Tambaqui

Water parameters

Minimum tank: 3000 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 5000 g adult eats about 60.0 g of feed per day at optimum. 10 fish at adult size: ~600 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 and Orinoco basins of tropical South America, in floodplain lakes, river channels and seasonally flooded forest. It is the largest member of the family Serrasalmidae, the group that also holds piranhas, the heaviest characin in the Americas and, after the arapaima, the second-heaviest scaled freshwater fish on the continent. Tambaqui reaches about 1.1 m and 44 kg, though most fish are nearer 70 cm, and farmed fish are taken at 1–3 kg. It is mainly a fruit and seed eater, using molar-like teeth to crush nuts and seeds that drop from flooded-forest trees, while long gill rakers also let it filter zooplankton. The flesh is firm, mild and moderately fatty, and the fish is prized across Brazil, Colombia and Peru. It is the most important native food fish in the Amazon and the leading native species in South American aquaculture; in Brazil the native round-fish group of tambaqui, pacu, pirapitinga and their hybrids totals well over a hundred thousand tonnes a year, behind only tilapia.

Climate and outdoor ponds

Climate

tropical (needs warm water year-round)

USDA zones

11–13 (winter low around 4°C or warmer)

Heating needed

yes

Cooling needed

no

Care notes

The benchmark warm-water food fish for tropical South American aquaponics. It grows well between about 25°C and 32°C, does poorly below 23°C, and dies if water stays under roughly 15°C for several days, so it needs heated water outside the tropics. Growth is quick, around 1–2 kg in 8 to 12 months on commercial pellet of 28 to 35 percent protein, with feed conversion reported from about 1.5 to 2.5 depending on the system. The fruit-and-seed feeding habit is a real advantage: tambaqui readily take fruit, seeds, duckweed and vegetable trimmings, trimming pellet costs in integrated systems. Stock around {density:15}-{density:30}, keep dissolved oxygen above about 3 mg/L and pH between 6 and 8. They shoal and do best in groups, and cannibalism is minor given the plant-based diet. Fingerlings are widely sold by hatcheries in Brazil, Colombia and Peru. The widely farmed tambacu is a cross of female tambaqui with male pacu, Piaractus mesopotamicus, valued for faster growth, disease resistance and better cold tolerance; the cross with pirapitinga, Piaractus brachypomus, is instead called tambatinga. In the United States, Colossoma is prohibited or restricted in several states, so check local rules before stocking.

Further reading

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