Investigation of anesthetizing effect of tobacco (Nicotiana tabacum) aqueous and alcoholic extract on Rainbow trout (Oncorhynchus mykiss)

The main goal of anesthesia in rainbow trout is decrease mobility and reduce stress of fish while breeding, and also facilitate operation such as manipulation to Tagging, Biometry, Sorting, Inspection and Sampling for pathology test. In the present study, Aqueous and alcoholic extract of tobacco plant (Nicotiana tabacum) for Anaesthetizing Rainbow trout (Oncohrynchus mykiss) in 3 weight groups: fry (less than 80 g), growing(about 200 g) and breeding(larger than 1500g) were used. The effective dose of tobacco in treatments 200, 400, 800 and 1600mg/lit in aqueous and 0.7, 1, 1.7 and 3.5mg/lit in alcoholic extract were tested. Totally, we can say that tobacco extract Anaesthetizes the rainbow trout in less than 3 minutes and recovery time is less that 5 minutes. Regarding to anesthetizing time, recovery time and fish relaxing during anesthesia, aqueous extract applies more gentle anesthesia in rainbow trout, and dose 200 to 800 mg/lit of aqueous extract were more successful. Also Regarding to significant correlation between doze and Anesthetics extremity and recovery time (P<0.05), lower dose of tobacco extract can be used to making fish calm for transportation.