Data from: Molecular assessment of heterotrophy and prey digestion in zooxanthellate cnidarians

Zooxanthellate cnidarians are trophically complex, relying on both autotrophy and heterotrophy. Although several aspects of heterotrophy have been studied in these organisms, information linking prey capture with digestion is still missing. We used prey-specific PCR-based tools to assess feeding and prey digestion of two zooxanthellate cnidarians - the tropical sea anemone Aiptasia sp. and the scleractinian coral Oculina arbuscula. Prey DNA disappeared rapidly for the initial one to three days, whereas complete digestion of prey DNA required up to ten days in O. arbuscula and five or size days in Aiptasia sp. depending on prey species. These digestion times are considerably longer than previously reported from microscopy-based examination of zooxanthellate cnidarians and prey DNA breakdown in other marine invertebrates, but similar to prey DNA breakdown reported from terrestrial invertebrates such as heteroptera and spiders. Deprivation of external prey induced increased digestion rates during the first days after feeding in O. arbuscula, but after six days of digestion there were no differences in the remaining prey levels in fed and unfed corals. This study indicates that prey digestion by symbiotic corals may be slower than previously reported and varies with the type of prey, the cnidarian species and it’s feeding history. These observations have important implications for bioenergetic and trophodynamic studies on zooxanthellate cnidarians.

虫黄藻共生刺胞动物（zooxanthellate cnidarians）具备复杂的营养模式，兼营自养与异养营养方式。尽管学界已对这类生物的异养营养多个方面开展研究，但仍缺乏将猎物捕获与消化过程相关联的系统性数据。
本研究采用猎物特异性聚合酶链式反应（PCR）工具，对两种虫黄藻共生刺胞动物的摄食与猎物消化情况进行评估——分别为热带海葵艾氏海葵（Aiptasia sp.）以及石珊瑚树状孔珊瑚（Oculina arbuscula）。
猎物DNA在摄食后的初始1至3天内快速降解；而树状孔珊瑚完全消化猎物DNA最长需10天，艾氏海葵则需5至6天，具体时长取决于猎物种类。该消化时长显著长于此前基于显微镜观察虫黄藻共生刺胞动物以及其他海洋无脊椎动物猎物DNA降解的相关研究报道，但与半翅目（Heteroptera）昆虫、蜘蛛等陆生无脊椎动物的猎物DNA降解时长相近。
在树状孔珊瑚中，外源猎物剥夺会在摄食后的初始阶段提升消化速率，但在消化进行六天后，投喂组与未投喂组珊瑚体内的残留猎物水平已无显著差异。
本研究表明，共生珊瑚的猎物消化过程可能比此前报道的更为缓慢，且其消化时长会随猎物种类、刺胞动物物种以及摄食历史的不同而发生变化。
上述研究结果对虫黄藻共生刺胞动物的生物能学及营养动态学（trophodynamic）研究具有重要参考价值。