运输时间和MS-222浓度对翘嘴鲌皮质醇、乳酸及氧气袋内水质的影响

釆用MS-222浓度为0(C0组)、5 mg/L(C1组)、10 mg/L(C2组)、15 mg/L(C3组)、20 mg/L(C4组),运输时间为0、2、4、6、8、10 h,运输密度为33 g/L,采用5×6双因素实验,氧气袋运输翘嘴鲌(Culter alburnus)稚鱼,研究了运输时间和MS-222浓度对翘嘴鲌全鱼皮质醇、乳酸含量及氧气袋内水质的影响。结果显示:翘嘴鲌全鱼皮质醇、乳酸水平随运输时间呈现先升高后降低的趋势,随麻醉剂浓度的增加而显著降低;C1-C4组的DO、p H随运输时间呈现先降低后升高的趋势,C0组则随运输时间的增加显著降低,各组的DO和p H随MS-222浓度的增加而显著增加;C1-C4组的氨氮(TAN)和游离CO_2浓度随运输时间呈现先升高后降低的趋势,而C0组则随运输时间的增加显著升高,各组的TAN和游离CO_2浓度随MS-222浓度的增加而显著降低。时间和浓度的交互作用都显著。运输时间T6 h时,MS-222刺激翘嘴鲌,不利于运输,运输时间T6 h时,MS-222能显著降低其应激水平及代谢强度,其中C4组皮质醇、乳酸含量最低,C3、C4组水质条件最好,其适宜的麻醉剂浓度为15~20 mg/L。

Effect of transport time and MS-222 concentration on cortisol,lactate levels of juvenile topmouth culter and the water quality indexes in O2-aerated bags

This study which used 5 ×6 factorial design was to determine the effect of transport time (0, 2, 4, 6, 8, 10 h) and MS-222 concentration (0 (C0), 5 mg/L (C1), 10 mg/L (C2), 15 mg/L (C3), 20 mg/L (C4)) on whole body cortisol, lactate levels of juvenile topmouth culter (Culter alburnus) and the water quality indexes in the O 2-aerated bags used for transporting the fish.At the end of the experiment , the whole body cortisol and lactate levels of juvenile top -mouth culter increased during the first 2 hours, then it decreased with the increasing of the transport time , while the two levels significantly decreased with the increasing of MS -222 concentration.Dissolved oxygen (DO) and pH values in group C1-C4 declined during the first 6 hours of transport, then increased with transport time, while DO and pH value in group C0 declined with the increasing of transport time .Besides, DO and pH values in groups C0-C4 significantly increased with the increasing of MS-222 concentration.Total ammonia-nitrogen (TAN) and CO2 (aq) levels in groups C1-C4 increased during the first 8 hours, then decreased with the increasing of transport time , and the two indexes significantly decreased with the increasing of the MS-222 concentration.While, TAN and CO2 (aq) levels in group C0 increased with time of transport.The significant interaction between transport time and MS -222 concentration on cortisol, lactate levels and the water quality indexes was observed .In conclusion, our results suggested that an obvious irritant action of MS -222 on ju-venile topmouth culter was observed during the first 6 h of transport.When the transport time of juvenile topmouth culter was longer than 6 hours, the appearance of MS-222 would reduce the stress response and metabolism rate of the topmouth culter, and the optimal MS-222 concentration would be 15 ~20 mg/L according to the minimum of cortisol and lactate level in group C4.