It was performed in this work the economic analysis of juvenile Nile Tilapia farming using different stocking densities. The experiment was carried out in an aquaculture area, using random block designs with four stocking densities (100, 200, 300 and 400 fish m-3), evaluated with six replicates, in two rearing periods: from March to April, 2005 (52 days - initial weight 43.08 ± 2.98 and final weight of 262.14 ± 47.86 g) and from March to April 2006 (58 days - initial weight of 43.16 ± 5.34 g and final weight of 314.24 ± 73.30 g). The following economic variables were analyzed: ration cost plus unit cost of juvenile divided by biomass, in R$ kg-1; percentage of ration cost per kilogram of fish produced upon sales price; percentage of juvenile cost per kilogram of fish produced upon sales price and percentage of ration costs plus juvenile cost per kilogram of fish produced upon sales price. From the smallest (100) to the highest stocking density (400), there was a decrease in the daily weight gain and an increase in the apparent feed conversion index, but this reduction did not compromise survival rate. However, the biomass gain increased with fish crowding. The highest net incomes were obtained in stocking densities of 100 and 200 fish m-3. The prices used did not remunerate the operational costs (effective and total costs), at higher densities (300 and 400 fish m-3). The best results for the juvenile Nile Tilapia breeding were obtained using densities of up to 200 fish m-3.
economical variables; farm fishing; intensive system; revenue; zootecnic parameters
