Effects of Stocking Density on Growth Performance and Production of Mola, Amblypharyngodon mola

An experiment was conducted to determine the effects of stocking density on growth performance and production of Amblypharyngodon mola during 9 July to 9 October, 2011. There were three treatments, each with three replications in nine earthen ponds with an average depth of 1.5 m. Ponds of three treatments T-1, T-2 and T-3 were stocked with mola at the density of 145000; 73000 and 36500 ind. ha(-1). Water temperature, transparency, total alkalinity, pH, dissolved oxygen, Nitrate-nitrogen, nitrite-nitrogen, ammonia-nitrogen, phosphate-phosphorus and chlorophyll-a of the ponds water were measured weekly. Among water quality parameters, significant differences (p<0.05) were observed in case of temperature and dissolved oxygen. The lowest PO4-P and chlorophyll-a concentration were observed in T-1. All water quality parameters were in suitable range of fish culture. The numbers of fishes at harvest were 155633.31 +/- 11.5; 84200 +/- 4 and 45600 +/- 7.21 indi. ha-1 in T-1, T-2 and T-3, respectively. The mean weight of mola during harvest decreased significantly (p<0.05) with increasing stocking density. The net production of mola was significantly higher in treatment T-3 (43.22 +/- 8.66 kg ha-1) than T-2 (34.82 +/- 6.53 kg ha-1) and T-1 (32.74 +/- 6.53 kg ha-1). Considering the highest net production among the three tested densities, the stocking density applied in T-3 was found the best.