Silver Arowana
Silver Arowana
Silver Arowana (Osteoglossum bicirrhosum) is one of the most ancient and spectacular freshwater fish in the hobby — a living fossil whose lineage dates back to the Jurassic period. The elongated, silver-scaled body, large upturned mouth with bony tongue, and flowing dorsal and anal fins create a fish of extraordinary presence. Juveniles are one of the most frequently impulse-purchased and subsequently rehomed fish in the hobby due to their rapid growth rate.
Feeding & Care Tip: Hikari Micro Pellets and Hikari Sinking Wafers are good dry food staples. Supplement regularly with Hikari Frozen or Freeze-Dried Bloodworms, Hikari Frozen or Freeze-Dried Brine Shrimp, and surface insects (crickets, mealworms). Silver Arowanas are surface feeders — all food should be offered at or near the surface. A very tight-fitting lid is absolutely essential — Arowanas are extraordinary jumpers.
⚠ Size Warning: Silver Arowanas are commonly sold as attractive juveniles of 4–6 inches. They grow rapidly to 35–40 inches (90–100 cm) and require an aquarium of at least 250 gallons as adults. Juveniles outgrow a standard aquarium within 12–18 months. Purchase only if you can commit to providing an appropriately large long-term setup. In many US states, Arowanas require a permit to keep.
Native to the floodplains of the Amazon basin — Brazil, Peru, and Colombia. Wild Silver Arowanas are mouthbrooders — the male carries the eggs and young fry in his mouth. In the wild they reach 35–40 inches; in captivity 25–30 inches is typical. In many US states, Arowanas require a permit to own. Check your local regulations before purchasing.
Silver Arowanas grow fast — a 4-inch juvenile can reach 12 inches within a year and 20 inches within two. A 250-gallon aquarium minimum is needed for an adult, with a 6-foot length minimum. Compatible with large, robust fish that cannot be swallowed — large cichlids, large catfish, and large plecos. Any fish that fits in the Arowana's large mouth will be eaten.
The Silver Arowana is a fish for dedicated, experienced aquarists with the infrastructure to house it properly. In the right setup it is one of the most magnificent freshwater fish available — a living connection to the Jurassic age that rewards the commitment it requires.
Care & Ideal Parameters
| Difficulty | Advanced |
| Temperament | Predatory — large fish only |
| Typical Adult Size | 25–30 inches (64–76 cm) in captivity |
| Min. Group Size | Singly — 250+ gallon minimum for adults |
| Ideal Temp | 75–84°F (24–29°C) |
| Ideal pH | 6.0–7.5 |
| Ideal GH | 2–12 dGH |
| Ideal KH | 0–6 dKH |
| Staple Food | Hikari Micro Pellets; Hikari Sinking Wafers |
| Treat / Supplement | Hikari Frozen or Freeze-Dried Bloodworms; Hikari Frozen or Freeze-Dried Brine Shrimp; surface insects |
| Origin | Amazon basin floodplains, Brazil, Peru, Colombia |
| Notes | Grows to 25–30 inches in captivity — 250+ gallon tank required as adult. Extraordinary jumper — heavy sealed lid essential. Permit required in many US states. Mouthbrooder in wild. Ancient lineage — Jurassic era. |
