摘要
In recent years, jellyfish blooms have attracted considerable scientific interest for the potential impacts on marine organism and ecosystem functioning, with much attention paid to jellyfish as predators. Other than qualitative data and observations, few studies have quantified direct predation on jellyfish. This study is designed to test the predation between edible jellyfish Rhopilema esculenta and moon jellyfish Aurelia aurita with the average time and captured rate. And comparisons are done using the least significant difference （LSD） test at P 〈 0.05 and P 〈 0.01. The young edible jellyfish and moon jellyfish are bred and observed on the predatory behavior in Qingdao aquarium. A total of 520 jellyfish are sampled to quantify predation between moon and edible jellyfish in four tests. The results show that moon jellyfish of 10-11 mm in umbrella diameter prey on edible jellyfish of 4-5 mm in 16 min, and the predation rate is 100%. Moon jellyfish of 18-20 mm spend a longer time to feed all edible jellyfish of 9-12 mm. Edible jellyfish can not be caught, if its umbrella diameter is more than 20 mm. Though edible jellyfish is bigger than moon jellyfish, the former can not prey on the later in a tank. The differences between the four groups are very significant （P 〈 0.01）. The observation indicates that moon jellyfish is one of the natural enemies of the young edible jellyfish. Early prediction and reduction of moon jellyfish can not only effectively defense adult jellyfish outbreaks, but also improve the yield of edible jellyfish. With the edible jellyfish growing, its defense is enhancing. Edible jellyfish can not prey directly on moon jellyfish, but they still interact in the food, water quality and the survival space.
