Stocking density positively influences the yield and farm profitability in cage aquaculture of sutchi catfish, Pangasius sutchi

The sutchi catfish (Pangasius sutchi Fowler 1937) was cultured at 10 different densities in cages suspended in a river‐fed channel during the summer of 2000. Catfish fingerlings (mean length 9.14–9.74 cm; mean weight 5.92–6.7 g) were stocked at densities of 60, 70, 80, 90, 100, 110, 120, 130, 140, and 150 fish m^?3, which were equivalent to 397, 427, 488, 551, 604, 656, 710, 871, 981, and 899 g m^?3 respectively. At the end of 150 days, the growth and yield parameters were studied and a simple economic analysis was performed to calculate profitability. Gross yields were 15.6 ± 0.27, 17.1 ± 0.31, 19.5 ± 0.30, 21.9 ± 0.29, 26.8 ± 0.22, 28.6 ± 0.40, 30.0 ± 0.37, 31.1 ± 0.45, 32.7 ± 0.31, and 34.5 ± 0.44 kg m^?3; net yields were 15.2 ± 0.22, 16.7 ± 0.28, 19.0 ± 0.29, 21.3 ± 0.21, 26.2 ± 0.19, 27.9 ± 0.33, 29.3 ± 0.33, 30.3±0.37, 31.8 ± 0.29 and 33.5 ± 0.36 kg m^?3, respectively, with stocking densities of 60, 70, 80, 90, 100, 110, 120, 130, 140, and 150 fish m^?3. Mean weights of fish at harvest were inversely related to stocking density. Both gross and net yields were significantly different and were directly influenced by stocking density, but the survival rates and feed conversion were unaffected. Higher stocking density resulted in higher yield per unit of production cost and lower cost per unit of yield, with a net revenue being higher with increasing stocking density. It was concluded that the density of 150 fish m^?3 produced the best results among the densities tested in this experiment.