Spatial distribution patterns of protists in the deep sea are not yet understood and due to the remoteness of the deep-sea biome this is a challenging task. Here, we investigated the structure and dispersal of protist communities in abyssal sediments at three sites in the Caribbean Sea (15°53.21′N/68°55.73′W), the northwestern Atlantic (23°33.23′N/48°05.04′W) and the central Atlantic Ocean (10°20.38′N/36°57.76′W), focusing especially on small horizontal (∼1 m) and vertical (1 cm) spatial scales. High-throughput sequencing of the V9 SSU rDNA, revealed diverse protist communities dominated by diplonemids and dinoflagellates. Only 12% of OTUs were shared between the three deep-sea regions (4000–5134 m deep), indicating patterns of protistan distribution at large spatial scales in deep-sea sediments. The analyses of sediment samples taken from cores of the same Multi-Corer deployment, separated by ∼1 m, showed differences in the community structure, indicating a distinct microbial eukaryotic diversity even at a local horizontal scale. At a vertical scale, in different sediment depth layers (upper 2 mm layer, 1 cm, 2 cm, 3 cm) of the same core, only 4–11% of OTUs were shared. We could show, that already at small spatial scales protist communities varied strongly, indicating an underestimated complexity of deep-sea microbial food webs.

深海原生生物的空间分布模式尚不明确，由于深海生物群落的偏远性，这是一项艰巨的任务。在这里，我们研究了加勒比海（15°53.21′N / 68°55.73′W），西北大西洋（23°33.23′N / 48°05.04′W）三个站点深渊沉积物中原生生物群落的结构和分布）和大西洋中部（10°20.38'N / 36°57.76'W），特别关注较小的水平（〜1 m）和垂直（1 cm）空间尺度。V9 SSU rDNA的高通量测序揭示了以倍耐隆和双鞭毛虫为主的多样的原生生物群落。在三个深海区域（4000-5134 m深）之间只有12％的OTU共享，这表明深海沉积物中大量空间上的protistan分布模式。从相同的多Corer部署的岩心采集的沉积物样品的分析（相距约1 m）显示出群落结构的差异，表明即使在局部水平尺度上，微生物的真核生物多样性也不同。在垂直尺度上，在同一岩心的不同沉积物深度层（上2 mm层，1 cm，2 cm，3 cm）中，只有4-11％的OTU被共享。我们可以证明，在较小的空间尺度上，生物界存在很大差异，表明深海微生物食物网的复杂性被低估了。只有4-11％的OTU被共享。我们可以证明，在较小的空间尺度上，生物界存在很大差异，表明深海微生物食物网的复杂性被低估了。只有4-11％的OTU被共享。我们可以证明，在较小的空间尺度上，生物界存在很大差异，表明深海微生物食物网的复杂性被低估了。