The effect of different oxygen concentrations on oxidative stress and some biochemical parameters in the transfer of adult rainbow trout (Oncorhynchus mykiss)

In order to meet the food needs of the growing world population, aquaculture is one of the most suitable and environmentally friendly methods for obtaining quality protein with low emissions. Live fish transfers are made in order to increase the yield by using water resources in the most effective way. However, transfer operations are one of the stress sources that cause mortality in fish. It is possible to reduce the harmful effects of stress by providing optimum living conditions during the transfer. One of the most important parameters for optimum living conditions in fish is the dissolved oxygen level in water. In this study, the effects of different dissolved oxygen concentrations on oxidative stress and some biochemical parameters during the transfer of adult rainbow trout (Oncorhynchus mykiss) were investigated to determine the optimum dissolved oxygen concentration during transfer. For this purpose, GSH-Px, SOD, and LDH enzyme activities, MDA, Cp, TOS, TAS, OSI, cortisol, glucose, urea, uric acid, creatinine, Ca, Mg and MDA, Cp, TOS, TAS and OSI values in serum and muscle tissue were investigated in control and groups with four different dissolved oxygen concentrations. According to the results of the analyses, oxidative parameters and some markers of tissue damage were compared, and it was observed that transfer and preparation for transfer caused oxidative damage in fish. When the transferred groups were compared among themselves, it was found that transfer in hypoxic and hyperoxic conditions increased ROS and suppressed the antioxidant mechanism, and caused oxidative stress. When 8 and 10 mg/L dissolved oxygen transfer groups were compared among themselves in normoxic conditions, it was observed that transfer procedures performed at 10 mg/L dissolved oxygen concentration minimized oxidative stress and tissue damage.