中华小长臂虾(Palaemonetes sinensis)低温麻醉研究

Cold Anaesthetization of Palaemonetes sinensis

中华小长臂虾(Palaemonetes sinensis)是我国北方常见淡水小型虾类,具较高的观赏价值和食用价值。为寻求一种安全有效的麻醉方法,研究了直接低温(直接放置于≤4℃低温度水浴中)和快速分级低温(分阶段依次放入≥4℃的水浴适应较短时间后,迅速放置于≤4℃低温度水浴中)对3种规格[大(3.53~4.58cm);中(2.90~3.15cm);小(2.05~2.67)cm]虾的麻醉效果和复苏后成活率。结果表明:直接低温麻醉和快速分级低温麻醉后,3种规格的中华小长臂虾体重均有增加,平均增重(14.24±2.32)%(5.36%~28.33%);在直接低温麻醉试验中,中华小长臂虾复苏时间和复苏后的存活率与麻醉温度和麻醉时间成反相关。1℃直接低温麻醉效果好,但复苏后成活率低。此外,麻醉后的复苏时间和存活率受虾的规格影响显著(p<0.05);4℃直接低温麻醉效果差。快速分级低温试验结果表明,分级麻醉与直接麻醉相比能显著提高复苏后的成活率。其中,3种规格的中华小长臂虾在3℃麻醉1min后迅速放入1℃麻醉1min条件下(3-1℃)可全部进入麻醉期,相比其他组别麻醉效果好。因此,综合考虑中华小长臂虾麻醉效果、体重增加率、复苏48h后存活情况及低温操作的可行性,采用3-1℃分级低温麻醉最为合适。

Chinese grass shrimp,Palaemonetes sinensis(Sollaud,1911),is an economically important freshwater shrimp in China and adjacent areas.The aim of this study was to seek a safe and efficient method for anesthetizing Palaemonetes sinensis.Effects of rapid transition(transition anesthetized in temperature above4℃in a short time,then in temperature below4℃immediately)and non-transition cold anaesthetization(anesthetized in temperature below4℃directly)on P.sinensis of three sizes(small2.05-2.67cm,medium2.90-3.15cm,large3.53-4.58cm)were investigated.The results showed that wet weight of all size P.sinensis increased after both cold anaesthetization methods and the percentage weight gain was(14.24±2.32)%(5.36%-28.33%).In non-transition cold anaesthetizaition experiment,the palinesthesia time and survival rate of P.sinensiswere decreased with the increasing of anesthetic time and temperature.Unlike4℃,the temperature of1℃had better effect for anaesthetization than the other temperatures,but the survival rate was lower.Moreover,recovery times and survival rate for P.sinensis were size-dependent(p<0.05).The results of transition cold anaesthetization showed that the survival rate of all size shrimps were significant improved than non-transition cold anesthesia group.Among them,the anesthetic effect of shrimps anaesthetized from3℃in1min to1℃in1min group(3-1℃)were significant higher than other groups.Based on the anesthetic effect,weight gain,alinesthesia time and survival rate,the transition anaesthetization was the best protocol for anaesthetizing P.sinensis.