Impact of Transient Temperature Disturbance on the Oxidative Stress Indices and Glucose Levels of Juvenile Koi Carps (Cyprinus carpio Var koi)

Background The present study reports the changes in the redox state and glucose activity in gills and muscles of Koi carps, exposed to a short duration of acute thermal stress. The variation in levels of lipid peroxidation (LPO) and glutathione (GSH), catalase (CAT) and glutathione-S-transferase (GST) activity, in addition to glucose levels, were analysed after exposing the fishes to 15 °C (low), 25 °C (control) and 35 °C (high) for a duration of 3 and 6 h. The upper and lower temperatures regimes were decided by the Critical Thermal Limit (CTMAX and CTMIN). Results The CAT activity was high in both the tissues at 35 °C within 3 h, while LPO activity decreased throughout the study when compared with the control group indicating immoderate cellular disturbance and surplus oxidative stress. At 15 °C (3 h), tissues reported more glucose compared with the upper thermal slab. GSH increased in both the tissues at 15 °C compared with the control for 3 and 6 h. GST activity, however, flourished at 35 °C in muscles and gills for the 3-h regime. Conclusion The current study demonstrated disturbing impacts of temperature on the survivability of the Koi carps in a domesticated environment