These worms have no mouths, no stomachs, and no intestines, yet they clearly thrive, some species growing up to eight feet in length.
They need no eating apparatus because their bodies house billions of bacteria that feed them.
The tubeworms’ tissues are lined with bacteria that convert hydrogen sulfide from the hydrothermal vents into molecules that serve as usable nutrients for the worms.
The worm’s gills look like a red plume sticking out from its protective tube. Its blood contains a special type of hemoglobin that transports sulfides, oxygen, and carbon dioxide into its tissues, where the bacteria turn them into food for themselves and their host. In return, the worms provide the bacteria with a protected and stable home.