Strain 121 was discovered in one of these ecosystems. An organism that lives in these ecosystems uses multiple forms of hemoglobin to shuttle gas to symbiotic bacteria colonizing the trophosome that takes up its coelom instead of a gut. Martin et al. proposed that acetate production during serpentinization in these ecosystems is driven by a natural form of chemiosmosis facilitated by the alkalinity of peridotites. The "ir
Strain 121 was discovered in one of these ecosystems. An organism that lives in these ecosystems uses multiple forms of hemoglobin to shuttle gas to symbiotic bacteria colonizing the trophosome that takes up its coelom instead of a gut. Martin et al. proposed that acetate production during serpentinization in these ecosystems is driven by a natural form of chemiosmosis facilitated by the alkalinity of peridotites. The "iron-sulfur world" theory is based on studies of these ecosystems, which are inhabited by scavenging "dandelions" and Riftia tube worms. The Lost City field and Loki's Castle black smokers are examples of these ecosystems, which are more volatile than cold seeps. For 10 points, name these chemosynthetically-driven geothermal ecosystems on the ocean floor.