King Cobra

from Wikipedia, the free encyclopedia
King Cobra
King Cobra

King Cobra

Systematics
Subordination : Snakes (serpentes)
Superfamily : Adder-like and viper-like (Colubroidea)
Family : Poison Snakes (Elapidae)
Subfamily : True poisonous snakes (Elapinae)
Genre : Ophiophagus
Type : King Cobra
Scientific name of the  genus
Ophiophagus
Günther , 1864
Scientific name of the  species
Ophiophagus hannah
( Cantor , 1836)

The king cobra ( Ophiophagus hannah ) is a species of snake belonging to the poisonous snake family and the only species in the genus Ophiophagus . The generic name ( Greek 'snake-eating') refers to the food that is almost exclusively made up of snakes and lizards . The species is usually three to four meters long. The maximum length is proven to be at least 5.59 meters (see under physique), making it the largest venomous snake in the world (but not the most poisonous). The king cobra occurs in large parts of Southeast Asia, is mainly bound to forests and lives on the ground. Reliable information on the biology of the species is scarce and often contradicting itself. The bite often leads to death in humans; However, bite accidents are very rare due to the mostly low level of aggressiveness and the withdrawn lifestyle of the animals.

features

anatomy

King cobras are extremely large venomous snakes. The total length is regularly three to four meters, well established maximum dimensions are from the province of Nakhon Si Thammarat in the south of Thailand with 5.59 m as well as near the city of Krabi with "a good six meters" and from the Philippines with 4.25 m. Your body weight is usually around 6 kg, in extreme cases over 20 kg. This makes the species the largest venomous snake in the world. The tail accounts for about 20% of the total length. The rule laid down in threat behind the head neck shield is compared with the genuine cobras ( Naja narrow) and extends further to the rear.

Scaling

Like all venomous snakes, the king cobra has nine large, symmetrical shields on the top of its head. In addition, the species has a pair of large, touching occipitalia behind the parietalia . The number of supralabials is seven, the third supralabial touches both the posterior nasal and the eye, the fourth supralabial also touches the eye. The back scales are smooth. The number of ventral scales ( ventral shields ) varies between 240 and 254, the number of divided subcaudalia between 84 and 104. The anterior subcaudalia are undivided. The animals have 15 dorsal rows of scales in the middle of the body. The scales of the middle dorsal row of scales and those of the lowest row of scales on the flanks are enlarged, the flank scales are elongated and arranged in oblique rows.

Head scaling of the king cobra. Note the large occipital shields ( Occ ) to distinguish it from the real cobras ( Naja spp. )
Distribution area of ​​the king cobra
King cobra from South India with still clearly recognizable transverse bands

coloring

In adult animals, the basic color of the upper side is obviously light brown, dark olive brown, brown, dark brown or black, depending on the origin. Adults are occasionally monochrome; mostly the animals show a series of more or less distinct, light beige to whitish transverse bands on this ground. In the front area of ​​the body, these ligaments are narrow in the middle of the back and become significantly wider towards the belly, but further towards the tail they are more parallel-edged. The throat and front neck are very conspicuously yellow-orange or yellowish white, the rest of the abdomen is whitish or gray-white. The top of the hood is not drawn. Young animals have a clear warning sign, they are dark brown or black in color and with more contrasting whitish or yellow bands.

distribution and habitat

The range of the king cobra covers large parts of the tropics of South and Southeast Asia. The area extends from the south and east of India to the east over the whole of rear India to south-east China; in addition, the species occurs in large parts of Indonesia and the Philippines . The king cobra is mainly described as a forest dweller, especially as an inhabitant of forest areas that border on bodies of water. At least in Malaysia and Myanmar , however, the species is also found in a wide range of other habitats , including mangrove swamps , plantations, open grasslands and agricultural areas.

Systematics

The king cobra was scientifically described by Theodore Edward Cantor in 1836 as Hamadryas hannah ; however, the name Hamadryas was already in use for a genus of butterflies. Albert Günther placed the king cobra in the new genus Ophiophagus in 1864 . The now generally recognized scientific name Ophiophagus hannah , formed from these components, was introduced in 1945 by Charles Mitchill Bogert . The king cobra is the only species of the monotypical genus Ophiophagus . No subspecies are recognized.

According to molecular genetic studies, the king cobra is not closely related to the cobras of the genera Aspidelaps , Boulengerina , Hemachatus , Naja , Paranaja and Walterinnesia . Closest related to the king cobra are the kraits ( Bungarus ), the African garter otters ( Elapsoidea ) and the mambas ( Dendroaspis ). An exact clarification of the closer relationship is still pending.

Way of life and reproduction

The species is usually described as living on the ground, but several authors emphasize that the animals can climb trees very well. Depending on the author, the king cobra is described as diurnal, nocturnal or both diurnal and nocturnal. The food apparently consists exclusively of snakes and lizards, both non-poisonous and poisonous snakes are preyed on. The prey is held after the bite until it is dead or at least immobile; this can take 10–30 minutes.

The king cobra is egg-laying ( oviparous ) and the only type of snake that apparently builds ground nests, the clutches contain 20–40 eggs. In India, eggs are laid from April to July. A nest found in southern China in August 1983 consisted of leaves and contained 25 eggs in three layers on top of each other, measuring an average of 65.5 × 33.2 mm. The females curl up over the clutch and defend it vehemently against potential enemies. When approaching, the animals move towards the intruder, straighten their front body, spread the hood, present the orange throat and then quickly bite. Newly hatched young animals in India are 50–53 cm long.

Poison

Apart from the defense of the nest, the king cobra is described quite uniformly as a less aggressive and evasive species. The poison is essentially neurotoxic , but also has components that destroy blood vessels. It is of medium effectiveness. The average amount of poison per bite is given very differently with 384 mg (102 mg dry weight) or 420 mg dry weight. Different data are also available for the LD 50 value in mice after intravenous administration. Zhao gives 0.34 mg per kg body weight, Tin-Myint et al. 1.2-3.5 mg per kg body weight.

Due to the large amount of poison, the bite is often fatal for humans. Typical symptoms of a bite are severe swelling, which can extend to the entire limb that has been bitten, and fatal respiratory failure. In documented deaths, death occurred after 20 minutes to 12 hours. In one case described in detail, breathing stopped 90 minutes after the bite. The patient was artificially ventilated for 65 hours, whereby a specific antiserum could only be administered 30 hours after the bite. After 10 days the patient could be discharged as cured.

However, due to its low aggressiveness, the relative rarity and the avoidance of human settlements, the species is unanimously described as hardly relevant from a medical point of view; bite accidents are apparently very rare. Among the documented bite accidents in Myanmar, only workers in the dense jungle, reptile animal keepers in zoos and snake charmers are affected. From the entire range of the species a total of only 35 bite accidents were known up to 1991, of which 10 were fatal.

Existence and endangerment

There is no data on the size of the total population or the population trend. However, the species is listed as vulnerable by the International Union for Conservation of Nature and Natural Resources (IUCN) due to its shrinking habitat and decreasing population sizes. It is also mentioned in Appendix II of the Washington Convention on the Protection of Species (CITES), which means that trade in it for the purpose of protecting species is subject to restrictions.

swell

Individual evidence

  1. ↑ Chulalongkorn Hospital and Thai Red Cross: Venomous Snakes and Snake Bite in Thailand. In: P. Gopalakrishnakone, LM Chou: Snakes of Medical Importance. Venom and Toxin Research Group, National University of Singapore, 1990, pp. 557-583.
  2. ↑ STIN: Krabi: Woman discovers 6m long king cobra and calls the rescue team after 2 days Beautiful Thailand - Info & News. In: Beautiful Thailand - Info & News. Retrieved on February 28, 2020 (German).
  3. ↑ by Pedder: Bigger than ever, 6-meter king cobra found in Krabi. In: ThailandTIP. February 27, 2020, accessed on February 28, 2020 (German).
  4. ↑ Lim Boo Liat: Venomous Land Snakes of Malaysia. In: P. Gopalakrishnakone, LM Chou: Snakes of Medical Importance. Venom and Toxin Research Group, National University of Singapore, 1990, p. 402.
  5. ^ Alan E. Leviton, Guinevere OU Wogan, Michelle S. Koo, George R. Zug, Rhonda S. Lucas and Jens V. Vindum: The Dangerously Venomous Snakes of Myanmar - Illustrated Checklist with Keys. Proceedings of the California Academy of Sciences 54 (24), 2003, pp. 426-427.
  6. ^ Ophiophagus hannah in The Reptile Database ; Retrieved January 9, 2011.
  7. ↑ JB Slowinski and J. Scott Keogh: Phylogenetic Relationships of Elapid Snakes Based on Cytochrome b mtDNA Sequences. Molecular Phylogenetics and Evolution 15, No. 1, 2000, pp. 157-164.
  8. ↑ W. Wüster, S. Crookes, I. Ineich, Y. Mane, CE Pook, J.-F. Trape, DG Broadley: The phylogeny of cobras inferred from mitochondrial DNA sequences: Evolution of venom spitting and the phylogeography of the African spitting cobras (Serpentes: Elapidae: Naja nigricollis complex). Molecular Phylogenetics and Evolution 45, 2007, pp. 437-453.
  9. ↑ Lim Boo Liat: Venomous Land Snakes of Malaysia. In: P. Gopalakrishnakone, LM Chou: Snakes of Medical Importance. Venom and Toxin Research Group, National University of Singapore, 1990, p. 414.
  10. ↑ RC Sharma: Fauna of India and the adjacent countries - Reptilia, Volume III (Serpentes). Kolkata, 2007, ISBN 978-81-8171-155-7 , p. 309.
  11. ^ E. Zhao: Venomous Snakes of China. In: P. Gopalakrishnakone, LM Chou: Snakes of Medical Importance. Venom and Toxin Research Group, National University of Singapore, 1990, pp. 253-255.
  12. ↑ a b E. Zhao: Venomous Snakes of China. In: P. Gopalakrishnakone, LM Chou: Snakes of Medical Importance. Venom and Toxin Research Group, National University of Singapore, 1990, p. 255.
  13. ↑ a b Tin-Myint, Rai-Mra, Maung-Chit, Tun-Pe and DA Warrell: Bites by the King Cobra (Ophiophagus hannah) in Myanmar: Successful Treatment of Severe Neurotoxic Envenoming. Quarterly Journal of Medicine , New Series 80, No. 293, 1991, p. 751.
  14. ↑ a b Tin-Myint, Rai-Mra, Maung-Chit, Tun-Pe and DA Warrell: Bites by the King Cobra (Ophiophagus hannah) in Myanmar: Successful Treatment of Severe Neurotoxic Envenoming. Quarterly Journal of Medicine, New Series 80, No. 293, 1991, p. 752.
  15. ↑ Tin-Myint, Rai-Mra, Maung-Chit, Tun-Pe and DA Warrell: Bites by the King Cobra (Ophiophagus hannah) in Myanmar: Successful Treatment of Severe Neurotoxic Envenoming. Quarterly Journal of Medicine, New Series 80, No. 293, 1991, pp. 751-762.
  16. ↑ MM Aye: Venomous Snakes of Medical Importance in Burma. In: P. Gopalakrishnakone, LM Chou: Snakes of Medical Importance. Venom and Toxin Research Group, National University of Singapore, 1990, pp. 211-241.
  17. ↑ Appendices I, II and III valid from July 1, 2008. CITES, accessed on February 17, 2009 (English).

literature

  • Alan E. Leviton, Guinevere OU Wogan, Michelle S. Koo, George R. Zug , Rhonda S. Lucas and Jens V. Vindum: The Dangerously Venomous Snakes of Myanmar - Illustrated Checklist with Keys. Proceedings of the California Academy of Sciences 54 (24), 2003, pp. 407-462.
  • Lim Boo Liat : Venomous Land Snakes of Malaysia. In: P. Gopalakrishnakone, LM Chou: Snakes of Medical Importance. Venom and Toxin Research Group, National University of Singapore, 1990, ISBN 9971-62-217-3 , pp. 387-417.
  • Tin-Myint, Rai-Mra, Maung-Chit, Tun-Pe and DA Warrell: Bites by the King Cobra (Ophiophagus hannah) in Myanmar: Successful Treatment of Severe Neurotoxic Envenoming. Quarterly Journal of Medicine, New Series 80, No. 293, 1991, pp. 751-762.
  • RC Sharma: Fauna of India and the adjacent countries - Reptilia, Volume III (Serpentes). Kolkata, 2007, ISBN 978-81-8171-155-7 , pp. 308-309.
  • E. Zhao: Venomous Snakes of China. In: P. Gopalakrishnakone, LM Chou: Snakes of Medical Importance. Venom and Toxin Research Group, National University of Singapore, 1990, ISBN 9971-62-217-3 , pp. 243-279.

Web links

Commons : King Cobra ( Ophiophagus hannah )  - Collection of images, videos and audio files
This version was added to the list of articles worth reading on February 21, 2009 .