Cobra (snake)

Дата канвертавання25.04.2016
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Cobra (snake)

Cobra (snake), common name for certain members of a family of venomous snakes, known for their intimidating behavior and deadly bite. Cobras are recognized by the hoods that they flare when angry or disturbed; the hoods are created by the elongate ribs that extend the loose skin of the neck behind the cobras' heads. These reptiles are found throughout the Philippines, southern Asia, and Africa.

The king cobra is the world's longest venomous snake. It averages 3.7 m (12 ft) in length but is known to grow to 5.5 m (18 ft). It is olive or brown in color, with bronze eyes; some individuals are banded. It is found in the Philippines, Malaysia, southern China, Myanmar (formerly known as Burma), India, Thailand, and the Malay Peninsula. It eats primarily other snakes. The other cobra of Asia is known variously as the common, Asian, Indian, or spectacled cobra (due to the eyeglass-shaped pattern on its skin). It seldom reaches a length of more than 1.8 m (6 ft). The hood of the common cobra is, proportionately, much larger than that of the king cobra and is usually yellow to brown, with a black-and-white spectacle pattern on top and two black and white spots on the lower surface. This snake causes many deaths each year in India, where it is regarded with religious awe and is seldom killed. The common cobra is frequently used by snake charmers. It ranges from the eastern shore of the Caspian Sea to China and Malaysia.

Many species of cobras are natives of Africa. Among them is the spitting, or black-necked, cobra, found from southern Egypt to northern South Africa. This snake can spray its venom from a distance of about 2.4 m (8 ft) into the eyes of its victims, causing temporary blindness and great pain. Varieties of the spitting cobra range in color from dull black to pink, the paler-colored ones marked by a black band around the neck. The ringhals, a different type of spitting cobra confined to southern Africa, is one of the smallest of the cobras, reaching only about 1.2 m (4 ft) in length. It is dark brown or black with ridged, or keeled, scales and pale rings on the neck. The asp, or Egyptian cobra, is found along the northern coast of Africa.

The venom of cobras often contains a powerful neurotoxin and acts on the nervous system. With effective serum more available, however, the high death rate from cobra bites in some areas of Asia has decreased. Cobra venom has been used for many years in medical research because it has an enzyme, lecithinase, that dissolves cell walls as well as membranes surrounding viruses. See also Asp; Venom.

Scientific classification: Cobras belong to the family Elapidae. The king cobra is classified as Ophiophagus hannah, the common cobra as Naja naja, the spitting cobra as Naja nigricollis, the ringhals as Hemachatus haemachatus, and the asp as Naja haje.

Microsoft ® Encarta ® Encyclopedia 2002. © 1993-2001 Microsoft Corporation. All rights reserved.

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