Indian cobra

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Indian cobra
Naja naja with hood spread open
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Order: Squamata
Suborder: Serpentes
Family: Elapidae
Genus: Naja
Species: N. naja
Binomial name
Naja naja
(Linnaeus, 1758)[1]
Synonyms

Coluber naja Linnaeus, 1758
Naja fasciata Laurenti, 1768
Vipera naja Daudin, 1803
Naja tripudians Gray, 1834
Naia tripudians Boulenger, 1896

Indian cobra (Naja naja) also known as Asian cobra or spectacled 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.[2] 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).

Description

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 that can be found 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 (நாகப் பாம்பு/நல்ல பாம்பு) (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]

Distribution, habitat and ecology

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.


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 11.8 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]

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]

Hindu culture

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 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.

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. 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.[19]

Gallery

  • Indian cobra displaying an impressive hood.

  • Biocellate cobra

  • Indian cobra outside a home in Yelandur, Karnataka, South India

  • The ocellation of the spectacled cobra

References

  1. ↑ Naja naja. Itis.gov. Retrieved on 2013-01-03.
  2. ↑ 2.0 2.1 2.2 2.3 Whitaker, Romulus; Captain, Ashok (2004). Snakes of India: The Field Guide. Chennai, India: Draco Books. ISBN 81-901873-0-9. 
  3. ↑ Reptiles of Pakistan. Wildlifeofpakistan.com. Retrieved on 2013-01-03.
  4. ↑ Asiatic Naja. Biology.bangor.ac.uk (2001-10-09). Retrieved on 2013-01-03.
  5. ↑ Smith, M.A. (1943). Serpentes. "The Fauna of British India, Ceylon and Burma, Including the Whole of the Indo-Chinese Sub-Region". Reptilia and Amphibia 3 (London, England: Taylor and Francis). pp. 427–436. 
  6. ↑ 6.0 6.1 6.2 6.3 Daniel, J.C. (2002). The Book of Indian Reptiles and Amphibians. Oxford, England: Bombay Natural History Society and Oxford University Press. pp. 136–140. ISBN 0-19-566099-4. 
  7. ↑ 7.0 7.1 7.2 7.3 "Naja naja". University of Adelaide. 
  8. ↑ Achyuthan, K. E. and Ramachandran, L. K. (1981). "Cardiotoxin of the Indian cobra (Naja naja) is a pyrophosphatase". J. Biosci. 3 (2): 149–156. doi:10.1007/BF02702658. 
  9. ↑ "IMMEDIATE FIRST AID for bites by Indian or Common Cobra(Naja naja naja)". 
  10. ↑ "LD50". Séan Thomas & Eugene Griessel – Dec 1999;Australian Venom and Toxin database. University of Queensland. Retrieved 1 December 2011. 
  11. ↑ 11.0 11.1 Brown Ph.D, John H. (1973). Toxicology and Pharmacology of Venoms from Poisonous Snakes. Springfield, IL USA: Charles C. Thomas Publishers. p. 81. ISBN 0-398-02808-7. 
  12. ↑ Whitaker, Captain, Romulus, Ashok (2004). Snakes of India, The Field Guide. India: Draco Books. p. 372. ISBN 81-901873-0-9. 
  13. ↑ World Health Organization. "Zoonotic disease control: baseline epidemiological study on snake-bite treatment and management". Weekly Epidemiological Record (WER) 62 (42): 319–320. ISSN 0049-8114. 
  14. ↑ Snake-bites: a growing, global threat. BBC News (2011-02-22). Retrieved on 2013-01-03.
  15. ↑ Martz, W. (1992). "Plants with a reputation against snakebite". Toxicon : official journal of the International Society on Toxinology 30 (10): 1131–1142. PMID 1440620. 
  16. ↑ Daduang; Sattayasai, N.; Sattayasai, J.; Tophrom, P.; Thammathaworn, A.; Chaveerach, A.; Konkchaiyaphum, M. (2005). "Screening of plants containing Naja naja siamensis cobra venom inhibitory activity using modified ELISA technique". Analytical Biochemistry 341 (2): 316–325. doi:10.1016/j.ab.2005.03.037. PMID 15907878. 
  17. ↑ Katshu, M. Z. U. H.; Dubey, I.; Khess, C. R. J.; Sarkhel, S. (2011). "Snake Bite as a Novel Form of Substance Abuse: Personality Profiles and Cultural Perspectives". Substance Abuse 32 (1): 43–46. doi:10.1080/08897077.2011.540482. PMID 21302184. 
  18. ↑ Snake myths. wildlifesos.com
  19. ↑ Prevention of Cruelty to Animals Act 1960. indialawinfo.com

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