Arowana

Also known as: Scleropages formosus

The Asian Arowana (Scleropages formosus) is a large, elongated freshwater fish known for its metallic scales and barbels. The Arowana originates from Southeast Asia, including Malaysia, Indonesia, and Thailand, inhabiting slow-moving blackwater rivers and peat swamps with dense vegetation., reaches Adult size: 90 cm in captivity, typically lives 10-15 years, and is kept at 24-28°C (75-82°F). Individual fish vary, so treat this as a general guide rather than a guarantee.

Species at a glance

Origin: Southeast Asia, including Malaysia, Indonesia, and Thailand, inhabiting slow-moving blackwater rivers and peat swamps with dense vegetation.
Adult size: Adult size: 90 cm (35 inches)
Life span: 10-15 years
Temperament: Solitary, territorial, and highly aggressive toward conspecifics and similarly sized fish; best kept alone.
Tank size: Minimum 1135 liters (300 gallons)
Water temp: 24-28°C (75-82°F)
pH range: 6.0-7.0
Diet: Carnivorous; feeds on live fish, insects, crustaceans, and high-protein pellets; requires varied diet to prevent nutritional deficiencies.
Other names: Scleropages formosus

About the Arowana

The Asian Arowana (Scleropages formosus) is a large, elongated freshwater fish known for its metallic scales and barbels. It is a surface-dwelling predator that jumps to catch prey above water. Due to its size, aggression, and specific care needs, it is considered a 'monster fish' unsuitable for most home aquariums. Wild populations are endangered due to habitat loss and overcollection for the aquarium trade.

Lifespan and health

With optimal care, Asian Arowanas commonly live 10-15 years in captivity, though exceptional specimens may reach 20 years; longevity depends heavily on diet, water quality, and stress reduction. Common health issues include drop-eye (caused by poor diet or substrate irritation), fin rot from bacterial infections in suboptimal water, and parasitic infestations like ich or flukes; obesity and swim bladder disorders are also prevalent from overfeeding or inappropriate food types. Preventative care includes maintaining pH 6.0-7.0, temperature stability within ±1°C, providing a varied diet with vitamin supplementation, and avoiding sharp decorations; quarantine new food sources and observe for signs of lethargy, loss of appetite, or abnormal swimming behavior.

Overview

Care and tank setup

Tank setup requires a minimum of 1135 liters (300 gallons) with a long, wide footprint to accommodate swimming; use a tight-fitting, weighted lid as Arowanas are powerful jumpers. Substrate should be soft sand or fine gravel, with minimal decor to avoid injury; driftwood and hardy plants like Anubias can be added for cover but must be securely anchored. Water must be exceptionally clean with strong filtration (turnover rate 6-8x tank volume per hour) and weekly 25% water changes to maintain low nitrates (<20 ppm). Feeding should occur 2-3 times weekly with live or frozen foods such as feeder fish, shrimp, or crickets, supplemented with high-quality carnivore pellets; avoid overfeeding to prevent obesity and water quality issues. Tankmates are not recommended due to extreme aggression; if attempted, only very large, fast-moving species like certain catfish or plecos may coexist, but success is rare and monitoring is essential.

Adding a Arowana? Research the species’ adult size and temperament carefully, quarantine new fish before introducing them to your tank, and buy from reputable aquarium stores or breeders.

Breed information on this page is based on the Wikipedia article on the Arowana, supplemented with additional research. Reviewed for accuracy.