关键环境因子对海月水母浮浪幼虫附着变态的影响

Effects of key environmental factors on the settlement of moon jellyfish(Aurelia coerulea)planula

海月水母的生活史包括底栖的螅状体世代和浮游的水母体世代。水母成体通过有性生殖释放精子和卵子,形成受精卵,受精卵随后经由浮浪幼虫变态发育成螅状体。浮浪幼虫经附着变态成为螅状体的阶段因在海底发生,不易观察,常被忽视。本文选取温度、盐度、光照3个关键环境因子,在实验室条件下开展了其对海月水母浮浪幼虫附着变态影响的研究。结果表明:(1)21℃为海月水母浮浪幼虫附着变态的最适宜温度,在此温度下浮浪幼虫附着所需时间最短(48 h),温度过高(24℃)或者过低(12℃)都不利于浮浪幼虫附着;(2)在试验的盐度范围内(18~33),盐度越低,浮浪幼虫附着率越高;(3)在试验所设置的光照范围内(0~300 Lux),随着光强的增加,海月水母浮浪幼虫的附着率提高。本研究有助于人们了解海月水母的生活史,并为近岸水母暴发的防治提供数据参考。

The life cycle of Aurelia coerulea consists of two stages:the benthic polyp stage and the planktonic medusa stage;however,the polyp stage is often neglected because of the difficulty in detecting and identifying these tiny individuals.In this study,we chose three key environmental factors,i.e.temperature,salinity and illumination,to clarify their effects on the settlement and metamorphosis of A.coerulea planula in laboratory.The results revealed that 21℃was the optimal temperature for the settlement and metamorphosis of A.coerulea planula,and the duration of settlement at 12℃was the shortest(48 h).In the salinity test(18~33),the settlement rate of A.coerulea planula increased with the salinity decreasing.In the illumination test(0~300 Lux),the settlement rate of A.coerulea planula increased with the illumination enhancing.This study may contribute to monitoring and management of moon jellyfish blooms in coastal waters of China.