Spotted snakehead, Channa punctata (Bloch, 1793), stocking density effects on water quality, live food, and growth performances in Indian major carp polyculture system

Abstract

Experiment conducted to examine the effect of stock densities of Channa punctata on water quality parameters, live food production, and growth performance in Indian major carps polyculture system at 12 earthen ponds (area: 200 m2, 1.5 m depth) for 120 days. Stocking densities of C. punctata, 0 (T1), 2000 (T2), 3000 (T3), and 4000 (T4) individual ha-1 and rohu (Labeo rohita), silver carp (Hypophthalmichthys molitrix), catla (Catla catla), and mrigal (Cirrhinus cirrhosis) at the constant rate of 3000, 2500, 2000 and 2000 individual ha-1, respectively with three replications. The mean initial weight of spotted snakehead and carps fingerlings were 1.50±0.07 g and 7.86±0.03 g, respectively; fingerlings fed commercial pellets twice daily. Water quality parameters were significantly different in all treatments. Zooplankton and benthos decreased with increasing stocking density of fish. The mean specific growth rate of carps was not significantly different with and without C. punctata. Food conversion ratio was low in T1, while fingerlings survivability range was 67% to 89% in all treatments. The gross production of C. punctata in T3 was the highest (143.53 kg ha-1) followed by T4 (123.26 kg ha-1), and T2 (97.66 kg ha-1). The combined total production of spotted snakehead with carps was the highest in T2 (1836.95 kg ha-1) compared with T3 (1760.53 kg ha-1), T1 (1806.18 kg ha-1), and T4 (1621.46 kg ha-1). Overall, maximum yield of T2 reflected proper feed utilization and appropriate species combinations.