When you think of worms (not the nasty things you normally associated with stomachs), what first comes to mind are long and slimy creatures burrowing themselves in the ground. Not all worms are like that, though. Take for example the Christmas tree worms we featured back in 2012 (see article here). At first glance, without a background check on the species, surely you won't think that it's a worm.
Here we feature a "not so ordinary" worm, that is, the giant tube worm, Riftia pachyptila. It is the world’s largest deep sea annelid worm (Family Siboglinidae, Order Sabellida, Class Polychaeta) found in hydrothermal vents in the East Pacific, measuring up to 2 m in length. This is a sessile worm, contrary to the picture of worms moving about. Although it lacks a digestive system, its nutrition is dependent on vent plumes through an endosymbiotic relationship with a chemoautotrophic bacteria stored in a specialized organ called trophosome . The plume is a gill-like organ, made up of a complex network of blood vessels thus the red coloration (see image below) .
|Giant tube worm plume (photo by Peter Batson, posted in www.arkive.org).|
Little is known on the biology of this species (see what SeaLifeBase has on it here). Thus, if you have other information on them, you can e-mail us at firstname.lastname@example.org or come be a collaborator.
 Van Dover, CL. 2000. The ecology of deep sea hydrothermal vents. Princeton University Press, New Jersey, 424 p.