Optimization of stocking density of Gulsha (Mystus cavasius) in circular shaped net cages in pond conditions

Influence of stocking density on growth and production of Mystus cavasius (local name: gulsha) in circular shaped cages was studied in earthen pond conditions for a period of 90 days. The cages were uniform in size of 1.80 m3 and were stocked with gulsha fry at the rate of (i) 200 fry/ m3 (T1), ii) 300 fry/ m3 (T2), and (iii) 400 fry/ m3 (T3). No significant differences were observed among the treatments in weight gain {11.46±0.16g (T1); 11.40±0.14g (T2); 11.48±0.04g (T3)}, SGR {2.77±0.06 (T1); 2.70±0.10 (T2); 2.71±0.09 (T3) day-1}, and survival rates {87.3±6.6 (T1); 85.7±4.7 (T2); 84.9±5.4 (T3) %}. A significantly higher (p<0.05) gross production of 4.29±0.32 kg/ m3 in 90 days was obtained in T3 (400 fry/ m3) treatment compared to T2 and T1. The coefficient of determination values (r2) of length-weight relationship (LWR) was 0.95, 0.94, and 0.94 in T1, T2, and T3 treatments, respectively indicating a good linear regression between length and weight. The results demonstrate that the cage culture of gulsha in pond condition is possible where 400 fry/ m3 stocking density in circular shaped cages may be suitable for higher growth, survival and production.