Gómez Fernando, Wang Lu, Lin Senjie
Carmen Campos Panisse 3, E-11500 Puerto de Santa María, Spain.
State Key Laboratory of Marine Environmental Science and Marine Biodiversity and Global Change Research Center, Xiamen University, Xiamen, China; Department of Marine Sciences, University of Connecticut, Groton, CT, USA; Institute of Oceanography, Minjiang University, Fuzhou, China.
Protist. 2018 Apr;169(2):268-279. doi: 10.1016/j.protis.2018.03.003. Epub 2018 Mar 20.
Consortia of the peritrich ciliate Vorticella oceanica and the planktonic diatom Chaetoceros coarctactus are reported from the South Atlantic Ocean. The morphologies of the constituent species were similar to their counterparts from other geographical regions, revealing a widespread distribution in tropical waters. Besides, we describe Pseudovorticella coscinodisci sp. nov. that lives on Coscinodiscus wailesii and other pelagic diatoms off Brazil. The zooids were 34-45μm long, and 19-30μm wide with a stalk too short to coil. The cell surface showed a reticulate pellicle with 18-19 and 11-12 rows above and below the aboral ciliary wreath, respectively. In the SSU rDNA phylogeny V. oceanica clustered between the clades of Vorticella and Pseudovorticella/Epicarchesium, and Pseudovorticella coscinodisci sp. nov. clustered as a sister group of Pseudovorticella paracratera and P. sinensis. The V. oceanica-C. coarctactus consortium likely represents an obligate species-specific mutualistic symbiosis as the constituents are not known as free-living forms. In contrast, the diatom hosts are known as free-living forms in the consortia of Pseudovorticella coscinodisci. The new molecular data and species description will be valuable dataset for future research on the diversity and ecological significance of ciliate-diatom epibiotic consortia.
据报道，在南大西洋发现了周丛生纤毛虫海洋钟虫（Vorticella oceanica）与浮游硅藻紧挤角毛藻（Chaetoceros coarctactus）的聚生体。组成物种的形态与来自其他地理区域的同类相似，表明其在热带水域广泛分布。此外，我们描述了一种寄生于巴西近海的威氏圆筛藻（Coscinodiscus wailesii）和其他浮游硅藻上的新物种——科斯圆筛藻伪钟虫（Pseudovorticella coscinodisci sp. nov.）。虫体体长34 - 45μm，宽19 - 30μm，柄短，无法盘绕。细胞表面在反口纤毛环上方和下方分别有18 - 19行和11 - 12行网状表膜。在小亚基核糖体DNA系统发育树中，海洋钟虫聚集在钟虫属与伪钟虫属/表壳虫属（Epicarchesium）的进化枝之间，而科斯圆筛藻伪钟虫作为副火山口伪钟虫（Pseudovorticella paracratera）和中华伪钟虫（P. sinensis）的姐妹群聚集在一起。海洋钟虫 - 紧挤角毛藻聚生体可能代表一种专性的物种特异性互利共生关系，因为其组成部分并非自由生活形态。相比之下，在科斯圆筛藻伪钟虫的聚生体中，硅藻宿主是已知的自由生活形态。这些新的分子数据和物种描述将为未来关于纤毛虫 - 硅藻体表聚生体的多样性和生态意义的研究提供有价值的数据集。
