Unknown species have been discovered on the seafloor near Antarctica, clustered in the hot, dark environment surrounding hydrothermal vents.
The discoveries, made by teams from the universities of Oxford and Southampton and the British Antarctic Survey, include new species of yeti crab, starfish, barnacles, sea anemones and potentially an octopus.
Researchers used a Remotely Operated Vehicle (ROV) for the first time to explore the East Scotia Ridge deep beneath the Southern Ocean where hydrothermal fissures on seabed, from which geothermally heated water issues, create a unique environment that lacks sunlight.
"Hydrothermal vents are home to animals found nowhere else on the planet that get their energy not from the sun but from breaking down chemicals such as hydrogen sulphide," said Alex Rogers, professor of zoology at Oxford University who led the research, the journal Public Library of Science Biology reports.
Highlights from the ROV dives include images showing huge colonies of the new species of yeti crab, thought to dominate the Antarctic vent ecosystem, clustered around vent chimneys, according to an Oxford university statement.
Elsewhere, the ROV spotted numbers of an undescribed predatory sea-star with seven arms crawling across fields of stalked barnacles. It also found an unidentified pale octopus, nearly 2,400 metres down, on the seafloor.
"What we didn't find is almost as surprising as what we did," said Rogers. "Many animals such as tubeworms, vent mussels, vent crabs, and vent shrimps, found in hydrothermal vents in the Pacific, Atlantic and Indian Oceans, simply weren't there."