Light microscopy image of the undescribed species of Spinoloricus (stained with Rose Bengal). Scale bar is 50 µm. Photo: Roberto Danovaro; used under Creative Commons licence
Did you know ... ? Who needs oxygen?
Between 6 and 5.5 million years ago, the Straits of Gibraltar closed and reopened several times. Each time, over the space of only a thousand years, the Mediterranean Sea evaporated, leaving thick salt deposits behind.
Beginning about 35 000 years ago, some of this salt became exposed in the sea bed and began to dissolve into the water. Because its density is greater than that of regular sea water, this hypersaline water runs downhill to pool in at least three places to form lakes beneath the Mediterranean: the l’Atalante, Discovery and Urania basins.
Earlier this year, researchers discovered the first known animals that live their whole life cycles without any oxygen. These animals, called Loricifera (Latin for corset-wearer), belong to a group (a phylum) first identified only in 1983. They are no more than 1 mm long.
The three species found in l’Atalante basin are the first animals and the first multicellular organisms known to live entirely without oxygen. Their existence now challenges established theories of the origin of multicellular life, which might have begun before photosynthesisers released oxygen into Earth’s early oceans.
Further reading
Wikipedia. L’Atalante basin.
Wikipedia. Loricifera.
Fang J. 2010. Animals thrive without oxygen at sea bottom. Nature News.
Lane N. 2010. Hydrogen bombshell: Rewriting life’s history. New Scientist 4 Aug.