Archaea are ubiquitous and abundant members of the marine plankton. Once thought of as rare organisms found in exotic extremes of temperature, pressure, or salinity, archaea are now known in nearly every marine environment. Though frequently referred to collectively, the planktonic archaea actually comprise four major phylogenetic groups, each with its own distinct physiology and ecology. Only one group-the marine Thaumarchaeota-has cultivated representatives, making marine archaea an attractive focus point for the latest developments in cultivation-independent molecular methods. Here, we review the ecology, physiology, and biogeochemical impact of the four archaeal groups using recent insights from cultures and large-scale environmental sequencing studies. We highlight key gaps in our knowledge about the ecological roles of marine archaea in carbon flow and food web interactions. We emphasize the incredible uncultivated diversity within each of the four groups, suggesting there is much more to be done.

中文翻译：

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浮游生物海洋古细菌。

古细菌是海洋浮游生物中无处不在且丰富的成员。曾经被认为是在温度，压力或盐度异乎寻常的极端情况下发现的稀有生物，古细菌现已在几乎所有海洋环境中广为人知。尽管经常被统称为浮游古细菌，但实际上它包括四个主要的系统发育组，每个组都有其自己独特的生理学和生态学。仅有海洋海藻（Thaumarchaeota）这样的一个群体曾培养过代表菌，这使得海洋古细菌成为不依赖培养的分子方法最新发展的一个有吸引力的焦点。在这里，我们使用来自文化和大规模环境测序研究的最新见解，回顾了四个古细菌群体的生态，生理和生物地球化学影响。我们在了解海洋古细菌在碳流和食物网相互作用中的生态作用方面的知识方面突出了主要差距。我们强调了这四个群体中令人难以置信的未经培养的多样性，这表明还有很多事情要做。