Scientists collected specimens from up to 6,500 feet (2,000 meters) beneath the surface of the Southern Ocean as part of an international project to take a census of Antarctic marine life.
Some of the animals far under the sea grow to unusually large sizes, a phenomenon called gigantism that scientists still do not fully understand.
"Gigantism is very common in Antarctic waters," Martin Riddle, the Australian Antarctic Division scientist who led the expedition, said in a statement. "We have collected huge worms, giant crustaceans, and sea spiders the size of dinner plates."
The specimens were being sent to universities and museums around the world for identification, tissue sampling, and DNA studies.
"Not all of the creatures that we found could be identified and it is very likely that some new species will be recorded as a result of these voyages," said Graham Hosie, head of the census project.
The expedition is part of an ambitious international effort to map life forms in the Antarctic's Southern Ocean and to study the impact of forces such as climate change on the undersea environment.
The work is part of a larger project to map the biodiversity of the world's oceans.
The French and Japanese ships sought specimens from the mid- and upper-level environment, while the Australian ship plumbed deeper waters with remote-controlled cameras.
"Fins in Various Places"
"In some places every inch of the sea floor is covered in life," Riddle said. "In other places we can see deep scars and gouges where icebergs scour the sea floor as they pass by."
Among the bizarre-looking creatures the scientists spotted were tunicates, plankton-eating animals that resemble slender glass structures up to a yard tall "standing in fields like poppies," Riddle said.
Other animals were equally baffling.
"They had fins in various places; they had funny dangly bits around their mouths," Riddle told reporters. "They were all bottom dwellers so they were all evolved in different ways to live down on the seabed in the dark. So many of them had very large eyes—very strange-looking fish."
Scientists are planning a follow-up expedition in 10 to 15 years to examine the effects of climate changes on the region's environment.
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