The calanoid copepod Calanus finmarchicus is one of the most abundant and ecologically important species of the zooplankton assemblage of the North Atlantic Ocean and occupies a pivotal position in the pelagic food web. This study used metabarcoding analysis (high throughput DNA sequencing of target gene regions) to examine the diversity of the copepod gut content, including both eukaryotic and prokaryotic components of the diet and microbiome. Zooplankton samples were collected during the 2013 EuroBASIN cruise of the R/V G.O. Sars, which crossed the North Atlantic to survey in the Norwegian, Icelandic, Irminger, and Labrador Seas. Zooplankton samples were examined microscopically for C. finmarchicus; species identification was confirmed by genetic markers based on insertion-deletion sequence variation. DNA was extracted from the dissected gut contents of adult female copepods and sequenced for eukaryotic 18S V4 and prokaryotic 16S V3–V4 rRNA hypervariable regions. Prokaryotes identified in the gut contents of all copepods analyzed included Cyanobacteria, Proteobacteria, Bacteroidetes, Planctomycetes, Actinobacteria, and Acidobacteria. The eukaryotic gut content assemblage was diverse, dominated by Ocrophyta (diatoms), Dinophyta (dinoflagellates), Ciliophora (ciliates), as well as Cnidaria and Ctenophora. The diverse assemblage revealed by metabarcoding analysis of copepod gut contents likely represents prey, microbiome, parasites, symbionts, and pathogens. Significant differences in prokaryotic and eukaryotic diversity of the gut contents of copepods collected from four regional seas of the North Atlantic Ocean reflect and contribute to basin-scale differences in the pelagic food web of these ecosystems. This study provides evidence that diversity and variation of the copepod gut contents may both reflect and impact the functioning of pelagic food webs and regional variation in ocean ecosystems.

cal足类pe足类鱼类（Calanus finmarchicus）是北大西洋浮游动物组合中数量最多，最重要的生态物种之一，在远洋食物网中占有举足轻重的地位。这项研究使用元条形码分析（目标基因区域的高通量DNA测序）来检查the足动物肠道含量的多样性，包括饮食和微生物组的真核和原核成分。浮游生物样本是在2013年EuroBASIN R / V GO Sars巡游期间采集的，该游轮穿越北大西洋在挪威，冰岛，艾明格和拉布拉多海进行了调查。对浮游动物样本进行了显微镜检查，以检查其鳍金枪鱼; 通过基于插入-缺失序列变异的遗传标记确认物种鉴定。从成年雌性pe足类动物的肠道内容物中提取DNA，并对真核18S V4和原核16S V3-V4 rRNA高变区进行测序。在分析的所有co足类动物的肠内容物中鉴定出的原核生物包括蓝细菌，变形细菌，拟杆菌，扁平菌，放线菌和酸性细菌。真核生物肠道内含物的组成是多种多样的，其中以豆科植物（硅藻），恐龙科（恐龙鞭毛虫），纤毛虫（纤毛虫），以及矢车菊和纤毛虫为主。通过meta足类动物肠道内容的元条形码分析揭示的各种组合可能代表猎物，微生物组，寄生虫，共生体和病原体。从北大西洋四个区域海收集的co足类动物的肠道内容物的原核和真核生物多样性的显着差异反映了这些生态系统的中上层食物网中流域尺度的差异，并对此做出了贡献。这项研究提供了证据，证明pe足类动物肠道内含物的多样性和变化可能既反映并影响了中上层食物网的功能以及海洋生态系统的区域变化。