【摘要】 为提高红螯螯虾离体胚胎孵化的效果,提供其大规模离体胚胎孵化基础水质数据,应用韩国施奇公司（ZISS）孵化器探讨p H对红螯螯虾离体胚胎孵化的影响,设置具体参数如孵出时间（至可自由运动的3期幼虾的时间）、出苗量（3期幼虾数量）、孵化率和出苗率等,以期筛选出最优p H条件。在水温28±0.5℃下,用梳子剥出7对红螯螯虾附肢期胚胎,经过3 000 mg/L甲醛浸泡15 min,然后置于ZISS孵化器中,用30%～40%的HCI和Na OH调节水体p H为6.8、7.7、8.4、8.9和9.4,进行离体孵化,试验共25 d。结果显示:各组间孵化率均在84.0%以上,无显著性差异（P>0.05）;p H 7.7组和p H 8.4组出苗率显著高于其他3组（P<0.05）,p H 6.8组出苗率为0%,与p H 9.4组无显著性差异（P>0.05）,均显著低于其他3组（P<0.05）;p H 7.7～9.4之间出苗率呈下降趋势;p H的变化不会导致孵化期间胚胎大量死亡,各p H组胚胎死亡高峰集中在第5天,且p H 6.8组胚胎孵化时间较长;p H 6.8组与p H 9.4组幼虾出现大量死亡现象,中间3组未出现该现象,出苗集中在第19天和第25天。在p H为6.8～9.4范围内,红螯螯虾离体胚胎孵化率不受p H影响,p H过低会造成胚胎孵化时间延长,造成孵化后的幼虾无法存活,存在酸中毒的现象,造成胚胎以及幼虾生理性缺氧,最终死亡;而p H过高,钙离子含量降低以及CO₃^2-中毒可能是造成幼虾最先出现大量死亡的原因。研究表明,红螯螯虾离体胚胎孵化最适的p H为8.1,该研究结果对孵化过程中的最适p H范围进行了精确化,有助于提高孵化率和出苗率,对于实际生产有指导作用。更多还原

【Abstract】 To improve the hatching effect of Cherax quadricariratus embryos in vitro and provide basic water quality data for large-scale incubation,in this study,the ZISS incubator was used to explore the effect of pH on the in vitro incubation performances of red claw crayfish embryos, such as hatch time（ to freely moving juveniles stage 3）,hatching amount（ the number of juvenile shrimps reaching stage 3）,hatching rate and survival rate etc.,in the wish to find out the optimal p H level. At water temperature of 28±0. 5℃,7 pairs of appendage embryos were stripped with a comb,soaked in 3 000 mg/L formaldehyde for 15 min,then incubated in a ZISS incubator respectively at pH of 6. 8,7. 7,8. 4,8. 9 and 9. 4 adjusted by 30%-40% HCI and NaOH,for a 25-day experiment. The results showed that there was no significant difference in hatching rate among all the groups（P>0. 05）. However,the red claw crayfish exposed to pH 7. 7 and pH 8. 4 had significantly higher survival rates than those in the other three groups（P<0. 05）,with 0% survival rate in pH 6. 8 group,and without significant difference from that in p H 9. 4 group（P>0. 05）. There was significantly lower survival rate in the two groups than that in the other three groups（P<0. 05）,with downward trend of survival rates between pH 7. 7 and 9. 4 groups. Changes in pH value during incubation did not led to a large number of embryo death,with the death peak of embryo in all p H groups on the 5 th day,and the longer incubation period of the embryos in pH 6. 8 group. In the pH 7. 7 and 9. 4 groups,a large number of death juveniles were found,while not found in the three middle pH value groups. Red claw crayfish juveniles were observed in 19 d and 25 d.The results showed that the hatching rate of in vitro embryos of red crayfish was not affected by pH changes within a pH range of 6. 8-9. 4. However,low p H will prolong the incubation time of embryos and make the young shrimps unable to survive after hatching, leading to the phenomenon of acidosis and resulting in physiological hypoxia and final death of embryos and young crayfish. While when pH is too high,the decrease of calcium ion content and CO₃^2- poisoning may be the reasons for the first mass death of young shrimps.According to the experiment,,the optimal pH for in vitro embryo hatching of red crayfish is 8. 1. This result provides a concrete optimal p H value for the hatching processes,which will be helpful to improve the hatching rate and survival rate,and play a guiding role in future practical production.更多还原