Parâmetros sangüíneos de pacu Piaractus mesopotamicus Piaractus mesopotamicus

Hematological parameters of pacu Piaractus mesopotamicus (Holmberg, 1887) fed diets supplemented with trivalent chromium in two stocking densities. This work evaluated the effects of chromium supplementation on the hematological parameters of Piaractus mesopotamicus Holmberg, 1887 maintained in two stocking densities. Fish were fed diets supplemented with 0, 6, 12 and 18 mg trivalent chromium kg -1 dry ration and maintained at 4 and 20 kg m -3 . The fish under high stocking density and fed diets supplemented with 0 and 6 mg kg -1 showed reduction in the number lymphocytes, which suggests non-adaptation to this condition of high density. This was not observed in fish fed diets supplemented with 12 and 18 mg chromium kg -1 , but an increase in the number of thrombocytes was evident. The lack of difference between treatments after 30 days may suggest a possible adaptation of fish to the situation. It can be added that supplementation with 12 and 18 mg chromium kg -1 is an interesting feeding strategy for a