Esfandani Keysomi MM *,Sudagar M ,Nasirir Asl
It is often necessary to transfer live fish between aquaculture facilities to permit on-growing or fishing, handling and the physical disturbances associated with loading, transport, and discharge could be regarded as the potential to cause distress and injury, and then leading to possible long term health impairment. Fish in different ways keep its stability (homeostasis) after stress responds. Stress response is involved in many physiological changes. One of the main reactions to stress is increasing the plasma cortisol level. Purpose of this study was to examine the effect of a selective serotonin reuptake inhibitor (citalopram) on plasma cortisol, and handling stress of rainbow trout. Immature rainbow trout (Oncorhynchus mykiss) with an average of 50 ± 7 g weight set in three treatments, control, acute (5 mg/l for 48 hours) and chronic (5 μg/l for 10 days). Plasma cortisol before transport in the control group was 22.11 ± 5.33 (ng/ml), chronic dose was 15.99 ± 5.85 (ng/ml) and in the acute treatment was 18.81 ± 7.42 (ng/ml). Mean plasma cortisol after transportation in the control, acute and chronic treatment respectively was 286.01 ± 54.26, 107.12 ± 25.53 and 239.89 ± 57.56 ng/ml. Based on the results, significant difference observed (p<0.05) between mean plasma cortisol before and after transportation in chronic treatment. Also in acute dose, there was a significant difference in mean plasma cortisol before and after transportation (p<0.05). As a conclusion it can be expressed that, chronic treatment was more effective than acute treatment in reducing handling stress in rainbow trout.