Indian Cobra

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) or Spectacled Cobra is a species of the genus Naja found in the Indian subcontinent and a member of the "big four", species inflicting 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 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]

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 (Singhalese), Naaga Pamu (Telugu),^[6]Nagara Haavu (Kannada),^[6] Nalla pambu or Naja Pambu (Tamil)^[6] 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]

Lifecycle

The Indian cobra is native to the Indian subcontinent which includes present day 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 2000m.^[2] Cobras 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 from 10 to 30 eggs in rat holes or termite mounds and the eggs hatch 48 to 69 days later. Newborn cobras measure between 8 and 12 inches (20–30 cm). The young when hatched are exact replicas of the parents 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 to 2 hours following the bite ^[9] and can be fatal in an hour in severe cases of envenomation.^[9]

In mice, the SC LD₅₀ values of this species are 0.45 mg/kg^[10][11]—0.565 mg/kg^[7] The average venom yield per bite is between 169 —250 mg.^[7] Mortality rate for untreated bite victims is between 30% and 35%.^[12]

The Indian Cobra is one of the Big four snakes of South Asia (mostly India). The "Big Four" are the four snake which are responsible for the majority of human deaths as a result of snakebites in Asia. Polyvalent serum is available for treating snakebites caused by this species.^[13] Zedoary, a local spice with a reputation for being effective against snakebite,^[14] has shown promise in experiments testing its activity against cobra venom.^[15]

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.^[16]

Hindu culture

Cobra in a basket, raising its head and spreading its hood.

The spectacled cobra is much 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, the preserver of the universe, is usually portrayed as reclining on the coiled body of Sheshnag, 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.^[17]

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. 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.^[18]

Gallery

• 

  Close-up of the head

• 

  Binocellate Cobra

• 

  Indian Cobra outside a home in Yelandur, Karnataka, South India.

References

1. ^ ITIS report: Naja naja
2. ^ ^{a b c d} Whitaker, Romulus & Captain, Ashok (2004) Snakes of India: The Field Guide
3. ^ http://www.wildlifeofpakistan.com/ReptilesofPakistan/cobra.htm Reptiles of Pakistan
4. ^ Asiatic Naja
5. ^ Smith, Malcolm A. (1942) The Fauna of British India - Vol III (Serpentes), pp 427-436.
6. ^ ^{a b c d} Daniels, J. C. (2002) The Book of Indian Reptiles and Amphibians, BNHS & Oxford University Press, Mumbai, pp 136-140.
7. ^ ^{a b c d} "Clinical Toxinology Resources-Naja naja". http://toxinology.com/fusebox.cfm?fuseaction=main.snakes.display&id=SN0041. 
8. ^ Achyuthan, K. E. and L. K. Ramachandran(1981) Cardiotoxin of the Indian cobra (Naja naja) is a pyrophosphatase. J. Biosci. 3(2):149-156 PDF
9. ^ ^{a b} "IMMEDIATE FIRST AID for bites by Indian or Common Cobra(Naja naja naja)". http://drdavidson.ucsd.edu/Portals/0/snake/Naja2.htm. 
10. ^ "LD50". http://www.seanthomas.net/oldsite/ld50tot.html. 
11. ^ "LD50 menu". http://www.kingsnake.com/toxinology/LD50/LD50men.html. 
12. ^ 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. 
13. ^ BBC (Snake-bites: a growing, global threat)
14. ^ Martz W (October 1992). "Plants with a reputation against snakebite". Toxicon 30 (10): 1131–1142. doi:10.1016/0041-0101(92)90429-9. PMID 1440620. 
15. ^ 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.  edit
16. ^ [1], Katshu, Mohammad Zia Ul Haq , Dubey, Indu , Khess, C. R. J. and Sarkhel, Sujit (2011) 'Snake Bite as a Novel Form of Substance Abuse: Personality Profiles and Cultural Perspectives', Substance Abuse, 32:1, 43 - 46
17. ^ http://www.wildlifesos.com/rprotect/snakemyths.htm Snake myths
18. ^ http://www.indialawinfo.com/bareacts/pca.html Prevention of Cruelty to Animals Act 1960

• Daniel, J.C. (2002). The Book of Indian Reptiles and Amphibians. Oxford, England: Bombay Natural History Society and Oxford University Press. ISBN 0-19-566099-4. ^{[clarification needed]}
• Smith, M.A. (1943). "The Fauna of British India, Ceylon and Burma, Including the Whole of the Indo-Chinese Sub-Region". Reptilia and Amphibia (London, England: Taylor and Francis) 3 (Serpentes). ^{[clarification needed]}
• Whitaker, Romulus; Captain, Ashok (2004). Snakes of India: The Field Guide. Chennai, India: Draco Books. ISBN 81-901873-00-9. ^{[clarification needed]}