Nature's Oddities Part 3: Giant Tubeworms

Another oddball from the deep! Even deeper than the hagfish (over 5000 feet), in the thermal vents on the bottom of the pacific ocean, lies large colonies of the Giant (up to 8 feet long) Tubeworm, or Rifita. Pachyptila.



Discovered in 1977 by the unmanned deep sea exploration vessel Alvin (not from Alvin and the Chipmunk’s fame), giant tubeworms prefer to live near “black smokers,” a type of hydrothermal vent on the ocean floor characterized by superheated water rich in dissolved minerals (mostly sulfides) which crystallize to create the black plume that gives “black smokers” their name.



Giant tubeworms exploit lithotrophic bacteria to nourish themselves. Almost all organisms on earth are phototrophic (derive energy from light: plants) or autotrophic (derive energy from organic materials: animals, fungi). Lithotrophic organisms derive their energy directly from inorganic chemical reactions such as the oxidation of hydrogen sulfide (the gas that gives rotten eggs their odor). The bacteria make food for themselves using the energy from these reactions and can synthesize all the amino acids, carbohydrates, lipids, and other important bio-molecules they need just from hydrogen sulfide, carbon dioxide, oxygen and trace amounts of certain minerals.

The juvenile tubeworm has a primitive mouth and gut and ingests these bacteria, but does not digest them. As it grows and accumulates enough of these symbiotic bacteria, its mouth and gut are lost, making the adult tubeworm the only creature (that I know of at least) where the adult is less morphologically sophisticated than the juvenile. The bacteria take some of the food for themselves, but most of it is passed off to the enormous tubeworms for nourishment.

The tubeworm’s adult body is a veritable Garden of Eden for these bacterial. It’s highly vascularized “plume” near the top of the tubeworm and features the worlds most remarkable hemoglobins in order to capture oxygen (like crack cocaine for these bacteria) that is very difficult in an environment so enriched in sulfur.

The hemoglouins are enormous! Sometimes a hundred globins long (mammals have 2 pair of globins in our hemoglobin), and it is truly a biochemical marvel.



The environment these tubeworms call home would simultaneously boil (752 degrees F), crush (2000 PSI), and poison a human or just about any other creature. The tubeworm’s ability to not only endure, but thrive, in these conditions is incredible. How their tissues can withstand such extreme makes one re-think the capabilities of living things. The first high-strength metal vessels that went to these depths were easily crushed, and none could have hoped to endure the extreme temperatures. Alvin was the first to manage, and it was not developed until the 1965. Russians had been launching people into space by this time. We were only four years away from landing on the moon, but we were just starting to explore the depths of our own rock orbiting the sun!