斑节对虾虾苗活力检测方法

Methods of testing vitality of postlarvae of Penaeus monodon

该研究通过肉眼观察、镜检,进行干露、饥饿、盐度突降、福尔马林等抗性试验,并采用病毒检测等方法,以期建立评估斑节对虾(Penaeus monodon)虾苗活力和质量标准。结果表明,斑节对虾健康虾苗具有趋光性、集群性,体表光洁,肌肉透亮,肠胃食物充盈等特性。测试虾苗干露时间以15min为宜,健康虾苗干露后能立即恢复活力,而病弱虾苗多出现死亡、昏迷现象;虾苗的成活率随饥饿时间的延长而降低,随福尔马林浓度升高和时间延长而降低,随盐度突降幅度增加而降低。健康虾苗能忍受100～200μL.L-1福尔马林溶液30min,成活率近100%;在盐度20～30下虾苗的成活情况较好,而其在淡水中仅能存活1h。对虾苗进行病毒检测,可以避免养殖中因虾苗携带病毒而可能导致的病毒性疾病的暴发。

In the current study, to establish the standard system for assessing the activity and quality of larval Penaeus monodon, whose tolerance to drying, starving, sharply-decreased salinity and formalin were investigated by methodologies of visualizing, microscopy and virus detection. The results showed that healthy postlarvae were featured with phototaxis and gregariousness; their bodysurface was clean and the tissue was transparent ; the stomach and intestine were full. The appropriate time for postlarvae to live without water was 15 minutes. After that, healthy postlarvae resumed vitality quickly while the sick ones were dead or narcose. The survival rate of postlarvae decreased with an extention of starvation time, with an increase of concentration of formalin and time, as well as with an abrupt drop of salinity. Healthy postlarvae could sustain about 30 minutes in 100 -200μL·L^-1 formalin and the survival rate almost reached 100%. The appropriate range of salinity for postlarvae was 20 -30, but they only sustained 1 hour in fresh water. Virus detection could avoid the outbreak of disease that might result from the postlarvae carrying with virus.