MS-222对许氏平鲉幼鱼麻醉效果的研究

Anesthetic effect of MS-222 on juvenile black rockfish (Sebastes schlegelii)

中文关键词: 许氏平鲉  MS-222  麻醉  镇静

英文关键词: Sebastes schlegelii  MS-222  Anesthesia  Sedation

中文摘要:

      本研究测试了不同浓度MS-222对许氏平鲉(Sebastes schlegelii)幼鱼的麻醉效果，确定了3种规格幼鱼在不同浓度MS-222作用下达到深度镇静期(A2)和麻醉期(A4)的效应时间及最佳镇静、麻醉浓度和适宜运输浓度。结果显示，在水温为(14.5±0.5) ℃、pH为7.85、盐度为30、溶解氧浓度大于7.5 mg/L条件下，平均体质量为(10.11±2.13) g (W10)、(42.38±5.19) g (W40)和(80.79±6.65) g (W80)的3种规格幼鱼达到A2期和A4期的效应时间随麻醉剂浓度升高逐渐缩短，同一麻醉浓度下效应时间随体质量增加逐渐延长，通过二次曲线回归分析各规格幼鱼达A2期和A4期的效应时间与MS-222浓度的关系，效应时间为180 s时，W10、W40和W80组达A2期对应的MS-222浓度分别为27.38、29.94和40.39 mg/L，达A4期对应的MS-222浓度分别为95.32、107.32和116.58 mg/L；A2期不同规格幼鱼的呼吸频率与对照组无显著差异，A4期幼鱼呼吸频率随麻醉剂浓度升高逐渐下降，且显著低于对照组(P<0.05)；MS-222浓度为30~50 mg/L时，8 h模拟运输中W10、W40和W80幼鱼存活率均为100%，显著高于对照组，60 mg/L时，幼鱼运输存活率分别为60%、80%和100%，W10、W40和W80适宜运输浓度范围建议为27.38~50.00、29.94~50.00、40.39~60.00 mg/L。相关结果可为许氏平鲉不同规格幼鱼的安全转运、生物学实验的抗应激操作提供指导。

英文摘要:

      The black rockfish, Sebastes schlegelii, is the main marine fish species produced via offshore cage culture in China. Moreover, it is essential to select a convenient, safe, and harmless anesthetic that can effectively reduce the physiological stress response of juveniles during land–sea relay transport. MS-222 has been widely used in fish and other aquatic creatures during handling and transportation because of its secure induction and rapid recovery. In this study, the anesthetic effect of MS-222 (tricaine methanesulfonate; anesthetic effect: 20–130 mg/L, interval of 10 mg/L, total of 12 concentration gradients; simulated transportation: 30–60 mg/L, interval of 10 mg/L) on three specifications of juvenile black rockfish (W10, W40, and W80; average body weight of (10.11±2.13) g, (42.38±5.19) g, and (80.79±6.65) g, respectively) was investigated. The times to deep sedation (A2) and anesthesia (A4) under different concentrations of MS-222 and the optimal sedation and anesthetic concentrations of MS-222 were determined. The results showed that in water with a temperature of (14.5±0.5) ℃, pH of 7.85, salinity of 30 and dissolved oxygen concentration above 7.5 mg/L, the time required for W10, W40, and W80 juveniles to reach the A2 and A4 stages decreased with an increase in anesthetic concentration and increased with an increase in body weight at the same anesthetic concentration. Quadratic regression analysis was performed to analyze the relationship between the A2 and A4 stage effect times and the concentrations of MS-222. The equations describing the relationship between the A2 stage effect time (y) and anesthetic concentration (x) in W10, W40, and W80 groups were y = 0.210 7x2  21.207x + 602.6 (R2 = 0.95), y = 0.202 1x2  21.501x + 642.6 (R2 = 0.98) and y = 0.089 3x2  14.153x + 606 (R2 = 0.91), respectively. Those for A4 stage effect time and the concentration of MS-222 were y = 0.043 1x2  10.755x + 813.57 (R2 = 0.97), y = 0.062 1x2  16.221x + 1 205.6 (R2 = 0.97) and y = 0.059 6x2  15.954x + 1 229.9 (R2 = 0.92), respectively. Therefore, the optimal sedative and anesthetic concentrations of MS-222 for juvenile W10, W40, and W80 black rockfish were 27.38, 29.94, and 40.39 mg/L (A2), and 95.32, 107.32, and 116.58 mg/L (A4), respectively, according to the optimal effect time of 180 s. No significant difference was observed between the respiratory rates of juvenile fish in the A2 stage and those in the control group; however, the respiratory rates of juvenile fish in the A4 stage gradually decreased with an increase in anesthetic concentration and were significantly lower than those of the control group (P < 0.05). The results of simulated transport over 8 h demonstrated that the survival rate of all fish remained at 100% within a concentration range of 30–50 mg/L for MS-222. However, when the concentration reached 60 mg/L, the survival rate decreased to approximately 60% for the W10 group and 80% for the W40 group, though it was still maintained at 100% for the W80 group. Therefore, suggested transport concentrations for juvenile W10, W40, and W80 black rockfish are in the ranges of approximately 27.38–50.00, 29.94–50.00, and 40.39–60.00 mg/L, respectively. These findings provide valuable guidance for the safe transportation of juvenile black rockfish during stock enhancement and offshore cage land-sea transportation. Moreover, the optimal anesthetic concentration can serve as a reference point for biological experiments involving measurement, labeling, or sample collection with juveniles of varying sizes.