Silver arowana - Osteoglossum bicirrhosum

Scientific name: Osteoglossum bicirrhosum

Common name: Silver arowana

Family: Osteoglossidae

Usual size in fish tanks: 90 - 100 cm (35.43 - 39.37 inch)

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Recommended pH range: 6 - 7.5

Recommended water hardness: 4 - 12°N (71.43 - 214.29ppm)

0°C 32°F30°C 86°F

Recommended temperature range: 24 - 30 °C (75.2 - 86°F)

The way how these fish reproduce: Spawning

Where the species comes from: South America

Temperament to its own species: aggressive/territorial

Temperament toward other fish species: peaceful

Usual place in the tank: Top levels

General Information

Osteoglossum bicirrhosum, commonly known as the Silver Arowana, is a large prehistoric-looking fish from the Amazon basin. This species is famous for its elongated body, metallic coloration, and surface-dwelling behavior. Silver Arowanas are powerful jumpers capable of leaping out of the water to catch insects and small prey. Because of this, a tightly fitted aquarium lid is absolutely essential.

Silver Arowanas grow extremely large, often reaching 80–100 cm in aquariums. Due to their size and active swimming behavior, they require very large tanks. A long aquarium is more important than height, as these fish swim continuously near the surface. Adult specimens may require aquariums exceeding 300 cm (10 feet) in length.

This species is considered exotic and is suitable only for experienced aquarists who can provide the required space, filtration, and long-term care. Silver Arowanas produce significant waste and require powerful filtration and regular water changes.

Food and Feeding

Silver Arowanas are carnivorous predators that feed primarily at the water surface. In the aquarium, they should be offered a varied diet of meaty foods. Suitable foods include shrimp, mussels, fish fillets, insects, krill, and high-quality carnivorous fish pellets.

Juveniles may initially prefer live foods, but they should be trained to accept frozen or prepared foods. Avoid feeding live feeder fish regularly, as these may introduce parasites and provide poor nutrition. Feeding once daily is usually sufficient for adults.

Origin

Osteoglossum bicirrhosum originates from the Amazon basin in South America. They inhabit slow-moving rivers, floodplains, and forested waterways. These habitats often contain submerged branches and floating vegetation, providing hunting opportunities near the surface.

Tank Setup and General Care

A large aquarium with open swimming space is essential. Decorations should be minimal and smooth to prevent injuries. Floating plants may be used, but ensure they do not obstruct swimming space. Strong filtration and excellent water quality are required.

Because Silver Arowanas are powerful jumpers, the aquarium must have a tightly fitted lid. Even small openings may allow them to escape. Soft to slightly acidic water is preferred, although they are adaptable if water quality is maintained.

Temperament and Compatibility

Silver Arowanas are generally calm but predatory. They will eat smaller fish that fit into their mouth. Suitable tank mates include large peaceful species such as large catfish, stingrays, or other large non-aggressive fish. Avoid small community fish.

Keeping multiple Arowanas together is difficult and usually results in aggression unless the aquarium is extremely large.

Sexing

Sexing Silver Arowanas is difficult. Mature males may develop a slightly larger mouth due to mouthbrooding behavior. Otherwise, there are no reliable visual differences between sexes.

Breeding

Silver Arowanas are paternal mouthbrooders. After spawning, the male collects the eggs and incubates them in his mouth. The incubation period is long, and the male releases large, well-developed fry. Breeding in aquariums is rare due to the large space required.

Lifespan

With proper care, Silver Arowanas can live between 10 and 15 years. Large aquariums, excellent water quality, and a varied diet contribute to their longevity.