Giant Tube Worm

Riftia pachyptila, commonly called the giant tube worm or giant beardworm, is the sole species of the monotypic genus Riftia, an annelid worm in the polychaete family Siboglinidae, its name reflecting both the volcanic rift zones where hydrothermal vents form and its thick, feather-like anterior plume. It can reach three metres in length with a body about four centimetres in diameter, and its red, feather shaped branchial plume, coloured by haemoglobin, extends from a chitinous protective tube that the worm secretes and that grows ten to eighty five centimetres per year. It lives clustered in large colonies at deep sea hydrothermal vents along the East Pacific Rise and the Galapagos Rift, in waters ranging from two to thirty degrees Celsius that carry hydrogen sulfide from the vents. Adult giant tube worms have no mouth, gut or anus, and depend entirely on symbiotic sulfur-oxidising bacteria housed in an internal organ called the trophosome, which convert the vent's chemical energy into carbohydrates through chemosynthesis, a discovery that transformed the scientific understanding of life without sunlight.