Growth and Hematology of Juvenile Piaractus Mesopotamicus Stocked At 10 Up To 40kg/m3 For Twenty-One Days

Pacu Piaractus mesopotamicus, a freshwater fish, has great potential for intensive commercial production, showing resistance to adverse conditions, such as high stocking density. Growth performance and hematological condition were evaluated in juvenile pacu stocked at high density. Juveniles were distributed into different stocking densities: 10, 20, 30 and 40kg of fish/m3 (n=4) and fed with a commercial feed for 21 days. Growth data were collected at 0 and 21 days and blood samples every 7 days. Differences were not detected in performance of pacu under different stocking densities (P > 0.05). Feed conversion rate (3.9±0.5) and specific growth rate (4.0±0.1%/ day) were worse than normally observed at this stage of life, indicating an unsuitable condition. Hematocrit of juveniles stocked at 30 and 40kg/m3 showed higher values than ones at 10kg/m3. Thus, stocking density from 10 up to 40kg/m3 did not affect growth and hematology of pacu after 21 days. However, the low growth rates indicate that all stocking densities could have determined an adverse condition to fish. Considering the high stocking density used in the present work and the intensive management without mortality, we suggest that pacu is very resistant and a promising species for fisheries.