COMMON COBRA
Cobra is any of various species of venomous snakes usually belonging to the family Elapidae, most of which can expand their neck ribs to form a widened hood. Not all snakes commonly referred to as cobras are of the same genus, or even of the same family. The name is short for cobra de capelo or cobra-de-capelo, which is Portuguese for "snake with hood", or "hood-snake".[1] When disturbed, most of these snakes can rear up and spread their necks (or hoods) in a characteristic threat display. A favorite of snake charmers, cobras are found from southern Africa, through southern Asia, to some of the islands of Southeast Asia.
Cobra may refer to:
Naja, also known as typical cobras (with the characteristic ability to raise the front quarters of their bodies off the ground and flatten their necks in a threatening gesture), a group of venomous elapids found in Africa and Asia
The king cobra is the world’s largest venomous snake, with an average length of 12 feet but known to grow up to 18.5 feet. While it preys chiefly on other snakes, the king cobra is highly aggressive, extremely fast and agile, and injects a larger amount of venom per bite (as much as 600 mg) than most snakes. The king cobra is unique among snakes as it makes a nest for its eggs and remains until the young hatch. An adult human can die from a single bite in less than 15 minutes, making the king cobra one of the most feared and deadly snakes in the world.
The other cobra of Asia is known as Asian, Indian or Spectacled cobra due to the eyeglass-shaped pattern on its skin. The hood of the Asian cobra is larger than that of king cobra and is usually yellow or brown with a black and white spectacle pattern on top and two black and white spots on the lower surface.
The Ringhals, a different type of spitting cobra confined to southern Africa, are the smallest, reaching only about 4 feet in length. It is dark brown or black with ridged, or keeled, scales and light rings on the neck.
Cobras very rarely attack people unprovoked, but when disturbed, they make full use of their deadly bite.
Spectacle pattern on a snake's hood.
On the rear of the snake's hood are two circular ocelli patterns connected by a curved line, evoking the image of spectacles. Hindus believe them to be the footmarks of Krishna, who danced on Kāliyā, the hundred and ten hooded snake's head. An average cobra is about 1.9 meters (6 feet) in length and rarely as long as 2.4 meters (nearly 8 feet). The most distinctive and impressive characteristic of the Indian cobra is the hood, which it forms by raising the anterior portion of the body and spreading some of the ribs in its neck region when it is threatened. [3] The spectacle pattern on the hood varies greatly, as does the overall colour of the snake.[4]
An additional line is seen above the spectacle in this cobra. This is just one of the many different patterns you can find on a cobra.
The genus name Naja comes from Indian languages. The Indian cobra[5][6] or spectacled cobra,[2] being common in South Asia, is referred to by a number of local names deriving from the root of Naag (Hindi, Sanskrit, Oriya, Marathi), Moorkan (Malayalam), Naya (Sinhalese), Naagu Pamu (Telugu),[6] Nagara Haavu (Kannada),[6] Naaga Pambu or Nalla pambu (Tamil)[6] "Phetigom" (Assamese) and Gokhra (Bengali).
The Oriental ratsnake Ptyas mucosus is often mistaken for the cobra; however this snake is much longer and can easily be distinguished by the more prominent ridged appearance of its body. Other snakes that resemble Naja naja are the banded racer Argyrogena fasciolata and the Indian smooth snake Coronella brachyura.[2]
Indian cobra in its habitat
The Indian cobra is native to the Indian subcontinent which includes present day Nepal, Pakistan, India, Bangladesh, and Sri Lanka. It can be found in plains, jungles, open fields and the regions heavily populated by people. Its distribution ranges from sea-level up to 2,000 metres (6,600 ft) above sea-level.[2] This species normally feed on rodents, toads, frogs, birds and other snakes. Its diet of rats leads it to areas inhabited by humans including farms and outskirts of urban areas.
In mice, the SC LD50 range for this species is 0.45 mg/kg[10] – 0.80 mg/kg.[7][11] The average venom yield per bite is between 169 and 250 mg.[7] Though it is responsible for many bites, only a small percentage are fatal if proper medical treatment and anti-venom are given.[12] Mortality rate for untreated bite victims can vary from case to case, depending upon the quantity of venom delivered by the individual involved. According to one study, it is approximately 15–20%.[13] but in another study, with 1,224 bite cases, the mortality rate was only 6.5%.[11] This shows that the cobra tends to deliver a warning bite, which involves non-fatal doses of venom, first when acting in defense.
Spectacled cobra with hood lowered in a bamboo shrub.
The Indian cobra is one of the Big four snakes of South Asia (mostly India) which are responsible for the majority of human deaths by snakebite in Asia. Polyvalent serum is available for treating snakebites caused by this species.[14] Zedoary, a local spice with a reputation for being effective against snakebite,[15] has shown promise in experiments testing its activity against cobra venom.[16]
The venom of young cobras has been used as a substance of abuse in India, with cases of snake charmers being paid for providing bites from their snakes. Though this practice is now seen as outdated, symptoms of such abuse include loss of consciousness, euphoria, and sedation.[17]
Cobra in a basket, raising its head and spreading its hood.
The spectacled cobra is greatly respected and feared, and even has its own place in Hindu mythology as a powerful deity. The Hindu god Shiva is often depicted with a protective cobra coiled around his neck. Vishnu is usually portrayed as reclining on the coiled body of Adishesha, the Preeminent Serpent, a giant snake deity with multiple cobra heads. Cobras are also worshipped during the Hindu festival of Nag Panchami.
There are numerous myths about cobras in India, including the idea that they mate with ratsnakes.[18]
Cobra is any of various species of venomous snakes usually belonging to the family Elapidae, most of which can expand their neck ribs to form a widened hood. Not all snakes commonly referred to as cobras are of the same genus, or even of the same family. The name is short for cobra de capelo or cobra-de-capelo, which is Portuguese for "snake with hood", or "hood-snake".[1] When disturbed, most of these snakes can rear up and spread their necks (or hoods) in a characteristic threat display. A favorite of snake charmers, cobras are found from southern Africa, through southern Asia, to some of the islands of Southeast Asia.
Cobra may refer to:
Naja, also known as typical cobras (with the characteristic ability to raise the front quarters of their bodies off the ground and flatten their necks in a threatening gesture), a group of venomous elapids found in Africa and Asia
The king cobra is the world’s largest venomous snake, with an average length of 12 feet but known to grow up to 18.5 feet. While it preys chiefly on other snakes, the king cobra is highly aggressive, extremely fast and agile, and injects a larger amount of venom per bite (as much as 600 mg) than most snakes. The king cobra is unique among snakes as it makes a nest for its eggs and remains until the young hatch. An adult human can die from a single bite in less than 15 minutes, making the king cobra one of the most feared and deadly snakes in the world.
The other cobra of Asia is known as Asian, Indian or Spectacled cobra due to the eyeglass-shaped pattern on its skin. The hood of the Asian cobra is larger than that of king cobra and is usually yellow or brown with a black and white spectacle pattern on top and two black and white spots on the lower surface.
The Ringhals, a different type of spitting cobra confined to southern Africa, are the smallest, reaching only about 4 feet in length. It is dark brown or black with ridged, or keeled, scales and light rings on the neck.
Cobras very rarely attack people unprovoked, but when disturbed, they make full use of their deadly bite.
Description
The Oriental ratsnake Ptyas mucosus is often mistaken for the cobra; however this snake is much longer and can easily be distinguished by the more prominent ridged appearance of its body. Other snakes that resemble Naja naja are the banded racer Argyrogena fasciolata and the Indian smooth snake Coronella brachyura.[2]
Distribution, habitat and ecology
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Reproduction
Indian cobras are oviparous and lay their eggs between the months of April and July. The female snake usually lays between 10 to 30 eggs in rat holes or termite mounds and the eggs hatch 48 to 69 days later. The hatchlings measure between 20 and 30 centimetres (7.9 and 12 in) in length. The hatchlings are independent from birth and have fully functional venom glands.Venom
The Indian cobra's venom mainly contains a powerful post-synaptic neurotoxin[7] and cardiotoxin.[7][8] The venom acts on the synaptic gaps of the nerves, thereby paralyzing muscles, and in severe bites leading to respiratory failure or cardiac arrest. The venom components include enzymes such as hyaluronidase that cause lysis and increase the spread of the venom. Envenomation symptoms may manifest between 15 minutes and 2 hours following the bite.[9]In mice, the SC LD50 range for this species is 0.45 mg/kg[10] – 0.80 mg/kg.[7][11] The average venom yield per bite is between 169 and 250 mg.[7] Though it is responsible for many bites, only a small percentage are fatal if proper medical treatment and anti-venom are given.[12] Mortality rate for untreated bite victims can vary from case to case, depending upon the quantity of venom delivered by the individual involved. According to one study, it is approximately 15–20%.[13] but in another study, with 1,224 bite cases, the mortality rate was only 6.5%.[11] This shows that the cobra tends to deliver a warning bite, which involves non-fatal doses of venom, first when acting in defense.
The venom of young cobras has been used as a substance of abuse in India, with cases of snake charmers being paid for providing bites from their snakes. Though this practice is now seen as outdated, symptoms of such abuse include loss of consciousness, euphoria, and sedation.[17]
Hindu culture
There are numerous myths about cobras in India, including the idea that they mate with ratsnakes.[18]
Snake charming
The Indian cobra's celebrity comes from its popularity as a snake of choice for snake charmers. The cobra's dramatic threat posture makes for a unique spectacle as it appears to sway to the tune of a snake charmer's flute. Snake charmers with their cobras in a wicker basket are a common sight in many parts of India only during the Nag Panchami festival. The cobra is deaf to the snake charmer's pipe, but follows the visual cue of the moving pipe and it can sense the ground vibrations from the snake charmer's tapping. For safety, all the venoms in cobra's teeth are removed. The snake-charmers sell the venom at a very high price. In the past Indian snake charmers also conducted cobra and mongoose fights. These gory fight shows, in which the snake was usually killed, are now illegal.
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