Influência de diferentes densidades de estocagem no desempenho produtivo de tilápia do Nilo Oreochromis niloticus (Linnaeus, 1758) cultivada com tecnologia de bioflocos

Abstract

Among alternatives of aquaculture production with limited water use for fish farming, the biofloc technology of densities with good production results. Thus, the present study evaluated different stocking densities with biofloc technology, in the nursery and growout phases of Nile tilapia Oreochromis niloticus. The nursery phase lasted 67 days and the tanks were stocked with fingerlings (5.71 g) of tilapia sexually reversed. Treatments consisted of three different stocking densities, with three replicates: 1) D200 (200 fishes.m-3); 2) D350 (350 fishes.m-3) and 3) D500 (500 fishes.m-3). The water quality variables showed no significant difference among treatments (P ≥ 0.05). The best performance was obtained at density of 200 fishes.m-3, with a weight gain of 69.47 g, specific growth rate of 3.71%.day-1, feed conversion ratio of 1.20 and survival of 82.62%. Growout phase lasted 128 days and the tanks were stocked with juveniles (123.3 g) of tilapia using three treatments and four replicates involving different stocking densities: 1) D15 (15 fishes.m-3); 2) D30 (30 fishes.m-3) and 3) D45 (45 fishes.m-3). The best performance was obtained in the density of 45 fishes.m-3, with final weight of 404.37 g, specific growth rate of 0.93%. day-1, survival of 90.97% and feed conversion ratio of 1.6. The use of bioflocs technology presents by itself as a good choice for tilapia intensive production, besides to being a compatible technique with the principles of sustainability, make possible the stocking and productivity of 200 fishes.m-3 with 12.44 Kg.m-3, and 45 fishes.m-3 with 16.57 Kg.m-3, respectively for nursery and growout phases.