Asian Arowana
- Aquarium size — from 1000 L
- Temperature — 24–30°C
- pH — 6.0–7.5
- Water hardness — soft to medium (2–15 dGH)
- Substrate — any
- Lighting — dim to moderate
- Brackish water — no
- Water movement — weak or none
- Adult size — up to 90 cm
- Diet — live and meaty foods
- Temperament — territorial, aggressive
Overview
The Asian Arowana, Scleropages formosus, is one of the most famous and expensive ornamental fish in the world. It belongs to the ancient family Osteoglossidae and is often associated with the so‑called “dragon fish” in East Asian culture. Due to its resemblance to the Chinese dragon, a symbol of prosperity and good fortune, the species has become a status symbol and is highly prized by collectors.
Because of heavy fishing pressure and habitat loss, wild populations of Asian Arowana declined sharply, and the species is now listed on CITES and protected by law. Wild‑caught export is prohibited, and fish sold for the aquarium trade come from licensed farms that breed the species in captivity. Each legally farmed specimen carries an individual microchip and certificate to confirm its origin.
Habitat
Asian Arowanas are distributed across much of Southeast Asia, including parts of Malaysia, Indonesia and surrounding archipelagos. They inhabit slow‑moving or standing waters such as blackwater rivers, forest streams, flooded forests, backwaters and swampy lakes. These habitats are typically shaded, with overhanging vegetation, submerged roots and branches.
The water in their natural environment is usually warm, soft and slightly acidic, enriched with humic substances from decaying plant material. In the aquarium it is recommended to provide similar conditions: clean, well‑filtered water with stable parameters, moderate lighting and some driftwood, branches and plants to create shaded areas.
Description
Adult Asian Arowanas can reach around 90 cm in length. They have an elongated body, large pectoral fins and dorsal and anal fins set far back toward the tail. Compared with the Silver Arowana, the caudal fin is larger and more rounded. The scales are very large, each one reaching up to 2 cm in diameter, and form clearly visible rows along the body.
The coloration varies widely depending on the geographic form and selective breeding. Common varieties include green, silver, golden and several red forms, with the red and gold strains being especially valuable. Strong, even colour and clean scale pattern are highly prized traits in the ornamental fish trade.
Behavior and compatibility
In the wild Asian Arowanas are surface‑dwelling predators that patrol the upper water layers, often staying near overhanging vegetation and submerged structures where potential prey may appear. They are most active at dusk and during the night. In captivity they are territorial and generally kept singly to avoid aggression.
Suitable tank mates include large, robust bottom dwellers or mid‑water fish that are too big to be swallowed, such as large catfish or some big characins. Small fish are quickly eaten, and similar surface‑dwelling predators may compete for space, so such combinations are best avoided.
Care and aquarium setup
Asian Arowanas require very spacious aquariums of 1000 litres or more, with a long footprint and secure, tight‑fitting cover. These fish are powerful jumpers and can easily exit the tank if given the chance. The décor should provide open swimming space at the surface, with vertical pieces of driftwood and roots breaking up the line of sight and adding a natural feel.
Soft, slightly acidic water enriched with tannins is considered ideal. This can be achieved using peat, leaf litter or commercially available blackwater extracts, as well as natural décor pieces such as bark and dried leaves. Filtration must be strong and reliable, and regular water changes are crucial, because large carnivorous fish produce considerable waste.
Feeding
The long‑term health of Asian Arowanas depends heavily on a properly varied diet. In the wild they prey on fish, insects, amphibians and other animals that fall or move near the water surface. In captivity they should be fed live or frozen foods such as shrimp, crickets, mealworms, earthworms, feeder fish from safe sources and other similar items.
Many farmed fish are trained to accept high‑quality floating pellets for large carnivores, which can be used as part of the diet. However, just like with the Silver Arowana, mammal and poultry meat should be avoided due to inappropriate fat composition. A varied menu helps support strong colour, proper growth and a robust immune system.