A tiny nematode from a shaft of the Beatrix mine in South Africa is the first known multicellular organism to dwell at such depths.
Single-cell organisms have been known to live deep in the earth, more than 9,000 feet below the surface.
But until now, it was thought that the temperature, energy, oxygen and space constraints of the subsurface biosphere were too extreme for multicellular organisms.
Now, Tullis Onstott, a geoscientist at Princeton University, and colleagues from Belgium, South Africa and the Netherlands report their discovery of a small multicellular worm that dwells at these depths.
The worm, known as Halicephalobus mephisto, is tiny — two hundredths of an inch at the longest — and belongs to the vast and diverse phylum of nematodes. Its discovery, in a shaft of the Beatrix gold mine in South Africa, is reported in the journal Nature.
The worm appears to tolerate temperatures exceeding 100 degrees Fahrenheit and feeds on subsurface bacteria.
The researchers studied soil and water samples from the mines to determine that the newly identified nematodes are uniquely subsurface organisms. The samples indicated that while the nematodes live in the deep fracture water of the mines, they do not inhabit the surface-level mining water.
The researchers say their findings should be considered as scientists search for life in other extreme conditions — like those on Mars and other planets in the solar system.
Source: New York Times
