Physiological response of Aurelia coerulea polyps to elevated seasonal temperatures

Abstract

The moon jellyfish Aurelia coerulea is the most common blooming scyphozoan jellyfish in global coastal waters. A. coerulea polyps can rapidly increase their population through asexual reproduction, which is influenced directly by the ambient seawater temperature. However, the physiological responses of A. coerulea polyps to future elevated seasonal seawater temperature scenarios are largely unknown. In this study, we performed an experiment to test the hypothesis that the elevated seasonal seawater temperatures (current seawater temperatures + 3°C) will increase the asexual reproduction, feeding, and respiration rates of A. coerulea polyps. After 42 days of exposure, the asexual reproductionand feeding rates of the A. coerulea polyps increased under the elevated seawater temperatures predicted for all seasons. The highest asexual reproduction rates occurred in predicted average summer seawater temperatures. The respiration rates of A. coerulea polyps were suppressed significantly under winter temperature conditions, suggesting that more available energy was allocated to asexual reproduction than to metabolism after warming. Overall, this study suggests that A. coerulea polyp populations will benefit from the predicted higher seawater temperatures in all four seasons, thereby further increasing the potential and scale of A. coerulea blooms.