The potential toxicity of copper nanoparticles and copper sulphate on juvenile Epinephelus coioides

Copper nanoparticles (Cu-NPs) were widely used in various industrial and commercial applications. In this study the effects of Cu-NPs and soluble Cu were investigated on juvenile Epinephelus coioides . The fish were exposed in triplicate to control, 20 or 100   μg   Cu   L −1 as either copper sulphate (CuSO 4 ) or Cu-NPs in a semi-static aqueous culture for 25 days. The growth parameters were significantly lower at 100   μg   Cu   L −1 as CuSO 4 or Cu-NPs treatment compared to control. Time-dependent Cu accumulation in all tissues increased with increasing the Cu dose. The percentage of total Cu found in remaining tissues (head, bones, fins, etc.) decreased more in the CuSO 4 than Cu-NPs treatment after 25 days, but increased in all other tissues (especially in liver). Compared with the control, either Cu-NPs or CuSO 4 induced higher malonaldehyde concentration in tissues by overwhelming total superoxide dismutase activity, total glutathione concentration and Na + /K + -ATPase activity, but the opposite results were recorded for the brain. With increasing the CuSO 4 or Cu-NPs dose, apoptosis was exacerbated in the liver and gills, more so by CuSO 4 than Cu-NPs. Overall, these findings showed that Cu-NPs had the toxic effects similar to dissolved Cu; hence, Cu-NPs need to be included in the assessment of toxicological impacts in the aquatic environment.