A sea snail feeding off a dead octopus’ beak is among the 30 new species found during an expedition to Antarctica‘s Amundsen Sea (map), according to the first study to shed light on the sea’s bottom dwellers.
The newfound sea snail, or limpet, is from a group that specializes in feeding on the decaying beaks of squid, octopi, and their relatives, according to study leader Katrin Linse of the British Antarctic Survey (BAS). (Also see “New Species of Naked Bone-Eating Worms in Antarctica.”)
Linse and a team of marine biologists from BAS and other institutions hauled up 5,469 specimens belonging to 275 species from the depths of the little-explored sea of the Southern Ocean during a 2008 research cruise.An Antarctic octopus, Pareledone turqueti. Photograph courtesy British Antarctic Survey
That year, scientists on the RSS James Clark Ross took advantage of the thin summer ice to get close to the edge of the ice shelf and bring up the thousands of specimens, including some newly discovered in Antarctic waters. At least 10 percent of all the species collected are new to science, and the figure is likely to rise, Linse said.
It’s taken a global team years to identify and categorize only a small fraction of the species, which are described October 1 in the journal Continental Shelf Research.
Many of the species new to Antarctica are echinoderms, a group that includes starfish and sea cucumbers.
Some of the other finds from the expedition:
—A funky, fuzzy bristle-cage worm, so called because of the long bristles on their heads. The critters thrive at a depth of over 3,000 feet (1,000 meters).
—Pareledone turqueti, or Turquet’s octopus, which has provided evidence for “cryptic speciation,” in which species appear the same from the outside but have a different form and structure inside. (See “‘Lost World’ of Odd Species Found Off Antarctica (Pictures).”)
—A sea lily or stalked crinoid, found nearly 5,000 feet (1,500 meters) down.
The Amundsen Sea has troughs and basins that can be over 5,000 feet (1,500 meters) deep.
These geological structures are left over from previous ice ages; animals, some of which persist today, might have taken refuge there.
The creatures found in the Amundsen Sea—such as starfish, urchins, and brittle stars—are surprisingly more mobile than those found in other seas around Antarctica, which are generally dominated by large, sedentary sponges, she said.
This suggests that in the past, the sea creatures could have moved to more habitable environments when needed. (Also see “Sea Lilies Evolved Escape Strategy From Predators Over 200 Million Years.”)
But more changes are coming to the Amundsen due to the breakup of the ice shelf caused by warming waters, so studying the animals now is crucial.
“Until now we knew nothing” about the animals that inhabit the Amundsen seafloor, Linse said.
“Our recent study gives us a first insight into the biodiversity of this region and can serve as a baseline to observe future changes.”