Selective feeding and linkages to the microbial food web by the doliolid Dolioletta gegenbauri
Selective feeding and linkages to the microbial food web by the doliolid Dolioletta gegenbauri
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DOI：
10.1002/lno.11740
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发表时间：
2021-04
影响因子：
4.5
通讯作者：
M. Frischer;L. Lamboley;T. Walters;J. Brandes;E. Arneson;L. E. Lacy;Natalia B. López-Figueroa;Á. Rodríguez‐Santiago;D. M. Gibson
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文献类型：
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作者：
M. Frischer;L. Lamboley;T. Walters;J. Brandes;E. Arneson;L. E. Lacy;Natalia B. López-Figueroa;Á. Rodríguez‐Santiago;D. M. Gibson
胶状浮游动物在远洋海洋食物网中起着至关重要的作用，然而，由于方法上的挑战和对其重要性的持续误解，胶状浮游动物的营养作用仍然很少被研究。对于小型胶状浮游动物，包括海洋中上层被囊动物（Dolioletta gegenbauri）来说尤其如此。格根宝丽和其他种类的水母持续出现在广阔的亚热带大陆架上，在那里它们经常产生大量的华花，与大陆架上升流条件有关。作为高效的滤食性动物和相对低密度的富有机聚集体的巨大生产者，人们了解到，水母对陆架生产、中上层生态和中上层-底栖生物耦合有重要贡献。利用分子肠道含量分析和稳定同位素分析方法，研究了北大西洋西部南大西洋湾大陆架在水华和非水华条件下浮游生物的营养相互作用。基于分子肠道含量分析，葛根鲍氏芽孢杆菌的相对摄食选择性随其生命阶段的不同而不同。在生命的各个阶段，珊瑚虫摄取的猎物类型和大小都很广泛，但对硅藻、纤毛虫和后生动物等较大的猎物类型表现出选择性。实验生长研究证实，后生动物的猎物被摄入，但表明它们没有被消化和同化。在开花和非开花条件下，野生捕获的橄榄石的稳定同位素组成（δ13C和δ15N）与添加碎屑的饮食最一致。这些观察结果表明，gegenbauri的摄食生态比以前报道的更为复杂，并且与微生物食物网有着强烈而不寻常的联系。
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.