Evaluation of growth and survival of Zebra fish, Danio rerio by flake food that formulated with spirulina

Danio rerio is one of the most beautiful ornamental fish living in fresh water and tropical water having a lot of fans in our country. This study aimed at investigating the effect of flaked diet with spirulina microalga feeding on growth and survival rates of Danio rerio in Mahshahr, south of Iran in 2014.  Three hundred and sixty zebra fish have been purchased and were randomly distributed among 12 aquariums, which the first group or control have been received commercial concentrated food (Energy co.), the 2nd group were fed basal diet enriched with 4% Spirulina. The 3rd group received enriched food with 12% of the same supplement diet and and finally, the 4th group was designed for 25% of Spirulina. The highest levels of condition factor and specific growth ratio were calculated for 4.394± 0.35 and 0.92 ±0.004, respectively. In addition, the lowest levels of daily feeding consumption and feed conversion ratio of 0. 35 ±0.035 and 0.037±0.01 were respectively obtained. In general, the inclusion of spirulina powder in feeding level of this fish would lead to gaining weight. Furthermore, the increase of spirulina microalga powder would affect the feed conversion ratio in its feeding level within a raising period of 60 days. Since there is no significant difference between 12 and 25% of the basal diet, it is concluded that the best feeding level is the basal diet enriched with4% spirulina.