This might have some impact on the search for extraterrestrial life. If these things can live in this sort of hostile environment, perhaps we’ll find similar life forms below the surface of other planets, such as Mars, which may have had surface life at one time.

Subterranean worms from hell

New species of nematode discovered more than a kilometre underground.

From Nature News, Nadia Drake

The discovery of multicellular creatures from the deepest mines sounds like something from the pages of J. R. R. Tolkien. But scientists have now found four species of nematode, or roundworm, lurking in South Africa’s gold mines at depths where only single-celled bacteria were thought to reside. And at least one of them, Halicephalobus mephisto, has never been described before.

The 0.5-millimetre-long H. mephisto, named in reference to the light-hating demon of the underworld, feeds on films of bacteria that grow more than a kilometre down within the warm walls of the Beatrix gold mine, located some 240 kilometres southwest of Johannesburg.

“It’s like 1 million times the size of the bacteria it eats — sort of like finding Moby Dick in Lake Ontario,” says Tullis Onstott, a geomicrobiologist at Princeton University in New Jersey and a co-author of the study, which is published today in Nature1.

Deep dwellers

Previously, nematodes had been found nearer the surface, with only bacterial populations living deeper down2,3. But the authors discovered H. mephisto existing happily at 1.3 km down — at which depth the temperature reaches around 37 °C, higher than most terrestrial nematodes can tolerate.

Different South African mines revealed other deep-dwelling roundworms. Two nematode species — one identified as Plectus aquatilis and one unknown species from the Monhysterid order — were found in the Driefontein mines at a depth of 0.9 km at 24 °C. The authors also recovered DNA from a second unknown monhysterid species in the Tau Tona mine, 3.6 kilometres down, where temperatures hover around 48 °C.

Finding the worms surprised even the study’s authors. “When I proposed to look in the deep underground, this was a complete ‘out of the box’ idea,” says nematologist Gaetan Borgonie, of the University of Ghent in Belgium. “It doesn’t happen often that you can redraw the boundaries of a biosphere on a planet.”

“That depth? Those temperatures? This is incredible,” says Diana Wall, a soil ecologist at Colorado State University in Fort Collins, who studies antarctic nematodes.

full story here

Nematoda from the terrestrial deep subsurface of South Africa

G. Borgonie, A. García-Moyano, D. Litthauer, W. Bert, A. Bester, E. van Heerden, C. Möller, M. Erasmus & T. C. Onstott

Nature 474, 79–82 (02 June 2011) doi:10.1038/nature09974

Received 15 February 2011 Accepted 01 March 2011 Published online 01 June 2011

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. h/t Dave Stealey

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