Potential effects of zinc oxide nanoparticles on growth, hematology, and serum and skin mucus biochemical parameters of common carp (Cyprinus carpio) juveniles.

This study investigated the effects of zinc oxide nanoparticles (ZnO-NPs) on the growth, blood parameters, skin mucus, and serum biochemistry of juvenile common carp (Cyprinus carpio). A total of 300 fish with an average weight of 12.00 ± 0.33 g were randomly distributed in 12 fiberglass tanks with a capacity of 300 L and fed with diets supplemented with ZnO-NPs at concentrations of 0 (control), 10.00, 50.00, and 100 mg kg-1 for 60 days. The results indicated that 50.00 mg kg-1 ZnO-NPs supplementation significantly improved fish weight, length, specific growth rate, and feed conversion ratio. There was no significant difference in survival rates between the treatments and control group; however, the highest survival rate was observed in the treatment with 50.00 mg kg-1 ZnO-NPs. This treatment also led to the highest red blood cell counts, hemoglobin levels, mean corpuscular hemoglobin concentration, and lymphocyte percentages. In contrast, the highest neutrophil counts were observed at 100 mg kg-1 ZnO-NPs. The highest serum biochemical parameters, including total immunoglobulin, lysozyme, and Zn levels were observed in the treatment with 50.00 mg kg-1 ZnO-NPs. While, in the skin mucus, total immunoglobulin, lysozyme, and alkaline phosphatase significantly increased at groups fed with 10.00 mg kg-1 ZnO-NPs. Overall, the findings suggest that dietary inclusion of 50.00 mg kg-1 ZnO-NPs can effectively promote growth and enhance immune responses of C. carpio juveniles, indicating their potential application in aquaculture practices. However, caution is advised at higher concentrations due to the potential adverse effects on fish health.