The effect of copper nanoparticles supplementation on freshwater prawn Macrobrachium rosenbergii post larvae

• Dietary Cu-NPs (20 mg kg−1) can promote the survival and growth performance of Macrobrachium rosenbergii.
• Cu-NPs have influence on the digestive enzymes secretion in M. rosenbergii.
• Dietary Cu-NPs can promote the nutrient absorption and muscle composition of M. rosenbergii.
• Elevated concentration of dietary Cu-NPs (40–80 mg kg−1) might produce toxic effects to M. rosenbergii.

The present study was performed to assess the effects of dietary supplementation of copper nanoparticles (Cu-NPs) on growth, biochemical constituents, digestive enzyme activities, antioxidant, metabolic enzyme levels, and non specific immune response of the freshwater prawn, Macrobrachium rosenbergii post larvae (PL). The Cu-NPs (200 nm) were synthesized by facile and environmental friendly hydrothermal method. Cu-NPs were supplemented at 0, 10, 20, 40, 60, and 80 mg kg−1 with the basal diets. These Cu-NPs supplemented diets were fed to M. rosenbergii PL for 90 days. Results showed significant (P < 0.05) improvements were observed in survival, growth, digestive enzyme activities, concentrations of biochemical constituents and total and differential haemocytes count of prawns fed with 20 mg Cu-NPs kg−1 supplemented feed. Prawns fed with 40–80 mg Cu-NPs kg−1 supplemented feed showed negative performance. Activity of antioxidants and metabolic enzymes in the muscle and hepatopancreas of prawns showed no significant alterations (P > 0.05) prawns fed with up to 20 mg Cu-NPs kg−1 supplemented feeds. Whereas, prawns fed with 40–80 mg Cu-NPs kg−1 supplemented feed showed significant (P < 0.05) elevations in antioxidant and metabolic enzymes activities. Hence, 40–80 mg Cu-NPs kg−1 diets may have toxic effect to M. rosenbergii. Hence, present study suggests that 20 mg Cu-NPs kg−1 can be supplemented for regulating better survival, growth and immune response of M. rosenbergii PL.