The current lack of knowledge on the trophic ecology of scyphozoans, particularly at the benthic stage, prevents a full understanding of the controls on many jellyfish blooms. The blooming scyphozoan (Aurelia coerulea) completes its entire life cycle in the Thau lagoon (southern France), where the annual population dynamics of both its benthic and pelagic stages have been described. This offered an exceptional framework to investigate the trophic processes regulating jellyfish populations over time. To this aim, stable isotopic signature analysis (δ¹³C and δ¹⁵N) was used to infer the diet of both A. coerulea scyphistomae and medusae over 1 year. These results were matched with medusae gut content analysis and with the monthly abundances of local plankton groups. Lastly, the isotopic signatures of A. coerulea scyphistomae and medusae were compared with those of the oysters (Crassostrea gigas) cultivated in the lagoon to evaluate the potential interspecific trophic competition. The results revealed two seasonal shifts in the trophic niche of A. coerulea and substantial overlap between the diets of its benthic and pelagic stages. Conversely, trophic niche overlaps with the oysters were restricted, suggesting a limited impact of the local jellyfish bloom on shellfish production. Phytoplankton, microzooplankton, mesozooplankton, and sedimentary organic matter were all important food sources during critical periods of A. coerulea life‐cycle. However, microzooplankton abundance was found to be key for the production of buds by the scyphistomae and, therefore it is likely to control the benthic population size and, thereby, to modulate the intensity of its annual bloom in Thau.

中文翻译：

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地中海沿海泻湖中盛开的水母（Aurelia coerulea）的营养生态

当前缺乏对鳞甲动物营养生态学的了解，尤其是在底栖阶段，无法充分理解许多水母花开的控制措施。盛开的海生藻（Aurelia coerulea）在Thau泻湖（法国南部）中完成了其整个生命周期，在那里描述了其底栖和上浮阶段的年度种群动态。这为研究随时间推移调节水母种群的营养过程提供了一个特殊的框架。为了这个目的，稳定同位素特征分析（δ ¹³ C和δ ¹⁵ N）被用来推断两者的饮食A.犁头甲癣和水母超过1年。这些结果与水母肠含量分析以及当地浮游生物群体的每月丰度相匹配。最后，将蓝藻天蛾和水母的同位素特征与在泻湖中培育的牡蛎（Crassostrea gigas）的同位素特征进行了比较，以评估潜在的种间营养竞争。结果显示蓝藻的营养位有两个季节性变化底栖阶段和中上层阶段的饮食之间存在大量重叠。相反，与牡蛎的营养小生境重叠受到限制，表明当地水母开花对贝类生产的影响有限。浮游植物，微型浮游动物，浮游动物和沉积有机质是在关键时期所有重要的食物来源A.犁头生命周期。然而，发现微藻浮游生物的丰度是鞘囊吸虫产生芽的关键，因此，它有可能控制底栖种群的大小，从而调节其在丘州的年盛花强度。