Effect of stocking density on growth and yield of Labeo bata fingerlings reared in cages

• Main Authors: Sona Yengkokpam, Basanta Kumar Das, Dipesh Debnath, Pronob Das, Anil Kumar Yadav, Niti Sharma, Simanku Borah, Ningthoujam Samarendra Singh, Kishore Kumar Sarma, Bipul Chandra Ray, Amulya Kakati, Birendra Kumar Bhattacharjya
• Format: Article
• Language: English
• Published: Elsevier 2020-11-01
• Series: Aquaculture Reports
• Subjects: Cage aquaculture; Growth rate; Biomass; Net revenue; Economics
• Online Access: http://www.sciencedirect.com/science/article/pii/S2352513420305962

An experiment was carried out to evaluate the growth performance and yield of Labeo bata reared in cages at different stocking densities in a floodplain wetland of Assam, India. Fifteen cages (effective water volume 40 m3 each) installed in the wetland were stocked with fingerlings of L. bata (mean length 8.20 ± 0.08 cm; mean weight 4.82 ± 0.13 g) at five different stocking densities, i.e., 25 (D25), 50 (D50), 75 (D75), 100 (D100) and 150 fingerlings m−3 (D150) in triplicates. Fish were fed with pelleted feed containing 30 % CP at 3–5 % body weight twice-a-day for six months. Specific growth rate of the reared fish recorded at different stocking densities were 1.08 ± 0.03, 0.89 ± 0.01, 0.90 ± 0.05, 0.77 ± 0.02 and 0.57 ± 0.02 % day-1, respectively, in D25, D50, D75, D100 and D150. The corresponding weight gain percent were 604.77 ± 35.63, 395.37 ± 11.32, 407.88 ± 44.91, 296.61 ± 13.07 and 180.70 ± 11.02. In general, growth performance of the reared fish was inversely proportional to stocking density. However, yield (biomass) increased with increase in stocking density of up to 75 fingerlings m-3 after which no significant increase was observed. Economics of the cage aquaculture system also showed highest net revenue and benefit-cost ratio at 75 fingerlings m-3. Rearing of fish at this stocking density yielded 50 % higher fish production and generated 92.5 % higher net revenue than rearing at the lowest stocking density. The results suggest 75 fingerlings m-3 as the optimum stocking density for rearing L. bata in net cages.