Histopathological impairment of common carp (Cyprinus carpio) induced through povidone‐iodine exposure

Histological biomarkers are one of the most advantageous tools in monitoring toxicological studies under experimental condition in laboratory. Since disinfectants are extensively inflowing into aquatic ecosystems, this study conducted on common carp to examine the effect of betadine solution on the liver and gill tissue. A 120‐carp were kept for 2 weeks in the 100‐l aquarium Different concentrations of povidone‐iodine (betadine) prepared in three replications and a control group was prepared with no betadine (0, 5, 7, 8, and 9 ppm). Most lesions observed at gill tissue include adhesion secondary lamella, bleeding, destruction of secondary lamellae, hyperplasia secondary blades, curvature second blade, destroying the primary lamellae. Whats more, most lesions observed in liver tissue include bleeding, ascites liver, destruction of liver cells, bile stagnation. Betadine solution, could cause damage to the liver and gills tissues, although gill lesions were more evident than liver. Also increase of concentration led to elevation at lesions of both organs. Overally, the results revealed that using povidon‐iodine as a disinfectant materials and entering into rivers and aquatic ecosystems could have undesirable effects and even death of this fish. Disinfectants, either in low or high concentration, could be very lethal for fish. However the defects seen in this study also could affect osmoregulation and metabolism as two main functions of gill and liver. • Due to the entrance of disinfectants materials to aquatic ecosystems, the effect of betadine solution on the liver and gill tissue of common carp has been examined.• Different concentrations of povidone‐iodine (betadine) was conducted in three replications within the control group (0, 5, 7, 8, and 9 ppm).• Most complications observed at gill tissue include: adhesion secondary lamella, bleeding, the destruction of secondary lamellae, hyperplasia secondary blades, curvature second blade, destroying the primary lamellae.• Most complications were observed in liver tissue include: bleeding, ascites liver, destruction of liver cells, bile stagnation.• The substance from low to high concentrations can be very lethal for fish.