The development of sustainable production systems, that uses less water and energy consumption, are become important in recent years. Among these options based on aquaculture, it can be mentioned recirculating aquaculture systems (RAS). Studies regarding stocking densities of tilapia crops have been carried out in RAS; those studies shows that in intensive crops, physical variables such as water temperature influence the growth of the fish, but also affected the quality of the meat produced. Previous research have not reported the effect of these variables on intensive crops, considering the maximum cultivation capacity for tilapia without sacrificing production or product quality. Thus, the aim of this study is to determine the optimal conditions of stocking density and water temperature to obtain the highest levels of growth and nutritional meet quality of tilapia in a recirculating aquaculture system.
Optimal conditions to obtain the highest growth levels and nutritional quality on tilapia (Oreochromis niloticus) in a recirculating aquaculture system were evaluated. During 60 days, fish were cultivated considering three cultivation densities (67, 135 and 270 fishes/m3) and water with and without temperature control (28 °C and environmental temperature). Water quality was measured through the determination of temperature, pH and dissolved oxygen. Biometric data were registered throughout the growth of fish, along with the determination of moisture, total ash, total lipids and protein on tilapia fillet. Results showed that temperature and stocking density did not impact on survival rate of tilapia fish; however, specific growth rate for the farmed fish was higher at 28 °C (Table 1). In addition, higher moisture percentage values ??were observed in tilapia fillet cultivated at 28 °C; while, those fillet obtained from cultivation at room temperature showed percentage higher values ??of ash and total fat. There was no significant difference between the treatments respect to percentage of total ashes and protein (Table 2). Treatments with the lowest density, with and without temperature control, presented the greatest significant difference in percentage of total fats. Overall, according to the results a culture with a density of 270 fish/m3 (equivalent to 80 kg/m3) to harvest of tilapia can be carried out without affecting the growth and quality of product, as long as there was a control system for physical conditions of the fish culture, such as temperature at 28 °C and oxygenation, main