anhydrobiosis is called the ability to survive on high dehydration as a result of drying atmospheric air. We observe this phenomenon
in many small aquatic animals (nematodes, rotifers beloides, tardigrades freshwater and terrestrial ...) that have the capacity to enter into a state of anhydrobiosis at any stage of the life cycle or only during certain stages of life, as with cladoraceas eggs (water fleas), the larvae of some flies, embryonic cysts coelenterates, etc.
In the case of frozen embryos of Artemia, one of the best studied cases, living desiccated persists does not mean that any water molecule. Proteins and other molecules are able to preserve what is called "structural water", ie molecules water trapped in the structures of other compounds, or are part of cohesive and adhesive bonding. This phenomenon is favored under conditions of high humidity, but still, anhydrobiotic forms contain less than 2% of water each hydrated state.
The most surprising feature of this vital state, is temporarily away signs of metabolic activity: These forms stop using O 2 , and accumulating waste products. But at any given time, under favorable conditions, the body can resume metabolism and "back to life."
In these organisms, it is often the accumulation of a disaccharide called trehalose, which prevents dehydration destabilize vital cellular structures, membranes, macromolecules ...
Animals anhydrobiosis state will tolerate many extreme conditions, as well as dehydration. And this state can be maintained for many years. Represents a highly useful evolutionary strategy, because these animals can be transported by air currents to other areas where conditions are more favorable, and once there, to establish a new colony to fall into the water.
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