Effects of microalgae inoculated diet on growth performance and blood parameters of Nile tilapia (Oreochromis niloticus)

This study was intended to evaluate growth performance, physicochemical and blood parameters of Oreochromis niloticus for comparing the effects of five test diets, prepared by replacing fish meal by 25%, 50% with microalgae Tetraselmis sp. and Nannochloropsis sp. with feed without replacement. Two hundred seventy Nile tilapia (mean individual weight 0.023±0.0001 g) were randomly allocated into five treatments in triplicate. The fry was raised in 15 rectangular glass aquarium (18 fish/tank within 18 L water) encompassing water holding capacity up to 30L (each). The results revealed that both the supplemented microalgae alone could not significantly enhance the growth performance in compare to control diet (p>0.05). Low palatability and antinutritional factors may be responsible for the poor growth performance. However, significantly higher survival, better TAN, NO2-N and SRP was noticed in T25 than control (p<0.05). The blood parameters exhibited significant increase of certain parameters within reference range, nevertheless significant decrease in some blood parameters was also noticed (p<0.05). Considering the beneficial impacts on water quality, survivality and blood parameters inclusion of microalgae in fish diet can be a better option for fish cultivation.