Giant Tube Worm Riftia pachyptila
When it was first discovered in the 1970s, living in great clusters in the deep sea around hydrothermal vents, the giant tube worm caused a sensation. It has many structural similarities to pogonophoran worms, but is huge. Like them, the giant tube worm lives in a permanent tube and has no mouth or gut. Most of the worm’s body remains hidden but a brilliant red plume of gills sticks up out of the tube and absorbs chemicals and oxygen from the water. Living within the giant tube worm’s tissues are bacteria that can make up over half the weight of the body.
The Giant Tube Worm Lives Without Sunlight
Giant tube worms obtain all their energy from chemicals in the hot water that pours out of hydrothermal vents. Chemosynthetic bacteria in their tissues oxidize sulfur to provide energy and fix carbon from vent chemicals. The giant tube worms thus gain their food with no direct or indirect reliance on sunlight.