Determination of optimum light sedation concentrations for long-term closed environment transfers in goldfish (carassius auratus) along with behavior and stress indicators

In this study, the anesthetic and sedative effects of clove oil on goldfish (Carassius auratus) individuals were thoroughly evaluated. The average weight of the fish used in the experiments was measured as 10.56 g. In the first phase of the study, optimal concentrations were determined to induce deep anesthesia within 3 minutes and complete recovery within 5 minutes. Clove oil was applied at concentrations of 30 µL/L, 45 µL/L, 60 µL/L, and 75 µL/L in anesthesia trials. Based on the obtained data, the most suitable anesthetic concentrations were identified as 45 µL/L and 60 µL/L. At these concentrations, the induction and recovery times of the fish exhibited a balanced trend. Following the anesthesia experiments, sedation trials lasting 24 hours, 48 hours, and 72 hours were conducted to assess the long-term effects of clove oil. During these trials, the impact of different concentrations on fish behavior, survival rates, water quality, and cortisol levels was analyzed. The concentrations used in the sedation trials were 3 µL/L, 4.5 µL/L, 6 µL/L, and 7.5 µL/L, and their effectiveness was examined in detail. The most optimal concentration for sedative effects was determined to be 6 µL/L, at which fish exhibited calm behavior and maintained high survival rates. It was observed that lower concentrations did not provide adequate sedation, whereas higher concentrations led to adverse effects with prolonged exposure. Plasma cortisol levels were analyzed from blood samples collected after sedation. The lowest cortisol level was recorded at the 6 µL/L concentration. Regarding cortisol levels, it was noted that concentrations below 6 µL/L did not exhibit sufficiently strong sedative effects, while the 7.5 µL/L concentration resulted in a moderate increase in stress-related factors due to prolonged exposure. These findings suggest that clove oil could be a safe and effective sedative agent for goldfish. The results of the study indicate that clove oil may serve as a valuable alternative in controlling stress, particularly in commercial applications and live fish transport. Anesthetic concentrations of 45 µL/L and 60 µL/L, along with a sedative concentration of 6 µL/L, were considered suitable options for enhancing the welfare of goldfish and minimizing environmental stress factors. These findings suggest that the widespread adoption of sedation practices could be beneficial in live fish transportation and aquaculture applications.