A strange species of sea anemone that lives upside down and glows orange has been discovered by accident by marine geologists in the icy waters of Antarctica.
Its upside-down orientation was not the only one strange about it. Its opaque-white body and what seemed like tentacles also have baffled the scientists. The most mystifying about this particular species is that it lived in burrows dug on the underside of the Ross Ice Shelf.
Last December, a team of scientists and engineers with the multi-national Antarctic Geological Drilling (ANDRILL) Program were at the Antarctic to study the ocean currents underneath the previously undocumented area of the ice shelf, which extends over 600 miles northward from the West Antarctic Ice Sheet to the Ross Sea.
They used a remotely operated and camera-equipped robot called the Submersible Capable of under-ice Navigation and Imaging ((SCINI), which they lowered through holes cut into the 885-foot thick ice. The images taken by the robot showed a fuzzy surface instead of the flat and uniform surface that is characteristic of an ice shelf. The team suspected an organism, and this made them curious enough to collect samples. They stunned the organisms with hot water and was able to suck 20 to 30 of them from their burrows by jury-rigging a vacuum tube out of a spare thruster borrowed from another robot. Then they transported the collected specimens to McMurdo Station for preservation and further study.
"When we looked up at the bottom of the ice shelf, there they were," said Frank Rack, executive director of the ANDRILL Science Management Office at the University of Nebraska-Lincoln (UNL), an associate professor of Earth and atmospheric sciences at UNL, and the US principal investigator for the environmental surveys that were conducted as part of the international ANDRILL Coulman High project.
Rack said that the discovery was "total serendipity." He also said that they had "found a whole new ecosystem that no one had ever seen before. What started out as a engineering test of the remotely operated vehicle during its first deployment through a thick ice shelf turned into a significant and exciting biological discovery."
The result of the study was published in the recent issue of PLOS ONE.
These newly discovered sea anemones were named Ewardsiella andrillae in honor of the ANDRILL program. They were small, measuring between 0.63 to 0.79 inches in length. Each sea anemone had from 20 to 24 tentacles, composed of an inner ring of eight longer tentacles and an outer ring of 12 to 16 tentacles. The sea anemones also emitted an orange glow, although it is still unclear what causes this glow. The scientists who studied the specimen have yet to figure out how these sea anemones reproduce, how they survive in freezing temperatures, how they create the burrows in the ice, and what they eat.
While other species of sea anemones have been found in Antarctica, these sea anemones were the first known species to live hanging upside down on ice. Prior to this discovery, sea anemones were known to attach themselves to hard surfaces like rocks or reefs, or on the ocean floor.
"Just how the sea anemones create and maintain burrows in the bottom of the ice shelf, while that surface is actively melting, remains an intriguing mystery," said Scott Borg, head of the Antarctic Sciences Section in the National Science Foundation's Division of Polar Programs. "This goes to show how much more we have to learn about the Antarctic and how life there has adapted."
Aside from the upside-down sea anemones, the researchers also saw polychaete worms, amphipods, and fish that swam upside down. They also saw what they nicknamed "the eggroll," a buoyant cylinder measuring four inches long and one inch in diameter, which appeared to swim with the help of appendages at both ends of its body, and which swam in the area of the sea anemones.
The US has been doing active research in the Antarctic region for 50 years, and explorers and scientists keep making exciting discoveries, such as this latest one. Biological studies in the region are significant because they allow scientists to come closer to figuring out the possibility of life on Jupiter's ice-covered moon Europa.
