COMPARISON OF CONTROLLED NURSERY REARING OF HYBRID TILAPIA SEEDS

Nursery rearing of hybrid tilapia young fry (Red strain) was undertaken in two types of rearing systems for 21 days. Young fry of hybrid tilapia (0.12 + 0.019 g ABW) were stocked in hapa (1.5 m L x 1 m B x 1 m D ) at a stocking density of  0.87 fish/lit  and in 5 aquarium tanks (each measuring 1 m L x 0.3 m B x 0.3 m D) at a stocking density of 0.88 fish/lit. Crumble feed of 30% CP was given per day 7 times in 1st week and 6 times in 2nd week and 5 times in 3rd week in both hapa and tank fishes. The physico-chemical parameters of hapa and aquarium tank were taken everyday.

Do, pH, TDS, Alkalinity, Temperature were higher in hapa water than tank water, where ammonia is found higher (0.5-1 mg/lit). After 21 days of trial, hapa stocked fishes had a weight gain of 3.48 g , while the fishes in aquarium tank had weight gain of 2.58 g. The survival rate in hapa was 97% and in aquarium tank was 85%. The hapa rearing resulted in 74% more growth than in the glass aquarium tank. The final ABW of fishes reared in hapa was 3.6 g while that of aquarium tanks was 2.7 g. The body colour of the fishes in hapa was brighter than the  tank of  fishes.