Pirapatinga

Water parameters

Minimum tank: 2500 L per individual at harvest size.

Feed and growth

Feed protein

30% target

Daily feed (warm)

1.20% of body weight

Daily feed (cool)

0.50% of body weight

Max density

30 g per litre

A 25000 g adult eats about 300.0 g of feed per day at optimum. 10 fish at adult size: ~3000 g daily.

Legality

Rules vary by jurisdiction and change over time. Verify with your local fisheries or wildlife authority before stocking.

Unlisted jurisdictions default to "check local regulations".

Origin and habitat

Native to the Amazon basin of tropical South America. Populations once lumped into this species from the Orinoco were described in 2019 as a separate fish, Piaractus orinoquensis, so the name now applies mainly to Amazonian stock. It belongs to the family Serrasalmidae, the group that also holds piranhas and the related tambaqui, Colossoma macropomum. Juveniles show the red to orange belly behind the common name red-bellied pacu; the fish is also called pirapitinga and cachama blanca. It grows to about 88 cm and 25 kg in the wild, while farmed fish are harvested near 0.8–2 kg. Feeding is mostly frugivorous, taking fruit, seeds and nuts in flooded forest, but the fish is opportunistic and will also eat zooplankton, insects, crustaceans and small fish, especially in the dry season. The flesh is white, firm and mild with moderate fat. The species is farmed across South America and has been moved into aquaculture in tropical Asia.

Climate and outdoor ponds

Climate

tropical (needs warm water year-round)

USDA zones

10–13 (winter low around -1°C or warmer)

Heating needed

yes

Cooling needed

no

Care notes

A warm-water food fish for tropical aquaponics, close in its needs to tambaqui. The reported optimum sits near 26°C, with growth slowing as water cools and the fish needing heated water outside the tropics. Farmed fish reach roughly 0.8–1.5 kg in 10 to 14 months on commercial pellet of about 24 to 35 percent protein, with feed conversion around 1.4 to 1.9. Because the species eats so much plant matter, fruit and vegetable trimmings can offset part of the pellet ration in integrated systems. Stocking is moderate, around {density:15}-{density:30}, and water-quality tolerance is fair: keep dissolved oxygen above about 3 mg/L, pH near 6 to 8 and ammonia low. These are social fish that do better in small groups, and because they feed mainly on plants, cannibalism is less of a concern than with predatory species, though size-grading still helps. Fingerlings come from hatcheries in Brazil, Colombia and tropical Asia. In Brazilian farming the pirapitinga is crossed with tambaqui to make the tambatinga hybrid; the better-known tambacu is a different cross, tambaqui with the southern pacu Piaractus mesopotamicus. In the United States it is regulated like other pacu, so check state rules before stocking.

Further reading

• Aquaponics water chemistry: balancing pH for fish and plants
• Fish for aquaponics: tilapia vs everything else