Rearing of fat snook (“Centropomus parallelus”) at different stocking densities

Abstract

Studies on the effect of stocking density on the growth of fat snook Centropomus parallelus were conducted in floating net cages in the north coast of the State of São Paulo, in Ubatuba City. Juveniles weighing 32.53 ± 6.54 g were stocked in densities of 20 and 40 fish/m3 and appraised for 160 days. Fish were fed commercial diet with 40% of crude protein, supplied twice a day, at the rate of 3% biomass of each tank-net. The environmental variables (water temperature, oxygen level, salinity and transparency) were according to the parameters considered ideals for the species. Survival and the apparent feed conversion were not different (p <0.05) between the treatments. The mean final weights, specific growth rate and daily gain weight, indicated that the treatment of lower density was (p <0.05) superior to higher density. In relation to total weight gain, an accretion was observed of 98.6 and 87.9 g for the densities of 20 and 40 fishes/ m3, respectively. However, final biomass was superior (p<0.05) for the treatment with higher density, demonstrating a straight relationship between density and biomass production observed in the fish farming.