They are isolated from what goes on above. These tubeworms thrive on the chemical energy expelled from deep-sea hydrothermal vents. These creatures have no mouth, no gut and no eyes. Instead of feeding, they host chemosynthetic bacteria that produce sugars for the tubeworms in a symbiotic relationship. Courtesy Woods Hole Oceanographic Institution.
Individual vents remain active for anywhere from a few decades to a few thousand years.
When a vent shuts off, the adult animals living there die. Yet as soon as a new vent emerges, it is rapidly colonized. Within a few years, a new vent undergoes a complete transformation from uninhabited to fully populated. By studying the similarities and differences among the animals that live at different vents, scientists have begun to piece together a picture of how organisms move from one vent to another, what are the natural barriers to such movement, and how the geography of the deep ocean affects the evolution of the species that inhabit it. Although similar types of animals can be found at both Atlantic and Pacific vent sites, there is more similarity among the vent ecosystems along the same ridge than there is between the two ridges.