Breeding / Egg scatterers

Egg scatterers · Hard

Breeding the black pacu

Not bred in home aquaria; bred in large numbers for food in South America and Asia, often using hormone-induced spawning.

Full species page

Step by step

Pairing

Needs a school of 6+ in a large tank; ripe females swell with eggs.

Breeding tank

Very large tank or pond with floating plants or mops, soft slightly acidic water and warm temperatures.

What starts it

Rainy-season style water changes with soft, slightly cooler water and plenty of greens and protein.

Eggs and young

Very fecund: FishBase gives a fecundity of 7,000-300,000 eggs per female. Sexual maturity at about 60-62 cm, at 7-10 years old in the wild.

Raising the fry

Fry take powdered food and brine shrimp nauplii, then chopped greens; grow fast and need space.

Common mistakes

Tank too small
Keeping too few fish
No cover for the eggs

Setup blueprint

Home setup

One breeding tank for the black pacu, drawn to scale from the breeding guide.

Breeding tank: 2,550 L · about 360 × 75 × 90 cm, the guide gives no size, so this is the smallest tank for this species
Sponge filter and air pump · gentle and safe for eggs and fry
Heater, 22–28 °C · this species' normal range
Spawning mop · named in the guide
Floating plants · named in the guide

Water: 22–28 °C · pH 5.5–7.5 · soft water

A plan from the breeding guide and an adult size of 60 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 black pacu in numbers.

1 breeding tank, 2,550 L · about 360 × 75 × 90 cm, set up like the home tank
2 grow-out tanks, 5,100 L each · about 360 × 110 × 130 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 12,750 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

Mature females are a little rounder-bellied than males; juveniles cannot be sexed.

Can I breed it in my tank?

Your tank (litres of water)

Use a separate small tank with a sponge filter and spawning mops, so the eggs aren't eaten.
Hard: for experienced breeders.

Day-by-day plan

Typical for egg scatterers

Spawning date

14 days beforeCondition the parents
Feed live or frozen food twice a day. Keep males and females apart if you can.
Day 0Spawning
Eggs are scattered over mops or fine plants, often at first light. Remove the parents straight after.
Day 1Eggs hatch
Most eggs hatch in 1–2 days. Keep the tank dim and remove white (fungused) eggs.
Day 4Free swimming, first food
Fry use up the yolk and start swimming. Feed infusoria or liquid fry food several times a day.
Day 8Baby brine shrimp
Switch to newly hatched brine shrimp or microworms. Start small, daily water changes.
Day 21Crushed flake
Add finely crushed flake. Sort fry by size so the big ones don't eat the small ones.
Day 60Ready to move
Most small fish reach about 2 cm in 2–3 months and can join the main tank.

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

Simulator: guided

Stage 1 of 7Condition the parents

Feed live or frozen food twice a day. Keep males and females apart if you can.

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.