One of the most distinctive creatures living around hydrothermal vents is the giant tubeworm (Riftia pachyptila). Reaching up to six feet in height, the tubeworm’s tube is primarily made of chitin, the same material found in crab and shrimp exoskeletons. The red plume at the top gets its color from hemoglobin, much like human blood. The hemoglobin absorbs oxygen, carbon dioxide, and hydrogen sulfide from the water, which chemosynthetic bacteria inside the tube use to produce food for themselves