Edwardsiella andrillae

Edwardsiella andrillae under the ice shelf

Edwardsiella andrillae is a sea anemone from the Southern Ocean, which was discovered under the Ross Ice Shelf in the Antarctic Ross Sea and in 2013 first described. It is the only known species of the genus Edwardsiella in Antarctica and lives in the water channels on the underside of the ice shelf.

Features

Edwardsiella andrillae is a sea anemone that lives in the form of a sessile polyp in the sea ice. It differs from other species of the genus mainly by the number of tentacles and the size and arrangement of the stinging cells. The species of the genus Edwardsiella are elongated polyp with a long stalk ( scape ) and a capitulum, which carries the existing 6- speed tentacles. The tentacles are furrowed, the furrows are usually the stinging cells.

Edwardsiella andrillae has a long body with 20 to 24 tentacles that taper towards the end. The inner tentacles are remarkably longer than the outer. Both the scape as well as the tentacles are translucent white, with no periderm. The body is contracted from 16 to 20 millimeters long and has a diameter of 6 mm. From the only other species of the genus from the Southern Hemisphere, Edwardsiella ignota from Chile to Edwardsiella different andrillae by the arrangement of stinging cells.

Dissemination

Edwardsiella andrillae is so far known only by samples from the bottom of the Ross Ice Shelf in the Antarctic Ross Sea. The animals live at the bottom of 250 to 260 meters thick layer of ice under which a water layer of about 40 meters depth is up to the seabed. It is the only known species of the genus in the Southern Ocean and in the Antarctic, only Edwardsiella ignota of the Chilean coast is known from the southern hemisphere. In addition, from the Antarctic, only two other types of Edwardsiidae known Edwardsia meridionalis ( Williams 1981) and Scolanthus intermedius ( McMurrich 1893).

Way of life

Edwardsiella andrillae like other sea anemones sessile and it is the first known species of sea anemone that lives in ice; other kinds of Antarctica live on rocks or in soft substrates on the seabed. It is located with the majority of her body in the ice channels on the underside of the ice shelf, protruding from which only the crown of tentacles in the sea water below the ice.

Due to the very limited material and the difficult ways of observing the lifestyle and physiological adaptations to the life of the species in the ice are largely unknown. While other polyps dig their burrows either by extraction of its basalt haste or with the aid of the tentacles, these two options for the Eiskanäle are rather unsuitable. Physiological adaptations to extremely low temperatures, such as are known about in segmented worms such as Mesenchytraeus solifugus could at Edwardsiella andrillae not be detected.

Discovery history

Edwardsiella andrillae was during the Coulman High Project ( CHP) in the framework of the research project ANDRILL ( ANtarctic geologic DRILLing ), funded by the U.S. National Science Foundation, Office of Polar Programs, and in New Zealand by the NZ Foundation for Research, Science and Technology, discovered and described. The program devoted himself from 2010 to 2011 researching this inaccessible and largely unexplored habitat below the sea ice. The animals were the Submersible Capable of under Ice Navigation and Imaging ( Scini ), one in two places lowered through a hole in the ice automatic research submersible was discovered. With the help of the cameras of the Scini was filmed at two locations per an area below the ice, which was covered by the polyps of Edwardsiella andrillae.

With the help of an improvised hook and collector, who was attached to the Scini, more than 20 single individuals could be removed and collected from the ice. In this case, hot water at the surface of the ice was pumped through a tube to the gripper to allow the removal of the animals from the ice support. Inlaid in ethanol individuals were taken by helicopter to McMurdo Station for investigation and preservation in formalin.

System

Edwardsiella andrillae 2013 was described as a distinct species of the genus Edwardsiella by researchers Mary Megan Daly, Frank Rack and Robert Zook. The species of the genus Edwardsiella be assigned to the Edwardsiidae resulting from numerous species of sessile and grave forming sea anemones in many coastal habitats, including deep-sea trenches or hypo- to hypersaline estuaries, composed.

The naming of the species name andrillae performed according to the research program Antarctic Drilling ANDRILL, under which the polyps were found.