2种麻醉剂对马口鱼幼鱼麻醉效果研究

Anesthetic Efficacy of Two Anaesthetics on Juvenile Chinese Hook Snout Carp Opsariichthys bidens

为减少马口鱼人工繁殖和运输过程中应激反应而导致的较高死亡率,通过使用间氨基苯甲酸乙酯甲磺酸盐、乙二醇苯醚对马口鱼[体质量(99.17±7.43)g]进行有效麻醉试验、深度麻醉后离水暴露试验、水温影响试验和镇静状态下模拟运输试验,研究其在最终麻醉状态及复苏过程中的行为特征。试验结果显示:(12.0±0.5)℃,间氨基苯甲酸乙酯甲磺酸盐使马口鱼在3 min内麻醉,5 min复苏的有效质量浓度为30~35 mg/L,麻醉效果随质量浓度的升高而增强,各组(20~40mg/L)之间均差异显著(P<0.05);经最适质量浓度35 mg/L的间氨基苯甲酸乙酯甲磺酸盐深度麻醉的马口鱼,在空气暴露8 min后,复苏率为100%。乙二醇苯醚使马口鱼在3 min麻醉,5 min复苏的有效剂量为0.30~0.38 mL/L,麻醉效果随乙二醇苯醚有效剂量的升高而增强,各组(0.26~0.42 mL/L)之间均差异显著(P<0.05);经最适有效剂量0.34 mL/L乙二醇苯醚深度麻醉的马口鱼,在空气暴露8 min后,复苏率为92%。2种麻醉剂的麻醉效果与水温密切相关,麻醉效果随水温的升高而增强。鱼水质量比1∶20情况下,24 h内间氨基苯甲酸乙酯甲磺酸盐最佳运输质量浓度为7 mg/L、乙二醇苯醚最佳运输剂量为0.10 mL/L。本试验为马口鱼筛选了合适的麻醉药物和剂量,结果可为提高马口鱼人工繁殖和养殖效率及运输存活率提供数据支持。

In order to reduce the high mortality of Chinese hook snout carp Opsariichthys bidens due to stress during artificial reproduction and transportation,the Chinese hook snout carp with body weight of(99.17±7.43)g were held in a 3.0 m×2.5 m×1.5 m tank with water depth of 0.7 m,and exposed to MS-222 at concentrations of 10,15,20,25,30,35 and 40 mg/L and 2-phenoxyethanol at concentrations of 0.18,0.22,0.26,0.30,0.34,0.38 and 0.42 mL/L at water temperature of(12.0±0.5)℃to determine the optimal anesthetic dose with a survival rate of 100%in 15 min of anesthesia with 3 min into anesthesia and recovery in 5 min.The effects of water temperature on the anesthetic effect of these two anesthetics were investigated at the concentrations of 35 mg/L MS-222 and 0.34 mL/L 2-phenoxyethanol at water temerature of(12.0±0.5),(15.0±0.5),(18.0±0.5),(21.0±0.5)and(24.0±0.5)℃.After the fish entered the deep anesthesia(A5)phase under the concentrations of the two anesthetics,they were exposed to air for 0,2,4,6,8,16 and 24 min,respectively,and then put back into clean water for recovery to evaluate the effect of anesthesia on air exposure.Anesthesia under 7 mg/L MS-222 and 0.10 mL/L 2-phenoxyethanol,the fish was simulated to the long-distance transportation in still water in a sealed and oxygenated plastic bag at water to fish weight ratio of 1∶25,1∶20 and 1∶15 to test the final anesthesia state and behavioral characteristics during recovery.The results showed that there was the effective mass concentration of 30—35 mg/L MS-222 at(12.0±0.5)℃,with the enhanced anaesthetic effect with the increasing concentration,and significant difference between all groups(20—40 mg/L)(P<0.05).The Chinese hook snout carp was deeply anaesthetised by MS-222 at the optimal mass concentration of 35 mg/L with recovery rate of 100%in the fish with air exposure for 8 min.The Chinese hook snout carp was anaesthetized by 2-phenoxyethanol at 3 min and recovery at 5 min with an effective volumetric concentration of 0.30 to 0.38 mL/L,with the enhanced anaesthesia effect with increasing volume concentration,and significant difference among all groups(0.26—0.42 mL/L)(P<0.05).Chinese hook snout carp deeply anaesthetised by the optimal volume concentration of 0.34 mL/L 2-phenoxyethanol had a recovery rate of 92%with air exposure for 8 min.The anaesthetic effects of the two anaesthetics were shown to be closely related to the water temperature,and the anaesthetic effects were increased with the increase in water temperature.The best 24 h transportation effects were found at 7 mg/L MS-222 and 0.10 mL/L 2-phenoxyethanol at a fish-water ratio of 1∶20.The findings provide technical support for improvement of the efficiency of artificial reproduction and culture and transport survival of Chinese hook snout carp via screening the appropriate anaesthetic drugs and dosages.