地壳下三千米即所谓的地表下岩石圈，这些厚重岩石的温度超过了40摄氏度。这里的水分由于缺乏氧气而能够使大多数人们熟悉的生物窒息，但是名为生物膜的一些细菌和其他微生物却能够在这里茁壮成长。如今，科学家在这个地狱般的环境中首次发现了一种贪婪的捕食者——被研究人员描述为地表深处的首个多细胞生物的一种线虫。

他们将这种生活在地下深处并耐热的物种命名为Halicephalobus mephisto（如上图）。这一名称借鉴了浮士德笔下的魔鬼Mephistopheles，意思是“不喜欢阳光的人”。

这些线虫身长最多约半毫米，以细菌为食，通过单性生殖方式不经交配来繁殖，能忍受生活环境（南非Beatrix金矿中三千米深的地方）中的高温。类似的生物预计也可能会出现在某些海床下的环境中。

多细胞生物在如此恶劣环境中的生存能力对于研究宇宙生物学也有参考价值。

研究人员在6月2日出版的《自然》杂志上报告了这一研究成果。

原文出处：

Nature    DOI:10.1038/nature09974

Nematoda from the terrestrial deep subsurface of South Africa

G. Borgonie; A. García-Moyano; D. Litthauer; W. Bert; A. Bester; E. van Heerden; C. M?ller; M. Erasmus; T. C. Onstott

Since its discovery over two decades ago, the deep subsurface biosphere has been considered to be the realm of single-cell organisms, extending over three kilometres into the Earth’s crust and comprising a significant fraction of the global biosphere1, 2, 3, 4. The constraints of temperature, energy, dioxygen and space seemed to preclude the possibility of more-complex, multicellular organisms from surviving at these depths. Here we report species of the phylum Nematoda that have been detected in or recovered from 0.9–3.6-kilometre-deep fracture water in the deep mines of South Africa but have not been detected in the mining water. These subsurface nematodes, including a new species, Halicephalobus mephisto, tolerate high temperature, reproduce asexually and preferentially feed upon subsurface bacteria. Carbon-14 data indicate that the fracture water in which the nematodes reside is 3,000–12,000-year-old palaeometeoric water. Our data suggest that nematodes should be found in other deep hypoxic settings where temperature permits, and that they may control the microbial population density by grazing on fracture surface biofilm patches. Our results expand the known metazoan biosphere and demonstrate that deep ecosystems are more complex than previously accepted. The discovery of multicellular life in the deep subsurface of the Earth also has important implications for the search for subsurface life on other planets in our Solar System.