Toxic effects of antibiotic oxytetracycline in the fish, Cyprinus carpio using a multi-biomarker approach

Aim: The present study was designed to assess the toxic effect of oxytetracycline in the fish Cyprinus carpio using multi-biomarker approach following acute exposure. Methodology: The fish were exposed to sub-lethal concentration (80 mg l-1) of oxytetracycline for 96 hrs. Blood samples were collected 24, 48, 72 and 96 hrs after treatment. Biomarkers such as genotoxicity, biochemical parameters and alteration of the morphology of scales were used to assess the health status of fish after exposure to oxytetracycline. Genotoxicity was assessed using blood cell micronucleus assay. Results: Significant alterations in the nucleus and cytoplasm were noticed such as the aberrant nucleus and vacuolated cytoplasm which were time dependent in the treatment group compared to the control. Biochemical parameters such as blood glucose, total plasma protein, aspartate transaminase and creatinine levels were significantly altered in the oxytetracycline exposed groups. The examination of body scales of treated fish revealed significant alterations such as uprooted and damaged lepidonts and dispersed chromatophores. Interpretation: The data of the present study indicates that oxytetracycline is toxic to fish at sub-lethal concentration. Key words: Antibiotics, Biomarkers, Cyprinus carpio, Genotoxicity, Oxytetracycline, Scale