The effects of Spirulina platensis levels in diet on growth indices and chemical body composition of Kutum fry (Rutilus frisii kutum)

The aim of this study was to evaluate the spirulina powder in the diet of the southern Caspian kutum and compare with basal diet (lack of spirulina). The experiment was conducted for 90 days under controlled conditions. In this experiment، five commercial diets containing 0 (basal diet)، 0. 5%، 1%،2% and 5% spirulina powder was considered and fed to Triplicate groups of fish. Four-hundred and fifty fish with initial average weight of 0. 475±0. 081g were randomly distributed between 15 glass aquarium tank of 50 liters capacity which was filled with 40 liters of fresh filtered ground water. The fishes were fed at satiation at three times (8، 12 and 18). With increasing spirulina powder to 5% level all growth factors and fed efficiency were not improvement and was significant with other treatments (P<0. 05). The use of spirulina powder has position effect in the survival rate of kutum fry up to 2% level after that (5%) has been decreased. The chemical body composition has no differences in treatments (P>0. 05). In general، considering the growth factors، feed efficiency، the treatment 1 (commercial basal diet) is more reliable in the diet of southern Caspian kutum.