dGH, pH 5.0–7.5, 24–30 °C. It can cope with low oxygen in the wild, but in an aquarium it needs strong filtration and frequent large water changes. Cover: a heavy, tight-fitting lid is essential. Silver arowanas are famous jumpers and can injure themselves on the lid or jump out. Eye health: arowanas kept in tanks can develop "drop eye", where the eye turns downwards. Keepers often link it to fish constantly looking down at food or tank traffic, and to fatty diets. A varied, lean diet and keeping activity away from the bottom of the tank may help. 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-bicirrhosum.html); Seriously Fish (seriouslyfish.com/species/osteoglossum-bicirrhosum/). Checked October 2026.

Diet

Surface predator: in the wild it eats fish and large insects, sometimes leaping out of the water to catch them. Young fish: bloodworm, small earthworms and chopped prawn. Adults: whole prawns, mussels, strips of white fish, river shrimp, earthworms, crickets and quality floating pellets. No mammal or poultry meat, and no live feeder fish.

Breeding

A paternal mouthbrooder. The male carries the eggs, larvae and young fry in his mouth for about six weeks, sometimes up to two months. A brood is usually 12–30 large fry, 5–7.5 cm long when released. Breeding in home aquariums is almost unheard of; fish in the trade are mostly collected or reared in South America.

Compatibility and tank mates

Peaceful with fish too large to swallow; anything that fits in its mouth will be eaten. Good tankmates are large cichlids, large catfish and other big fish living lower in the water. It can be aggressive towards other arowanas when space is limited, so keep one unless the tank is huge. Avoid other surface fish except in very large aquariums.

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

About Aquatic-Auctions

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