Why can camels resist sandstorms?

Wild camels have been found in many parts of the world in history, but only in western Mongolia and Ata Mountain in northwest China still exist in the wild. These areas are vast deserts, Gobi and other "barren lands", which are not only dry and short of water, but also extremely hot in summer, with the highest temperature of 55℃, the temperature of sand and gravel quicksand reaching 765,438+0-82℃, extremely cold in winter, and the temperature can drop to below zero when a cold current strikes. The harsh living environment makes wild camels practice extraordinary adaptability and have special physiological functions that many other animals do not have. They can not only endure hunger and thirst, but also endure heat, cold and sandstorm, so they are known as "boats in the desert".

Wild camels are tall and thin, with a body length of 2.2-3.5m, a tail length of 50-60cm, a shoulder height of 1.8-2m and a weight of 450-690kg. Small head, smelly glands on the back, secreting black smelly liquid. The snout is short, and the upper lip is split into two petals, like a rabbit's lip. There is a valve in the nostril that can be opened and closed at will, which can not only ensure smooth breathing, but also prevent sand from pouring into the nostril, and the water flowing out of the nose can also flow into the mouth along the nasal groove. The ear shell is small and round, with thick fine hair to stop the wind and sand, which can be folded tightly. There are two long and dense eyelashes outside the eyes and double eyelids. Double eyelids can be opened and closed independently, and clear vision can still be maintained in the diffuse wind and sand. It is said that it can also foresee the coming of storms. In the history of the north, there are: "Qiemo (a county in southern Xinjiang) has hundreds of miles of quicksand in the northwest, and there is hot air in summer, which is a travel disaster. Where the wind came, only the old camel foresaw it, that is, they gathered angrily and buried their noses and mouths in the sand. Whenever people think they are waiting, they cover their noses with blankets. It's windy. They must be exhausted. If they don't take preventive measures, they will be in danger. " Record.

The neck of a wild camel is long and curved, like a goose neck. Hair on the back can protect the skin from the scorching sun. The tail is short and has short fluff. There are two smaller meat humps on the back, the lower round tip is hard and conical, and the hairs on the peaks are short and sparse, without drooping hairs. In the past, it was thought that hump was an organ for storing water, but later studies showed that the structure of hump was mainly fat and connective tissue, which could accumulate up to 50 kilograms when it expanded, and gradually converted into heat energy needed by the body when it was hungry and deficient in nutrition. It also has an appropriately changing body temperature, which rises to 40℃ at night and drops to 34℃ at dawn to adapt to the large temperature difference in desert areas.

Wild camels have slender limbs, which are different from other ungulates. The third and fourth toes are particularly developed, with toenails at the toe end, big phalanges in the middle and big cracks between the two toes. The lower end of the 1 tubular bone connected with two metacarpals bifurcates into a "ya" shape, which is connected with the phalanx and has a spongy callus pad on the outside. The skin of the chest, the elbow of the front knee and the back knee is thickened, forming seven wear-resistant, heat-insulating and warm keratin pads for kneeling and lying in the sand.