Effect of different waterborne copper nanoparticles level on liver histopathology of rainbow trout (Oncorhynchus mykiss) fry

Copper is an essential element required by all living organisms, since around 30enzymes are known to use Cu as a cofactor. Copper is also toxic in excess and liverand gills are known to be target organs for it. In the present study totally 300 rainbowtrout fry with initial weight 6.44 ± 0.37 g (Mean ± SE) were randomly distributed in15 fiberglass tanks (with 45 L volume and 20 L water volume) at 5 different Cu-NPstreatments with 3 replicates. Treatments included control (no added Cu-NPs), 5, 10,20 and 40 μg/l Cu-NPs (mean primary particle size of 2-6 nm) in a semi-staticwaterborne exposure regime. In order to find the histopathological changes, samplingof liver in fish was carried out at day 10. Histological samples were dehydrated byroutine methods and embedded in paraffin wax. They were sectioned by microtomeand stained with H & E. Histopathologic signs such as dissociation (5 and 10 μg/lCu-NPs treatments), necrobiose (10 μg/l Cu-NPs treatment), degeneration (5, 10 and20 μg/l Cu-NPs treatments), Single cell necrosis and cloudy swelling (20 μg/l Cu-NPs treatment) and retention of bile (40 μg/l Cu-NPs treatment) were the mostobvious signs in the liver of the examined fish.

کلیدواژه ها:

Copper ، Nanoparticles ، Liver ، Rainbow trout ، Fry