Methane Ice Worms: Hesiocaeca methanicola Colonizing Fossil Fuel Reserves


 During a research cruise in July 1997 in the Gulf of Mexico we discovered a gas hydrate approximately 1 m thick and over 2 m in diameter which had recently breached the sea floor at a depth of 540 m. The hydrate surface visible from the submarine was considerably greater than that of any other reported hydrate. Two distinct color bands of hydrate were present in the same mound, and the entire exposed surface of the hydrate was infested (2500 individuals/m2) with 2 to 4 cm-long worms, since described as a new species, Hesiocaeca methanicola, in the polychaete family Hesionidae (Desbruyères and Toulmond 1998). H. methanicola tissue stable isotope values are consistent with a chemoautotrophic food source. No evidence of chemoautotrophic symbionts was detected, but geochemical data support the presence of abundant free living bacteria on the hydrate. The activities of the polychaetes, grazing on the hydrate bacteria and supplying oxygen to their habitats, appears to contribute to the dissolution of hydrates in surface sediments.

This is a preview of subscription content, access via your institution.

Author information



Additional information

Received: 16 August 1999 / Accepted in revised form: 19 January 2000

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Fisher, C., MacDonald, I., Sassen, R. et al. Methane Ice Worms: Hesiocaeca methanicola Colonizing Fossil Fuel Reserves. Naturwissenschaften 87, 184–187 (2000).

Download citation


  • Hydrate
  • Stable Isotope
  • Polychaete
  • Geochemical Data
  • Exposed Surface