The aim of this study was to evaluate management, erythrocyte features and blood glucose level of pacu (Piaractus mesopotamicus), stocked at different densities in cages. It was used 2,700 fish with initial average weight of142.11 ± 10.54 g distributed in nine cages of 5 m³ of useful volume during 240 days. A complete random design was used, with three densities (200, 300 and 400 fish per cage), each one with three replicates. Only final weight and weight gain decreased with the increase of stocking density. Final biomass increase according to the number of animals stocked per productive unit. Densities of farming did not influence carcass yield, but they affected total length, which was higher in fish raised in low density, which did not differ from those raised in intermediate density. Fish raised in lower density showed the greatest lipid deposition, but they did not significantly differ from those stocked in intermediate density. Erythrocyte variables like total erythrocytes, hemoglobin, hematocrit, average corpuscular volume, average corpuscular hemoglobin concentrations and average corpuscular hemoglobin did not present statistical differences among the used densities and they remain in the normal range for the species. Levels of glucose in the blood did not differ significantly among the analyzed densities. Stocking densities do not influence erythrocyte parameters, glucose level neither carcass yields of pacu fish. Density 200 fish/cage results in higher final weight and weight gain; however, it reduces productivity per area and increases lipid deposition of the fish.
hematological parameters; intensive rearing; native species; performance; Piaractus mesopotamicus
