Breeding / Mouthbrooders

Mouthbrooders · Hard

Breeding the asian arowana

Paternal mouthbrooder. After a courtship of weeks to months the female releases a cluster of orange-red eggs, the male fertilises them and takes them into his mouth; they hatch in about a week and the larvae stay in his mouth for another 7-8 weeks. Bred commercially in outdoor pools by registered (CITES) farms in Asia.

Full species page

Step by step

Pairing

Raise 6-8 juveniles together and let a pair form; this takes years.

Breeding tank

A 10,000 L+ pond or very large tank with excellent filtration and a secure lid.

What starts it

Stable warm water and a mature pair of 4+ years.

Eggs and young

Small clutches of large eggs (FishBase uses a fecundity of about 50 from concrete-tank breeding). The male broods about 8-9 weeks in all (about 1 week to hatching plus 7-8 weeks with larvae); young are about 6 cm when released.

Raising the fry

Fry leave the mouth at 5-6 cm with a yolk sac; feed live food and large pellets and grow them out separately.

Common mistakes

Keeping without CITES papers
Overcrowded rearing
Letting the fish jump out

Setup blueprint

Home setup

One breeding tank for the asian arowana, drawn to scale from the breeding guide.

Breeding tank: 10,000 L · about 540 × 125 × 150 cm, 10,000 L from the breeding guide
Sponge filter and air pump · gentle and safe for eggs and fry
Heater, 22–28 °C · this species' normal range
Cave · typical for this breeding type
Lid · from the guide

Water: 22–28 °C · pH 6–7.5

A plan from the breeding guide and an adult size of 90 cm. Tank shape is a standard 2 : 1 : 1.2 box, at least 6 adult lengths long. Check each step in the guide above.

Setup blueprint

Business setup

A row of tanks on their own stands for breeding the asian arowana in numbers.

1 breeding tank, 10,000 L · about 540 × 125 × 150 cm, set up like the home tank
2 grow-out tanks, 20,000 L each · about 540 × 175 × 210 cm; twice the breeding tank, never smaller than this species' smallest tank
Shared air pump and air line · one line along each shelf feeds a sponge filter in every tank
Heat the room or each tank · 22–28 °C

In total: 3 tanks, about 50,000 L of water. A litre of water weighs about 1 kg, so check that the floor and rack can take the weight.

Sizes are worked out from the breeding tank in the guide. Tanks fit a standard 120 cm rack when they can; bigger tanks go on their own stands.

Male or female

Male: Slimmer, longer lower jaw and wider mouth
Female: Deeper body, shorter jaw
Mouthbrooding males; confirmation by DNA or ultrasound

Can I breed it in my tank?

Your tank (litres of water)

Hard: for experienced breeders.

Day-by-day plan

Typical for mouthbrooders

Spawning date

21 days beforeGroup and condition
Usually one male with several females. Feed high-quality food.
Day 0Spawning
The female takes the eggs into her mouth and stops eating.
Day 21Release
After about 3 weeks the female releases fully formed fry. Many breeders move her to a quiet tank first.
Day 21First food
Fry eat crushed flake and baby brine shrimp straight away.
Day 90Grow-out
Fry are a few centimetres long after about 3 months.

A general guide for this breeding type. Days change with temperature and species.

Simulator: guided

Stage 1 of 5Group and condition

Usually one male with several females. Feed high-quality food.

Simulator: try it yourself

Set up a virtual breeding tank and see what would likely happen.

Temperature: 25 °C

Condition with live or frozen foodBig, cool water changePlants, mops or a breeding boxRemove the parents after spawning

No spawning

Without live or frozen food the parents aren't in breeding condition.

An educational estimate from the breeding rules, not a promise.