The effect of Chlorella vulgaris (Chlorophyta, Volvocales) microalga on some hematological and immune system parameters of Koi carp (Cyprinus carpio)

This study aimed to examine the effects of Chlorella vulgaris (CV) on the hematological and immune parameters of Koi carp (Cyprinus carpio). An experiment was designed with five treatments, including diets with 0, 2, 5, 7 and 10% of C. vulgaris each with three replicates for 8 weeks. At the end of experiment, the hematological and, immune system parameters were measured and analyzed. The results revealed that supplementation of C. vulgaris in diets resulted in higher percentage of haemoglobuling (Hb), haematocrit (Hct), red blood cells (RBC) and white blood cells (WBC). In addition, a significant increase in the levels of IgM, lysozyme and C4 complement levels were found in fish fed CV at different levels showing a positive effect by this microalgea on the immune status of Koi carp. Based on the results, supplementation of CV particularly at 5% of its dry powder in diet of Koi carp can play an important role in the stimulation of fish immune system.