盐度对不同温度下海月水母螅状体存活和无性繁殖的影响

Effects of salinity on the survival and asexual reproduction of Aurelia coerulea polyps at different temperatures

海月水母是全球近岸海域的主要致灾水母种类之一,其螅状体的繁殖情况与种群数量是影响水母暴发的重要因素.采用实验生态学的方法分别研究了高温(21℃)和低温(12℃)条件下,不同盐度梯度对螅状体存活与无性繁殖的影响.结果表明:高温条件下,盐度15~40时螅状体存活率均大于90%,适合出芽生殖盐度范围为20~32,其中28为最适盐度;在低盐(≤15)或高盐(≥36)环境下,螅状体会进行足囊生殖以度过不良环境条件.低温条件下,20~40盐度组螅状体存活率均大于90%,20~32盐度组适于螅状体出芽生殖,其中28盐度组出芽生殖效率最高;20~40盐度适于横裂生殖,其中28~32盐度组最利于螅状体横裂生殖.说明海月水母螅状体有较强的盐度耐受性,一定范围内盐度对螅状体无性生殖影响不显著.

The scyphozoan genus Aurelia is one of the main contributors causing jellyfish blooms in global coastal waters.The population and reproduction of polyps are important factors to the outbreak of jellyfish.In this study,the effects of different salinity on the survival and asexual reproduction of Aurelia coerulea polyps were explored,which were cultured at the high(21℃)and low temperature(12℃),respectively.The results showed that more than 90%polyps could survive in the salinity range of 15-40 at the high temperature,with a range of salinity for budding being 20-32 and an optimum value of 28.The polyps were able to produce podocysts to tolerate low(≤15)and high(≥36)salinity conditions.At the low temperature,the survival rates of polyps were more than 90%in the salinity range of 20-40.The polyps could produce more buds in the salinity range of 20-32,with an optimum of 28.The salinity range of 20-40 was suitable for strobilation,with an optimum range of 28-32.It is concluded that the polyps of Aurelia coerulea can tolerate wide salinity variations,and that the salinity in a certain range has no significant influence on the asexual reproduction of polyps.