Outcome of prolonged pH exposure on oxidative stress indices and glucose levels in gills and muscles of juvenile koi (Cyprinus carpio)

The impact of a 96-hour exposure period to pH grades on lipid peroxidation (LPO), catalase (CAT), reduced glutathione (GSH), glutathione-S-transferase (GST), and glucose activity in the muscles and gills of koi carp was investigated. Juveniles were exposed to pH grade from 4.0 to 10.0 for four days to observe variance in enzymatic activity. There was a strong correlation between oxidative stress and antioxidant defence activity as an evidential increase was noted in the CAT, GST, and GSH values. Glucose levels were elevated throughout the experimental conditions in both tissues. The fish exhibited a strong behavioral association with a gradual increase in pH grades. There were significant fluctuations in the pH grades with basicity having a greater impact than acidity on the tissues investigated.