Anaesthetic effects of MS- 222, clove oil and benzocaine on cultured American shad Alosa sapidissima finglings
DU Hao, WEI Qi-wei, YANG De-guo, LIU Jian-yi GAN Fang, CHEN Xi-huan, SHEN Li
1. Key Laboratory of Freshwater Fish C.ermplasm Resources and Biotechnology by Ministry of Agriculture,Yangtze River Fisheries Institute, Chinese Academy of Fishery Sciences, Jingzhou 434000, China ;2. Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi 21408, China
Abstract: Anesthetic effects of MS - 222, clove oil and benzocaine on American shad Alosa sapidissima fingerlings were studied and two - hour transportations of the shad were conducted at the optimal anesthetic concentration. The results showed that the American shad fingerlings stopped opereular movement less than half an hour after anesthetia when the fish were exposed to concentration of MS - 222 at 75 mg/L, clove oil at 20 mg/L and bezocaine at 40 mg/L. The fish recovered to normal behaviors again after exposed in air for less than 10 rain when transferred into fresh water. The shad fingerlings had good anaesthesia for more than 12 h at 20 - 30 mg MS - 222/L, 8 - 10 mg/L clove oil and 20 - 30 mg/L benzocaine. The anesthetic effects were enhanced at high water temperature and changed with fish sizes. Small fish were more easily in good anaesthesia than the bigger one in MS -222 while the opposite case was found in clove oil and in benzocaine. There were significantly higher serum cortisols in the fingerlings 2 hs after transportation with or without anaethetics than those in the initial fish （before transportation） （P 〈 0.05）. The serum cortisols in fish transported with clove oil （10 mg/L） or benzocaine （30 mg/L） were significantly lower than that in the control group （transportation without anaesthetics） （P 〈0.05 ）. There was no significant differences in serum cortisol between the fingerlings 2 hs after transportation with 20 mg/L MS -222 and the fish in the control group（ P 〉 0.05）. The results indicated that the anaethetics especially benzocaine, had catabatic effect on the transport stress.
2007, Vol. 22 
