Comparison of physiological and endocrine responses of rainbow trout (Oncorhynchus mykiss) after electroanesthesia and anesthesia with MS222 and clove oil
Amir Sattari1, Saed Mirzargar2, Adib Abrishamifar3 & Hoseinali Ebrahimzadeh Mosavi2
This study investigated electro-anesthesia of rainbow trout (Oncorhynchus mykiss) in comparison with MS222 and clove oil by using plasma cortisol and glucose level as stress indicators. A microcontroller-based apparatus was designed and constructed to allow a programmable voltage-time pulse-width modulated (PWM) electrical wave (AC) application through 19×20 cm submersible electrodes for 91 s in a 33 cm long tank to induce loss of equilibrium and immobility with recovery after 52±27 s. Recovery after 660±102 s was observed in MS222-anesthetized fish (after induction for 720±72 s) and a recovery time of 546±102 s was observed in clove oil-anesthetized fish (after induction for 144±42 s) both are significantly longer recovery times in comparison to electro-anesthesia (P<0.001). Direct ELISA for cortisol and enzymatic and colorimetric method for glucose assessments was used at 0, 1, 6, 12 h after anesthesia in all treatments. Trend of cortisol responses during 12 h of investigation was similar in all groups. The dilatory trend of glucose changes and response derived from anesthetics and electricity and its surge at 6 h after anesthesia (P<0.05) confirmed glucose as a second order indicator of stressresponses. Electro-anesthesia is a fast, economic, eco-friendly and safe anesthetic method provides desirable trout immobility for aquaculture activities.