A group of deep-sea hydrothermal vents recently discovered in the Indian Ocean is populated by thriving communities of organisms, most of which have never previously been seen.
The vent systems lie about 1,600 kilometers east of Madagascar, an area far from the five previously known hydrothermal regions, which are in other oceans. The Indian Ocean vents support ecosystems of crustaceans, mussels, and anemones (top); large snails (bottom, images from videotape); and sulfur-metabolizing bacteria.
The most common animal at the Indian Ocean vents, a shrimp species, is almost indistinguishable from one known only from North Atlantic vents. The other species of large organisms at the new sites appear to be closely related to species found at vent fields in the western Pacific. At least 70 percent of the species at these vents are new to scientists, says Cindy L. Van Dover, an oceanographer at the College of William and Mary in Williamsburg, Va. She and her team report their observations in an upcoming issue of Science.