Black-necked spitting cobra

Last updated

Contents

Black-necked spitting cobra
Naja nigricollis (Warren Klein).jpg
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Order: Squamata
Suborder: Serpentes
Family: Elapidae
Genus: Naja
Subgenus: Afronaja
Species:
N. nigricollis
Binomial name
Naja nigricollis
Hallowell, 1857 [2] [3]
Map-Africa snakes Naja-nigricollis.svg
The approximate range of Naja nigricollis in Africa
Synonyms [4]
  • Naja nigricollis atriceps
    Laurent, 1955
  • Naja nigricollis occidentalis
    Laurent, 1973
  • Naja crawshayi
    Broadley & Cotterill, 2004

The black-necked spitting cobra (Naja nigricollis) is a species of spitting cobra found mostly in sub-Saharan Africa. They are moderately sized snakes that can grow to a length of 2.2 to 3.0 m (7.2 to 9.8 ft) in length. Their coloration and markings can vary considerably. They prey primarily on small rodents. They possess medically significant venom, although the mortality rate for untreated bites on humans is relatively low (~ 5–10%, in endemic regions under 1%). Like other spitting cobras, they can eject venom from their fangs when threatened (one drop over 7 metres (23 ft) and more in perfect accuracy). The neurotoxic venom irritates the skin, causing blisters and inflammation, and can cause permanent blindness if the venom makes contact with the eyes and is not washed off.

Naja nigricollis belongs to the cobra genus Naja under the family Elapidae. It previously included two subspecies that have been moved to the species Naja nigricincta – the zebra spitting cobra (Naja nigricincta nigricincta) and the black spitting cobra (Naja nigricincta woodi).

Taxonomy

Naja nigricollis is classified under the genus Naja of the family Elapidae. It was first described by Norwegian zoologist Johan Reinhardt in 1843. The generic name Naja is a Latinisation of the Sanskrit word nāgá ( नाग ), meaning "cobra". The specific epithet nigricollis is Latin for "black-necked": niger, meaning "black", and collis, meaning "neck". [5]

Naja nigricollis previously included two subspecies – Naja nigricollis nigricincta and Naja nigricollis woodi. But genetic studies in 2007 by Wolfgang Wüster et al. have concluded that these subspecies should be treated under a separate species, Naja nigricincta . [6] [7]

Description

N. nigricollis is a moderately sized, venomous snake with a moderately distinct head; the shape of the head is due primarily to two large venom glands found on each side of the head. Its colour can vary depending on region of origin. Some specimens are black or pale grey with a yellow or reddish ventral side with a broad, black neck band, often with an orange or pinkish bar on the neck. Other specimens can be yellowish-brown or have a yellow copper colour and are missing the bandings around the neck and the reddish colour on the belly. Some other specimens are deep reddish-brown, and yet others are an olive brown. [8] Some can even be striped black and white or totally white (with dark eyes).[ citation needed ] There are 21–23 dorsal scales at the mid-body, 182–196 ventral scales, and 54–66 subcaudal scales. [9] This species generally grows to a length of 1.2 metres (3.9 ft) to 2.2 metres (7.2 ft). These sizes are subject to trends based on geographic location and subspecies.

Distribution and habitat

The species is very common and is widespread through much of sub-Saharan Africa and is found in western, eastern, central, and parts of southern Africa. It is absent from the rainforests of the Congo Basin. It has been recorded from Angola, Benin, Burkina Faso, Cameroon, Central African Republic, Chad, Democratic Republic of the Congo (except in the center), Congo, Ethiopia, Gabon, Ghana, Guinea Bissau, Guinea, Ivory Coast, Kenya, Liberia, Mali, Niger, Nigeria, Senegal, Sierra Leone, Gambia, Mauritania, Sudan, Tanzania, Somalia, Togo, Uganda, Zambia. [10] Older records from South Africa, Botswana, Zimbabwe, Eswatini, Mozambique, or most of Namibia refer to Naja mossambica or Naja nigricincta , which were formerly regarded as subspecies of N. nigricollis.

N. nigricollis usually inhabits savanna and semi-desert regions of Africa. However, they can be found at altitudes up to 1,800 metres (5,900 ft), as well as in tropical and subtropical regions of central Africa in moist savanna and cleared former forest regions, particularly near rivers and streams. [11] Adaptable snakes, Naja n. nigricollis occurs in southeastern Nigeria where their habitat has been transformed from rainforest to man-made farmlands, plantations, suburban areas, and a few fragmented forests. This species of cobra has found advantages in the drastic changes which have taken place in Nigeria's rainforests. A study by herpetologist Luca Luiselli suggests this snake now forages in much drier microhabitats. [12]

The range of Naja nigricollis is currently expanding from the southeastern regions of Nigeria to the more desert and arid conditions in the central part of the nation. [9] They also live in coastal scrubs and dry grasslands. Like other cobra species, they may find abandoned termite mounds or rodent holes to hide or cool off. However, tree trunks seem to be their favourite hiding places. They are excellent tree climbers, thus can be arboreal at times. Because they are so common across Africa, they are encountered in villages or small towns where they may come in direct contact with people. [9]

Behavior

Unlike other snakes, Naja nigricollis can be either nocturnal or diurnal depending on the time of year, geographic location, and average daytime temperature. This adaptability allows the snake to better regulate its body temperature and to gain access to the most abundant food sources of a particular area. It feeds primarily on small rodents, such as small rats and mice, birds, and fishes, but will also eat lizards, eggs, and other snakes. [13]

Like other snakes, it may fall prey to raptors, especially different species of snake eagles that migrate to Africa when it is winter in the Northern Hemisphere. The short-toed snake eagle (Circaetus gallicus) may be a particular threat, as it is almost strictly an ophiophagus raptor. [14] Other snakes also prey on this species. [15]

Like other spitting cobras, this species is known for its ability to project venom at a potential threat. The venom is an irritant to the skin and eyes. If it enters the eyes, symptoms include extreme burning pain, loss of coordination, partial loss of vision, and permanent blindness. N.  nigricollis is known for its tendency to liberally spit venom and bite with only the slightest provocation. [11] [13]

This species is sometimes found in captivity, and wild-caught individuals are generally nervous and prone to spitting. Captive-bred animals tend to be much more docile and calm when compared to their wild-caught counterparts. [8]

Reproduction

Like other cobra species, this snake is oviparous. [16] The mating season of this species can vary from the end of winter (September) to the beginning of summer (December). Usually, the mating season is the same whether in captivity or in the wild. Females will commonly lay 10 to 15 eggs but can lay anywhere between eight and 22 eggs at a time. [15] The gestation period lasts about 90–100 days, but once the eggs are laid, they hatch in 60–70 days, and need to be in a temperature of 28–30 °C (82–86 °F). At birth, the young are about 20 to 25 centimeters (7.9 to 9.8 in) in length and are completely independent.

Venom

The venom of Naja nigricollis is somewhat unusual among elapids in that it consists primarily of cytotoxins, [17] but with other components also. It retains the typical elapid neurotoxic properties while combining these with highly potent cytotoxins (necrotic agents) [18] and cardiotoxins. [19] Bite symptoms include severe external hemorrhaging and tissue necrosis around the bite area and difficulty breathing. Although the mortality rate in untreated cases is low (~ 5–10%), [20] when death occurs, it is usually due to asphyxiation by paralysis of the diaphragm. The LD50 of Naja nigricollis is 2 mg/kg SC and 1.15 mg/kg IV. The average venom yield per bite of this species is 200 to 350 mg (dry weight) according to Minton (1974). [11] [21]

Snake venom ophthalmia

In 1944, English ophthalmic surgeon Major Harold Ridley, published a short paper in the British Journal of Ophthalmology on spitting snakes and an account of the composition and action of snake venom in general. From his experiences in wartime Ghana, Ridley described snake venom ophthalmia in a 30-year-old labourer, who was cutting grass when a Black-necked cobra spat venom toward the man's right eye from a four- or five-feet distance. Ridley treated the man and followed his case until the eye had fully recovered –after about a week. In conclusion, after discussion on the therapeutic uses of snake venom, he conjectured that the diluted venom or a constituent of it might be used as a powerful anaesthetic in some cases of ophthalmic surgery. [22]

Related Research Articles

<span class="mw-page-title-main">Spitting cobra</span> Common name for several snakes

A ”spitting” cobra is any of several species of cobra that can intentionally, defensively shoot their venom directly from their fangs. This substance has two functions, with the first being as venom that can be absorbed via the victim’s eyes, mouth, or nose, and secondly as a toxungen, which can be sprayed on the target surface. Their ability to target and shoot venom is utilised in several different ways, self-defense being the most common instance. Studies have shown that the targets are far from random; rather, spitting cobras consciously take aim, directing their spray as close as possible to the eyes and face of an aggressor.

<span class="mw-page-title-main">Indian cobra</span> Species of snake

The Indian cobra, also known commonly as the spectacled cobra, Asian cobra, or binocellate cobra, is a species of cobra, a venomous snake in the family Elapidae. The species is native to the Indian subcontinent, and is a member of the "big four" species that are responsible for the most snakebite cases in India.

<span class="mw-page-title-main">Monocled cobra</span> Species of snake

The monocled cobra, also called monocellate cobra and Indian spitting cobra, is a venomous cobra species widespread across South and Southeast Asia and listed as Least Concern on the IUCN Red List.

<span class="mw-page-title-main">Caspian cobra</span> Species of snake

The Caspian cobra, also called the Central Asian cobra or Russian cobra, is a species of highly venomous snake in the family Elapidae. The species is endemic to Central Asia. First described by Karl Eichwald, a German physician, in 1831, it was for many years considered to be a subspecies of the Naja naja until genetic analysis revealed it to be a distinct species.

<span class="mw-page-title-main">Cape cobra</span> Species of snake

The Cape cobra, also called the yellow cobra, is a moderate-sized, highly venomous species of cobra inhabiting a wide variety of biomes across southern Africa, including arid savanna, fynbos, bushveld, desert, and semidesert regions.

<span class="mw-page-title-main">Philippine cobra</span> Species of snake

The Philippine cobra also called Philippine spitting cobra or northern Philippine cobra, is a stocky, highly venomous species of spitting cobra native to the northern regions of the Philippines. The Philippine cobra is called ulupong in Tagalog, carasaen in Ilocano.

<i>Naja</i> Genus of snakes

Naja is a genus of venomous elapid snakes commonly known as cobras. Members of the genus Naja are the most widespread and the most widely recognized as "true" cobras. Various species occur in regions throughout Africa, Southwest Asia, South Asia, and Southeast Asia. Several other elapid species are also called "cobras", such as the king cobra and the rinkhals, but neither is a true cobra, in that they do not belong to the genus Naja, but instead each belong to monotypic genera Hemachatus and Ophiophagus.

<span class="mw-page-title-main">Many-banded snake</span> Species of snake

The many-banded snake, also known commonly as the burrowing cobra, is a species of venomous snake in the family Elapidae. The species is native to Central Africa. There are three recognized subspecies.

<span class="mw-page-title-main">Mozambique spitting cobra</span> Species of snake

The Mozambique spitting cobra is a highly venomous species of spitting cobra native to Africa. It is largely found in Angola, Botswana, Malawi, Mozambique, Namibia, South Africa, Tanzania, Zambia, and Zimbabwe.

<span class="mw-page-title-main">Red spitting cobra</span> Species of snake

The red spitting cobra is a species of spitting cobra native to Africa.

<span class="mw-page-title-main">Egyptian cobra</span> Species of reptile (snake)

The Egyptian cobra is one of the most venomous species of snakes in North Africa, and has caused many snakebite incidents to humans. It averages roughly 1.4 metres (4.6 ft), with the longest recorded specimen measuring 2.59 metres (8.5 ft).

<i>Naja ashei</i> Species of snake

Naja ashei, commonly known as Ashe's spitting cobra or the giant spitting cobra, is a species of venomous snake in the family Elapidae. The species is native to Africa. It is the world's largest species of spitting cobra.

<span class="mw-page-title-main">Indochinese spitting cobra</span> Species of snake

The Indochinese spitting cobra also called the Thai spitting cobra, black and white spitting cobra, Siamese spitting cobra, is a species of spitting cobra found in Southeast Asia.

<span class="mw-page-title-main">Goldie's tree cobra</span> Species of snake

Goldie's tree cobra, also known commonly as the African tree cobra and as Gold's tree cobra, is a species of venomous tree cobra in the family Elapidae. The species is native to Central and Western Africa. This species is one of the two tree cobras in Africa, the other being the black tree cobra. Goldie's tree cobra is one of the most venomous snakes and creatures in Africa.

<span class="mw-page-title-main">Forest cobra</span> Species of snake

The forest cobra, also commonly called the black cobra and the black and white-lipped cobra, is a species of highly venomous snake in the family Elapidae. The species is native to Africa, mostly the central and western parts of the continent. It is the largest true cobra species with a record length of 3.2 metres.

<span class="mw-page-title-main">Equatorial spitting cobra</span> Species of snake

The Equatorial spitting cobra also called the Malayan spitting cobra, golden spitting cobra, Sumatran spitting cobra, or Palawan spitting cobra, is a species of spitting cobra found in Southeast Asia.

<i>Naja nigricincta</i> Species of snake

Naja nigricincta is a species of spitting cobra in the genus Naja, belonging to the family Elapidae. The species is native to the deserts and drier regions of southern Africa. The species is largely nocturnal, and is often found while crossing roads at night. There are two recognized subspecies.

<span class="mw-page-title-main">Anchieta's cobra</span> Species of snake

Anchieta's cobra, sometimes referred to as the Angolan cobra, is a species of venomous snake in the family Elapidae. The species is native to Southern Africa.

<span class="mw-page-title-main">Javan spitting cobra</span> Species of snake

The Javan spitting cobra, also called Indonesian cobra or Komodo spitting cobra, is a species of cobra in the family Elapidae, found in the Lesser Sunda Islands of Indonesia, including Java, Bali, Lombok, Sumbawa, Flores, Komodo, and others.

References

  1. ↑ Jallow, M., Luiselli, L., Penner, J., Rödel, M.-O., Segniagbeto, G., Niagate, B., Spawls, S., Howell, K., Msuya, C.A. & Ngalason, W. 2021. Naja nigricollis. The IUCN Red List of Threatened Species 2021: e.T13265913A13265918. https://dx.doi.org/10.2305/IUCN.UK.2021-2.RLTS.T13265913A13265918.en. Downloaded on 22 September 2021.
  2. ↑ "Naja melanoleuca". Encyclopedia of Life. Retrieved 2014-03-22.
  3. ↑ "Naja melanoleuca". Integrated Taxonomic Information System . Retrieved 11 January 2014.
  4. ↑ "Naja nigricollis REINHARDT, 1843". Reptile Database. reptile-database.reptarium.cz. Retrieved 14 February 2012.
  5. ↑ Reinhardt, J; Andreas Johann Wagner; Franz Hermann Troschel; Wilhelm Ferdinand Erichson; Carl Ernst Siebold (1847). "Herpetology". In George Busk; Alfred Tulk; Alexander Henry Haliday (eds.). Reports on zoology for 1843, 1844. Ray Society.
  6. ↑ Wüster, W., S. Crookes, I. Ineich, Y. Mane, C. E. Pook, J.-F. Trape & D. G. Broadley (2007) "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: 437–453.
  7. ↑ Naja nigricincta at the Reptarium.cz Reptile Database . Accessed 29 December 2008.
  8. 1 2 Mastenbroek, Richard. "Black-neck Spitting Cobra" (PDF). DEVENOMIZED. www.devenomized.com. Archived from the original (PDF) on 25 April 2012. Retrieved 20 December 2011.
  9. 1 2 3 Abriol, Sabrina. "Spitting cobra (Naja nigricollis)" (PDF). Herpetology – Dr. Dever. University of San Francisco, California. Retrieved 21 December 2011.[ permanent dead link ]
  10. ↑ "Black-neck Spitting Cobra". Reptile Database. www.reptarium.cz. Retrieved 14 May 2012.
  11. 1 2 3 "Naja nigricollis – General Details, Taxonomy and Biology, Venom, Clinical Effects, Treatment, First Aid, Antivenoms". WCH Clinical Toxinology Resource. University of Adelaide. Retrieved 20 December 2011.
  12. ↑ Luiselli, Luca (2001). "The ghost of a recent invasion in the reduced feeding rates of spitting cobras during the dry season in a rainforest region of tropical Africa". Acta Oecologica. 22 (5): 311–314. Bibcode:2001AcO....22..311L. doi:10.1016/S1146-609X(01)01113-4.
  13. 1 2 Spawls, Stephen; Branch, Bill (1995). Dangerous Snakes of Africa. London, UK: Blandford Press. p. 91. ISBN   978-0-7137-2394-6.
  14. ↑ Bauchot, Roland (2006). Snakes: A Natural History. New York, USA: Sterling; illustrated edition. p. 176. ISBN   978-1-4027-3181-5.
  15. 1 2 FitzSimons, Vivian FM (1970). A field guide to the snakes of Southern Africa. Canada: HarperCollins. ISBN   978-0-00-212146-0.
  16. ↑ Engelmann, Wolf-Eberhard (1981). Snakes: Biology, Behavior, and Relationship to Man. Leipzig; English version NY, USA: Leipzig Publishing; English version published by Exeter Books (1982). pp.  71. ISBN   978-0-89673-110-3.
  17. ↑ Marais, Johan (2004). A Complete Guide to the Snakes of Southern Africa. Cape Town, South Africa: Struik Nature. ISBN   978-1-86872-932-6.
  18. ↑ Chaim-Matyas, Adina; Ovadia, Michael (20 April 1987). "Cytotoxic activity of various snake venoms on melanoma, B16F10 and chondrosarcoma". Life Sciences. 40 (16): 1601–1607. doi:10.1016/0024-3205(87)90126-3. PMID   3561167.
  19. ↑ Fryklund, Linda; Eaker, David (July 1975). "Complete covalent structure of a cardiotoxin from the venom of Naja nigricollis (African black-necked spitting cobra)". Biochemistry. 14 (13): 2865–2871. doi:10.1021/bi00684a012. PMID   1148181.
  20. ↑ Warrell, David A. "Snake bite" (PDF). Seminar. Lancet 2010 (volume 375, issue 1). Archived from the original (PDF) on 29 October 2013. Retrieved 20 December 2011.
  21. ↑ Thomas, Sean. "LD50 for various snakes". Australian Venom and Toxin database. www.seanthomas.com. Archived from the original on 1 February 2012. Retrieved 20 December 2011.
  22. ↑ Ridley, Harold (November 1944). "Snake Venom Ophthalmia". Br J Ophthalmol. 28 (11): 568–572. doi:10.1136/bjo.28.11.568. PMC   510436 . PMID   18170065.
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.