Effects of Myrcene Addition to Water on Plasma Biochemical Characteristics of Common Carp, Cyprinus carpio, During Transportation

Background: Sedative agents are utilized to mitigate stress and improve fish welfare during and after transportation.  Objectives: We aimed to assess the effects of myrcene addition to the transportation water on the plasma biochemical profile of common carp, Cyprinus carpio.  Methods: For this purpose, common carp (mean weight of 45.3±1.65 g) were transported in plastic bags containing myrcene at concentrations of 0 (CTL), 10 (10 M), 20 (20 M), 30 (30 M), and 50 (50 M) µL/L for 6 h. Then, their plasma parameters were compared to those values before transportation (BT).  Results: Transportation significantly (P 0.05) decreased plasma total protein, albumin, alternative complement, lysozyme, sodium, and chloride, while increasing potassium, calcium, alanine aminotransferase, aspartate aminotransferase, and alkaline phosphatase in the CTL treatment, as compared to BT. Adding 50 µL/L myrcene to water prevented total plasma protein and albumin loss. Supplementing 20 µL/L myrcene to water prevented or reduced the changes in plasma ions, alanine aminotransferase, and alkaline phosphatase. Addition of 10-50 µL/L myrcene to water decreased the changes in plasma aspartate aminotransferase. Adding 20 and 30 µL/L myrcene to water mitigated the changes in plasma alternative complement, as 30 µL/L myrcene increased plasma lysozyme activity. Transportation and myrcene addition had no significant effects on plasma immunoglobulin (P 0.05). However, a significant increase was observed in plasma globulin in the 20 M treatment (P 0.05).  Conclusion: In summary, adding 20 µL/L myrcene to the transport water of common carp reduced hepatic enzyme levels and improved immune parameters, and therefore, the use of myrcene improves fish welfare during transportation.