CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China.
Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266237, China.
Sci Rep. 2023 Mar 8;13(1):3843. doi: 10.1038/s41598-023-30973-6.
Though diel variations are geographically widespread phenomena among phytoplankton and zooplankton, knowledge is limited regarding diel variations in planktonic ciliate (microzooplankton) community structure. In this study, we analyzed diel variations in community structure of planktonic ciliates in the northern South China Sea (nSCS) and tropical Western Pacific (tWP). Hydrological characteristics during day and night were slightly different over both the nSCS and tWP, while ciliate average abundance at night was clearly higher than in the day in the upper 200 m. In both the nSCS and tWP, abundance proportions of large size-fraction (> 30 μm) aloricate ciliates at night were higher than in the day. While for tintinnids, abundance proportion of large lorica oral diameter at night were lower than in the day. The relationship between environmental factors and ciliate abundance pointed out that depth and temperature were main factors influencing aloricate ciliate and tintinnid in both day and night. For some dominant tintinnid species, chlorophyll a was another important factor influencing their diel vertical distribution. Our results provide fundamental data for better understanding the mechanisms of planktonic ciliate community diel variation in the tropical Western Pacific Ocean.
尽管昼夜变化是浮游植物和浮游动物中广泛存在的地理现象，但关于浮游纤毛虫（微型浮游动物）群落结构的昼夜变化的知识有限。在这项研究中，我们分析了南海北部（nSCS）和热带西太平洋（tWP）浮游纤毛虫群落结构的昼夜变化。nSCS 和 tWP 的昼夜水文学特征略有不同，而在 200m 以上的上层水域中，纤毛虫的平均夜间丰度明显高于白天。在 nSCS 和 tWP 中，大尺寸（>30μm）有肋纤毛虫的丰度比例在夜间高于白天。而对于钟形虫，夜间大壳口直径的丰度比例低于白天。环境因素与纤毛虫丰度的关系指出，深度和温度是影响昼夜有肋纤毛虫和钟形虫的主要因素。对于一些优势钟形虫物种，叶绿素 a 是另一个影响其昼夜垂直分布的重要因素。我们的结果为更好地理解热带西太平洋浮游纤毛虫群落昼夜变化的机制提供了基础数据。
