Osteoglossum bicirrhosum

Silver Arowana from the Amazon River

09/04/2021 Off By Andy Ptyushkin

The Silver Arowana (Osteoglossum bicirrhosum) is a South American freshwater bony fish family Osteoglossidae. Silver Arowana’s are sometimes kept in aquariums, but they are predatory and require a very large tank.

This fish has relatively large scales, a long body, and a tapered tail, with the dorsal and anal fins extending all the way to the small caudal fin, with which they are nearly fused. Its maximum total length is typically considered to be 0.9 m (3.0 ft), but there are reports of individuals up to 1.2 m (3.9 ft). Unlike the black Arowana, the silver Arowana has the same colouring throughout its lifespan. Adults of the two species are very similar but can be separated by meristics.

Rio Branco

Rio Branco

This South American species is native to the Amazon, Essequibo, and Oyapock. It is absent from the Rio Negro basin, except the Branco River, which is inhabited by both silver and black Arowanas.

Tends to inhabit slow-moving to still tributaries, backwaters, and lagoons during the dry season, and moves into areas of flooded forest during periods of inundation.

It’s chiefly a surface dweller preying on smaller fishes and terrestrial insects and is famed for its ability to leap high out of the water to catch the latter.

Relatively unfussy although some surface cover in the form of floating or overhanging vegetation or branches is appreciated.

This species is a generalised predator with intestinal analyses of wild specimens revealing the natural diet to consist of other fishes, terrestrial insects, aquatic invertebrates, and plant material in the form of fallen nuts and fruits. Smaller specimens can be offered bloodworms, small earthworms, chopped prawns, and suchlike while adults will accept strips of fish flesh, whole prawns/shrimp, mussels, live river shrimp, larger earthworms, etc.

The Silver Arowana is often kept as a pet by experienced aquarists, being considered an accessible substitute for the Asian Arowana.