Pacu Tank Stocking

Pacu Stocking Density Calculator (Piaractus mesopotamicus)

A close cousin of the tambaqui, the pacu comes from the Paraná-Paraguay basin and shows up constantly in pesque-pague (pay-to-fish) operations around São Paulo, Mato Grosso do Sul and Minas Gerais. For earthen ponds, the recommended stocking density sits at 1–2 kg/m³. That is a touch below tambaqui, since pacu is the more active swimmer of the two. Convert the tank volume with m³ = L ÷ 1000, then multiply by your target density to land on the total biomass.

Reaching the commercial size of 1–1.5 kg takes 10–14 months, with the water held between 25 and 30°C. Pacu shrugs off parasites and puts up with handling, which is why it suits sport fishing so well, where the same fish gets caught and released over and over. EMBRAPA keeps research programmes going on the Pacu/Pintado-Bagre cross and on selective breeding for faster growth.

Applications

The people using it range widely: pesque-pague operators in São Paulo and Mato Grosso do Sul stocking their sport-fishing ponds, family fish farmers selling into regional markets, restocking programmes for rivers in the Paraná-Paraguay basin, and rural extensionists mapping out polyculture with tambaqui or curimbatá.

FAQ

What is the difference between pacu and tambaqui? They share the family Serrasalmidae and look a lot alike, but pacu (Piaractus) belongs to the Paraná-Paraguay system whereas tambaqui (Colossoma) is Amazonian. Pacu also stays smaller as an adult and carries finer scales.

Can I mix pacu with tilapia? You can. The polyculture works because pacu eats as an omnivore-fruitivore while tilapia filters plankton, so the two end up working different feeding niches in the same pond.

How many fingerlings per 1000 L? Start with roughly 1 to 2 fingerlings of 30 g, which end up as 1 to 2 adults of 1–1.5 kg by harvest, keeping to that 1–2 kg/m³ target.