Giant Tube Worm

The giant tube worm (Riftia pachyptila) is a red-plumed worm that lives next to hydrothermal vents on the deep East Pacific seafloor. It has no mouth or gut as an adult and instead feeds through symbiotic bacteria that turn vent chemicals into food.

🧬 Field Guide Specimen: Open Giant Tube Worm in the CRV Science Field Guide to log the specimen, see its place among the Lophotrochozoa lineages in the Cladogram Explorer, and test your recall in the Red List conservation game.

Vent fluids are rich in hydrogen sulfide. Bacteria inside the worm's trophosome organ oxidize sulfide to gain energy and fix carbon dioxide into organic molecules, which feed the worm. The discovery of such communities in 1977 at the Galápagos Rift showed that an ecosystem can run on chemical energy rather than sunlight. See Photosynthesis.

The red plume is full of blood containing a hemoglobin that can bind oxygen and sulfide at the same time without poisoning itself, delivering both to the bacteria. The worm is one of the fastest-growing marine invertebrates, reaching up to a couple of meters in length.

Hydrothermal vents are also candidate sites for the origin of life on Earth and perhaps elsewhere, such as under the ice of moons like Europa and Enceladus. See Abiogenesis.

• Bacteria — chemosynthetic symbionts
• Abiogenesis — vents and the origin of life
• Photosynthesis — light-based energy capture