Rhizaria are large protistan cells that have been shown to be a major component of the planktic community in the oceans and contribute significantly to major biogeochemical cycles such as carbon or silicon. However, unlike for many other protists, limited data is available on rhizarian cellular carbon (C) and nitrogen (N) content and cell volume. Here we present novel C and N mass to volume equations and ratios for nine Rhizaria taxa belonging to Radiolaria (i.e., Collozoum, Sphaerozoum, Collosphaeridae, Acantharia, Nassellaria, and Spumellaria) and Phaeodaria (i.e., Aulacantha, Protocystis, and Challengeria). The C and N content of collodarian cells was significantly correlated to cell volume as expressed by the mass : vol equations ng C cell⁻¹ = −13.51 + 0.1524 × biovolume (μm³) or ng N cell⁻¹ = −4.33 + 0.0249 × biovolume (μm³). Significant C and N content to volume correlations were also identified, and corresponding equations are proposed, for C : vol and N : vol of collodarian colonies (Radiolaria), and C : vol of the genus Protocystis (Phaeodaria). Furthermore, average C and N densities (mass per volume) are given for all studied Rhizaria. The densities and mass : vol equations established here could show that, with the exception of Aulacantha, biomass of most Rhizaria would have been underestimated using previously published generic protist C : vol ratios. We measured up to 35 times more C content for Acantharia than otherwise estimated, and between 1.4 and 21.5 times more for other taxa. Our mass : vol data will prove critical for model input and quantitative ecological studies of oceanic ecosystems.

中文翻译：

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碳和氮含量与根瘤菌海洋物种（Radi虫和ol虫）的生物量关系

根瘤菌是大型的前列腺素细胞，已被证明是海洋中浮游生物群落的主要组成部分，并且对主要的生物地球化学循环（如碳或硅）起着重要作用。但是，与许多其他生物不同的是，关于根茎细胞碳（C）和氮（N）含量以及细胞体积的数据有限。在这里，我们本发明的新的C，N的质量与体积的方程和比率为9个有孔虫界类群属于放射虫（即，Collozoum，Sphaerozoum，Collosphaeridae，Acantharia，Nassellaria，和Spumellaria）和Phaeodaria（即，Aulacantha，Protocystis和Challengeria）。collodarian细胞的C和N含量如由质量表示被显著与细胞体积：体积方程纳克C单元^-1 = -13.51 + 0.1524×biovolume（μ米³）或异常N个单元^-1 = -4.33 + 0.0249 ×biovolume（μ米³）。显著C和N含量对体积的相关性也被识别，并且对应的方程提出，为C：体积和N：collodarian菌落体积（放射虫），以及C：属的体积Protocystis（Phaeodaria）。此外，给出了所有研究的根茎的平均C和N密度（每体积的质量）。此处建立的密度和质量：vol方程可以表明，除了使用以前发表的通用原生生物C：体积比，会低估大多数根霉的生物量Aulacantha。我们测出刺五加的C含量比其他估计高出35倍，其他类群的C含量高出1.4到21.5倍。我们的质量：体积数据将被证明对于模型输入和海洋生态系统定量生态研究至关重要。