The “Devil’s Worm” defies the limits of life at extreme depths

It was in 2011 that biologist Gaetan Borgonie discovered Halicephalobus mephisto, nicknamed the “devil worm,” in the Beatrix gold mine in South Africa. The discovery upended our assumptions about the limits of life.

As the BBC notes, before the 1980s, it was believed that life could not survive more than 30 centimeters underground. Yet the “devil worm,” a tiny nematode, thrives at a depth of more than 1.3km in an environment that is extremely low in oxygen and entirely devoid of sunlight.

The microscopic predator feeds on bacteria found in the deep biosphere. Some of these microorganisms have been rooted there since the breakup of Pangaea (Earth’s only supercontinent) 165 million years ago. They also account for 12 to 20 percent of Earth’s microbial biomass.

According to Slate, in order to cope with these extreme temperatures and pressures, the organism relies on an abundance of genes that produce heat shock proteins. Halicephalobus mephisto also relies on parthenogenesis, a form of asexual reproduction that is ideal for compensating for the absolute isolation of the deep sea.

The existence of such an animal ecosystem under such hostile conditions pushes the boundaries of biology and offers new perspectives for the search for extraterrestrial life.