Distribution of Protists in the Deep South China Sea Revealed by High-Throughput Sequencing

  • Xinran Li
  • Alan Warren
  • Nianzhi Jiao
  • Dapeng XuEmail author


Protists (microbial eukaryotes) are indispensable members of the marine microbial food web. In recent years, organisms living in the deep sea (>1000 m water depth) have increasingly become the focus of research; however, studies on protistan assemblages are relatively scarce compared with their prokaryotic counterparts. In the present study, high-throughput sequencing of the hypervariable V9 region of the 18S rRNA gene was used to explore the community composition of protists in bathypelagic waters of the South China Sea. Based on the analysis of the alpha and beta diversities of 14 samples, we discovered: 1) members belonging to Rhizaria, Alveolata, and Excavata were the dominant groups in terms of both relative sequence abundance and operational taxonomic unit (OTU) richness in all samples, although their relative contributions differed among different samples; 2) cluster analysis showed that the distribution of protistan assemblages was related neither to the sampling location nor to the water depth, and other environmental factors might have caused the differences among the communities; 3) phototrophs, including members of the Bacillariophyta, Bolidophyceae, Dictyochophyceae, Prasinophyceae, and Prymnesiophyceae, were detected in all samples, which indicated their contributions to the downward transportation via the biological pump and the potential presence of phagotrophy of these phototrophic cells in the deep ocean.


bathypelagic water diversity microbial eukaryotes SSU rRNA gene 


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We thank the captain and crew of the R/V Dongfang-hong-2 for successful sampling. This work was supported by the National Natural Science Foundation of China (Nos. 41876142, 91751207 and 41861144018) and the Senior User Project of RV KEXUE (No. KEXUE2019 G08) funded by the Center for Ocean Mega-Science, Chinese Academy of Sciences.


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Copyright information

© Ocean University of China, Science Press and Springer-Verlag GmbH Germany 2020

Authors and Affiliations

  • Xinran Li
    • 1
  • Alan Warren
    • 2
  • Nianzhi Jiao
    • 1
  • Dapeng Xu
    • 1
    Email author
  1. 1.State Key Laboratory of Marine Environmental Science, Institute of Marine Microbes and Ecospheres, College of Ocean and Earth SciencesXiamen UniversityXiamenChina
  2. 2.Department of Life SciencesNatural History MuseumLondonUK

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