Thermal tolerances of deep-sea hydrothermal vent animals from the Northeast Pacific

Dense biological communities on sulfide structures at deep-sea hydrothermal vents survive in one of Earth's most extreme environments. The thermotolerance of vent animals dwelling on sulfide chimneys in the Northeast Pacific was determined by maintaining them in pressurized chambers under controlled temperature and chemical conditions. Observations indicated that lethal temperature correlates strongly with distributions observed in nature. One species studied, the alvinellid sulfide worm Paralvinella sulfincola, exhibited a thermal limit of 50-56 degreesC. Since observations of survival under controlled conditions are the only unambiguous means of demonstrating that an animal can tolerate a given environmental condition, the documented thermal limit for metazoan life at hydrothermal vents should be considered to be above 45 degreesC, but less than 60 degreesC.