Effects of different sub-lethal concentrations of silver nanoparticles on thyroid hormones, growth hormone, blood factors and liver enzymes of common carp (Cyprinus carpio)

Fish is in the highest level of aquatic food chain and has the ability to biologically magnify heavy metals, even at low concentrations in the environment. Biochemical methods and measuring blood parameters are among the important biological indicators that are widely used in assessing the health status of fish. The aim of this study was to investigate the effects of silver nanoparticles on thyroid hormones, growth hormone, blood factors and liver enzymes of common carp (Cyprinus carpio). In this study, 150 fish with weight of 12-15g after obtaining acute toxicity (LC50 96h), randomly exposed to concentrations of 0 (control), 5, 10 and 15 µg/L of LC50 96h silver nanoparticles with three replications for 7 days. At the end of the experimental period, blood samples were withdrawn by puncturing the vein in the fish tail. The results of this study showed that silver nanoparticles led to a significant difference in the number of white blood cells, percentage of neutrophils, lymphocytes and eosinophils and also amount of ALT and AST in the treatments (P<0.05). Also silver nanoparticles have negative effects on blood and biochemical parameters of common carp.