Abstract Most farmed shrimp worldwide are Indo-Pacific warm-water species and cannot be efficiently or economically cultivated in high-latitude regions due to falling water temperatures during autumn and winter. Consequently, indoor aquaculture systems are essential for maintaining production efficiency and ensuring biosecurity in these areas. We examined inorganic nitrogen dynamics of the water, feed utilisation, growth performance, and proximate composition of the Pacific white shrimp, Litopenaeus vannamei (Boone, 1931), and biofloc in a 42-day indoor culture treatment using biofloc technology (BFT) and a recirculating aquaculture system (RAS). Three sets of four treatments were evaluated under limited water-exchange conditions: BFT1 (C:N = 6; carbon supplementation only), BFT2 (C:N = 9; feed supplementation only), BFT3 (C:N = 15; feed plus carbon supplementation), and RAS (feed supplementation in a clean-water recirculating system). No significant variations were seen in the physicochemical parameters of water, as well as in suspended solids, volatile suspended solids, and total suspended solids (P 0.05), although total ammonia nitrogen, NO2−, NO3−, and total inorganic nitrogen exhibited substantial change across the treatments (P 0.05). The BFT2 and BFT3 treatments exhibited the best growth and the lowest feed conversion ratio (FCR), succeeded by the RAS system. The protein and lipid content of shrimp and biofloc exhibited significant differences among the treatments (P 0.05); however, moisture and ash content did not show significant differences (P 0.05). In the BFT systems, biofloc developed under a lower C:N ratio (BFT2, C:N = 9), dominated by microalgae and specific bacterial communities, supported better shrimp growth than biofloc formed under higher C:N conditions. This strategy may also reduce production costs by minimising carbon-source inputs and lowering oxygen demand. The findings demonstrate that well-managed BFT systems can achieve performance equal to or better than RAS while potentially reducing feed costs and improving nutrient recycling.
Kır et al. (Wed,) studied this question.