A Study On The Anesthetic Effect Of Eugenol To Cyprinus Carpio Linnaeus

Objective: To investigate the anesthetic effect and mechanism of eugenol in cyprinoid experinments, and obtain some basis data in the process to develope eugenol as a new environmental fishes anesthesic.Methods: The start time and recovery time of anesthesia, oxygen consumption, the gills movement number, rebound recovery time in the air of cyprinoid anesthetic-zed with the different concentration of eugenol and MS-222 (3-Aminobenzoic acid ethyl ester methanesulfonate, a common fish anesthetic recommended by FAD ) were tested. To investigate the anesthestic effect of eugenol for cyprinoid under the conditions of the operation out of water and transportation, the optimal anesthesitic concentration of eugenol and MS-222 were screened. The longest exposure times in the air, oxygen consumption, the gills movement of cyprinoid were detemined comparely after being dipped 20 minutes in the optimal density of eugenol and MS-222, and in low temperature water ( 12℃). The ammonia nitrogen content and several serum biochemical indicators of cyprinoid were tested after the process of analogic anesthesia transportation. To study anesthesia mechanism of eugenol for cyprinoid, the change of Nitric Oxide enzyme of cerebellum of anesthetized cyprinoid was detemined.Results: The results showed that the Eugenol possesses high anesthetic effect to cyprinoid fishes. The optimal anesthetic density of eugenol was 20mg/L, which was 4 times lower than MS-222, and the anethesia induction time was about 1.1 minutes in 20mg/L, it was shorter than MS-222 (1.8 minutes) in 80mg/L. Rebound recovery time of anesthesia cyprinoid fishe was extended from 2.06±0.31 minutes to 9.74±0.81 minutes as the concentration of eugenol in water was increased from 20 mg/L to 80 mg/L. The average oxygen consumption and the number of gills movement of anesthetic cyprinoid were no significantly different between the MS-222 group, eugenol group and cool water group, but there were significantly different between tested groups and control group. The longest exposure time of cyprinoid anesthetized by the eugenol in the air was 60 min, it was 20 min longer than by MS-222. The amount of ammonia nitrogen discharge in water and the serum biochemical indicator of cyprinoid had significant difference between anesthetic groups and the control group after the process of simulating anesthesia transportation. The anesthesia therapeutic index of eugenol for cyprinoid was 12.54, it revealed that eugnol was safely anesthetic to cyprinoid. The nitrogen monoxidum enzyme activity of cyprinoid cerebellum was significantly different between anesthesia group and the non-narcotic group.