how do chemoautotrophic bacteria and archaea that live near hydrothermic vents obtain energy
Giant tube worm They have a highly vascularized, red "plume" at the tip of their free end which is an organ for exchanging compounds with the environment (e.g., H2S, CO2, O2, etc.). The tube worm does not have many predators. If threatened, the plume may be retracted into the worm's protective tube. The plume provides essential nutrients to bacteria living inside the trophosome. Tube worms have no digestive tract, but the bacteria (which may make up half of a worm's body weight) convert oxygen, hydrogen sulfide, carbon dioxide, etc. into organic molecules on which their host worms feed. This process, known as chemosynthesis, was recognized within the trophosome by Colleen Cavanaugh.[6]