NURSERY REARING OF ALL MALE GIFT TILAPIA Oreochromis niloticus FOLLOWING GREEN WATER SYSTEM IN CEMENT TANK

The present study was undertaken to evaluate the effect of green water system on growth performance of all male GIFT tilapia (Oreochromis niloticus). GIFT tilapia, with an average initial length (3.06±0.23 cm) and weight (0.51± 0.00mg) were stocked at the rate of 250 nos m^-3 in cement tanks (2x1x1m).  Experiments were conducted for 60 days duration by feeding commercial floating tilapia starter feed with 32 % proteins at the rate of 5 % body weight in triplicate following Completely Randomized Design. The green water was developed by adding of organic manure before stocking the tilapia seed. The live phytoplanktons like Chlorophyta, Cyanophyta were dominated in green water system followed by zooplanktons like Cladocera, Copepoda and Rotifers. The maximum average length gain (197.30±138.81%), weight gain (4.427.06±3129.70%), specific growth rate 7.80±4.81 %), and survival (97.77±2.22%) were recorded significantly (p<0.05) in green water as compare to the control (without green water). Observations on the water quality parameters revealed that the dissolved oxygen values were slightly decreased with increase in culture duration. In contrast, the value of ammonia-nitrogen, nitrite-nitrogen, and nitrate-nitrogen increased with the increase in the culture period but was observed within the acceptable level.