Devil worm genes hold clues for how some animals survive extreme heat
You might expect a “devil worm” to have fiery eyes and a forked tail — or horns, at the very least. But under the microscope, Halicephalobus mephisto looks nothing like its nickname. Measuring a scant half of a millimeter, it’s a little squiggle of a critter. “There’s nothing particularly menacing about them,” says John Bracht, a molecular biologist at American University in Washington, D.C., and proud owner of the only live devil worms in a U.S. lab. Instead, the worm, a kind of nematode, earned that title because it somehow manages to live in hellish conditions, he says. First described in 2011, H. mephisto is one of the deepest-living land animals found to date. The only live one ever caught in the wild was filtered out of water from an aquifer 1.3 kilometers underground in a South African gold mine (SN: 6/1/11). At that depth, devil worms must cope with low oxygen, high methane levels and temperatures around 37° Celsius. The captured worm laid...