Researchers identify three new survivors

Bearded species come from Alaska, Kenya and Palau

Paramacriobiotus palaui, the new bearded species from the Pacific. © Schill / University of Stuttgart
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Tardigrada or Tardigrada are survivalists. You can survive complete dehydration or freezing - without any damage. So far, about 1, 000 species were known. But now researchers from Stuttgart and Würzburg have, thanks to a new method, discovered three other species of tardigrade, which they are introducing for the first time in the journal "Organisms, Diversity & Evolution".

The species come from the tropical island group Palau in the Indo-Pacific, from the cold north of Alaska, as well as from Kenya and are accordingly called Paramacriobiotus palaui, Paramacriobiotus fairbanksi and Paramacriobiotus kenianus. They have been considered cryptic species for some time, but they looked so similar that it was not possible to tell them apart.

CBC method first in use - in tardigrades

Therefore, the researchers applied to Ralph Schill from the Universities of Stuttgart and Würzburg - for the first time in the tardigrade - the so-called CBC method (Compensatory Base Change). Using molecular biological and bioinformatic techniques, a part of the ribosomal gene (rDNA) is amplified, sequenced, folded into its natural structure and then examined for base exchanges.

With a 93 percent probability new species can be identified by their genome, which are not sufficiently distinguishable with conventional sequences. Together with other molecular biological, biochemical and physical markers, the Stuttgart researchers have been certain that they are really dealing with three different species.

On the track survival mechanisms

Tardigrades are 0.2 to 1.0 millimeters in size and occur mainly in fresh water and habitats such as moss pads and damp soils. Perfectly mastering dehydration and freezing, they provide an ideal model system for studying these survival mechanisms. display

"A better understanding of these processes will lead to the development of new methods that will conserve cells and whole organisms without damage. This would be a great advantage for many areas in the biomedical and food sectors, "says Schill.

Little Waterbears

Tardigrads were mentioned for the first time literarily by the pastor Johann August Ephraim Goeze as "small Wasserb ren". He wrote Seltsam is this animal, because the whole structure of his body is extraordinary and strange, and because in its external appearance, according to the first sight, it is the largest Similarity with a B imre on a small scale has. This has also moved me to give him the name of the little Wasserb rs.

(idw - University Stuttgart, 07.07.2010 - DLO)