Eight thousand feet deep in the southern ocean between Antarctic and south America, a ghostly white octopus glides through a bizarre world of 700°F black smoking vents, mounds of white crabs that look strangely like David Hasselhoff and pale anemones dancing in the current.
UK scientists have found prodigious numbers of a new crab species on the Southern Ocean floor that they have dubbed "The Hoff" because of its hairy chest.
The animal was discovered living around volcanic vents off South Georgia.
Communities of never-before-seen life forms in the deep ocean were first found in 1977 during investigations of volcanic vents around the Galapagos Islands. Life had never been found around deep vents in Antarctic waters because the waves and storms were so harsh that scientists were not able to investigate the deep. The rich undersea communities discovered near Antarctic astonished scientists with their abundance and diversity.
It was "almost like a sight from another planet," said expedition leader Alex Rogers, a professor of zoology at Oxford University.
To see these animals in such huge densities was just amazing... We were absolutely stunned to see the animal communities, because they were so different from the hydrothermal vents seen elsewhere.
The yeti crabs seem to cultivate "gardens" of bacteria on their chests, which are covered with hairy tendrils. These bacterial mats almost certainly provides the crabs with sustenance, Rogers said. In turn, predatory seven-armed sea stars stalk the periphery of the vents, snacking on unfortunate crabs.
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PLOS Biology Author Summary
Deep-sea hydrothermal vents are mainly associated with seafloor spreading at mid-ocean ridges and in basins near volcanic island arcs. They host animals found nowhere else that derive their energy not from the sun but from bacterial oxidation of chemicals in the vent fluids, particularly hydrogen sulphide. Hydrothermal vents and their communities of organisms have become important models for understanding the origins and limits of life as well as evolution of island-like communities in the deep ocean. We describe the fauna associated with high-temperature hydrothermal vents on the East Scotia Ridge, Southern Ocean, to our knowledge the first to be discovered in Antarctic waters.
These communities are dominated by a new species of yeti crab, stalked barnacles, limpets and snails, sea anemones, and a predatory seven-armed starfish. Animals commonly found in hydrothermal vents of the Pacific, Atlantic, and Indian Oceans, including giant Riftia tubeworms, annelid worms, vent mussels, vent crabs, and vent shrimps, were not present at the Southern Ocean vents. These discoveries suggest that the environmental conditions of the Southern Ocean may act as a barrier to some vent animals and that the East Scotia Ridge communities form a new biogeographic province with a unique species composition and structure.
Geologic environment of the deep sea community around the Scotia black smokers
(A) The Scotia Sea showing the ESR in relation to the Scotia Plate (SCO), South Sandwich Plate (SAN), South American Plate (SAM), the Antarctic Plate (ANT), the Antarctic Peninsula (AP), and the South Sandwich Trench (SST). Oceanographic features shown include the Polar Front (PF), the Sub-Antarctic Front (SAF), and the southern Antarctic Circumpolar Current Front (SACCF). The sites E2 and E9 are indicated by red arrows. (B) Ship-based swath bathymetry of the vent sites at E2 showing the axial summit graben. The black circle indicates the sites of main venting. (C and D) ROV-based 3-D swath bathymetry of E2 (C) and high-resolution swath bathymetry of the major steep-sided fissure that runs north–south through the centre of the site, between longitude 30° 19.10′W and 30° 19.15′W (D). Dog's Head vent site is indicated. White arrows indicate vent sites not mentioned in text. (E) Ship-based swath bathymetry of the vent sites at E9 showing the axial fissures and the collapsed crater called the Devil's Punchbowl. The black spot indicates the sites of main venting. (F) ROV-based 3-D swath bathymetry of the vent sites at E9. The vent sites Ivory Tower, Car Wash, and Black and White are indicated. Other vent sites are indicated by white arrows.