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This study investigates the effects of silver nanoparticles (AgNPs) and silver nitrate (AgNO3) on gills and muscles in African catfish (Clarias garepinus). Changes in bioaccumulation, histopathological, and histochemical were used as biomarkers. The effects of AgNPs were recorded in some of these properties based on their size (20 and 40 nm) and their concentration (10 and 100 µg/L). The concentrations of silver (Ag) in gills and muscles tissues showed significant variations in all exposed groups compared to the control group. At tissue and cell levels, histopathological changes were observed. These changes include aneurism, collapse, subepithelial edema, epithelium lifting and hyperplasia of interlammellar epithelium, curling of secondary lamellae, epithelial cell necrosis, hypertrophy and proliferation of erythrocytes, bifurcation and fusion of filament, an increase in the number and size of mucous cells in the gills tissues. In addition, degeneration of muscle bundles, infiltration of inflammatory cells, focal areas of necrosis, splitting of muscle fibers, broken myofibrils, thickening of muscle bundles, dislocated striated muscles and shortening of muscle bundles in muscle tissues of fish exposed to AgNPs were exporated to evaluate the changes. Also, depletion of carbohydrates of the gill tissues and the muscle fibers with an increase in the number and size of mucous cells that condense in the secondary lamellae were observed. The 15-day recovery period improved most of the modifications in histopathological and histochemical parameters caused by AgNPs and AgNO3. In conclusion, one can assume the sensitivity of the gills and muscles of C. garepinus to AgNPs and recovery strategy is a must. Keywords: AgNPs, Clarias garepinus, Bioaccumulation, Histopathology, Histochemical, Gills, Muscles |
