From Natural Selection
The camel can go days without drinking water, surviving extreme dehydration and safely losing 40% of its body weight in water.
This ability is, in part, due to uniquely oval red blood cells (which carry oxygen). The long axis of these oval cells is oriented with the flow of blood, enabling the cells to cross over the smallest of blood vessels, even when blood thickens during times of dehydration. Additionally, the camel's red blood cells are capable of expanding up to 240% of their original volume without rupturing; most animals' cells can expand only 150%. This makes it possible for the camel to drink the necessarily large amount of water to recover from dehydration." Myth: The fat in the Camel's hump is the key to water balance. The hump provides shading and its fat contributes to water balance but only in an indirect way. The 10-to-15 kilogram hump does indeed shrink in a starved and dehydrated camel, but that is because fat is used up as an energy source. It is not like a load of drink, but more like a load of concentrated food. Source: http://tinyurl.com/pp3k4t2 &http://tinyurl.com/ps4h99g Extra source: Why We Run: A natural history by Bernd Heinrich
