Sublethal effects of copper nanoparticles on the histology of gill, liver and kidney of the Caspian roach, Rutilus rutilus caspicus

The current study has determined the toxicity effects of copper nanoparticles on the somevital organs such as gill, liver and kidney of Caspian Roach; Rutillus rutillus caspicus. For this purpose,120 fishes were used as experimental samples and exposed to 0.1, 0.2 and 0.5 mg/L of Cu nanoparticles for21 days, and 30 fishes assumed as the experiment control. The mean water temperature of the aquaria was22±2 ºC, dissolved oxygen 5.2 mg/L, pH at 7±0.004 and the concentration of calcium carbonate was 270ppm. On 7, 14 and 21 days after exposing the fishes to copper nanoparticles, three fishes were randomlyselected from each aquaria, sacrificed and samples from their gill, liver and kidney were taken and fixed incold 10 % buffered formalin. Then microscopic sections were prepared and examined by light microscopewhich showed histological alternations in the gill, liver and kidney tissues. Evaluation of these changescould be useful in estimating the harmful effects of copper nanoparticles. Histological alternation in gillsincluded: hyperplasia, fusion and detachment of secondary lamellae, blood congestion in vascular axis ofprimary filaments, reduced secondary lamellae length and cellular degeneration. Histological changes inliver included blood congestion in the central veins, cytoplasmic vacuolation of the hepatocytes, cellulardegeneration and congestion in the blood sinusoids and necrosis of the hepatocytes. Histological changesin kidneys included glomerular shrinkage, severe degeneration in the tubules cells, interstitial tissue andglomerulus, increase in interstitial tissue cells and macrophages aggregation. The degree of damages wasmore intensive at higher copper nanoparticles concentrations. The result of the study showed that coppernanoparticles could cause severe damages in the vital tissues of Caspian roach; Rutillus rutillus caspicusand have lethal effects for fish.

Keywords:

Caspian Roach , Copper nanoparticle (CuNPs) , Gill , Histopathology , Kidney , Liver