10. Variation of production performance of Gulsha (Mystus cavasius) monoculture with variation of water and soil quality parameters

Abstract

An on-farm experiment was carried out to evaluate the production performance of Gulsha (Mystus cavasius) for 120 days at different environmental conditions. Two areas were considered: one in Gazipur Sadar and another one in Narsingdi Sadar. Five ponds of almost similar size (30 decimal with an average water depth of 1.5 m) and water intensity were selected at each location with a stocking density of Gulsha 500 fry/decimal. Pre-stocking, stocking and poststocking management had been similar in each place. The significantly lower (p<0.05) value of soil pH (5.5±4.1) in Gazipur location caused pond water acidic and imbalanced the water buffering system for maintaining primary productivity. After 120 days of rearing period, the average harvest weight of Gulsha 48.10 ±7.12 g was significantly (p<0.05) higher for Narsingdi compared to the average weight 23.18 ± 6.24 g in Gazipur. The survival rate (p<0.05) 68% at Narsingdi area was the highest. The estimated average production of fish in 120 days in the Gazipur and Narsingdi region was 7.55 ± 5.61 kg/dec and 16.31 ± 6.13 kg/dec, respectively, that differed substantialy (p<0.05) from one another. Ponds of Narsingdi district in general, showed almost all of its physico-chemical and biological features suitable for fish production. However, ponds in the Gazipur area were found less productive for the cultivation of Gulsha particularly with lower primary and secondary productivity.