animal Type
Maximum Size

2 m

(6.6 feet)


1,900–3,600 m

(6,200–11,800 feet)


Hydrothermal vents


Nutrition provided by symbiotic sulfur-oxidizing bacteria


East Pacific Rise and Galapagos Islands


The world’s heaviest worms thrive in an extreme environment.

Towering colonies of giant tubeworms (Riftia pachyptila) grow where hot, mineral-laden water flows out of the deep seafloor. Unlike most animals, they don’t eat; instead, bacteria living in their guts transform sulfur into energy for them.

As harsh as their environment is, giant tubeworms live surrounded by a community of other animals—and their size doesn’t necessarily protect them. Their gills, which resemble foot-long red feathers, can be a vulnerable target for predators. The worms can quickly retract their gills into the tube if a hungry predator, like a vent crab, ventures too close.

When volcanic activity deep below the seafloor changes, the hot water sometimes stops flowing. In this case, the entire worm colony may die off. But when new hot springs pop up in other areas—often dozens or even hundreds of miles away—the tubeworm larvae quickly colonize them. Researchers are not sure how the larvae find the new vents, but deep-sea biologists are revealing new findings with every research expedition to these iconic deep-sea communities.



Video Clips


Girguis, P.R., and J.J. Childress. 2006. Metabolite uptake, stoichiometry and chemoautotrophic function of the hydrothermal vent tubeworm Riftia pachyptila: Responses to environmental variations in substrate concentrations and temperature. Journal of Experimental Marine Biology, 209: 3516–3528.

Girguis, P.R., J.J. Childress, J.A. Freytag, K.A. Klose, and R. Stuber. 2002. Effects of metabolite uptake on proton-equivalent elimination by two species of deep-sea vestimentiferan tubeworm, Riftia pachyptila and Lamellibrachia cf luymesi. Journal of Experimental Biology, 205: 3055–3066.

Goffredi, S.K., and J.J. Childress. 2001. Activity and inhibitor sensitivity of ATPases in the hydrothermal vent tubeworm Riftia pachyptila: A comparative approach. Marine Biology, 138: 259–265.

Goffredi, S.K., P.R. Girguis, J.J. Childress, and N.T. Desaulniers. 1999. Physiological functioning of carbonic anhydrase in the hydrothermal vent tubeworm Riftia pachyptila. Biological Bulletin, 196: 257–264.

Goffredi, S.K., J.J. Childress, F.H. Lallier, and N.T. Desaulniers. 1999. The ionic composition of the hydrothermal vent tube worm Riftia pachyptila: Evidence for the elimination of SO2-4 and H+ and for a Cl-/HCO-3 shift. Physiological and Biochemical Zoology, 72: 296–306.

Goffredi, S.K., J.J. Childress, F.H. Lallier, and N.T. Desaulniers. 1998. How to be the perfect host: CO2 and HS- accumulation and H+ elimination in the hydrothermal vent tube-worm Riftia pachyptila. Cahiers de Biologie Marine, 39: 297–300.

Kochevar, R.E., N.S. Govind, and J.J. Childress. 1993. Identification and characterization of two carbonic anhydrases from the hydrothermal vent tubeworm Riftia pachyptila Jones. Molecular Marine Biology and Biotechnology, 2: 10–19.

Coykendall, D.K., S.B. Johnson, S.A. Karl, R.A. Lutz, and R.C. Vrijenhoek. 2011. Genetic diversity and demographic instability in Riftia pachyptila tubeworms from eastern Pacific hydrothermal vents. BMC Evolutionary Biology, 11: 96.