Biofloc technology in recirculating aquaculture system as a culture model for green tiger shrimp, Penaeus semisulcatus: Effects of different feeding rates and stocking densities

Abstract

In this study, two different experiments were carried out in green tiger shrimp to evaluate the culture conditions under BFT and clear water applications using recirculation aquaculture systems (RAS). In the first experiment, the effects of four different feeding rates (3, 6, 9 and 12% body weight (BW) day−1) were determined comparatively in BFT and clear water systems (control), three per treatment. The second trial was conducted in BFT and control with four different test stocking densities (10, 20, 30 and 40 shrimps 0.24 m−2) three per treatment. These stocking densities were 41.67, 83.33, 125, 166.67 shrimps, respectively, per square meter. The feeding rate in Trial II was the optimum feed rate obtained from the first trial. In both trials, some water quality parameters such as alkalinity, ammonia, nitrite and nitrate were different between the two RAS. In Trial I, among the groups, best growth performance was observed in 6% BW day−1 feeding group in terms of weight gain and survival rate. In Trial II, better growth parameters were recorded with regard to weight gain and survival rate in all BFT groups than the control group. The best growth performance was found in the BFT group, having stocking density at 20 shrimps 0.24 m−2. According to histopathological evaluation, no pathological findings were detected in all groups. In both trials, BFT groups showed higher total bacteria counts than control groups. These results showed that green tiger shrimp could be cultured with better growth performance with a feeding rate of 6% BW day−1 and 20 shrimp 0.24 m−2 stocking density in BFT.