|Indian cobra distribution|
Indian cobra (Naja naja) also known as Spectacled cobra, Asian cobra or Binocellate cobra is a species of the genus Naja found in the Indian subcontinent and a member of the "big four", the four species which inflict the most snakebites in India. This snake is revered in Indian mythology and culture, and is often seen with snake charmers. It is now protected in India under the Indian Wildlife Protection Act (1972).
Etymology and names
Naja naja was first described by Swedish physician, zoologist, and botanist Carl Linnaeus in 1758. The generic name and the specific epithet naja is a Latinisation of the Sanskrit word nāgá (नाग) meaning "cobra".
The Indian cobra or spectacled cobra, being common in South Asia, is referred to by a number of local names deriving from the root of Nag (नाग) (Hindi, Oriya, Marathi), Moorkan (Malayalam), Naya (Sinhalese), Nagu Pamu (Telugu), Nagara Havu (Kannada), Naga Pambu or Nalla pambu (நாகப் பாம்பு/நல்ல பாம்பு) (Tamil) "Phetigom" (Assamese) and Gokhra (Bengali).
The Indian cobra is classified under the genus Naja of the family Elapidae. The genus was first described by Josephus Nicolaus Laurenti in 1768. The species Naja naja was first described by the Swedish physician, zoologist, and botanist Carl Linnaeus in 1758. The genus Naja was split into several subgenera based on various factors, including morphology, diet, and habitat. Naja naja is part of the subgenus Naja, along with all the other species Asiatic cobras, including Naja kaouthia, Naja siamensis, Naja sputatrix, and the rest. Naja naja is considered to be the prototypical cobra species within the Naja subgenus, and within the entire Naja genus. The below cladogram illustrates the taxonomy and relationships among species of Naja:
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.
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.  The spectacle pattern on the hood varies greatly, as does the overall colour of the snake.
Distribution, habitat and ecology
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. 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.
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 11.8 in) in length. The hatchlings are independent from birth and have fully functional venom glands.
The Indian cobra's venom mainly contains a powerful post-synaptic neurotoxin and cardiotoxin. 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.
In mice, the SC LD50 range for this species is 0.45 mg/kg – 0.80 mg/kg. The average venom yield per bite is between 169 and 250 mg. Though it is responsible for many bites, only a small percentage are fatal if proper medical treatment and anti-venom are given. 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%. but in another study, with 1,224 bite cases, the mortality rate was only 6.5%.
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. Zedoary, a local spice with a reputation for being effective against snakebite, has shown promise in experiments testing its activity against cobra venom.
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.
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 cobra coiled around his neck, symbolizing his mastery over "maya" or the world-illusion. 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.
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. Sometimes, for the sake of safety, all the venom in cobra's teeth is 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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