Hot springs and hydrothermal systems occurring within volcanic areas are inhabited by hyperthermophilic microorganisms, some of which grow at temperatures up to 110 °C. Hyperthermophiles grow anaerobically or aerobically by diverse metabolic types. Within the high temperature ecocystems, primary production is independent from solar energy.
Presented at the Session 
Water in the Solar System and Its Role in Exobiology
during the 26th General Assembly of the European Geophysical Society, 22–26 april 1991 in Wiesbaden, Germany.