Thursday, December 4, 2008

Antarctic Echinoderm Video Friday!

Today..some Video from some recent expeditions to Antarctica by The Census of Antarctic Marine Life!

to see the full Youtube channel for the Census of Antarctic Marine Life click here.

A News report from NDTV (New tang Dynasty TV)

Dance of the Feather Stars

Accompanying text on this video:
Video from the Deep Underwater Camera by Rob Beaman, research scientist in marine geology at James Cook University, Cairns, Australia.
Feather stars live fixed to a substrate (sediment, other organisms) by small appendices called cirri. To move about, they free themselves by opening the cirri and moving their arms in an organized fashion that releases them. They rise in the water column and move a few meters then drop like a parachute. The video shows several Antarctic feather stars swimming, here: Promachocrinus kerguelensis. It can move as a flight reflex when confronted with a potential predator or an environmental disturbance, due here to the approaching camera. Swimming time is brief (a few seconds) because the energy required to mobilize the arm muscles is quite substantial.

Polarstern-Census Antarctic Marine Life ROV footage

Accompanying text for this video (by Gauthier Chapelle):
13th of January 2007
Third ROV footage of the seafloor in the Larsen B area, Antarctica. It was taken at 250 m water depth, right in front of the new ice shelf edge after it collapsed in 2002. The bottom is composed of very fine sediment and occasional drop stones, which is surprising, so close to the ice shelf edge.
The first fifteen seconds show a recent ice scour left by an iceberg on the sea floor. Then, the first translucent species of holothurians (also known as sea-cucumbers) appears, which is feeding by extracting organic matter from the ingested muddy sediment. The second species, on the left side, is bigger, with a plumper shape, and is very rarely seen outside the deep sea in Antarctica. These two holothurians were the dominant species. The next animals are a solitary hydrozoan (related to corals), three yellow sea lilies, or stalked crinoids, also commonly found in the deep sea and finally a sea anemone. They are followed by two types of structure; firstly a crater-like, probably also created by a foraging animal, and secondly little mounds, possibly produced by burying worms. The sequence ends with two bushes of colonial hydrozoans and a glass sponge.

And...More ROV footage..keep your eyes open for the Antarctic cucumber!

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