Some have been found in geysers, black smokers, oil wells, and hot vents in the deep ocean.
The bubble takes them to the entrance of a cave filled with boiling hot thermal vents.
The surprisingly swift action took place at hot vents in the ocean floor that sometimes form atop volcanic fissures.
It turned out that the ecosystem's main energy source was sulfur compounds emitted by the hot vents, in particular hydrogen sulfide.
That's the sort of terrain where we're likely to find hot vents.
They are known from the littoral to the sublittoral zone (extending to the deep hot vents), and many species are common from coral reefs.
The temperature range for growth can vary from cold springs to hot vents while salinity can vary from fresh to ocean water.
This deep-sea research, if successful, is expected to produce a major step forward in scientific understanding of the mysterious hot vents at the bottom of the sea.
More than a mile down, surrounded by inky darkness, the robot scrutinized hot vents and bizarre life forms.
The light of the hot vents is far too faint to be detected by human eyes.