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{{Redirect|Krait|the ship|MV Krait|the CPU|Krait (CPU)}}
{{Redirect|Krait|the ship|MV Krait|the CPU|Krait (CPU)}}
{{Redirect|Karait|other meanings|Karaite (disambiguation){{!}}Karaite}}
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{{Taxobox
{{Taxobox

Revision as of 17:20, 1 January 2016

"Krait" redirects here. For the ship, see
Krait (CPU)
.

Bungarus
Bungarus fasciatus
 (the largest species of krait)
Scientific classification
Kingdom:
Animalia
Phylum:
Chordata
Subphylum:
Vertebrata
Class:
Reptilia
Order:
Squamata
Suborder:
Serpentes
Family:
Elapidae
Genus:
Bungarus

Daudin, 1803
Synonyms

Pseudoboa Oppel, 1811
Aspidoclonion Wagler, 1828
Megærophis Gray, 1849
Xenurelaps Günther, 1864

Bungarus is a

nominal
) recognized.

Distribution

Kraits are found in the

Indian Subcontinent (including Sri Lanka and Bangladesh) and Southeast Asia (including Indonesia and Borneo).[3]

Description

Kraits usually range between 1 and 1.5 m (3 ft 3 in and 4 ft 11 in) in length, although specimens as large as 2 m have been observed. The

dorsal ridge of the back are hexagonal. The head is slender and the eyes have round pupils. Kraits have pronounced dorsolateral flattening, and are triangular in cross section. The tail
tapers to a thin point.

Diet and behavior

Kraits are

lizards.[5]

All kraits are

nocturnal. They are more docile during the daylight hours; at night, they become very active, but are not very aggressive even when provoked. They are actually rather timid, and will often hide their heads within their coiled bodies for protection. When in this posture, they will sometimes whip their tails around as a type of distraction.[6]

Reproduction

Kraits are

eggs
in piles of leaf litter, and stay with them until they hatch.

Venom

Bungarus contains some species which are among the most venomous land snakes in the world to mice based on their

venom which can induce muscle paralysis. Clinically, their venom contains mostly presynaptic neurotoxins. These affect the ability of neuron endings to properly release the chemical that sends the message to the next neuron. Following envenomation with bungarotoxins, transmitter release is initially blocked (leading to a brief paralysis), followed by a period of massive overexcitation (cramps, tremors, spasms), which finally tails off to paralysis. These phases may not be seen in all parts of the body at the same time. Since kraits are nocturnal, they seldom encounter humans during daylight hours, so bites are rare, but a bite from a krait is potentially life-threatening, and should be regarded as a medical emergency
.

Typically, victims start to complain of severe abdominal cramps accompanied by progressive muscular paralysis, frequently starting with ptosis. As there are no local symptoms, a patient should be carefully observed for tell-tale signs of paralysis (e.g. the onset of bilateral ptosis, diplopia, and dysphagia), and treated urgently with antivenom. Frequently, little or no pain occurs at the site of a krait bite, which can provide false reassurance to the victim. The major medical difficulty of envenomated patients are the lack of medical resources (especially intubation supplies and mechanical ventilators in rural hospitals) and the ineffectiveness of the antivenom.

Once at a healthcare facility, support must be provided until the venom is

hypoxia
may occur, given the potentially long transport times to get medical care.

Mortality rates caused by bites from the members of this genus vary from species to species; according to University of Adelaide Department of Toxicology, bites from the banded krait have an untreated mortality rate of 1–10%,[8] while those of the common krait are 70—80%.[9] Several websites state the mortality rate is 50% even with treatment, but no specific species is mentioned and no original source in the medical literature for this statement is given. In common with those of all other venomous snakes, the death time and fatality rate resulting from bites of kraits depend on numerous factors, such as the venom yield and the health status of the victim.

Polyvalent Elapid Antivenom is effective in neutralizing of the venoms of B. candidus and B. flaviceps and rather effective for B. fasciatus. In this last case, the monovalent B. fasciatus antivenom is also moderately effective.[10]

Species

Species Authority Subsp.* Common name Geographic range
B. andamanensis Biswas & Sanyal, 1978 0
South Andaman krait
 India (Andaman Island)
B. bungaroides (
Cantor
, 1839) 		0
Northeastern hill krait
Cachar, Sikkim), Nepal, Vietnam
B. caeruleusT (
Schneider
, 1801) 		0 Common krait Afghanistan, Pakistan, India (Bengal, Maharashtra, Karnataka), Sri Lanka, Bangladesh, Nepal
B. candidus (Linnaeus, 1758) 0 Malayan krait, blue krait Cambodia,
Java, Sumatra, Bali, Sulawesi), Malaysia (Malaya), Singapore, Thailand
, Vietnam
B. ceylonicus Günther, 1864 1
Sri Lankan krait
 Sri Lanka
B. fasciatus (Schneider, 1801) 0 Banded krait Bangladesh, Brunei, Myanmar, Cambodia, south China (incl. Hong Kong, Hainan), north-east India,Eturnagaram[Warangal[Telangana]India], Bhutan, Nepal, Indonesia (Sumatra, Java, Borneo), Laos, Macau; Malaysia (Malaya and East Malaysia), Singapore, Thailand, Vietnam and Philippines
B. flaviceps (Reinhardt, 1843) 1 Red-headed krait South Thailand, South Myanmar, Cambodia, Vietnam,
Billiton, Borneo
)
B. lividus Cantor, 1839 0 Lesser black krait India, Bangladesh, Nepal
B. magnimaculatus Wall and Evans, 1901 0
Burmese krait
 Myanmar
B. multicinctus Blyth, 1861 1 Many-banded krait Taiwan, south China (Hong Kong, Hainan), Myanmar, Laos, northern Vietnam, Thailand and northern Philippines
B. niger Wall, 1908 0 Greater black krait India (Assam, Sikkim), Nepal, Bangladesh, Bhutan
B. persicus Abtin, Nilson, Mobaraki, Hosseini & Dehgannejhad, 2014 0 None Iran
B. sindanus Boulenger, 1897 2
Sind krait
 Southeast Pakistan, India
B. slowinskii[11] Kuch et al., 2005 0
Red River krait
 Northern Vietnam

*) Not including the nominate subspecies (typical form).
T) Type species

In fiction

Kraits have a reputation as deadly snakes and have figured in fiction as such.

Rudyard Kipling used a small sand-colored krait (in the story named Karait) as one of the three main villains in his short story "Rikki-Tikki-Tavi" (the other two villains being a pair of black cobras). In another Kipling short story, "The Return of Imray", a servant arrested for murder cheats the rope by stepping on a "karait".

Roald Dahl uses the krait as a device in his short story "Poison". A version of "Poison" is shown in Alfred Hitchcock Presents (TV series) October 5, 1958 and remade in Tales of the Unexpected (TV series) March 29, 1980.

The deadly snake in the Sherlock Holmes story "The Adventure of the Speckled Band" may have been a krait, although it is described in that work as an "Indian swamp adder". (The Russell's viper has also been considered as a possible culprit.)[12]

In James Patterson's The 8th Confession, kraits are the murder weapons used by a serial killer.

In Michael Crichton's "Micro", a Banded Krait appears in captivity and is used in an attempt to kill one of the main characters.

References

  1. ^ "krait, n". OED Online. Oxford University Press (accessed June 30, 2014).
  2. ^ [1] American Heritage Dictionary (accessed June 30, 2014).
  3. ^ SurvivalIQ: Krait
  4. ^ Smith, Malcolm A. Fauna of British India...Vol III - Serpentes, pages 411 to 413
  5. ^ Richard Mastenbroek's Elapid Pages: Kraits (Bungarus ssp.)
  6. ^ Living in Indonesia:Banded Krait
  7. ISBN 81-901873-0-9.{{cite book}}: CS1 maint: multiple names: authors list (link
    )
  8. ^ "Bungarus fasciatus". WCH Clinical Toxinology Resources.
  9. ^ "Bungarus caeruleus". WCH Clinical Toxinology Resources.
  10. ^ Prof Tan, Nget Hong. "Antivenoms against Malaysian poisonous snakes". University of Malaya. Retrieved 2009-09-23.
  11. ^ Kuch, U., D: Kizirian, Q.T. Nguyen, R. Lawson, M.A. Donnelly, & D. Mebs (2005). A new species of krait (Squamata: Elapidae) from the Red River System of Northern Vietnam. Copeia 2005(4): 818-833
  12. ^ "Fauna in the Canon". strangemag.com.

External links

Retrieved from "https://en.wikipedia.org/w/index.php?title=Bungarus&oldid=697748484"