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

Abstract

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.