How long a camel can go without drinking depends on the amount of food available to it, the temperature during the day and night, the wind, and whether it is resting or working. In the Sahara, camels can go 6 to 7 months without tasting a drop of water , but that doesn’t mean they don’t need water: they get it from the plants they eat. In general, if the temperature is between 30-35º C, they can go up to two weeks without drinking. Of course, if the temperature rises, they need their water ration more frequently. In Mauritania, where temperatures reach 48º in the day and 30º at night, camels drink every 5 days, although they can go up to 10 without a drop to put in their mouths. That yes, when they start drinking there is no one to stop them: they are capable of blowing 106 liters in one sitting and reaching 170 liters if left for a whole day (more than twice the volume of the gasoline tank of a normal car ).
In the same way, they withstand dehydration very well. If a human being loses 12% of his weight, he dies, but a camel can lose 40% in water before being really in danger. This has to do with the rugby ball shape of their blood cells, which allows them to pass past each other unhindered even though the plasma has been reduced due to dehydration. If all this were not enough, they can withstand internal temperatures of 42º C without falling ill ; we last rather little if the fever reaches 39º.
With all these data we could think that camels are really superanimals. And we are not wrong, although if we compare them with other living beings… For example, the Rose of Jericho or Anastatica hierochuntica , a member of the Brassicaceae , a small gray plant native to Syria that rarely reaches 15 cm in height: receives the peculiar name of Plant of the Resurrection.
To say that his behavior is peculiar is an understatement. After the wet season, it dies and dries up, folding its stamens into a ball that protects the seeds and prevents them from being dispersed too soon. These seeds are very resistant and can remain “dormant” for years. When it starts to rain, the plant opens up and the seeds scatter. Another plant often sold in stores under the name Rose of Jericho is Selaginella pilifera , a fern that revives and turns green when wet with a little water.
But it is in the animal world where we find the strangest situations. Just look at these mysterious animals that are no more than 1mm long and, despite being found in every humid habitat in the world, from tropical rainforests to the Arctic Ocean to backyard puddles, have not been discovered. until 1773 by the German zoologist Johann August Ephraim Goeze, who called them Kleiner Wasser Bärs , water bears. They belong to a more than unknown phylum of invertebrates, Tardigrada , of which around 800 different species have been described. Only 10% live in salt water and the rest in fresh water, attached to mosses, lichens, aquatic vegetation or in decomposing leaf beds.
Short-bodied and chubby, they have four pairs of poorly articulated limbs . But their most striking feature are some claws that are found at the end of them, forming groups of 4 to 8. They live surrounded by a thin layer of water that allows them to exchange gases with the outside world and prevents uncontrolled drying out. Because this is one of the most striking characteristics of these tiny animals: they can reversibly suspend their metabolism , in such a way that they lower it to 0.01% of its normal value -it can even become undetectable- and reduce its content. of water to less than 1%. This ability of some living beings to lose practically all the water in their body is called anhydrobiosis. The body shrinks longitudinally and folds as the limbs invaginate. In addition, the surface is covered with a layer of wax that helps reduce perspiration.
Tardigrades are really impressive: not only do they withstand extreme environmental dryness, but they also withstand high doses of X-rays (more than 1,000 times the fatal dose for a human being), temperatures above 150º C and -272.8º C, very close to absolute zero. And, to top it off, they withstand both very high pressures and the vacuum of space.
Other organisms capable of surviving without water are bdelloid rotifers, microscopic alien-like invertebrates. They are less than 0.5 mm long and are made up of about 1,000 cells. They have a nervous system and sensory elements such as eyes and antennae . We can find them in the moss, in streams, ponds, springs… All over the planet except in the polar areas. But what makes them fascinating in the eyes of researchers is not their ability to dry out, but because they abandoned sex 100 million years ago; they reproduce by parthenogenesis (the female egg develops without having been fertilized). Biologists have found no males, no hermaphrodites, or any trace of meiosis, the process that creates sex cells.
