Dietary toxicity of colloidal silver nanoparticles in rainbow trout (Oncorhynchus mykiss)

To evaluate the dietary toxicity of colloidal silver nanoparticles (AgNPs) in rainbow trout, fish were fed with diets containing 0, 20 and 50 mg.kg-1 of AgNPs for 5 weeks and then were fed free nanoparticles diet for a week. During this period, fish growth, as well as silver accumulation and elimination in liver, kidney, gastrointestinal tract and muscle were studied. According to our results, high doses of AgNPs in the fish diet decreased appetite and fish growth. In addition, feeding fish with the diet containing AgNPs (especially at higher doses) increases the accumulation of silver in fish tissues (silver concentration in liver> kidney> gastrointestinal tract > muscle). Although, a oneweek period considered for elimination of nanoparticles from fish tissues were not enough however, caused some changes in the accumulation of silver in different organs of the fish. Observed effects due to fish feeding with diets containing silver nanoparticles, suggests that nanoparticle ingestion could affect the fish health. Therefore, preventing the entry of these new materials into the food chain of aquatic organisms seems to be necessary.