مشخصات پژوهش

Regarding the important role of iron in the physiological process in fish bodies and the presence of iron nanoparticles (Fe-NPS) in the aquatic environment, this study was designed to evaluate the effects of Fe-NPS on the intestinal bacterial flora and histology of the intestine and kidney in a stellate sturgeon (Acipenser stellatus Pallas, 1771). Juvenile stellate sturgeon, averaging 182.09±9.05 g, were fed with diets containing varying doses of Fe-NPs: 0 (T0), 25 (T1), 50 (T2), and 100 (T3) mg∙kg-1 of food for 60 days. Based on the glucose and cortisol levels in different treatments, it seems that the best dose of Fe-NPs for stellate sturgeon was 50 mg∙kg-1 food (T2) under experimental conditions. The most important histological changes observed in the intestine were the shortening of the intestinal villi, a high number of mucus-secreting cells, and mucosal secretions within the intestinal tract. These changes in the kidney were shrinkage of renal glomeruli, increasing Bowman’s capsule space, mild degeneration of renal tubules, and infiltration of white blood cells into the kidney tissue. The most effective dose of Fe-NPs was 50 mg∙kg-1 Fe-NPs with a less negative effect on fish intestine and kidney histology. Fe-NPs led to a significant increase in the mean total count of aerobic bacteria and lactic acid bacteria. Generally, the fish food supplemented with 50 mg∙kg-1 Fe-NPs led to the least stress and histological damage in the kidney and intestine and the highest number of intestinal bacterial flora in the stellate sturgeon.