Gelatinous zooplankton play a crucial role in pelagic marine food webs, however, due to methodological challenges and persistent misconceptions of their importance, the trophic role of gelatinous zooplankton remains poorly investigated. This is particularly true for small gelatinous zooplankton including the marine pelagic tunicate, Dolioletta gegenbauri. D. gegenbauri and other doliolid species occur persistently on wide subtropical shelves where they often produce massive blooms in association with shelf upwelling conditions. As efficient filter feeders and prodigious producers of relatively low-density organic-rich aggregates, doliolids are understood to contribute significantly to shelf production, pelagic ecology, and pelagic–benthic coupling. Utilizing molecular gut content analysis and stable isotope analysis approaches, the trophic interactions of doliolids were explored during bloom and non-bloom conditions on the South Atlantic Bight continental shelf in the Western North Atlantic. Based on molecular gut content analysis, relative ingestion selectivity varied with D. gegenbauri life stage. At all life stages, doliolids ingested a wide range of prey types and sizes, but exhibited selectivity for larger prey types including diatoms, ciliates, and metazoans. Experimental growth studies confirmed that metazoan prey were ingested, but indicated that they were not digested and assimilated. Stable isotopic composition (δ¹³C and δ¹⁵N) of wild-caught doliolids, during bloom and non-bloom conditions, were most consistent with a detrital-supplemented diet. These observations suggest that the feeding ecology of D. gegenbauri is more complex than previously reported, and have strong and unusual linkages to the microbial food web.

中文翻译：

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Doliolid Dolioletta gegenbauri的选择性进食和与微生物食物网的联系

胶质浮游动物在远洋海洋食物网中起着至关重要的作用，但是，由于方法学上的挑战和对其重要性的持续误解，胶质浮游动物的营养作用仍未得到充分研究。对于小的胶质浮游动物尤其如此，包括海洋中上覆被膜，Dolioletta gegenbauri。格氏鲍里氏菌和其他doliolid物种持续出现在宽广的亚热带陆架上，在这些陆架上它们经常与陆架上升条件相关联地产生大量水华。作为密度相对较低的富含有机物的骨料的高效过滤器饲养者和惊人的生产者，人们知道白藜芦醇对货架生产，浮游生态学和浮游-底栖生物耦合有重大贡献。利用分子肠含量分析和稳定同位素分析方法，在北大西洋西部的南大西洋湾大陆架上的开花和非开花条件下，研究了多里奥利德的营养相互作用。基于分子肠含量分析，相对摄入选择性随根D虫的不同而变化人生阶段。在所有生命阶段，白do科动物都摄取各种各样的猎物类型和大小，但对较大的猎物类型（包括硅藻，纤毛虫和后生动物）表现出选择性。实验性生长研究证实已摄取了后生动物的猎物，但表明它们没有被消化和吸收。稳定同位素组成（δ ¹³ C和δ ¹⁵ N）野生捕获doliolids，在开花和非开花条件的，用一个碎屑补充饮食最一致。这些观察结果表明，革兰氏梭菌的摄食生态学比以前报道的更为复杂，并且与微生物食物网有很强且不同寻常的联系。