Effect of different level of spirulina meal on growth performance, feed efficiency, body composition and apparent digestibility of Oscar fish (Astronotus ocellatus)

The main objective of this study was to determine the effects of diets containing 0, 2.5, 7.5% spirulina platensis meal on growth performance, survival rate, skin pigmentation and digestibility of carotenoids in Oscar fish (Astronotus ocellatus). 288 Oscar fish with mean body weight of 10.73±0.09 randomly divided in to 24 aquariums with 45 liters’ water capacity. The experimental treatments were 0, 2.5, 5 and 7.5% spirulina in diet. Fish fed 42 days by experimental diets. To maintain water quality siphoning and water change performed daily and water quality parameters measured weekly. The results showed adding spirulina in diet didn't show any significant effect on growth performance, feed efficiency and survival of Oscar fish (p>0.05). Carotenoid digestability was high in all treatments (>97%) and there was no significant difference between 7.5% spirulina and control group (p>0.05) The highest skin carotenoid content was observed in fishes fed by 7.5 spirulina in their diet (p<0.05). By respect of significant increase in body pigmentation, the present results demonstrated that 7.5% S. platensis meal can a suitable dietary level in Oscar fish diet.