Mamba

Mamba
	Black mamba
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Reptilia
Order:	Squamata
Suborder:	Serpentes
Family:	Elapidae
Subfamily:	Elapinae
Genus:	Dendroaspis ; Schlegel, 1848
Species
	Dendroaspis angusticeps ; Dendroaspis jamesoni ; Dendroaspis polylepis ; Dendroaspis viridis ;
	D. polylepis D. angusticeps D. viridis

Last updated September 27, 2024

Mambas are fast-moving, highly venomous snakes of the genus Dendroaspis (which literally means "tree asp") in the family Elapidae. Four extant species are recognised currently; three of those four species are essentially arboreal and green in colour, whereas the black mamba, Dendroaspis polylepis, is largely terrestrial and generally brown or grey in colour. All are native to various regions in sub-Saharan Africa and all are feared throughout their ranges, especially the black mamba. In Africa there are many legends and stories about mambas.^[2]^[3]^[4]

Behaviour

The three green species of mambas are arboreal, whereas the black mamba is largely terrestrial. All four species are active diurnal hunters, preying on birds, lizards, and small mammals. At nightfall some species, especially the terrestrial black mamba, shelter in a lair. A mamba may retain the same lair for years. Resembling a cobra, the threat display of a mamba includes rearing, opening the mouth and hissing. The black mamba's mouth is black within, which renders the threat more conspicuous. A rearing mamba has a narrower yet longer hood and tends to lean well forward, instead of standing erect as a cobra does.

Stories of black mambas that chase and attack humans are common, but in fact the snakes generally avoid contact with humans.^[5] The black mamba (Dendroaspis polylepis) is a highly venomous snake species native to various parts of sub-Saharan Africa. Black mambas are fast-moving, nervous snakes that will strike when threatened. According to findings by Branch (2016), their venom comprises neurotoxins and cardiotoxins that can rapidly induce symptoms, including dizziness, extreme fatigue, vision problems, foaming at the mouth, paralysis, convulsions, and eventual death from respiratory or cardiac failure if untreated. Although black mamba venom is highly toxic, antivenom is available and can treat envenomation promptly.

Most apparent cases of pursuit probably are examples of where witnesses have mistaken the snake's attempt to retreat to its lair when a human happens to be in the way.^[6] The black mamba usually uses its speed to escape from threats, and humans actually are their main predators, rather than prey.^[2]

Venom

All mambas have medically significant venom, with dendrotoxins, short chain alpha-neurotoxins, cardiotoxins and fasciculins.^[7]^[2]^[8] All mambas are classified as snakes of medical importance by the World Health Organization.^[9]^{[lower-alpha 1]}

There are multiple components in dendrotoxins with different targets:

Dendrotoxin 1, which inhibits the K⁺ channels at the pre and post-synaptic level in the intestinal smooth muscle. It also inhibits Ca²⁺-sensitive K⁺ channels from rat skeletal muscle‚ incorporated into planar bilayers (Kd = 90 nM in 50 mM KCl).^[10])
Dendrotoxin 3, which inhibits acetylcholine M4 receptors.^[11]
Dendrotoxin 7, commonly referred to as muscarinic toxin 7 (MT7) inhibits acetylcholine M1 receptors.^[11]
Dendrotoxin K, structurally homologous to Kunitz-type proteinase inhibitors^[12] with activity as a selective blocker of voltage-gated potassium channels^[13]

Toxicity alone does not determine severity of envenomation; other factors include the snake's temperament, venom yields, proximity of wounds to the CNS and depth of punctures.^[14] Bites by all members of this genus are capable of causing rapid onsets of symptoms, but it is the black mamba whose bite has the worst prognosis, possibly as a result of its more terrestrial nature (having more potential for human contact), high defensiveness (having a higher possibility to deliver fatal bites instead of dry bites), large size (giving it a higher strike position proximal to the victim's brain), and higher average venom yields and potential toxicity (based on experimental results).^[15]^[16] A lethality rate of near 100% for untreated black mamba bites has been circulating between various sources,^[16] which is probably based on a single medical record made in a single district between 1957 and 1963 when specific antivenom had yet to be introduced. Seven out of seven victims of this species who received non-specific polyvalent antivenom, that had no effect on the species' toxins, succumbed to its bites.^[5] However, another snakebite survey in South Africa reported a death rate of approximately 43% among those who received ineffective treatments (15 fatal cases out of 35 patients).^[17] A mamba-specific antivenom was introduced in 1962, followed by a fully polyvalent antivenom in 1971; over this period, 5 out of 38 people in South Africa bitten by black mambas who received the antivenom died, according to the same report.^[17] Since then, the number has significantly dropped with the widespread use of specific antivenom.^[18]^[17]

Despite their fearsome reputation and often exaggerated notoriety, mamba envenomation occurs far less frequently than some other snakes', for instance the puff adder.^[16]^[5] Besides proximity to residences, behaviour of a given species is also a critical aspect when it comes to snakebite morbidities. Mambas are agile, usually fleeing from any confrontation with unambiguous threat display which allows early recognition of the serpent, avoiding escalation in tension.^[17]

Taxonomy

Dendroaspis, is derived from Ancient Greek déndron (δένδρον), meaning "tree",^[19] and aspis (ασπίς), which is understood to mean "shield",^[20] but also denotes "cobra" or simply "snake", in particular "snake with hood (shield)". Via Latin aspis, it is the source of the English word "asp". In ancient texts, aspis or asp often referred to the Egyptian cobra (Naja haje), in reference to its shield-like hood.^[21] The genus was first described by the German naturalist Hermann Schlegel in 1848,^[22] with Elaps jamesonii as the type species. It was misspelt as Dendraspis by Dumeril in 1856, and generally uncorrected by subsequent authors. In 1936, Dutch herpetologist Leo Brongersma pointed out that the correct spelling was Dendroaspis but added that the name was invalid as Fitzinger had coined Dendraspis in 1843 for the king cobra and hence had priority.^[23] However, in 1962 German herpetologist Robert Mertens proposed that the 1843 description of Dendraspis by Fitzinger be suppressed due to its similarity to Dendroaspis, and the confusion it would cause by its use.^[24]

Range and characteristics

Black mambas live in the savannas and rocky hills of southern and eastern Africa. They are Africa's longest venomous snake, reaching up to 14 feet in length, although 8.2 feet is more the average. They are also among the fastest snakes in the world, slithering at speeds of up to 12.5 miles per hour.^[2]^[6]

Species^[25]	Authority^[25]^{[lower-alpha 2]}	Subsp.*^[25]	Common name	Geographic range
Dendroaspis angusticeps	(Smith, 1849)	0	Eastern green mamba	Found in Kenya, Tanzania, Malawi, Mozambique, Zimbabwe, Eswatini, eastern South Africa
Dendroaspis jamesoni ^T	(Traill, 1843)	2	Jameson's mamba	Found in Central Africa in South Sudan, Gabon, Angola, Zambia, Republic of the Congo, Democratic Republic of the Congo, Cameroon, Equatorial Guinea, Nigeria, Kenya, Uganda, Rwanda, Burundi, Tanzania, Central African Republic, Benin, Togo, Ghana
Dendroaspis polylepis	Günther, 1864	0	Black mamba	Found in northern Central Africa to eastern Africa and southern Africa in Cameroon, northern Republic of the Congo, Central African Republic, northeast Democratic Republic of the Congo, and southwestern Sudan to Ethiopia, Eritrea, Djibouti, Somalia, Kenya, eastern Uganda, Rwanda, Burundi, Tanzania, southwards to Mozambique, Eswatini, Malawi, Zambia, Zimbabwe, Lesotho, and Botswana to KwaZulu-Natal in South Africa, and Namibia; then northeasterly through Angola to the southeastern part of the Democratic Republic of Congo
Dendroaspis viridis	(Hallowell, 1844)	0	Western green mamba	Found only in western Africa in southern Senegal, Gambia, Guinea-Bissau, Guinea, Sierra Leone, Liberia, Côte d’Ivoire, Ghana, Togo, Benin, and southwest Nigeria

* Including the nominate subspecies.
^T Type species.

Phylogeny

A 2018 analysis of the venom of the mambas, as well as a 2016 genetic analysis, found the following cladogram representative of the relationship between the species.^[26]^[27]

	Ophiophagus hannah

	D. j. jamesoni

	D. j. kaimosae

D. viridis

	D. angusticeps

	D. polylepis

Notes

↑ Snakes of medical importance include those with highly dangerous venom resulting in high rates of morbidity and mortality, or those that are common agents in snakebite.^[9]
↑ A binomial authority in parentheses indicates that the species was originally described in a genus other than Dendroaspis.

Related Research Articles

The king cobra is a venomous snake endemic to Asia. The sole member of the genus Ophiophagus, it is not taxonomically a true cobra, despite its common name and some resemblance. With an average length of 3.18 to 4 m and a record length of 5.85 m (19.2 ft), it is the world's longest venomous snake. The species has diversified colouration across habitats, from black with white stripes to unbroken brownish grey. The king cobra is widely distributed albeit not commonly seen, with a range spanning from the Indian Subcontinent through Southeastern Asia to Southern China. It preys chiefly on other snakes, including those of its own kind. This is the only ophidian that constructs an above-ground nest for its eggs, which are purposefully and meticulously gathered and protected by the female throughout the incubation period.

Antivenom, also known as antivenin, venom antiserum, and antivenom immunoglobulin, is a specific treatment for envenomation. It is composed of antibodies and used to treat certain venomous bites and stings. Antivenoms are recommended only if there is significant toxicity or a high risk of toxicity. The specific antivenom needed depends on the species involved. It is given by injection.

<span class="mw-page-title-main">Elapidae</span> Family of venomous snakes

Elapidae is a family of snakes characterized by their permanently erect fangs at the front of the mouth. Most elapids are venomous, with the exception of the genus Emydocephalus. Many members of this family exhibit a threat display of rearing upwards while spreading out a neck flap. Elapids are endemic to tropical and subtropical regions around the world, with terrestrial forms in Asia, Australia, Africa, and the Americas and marine forms in the Pacific and Indian Oceans. Members of the family have a wide range of sizes, from the 18 cm (7.1 in) white-lipped snake to the 5.85 m king cobra. Most species have neurotoxic venom that is channeled by their hollow fangs, and some may contain other toxic components in varying proportions. The family includes 55 genera with around 360 species and over 170 subspecies.

A snakebite is an injury caused by the bite of a snake, especially a venomous snake. A common sign of a bite from a venomous snake is the presence of two puncture wounds from the animal's fangs. Sometimes venom injection from the bite may occur. This may result in redness, swelling, and severe pain at the area, which may take up to an hour to appear. Vomiting, blurred vision, tingling of the limbs, and sweating may result. Most bites are on the hands, arms, or legs. Fear following a bite is common with symptoms of a racing heart and feeling faint. The venom may cause bleeding, kidney failure, a severe allergic reaction, tissue death around the bite, or breathing problems. Bites may result in the loss of a limb or other chronic problems or even death.

Snake venom is a highly toxic saliva containing zootoxins that facilitates in the immobilization and digestion of prey. This also provides defense against threats. Snake venom is usually injected by unique fangs during a bite, though some species are also able to spit venom.

The black mamba is a species of highly venomous snake belonging to the family Elapidae. It is native to parts of sub-Saharan Africa. First formally described by Albert Günther in 1864, it is the second-longest venomous snake after the king cobra; mature specimens generally exceed 2 m and commonly grow to 3 m (9.8 ft). Specimens of 4.3 to 4.5 m have been reported. Its skin colour varies from grey to dark brown. Juvenile black mambas tend to be paler than adults and darken with age. Despite the common name, the skin of a black mamba is not black; the color name describes rather the inside of its mouth, which it displays when feeling threatened.

The eastern green mamba is a highly venomous snake species of the mamba genus Dendroaspis native to the coastal regions of southern East Africa. Described by Scottish surgeon and zoologist Andrew Smith in 1849, it has a slender build with a bright green back and green-yellow ventral scales. Adult females average around 2 metres in length, and males are slightly smaller.

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.

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.

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.

The western green mamba is a long, thin, and highly venomous snake species of the mamba genus, Dendroaspis. This species was first described in 1844 by American herpetologist Edward Hallowell. The western green mamba is a fairly large and predominantly arboreal species, capable of navigating through trees swiftly and gracefully. It will also descend to ground level to pursue prey such as rodents and other small mammals.

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.

α-Bungarotoxin is one of the bungarotoxins, components of the venom of the elapid Taiwanese banded krait snake. It is a type of α-neurotoxin, a neurotoxic protein that is known to bind competitively and in a relatively irreversible manner to the nicotinic acetylcholine receptor found at the neuromuscular junction, causing paralysis, respiratory failure, and death in the victim. It has also been shown to play an antagonistic role in the binding of the α7 nicotinic acetylcholine receptor in the brain, and as such has numerous applications in neuroscience research.

<span class="mw-page-title-main">Calciseptine</span> Neurotoxin

Calciseptine (CaS) is a natural neurotoxin isolated from the black mamba Dendroaspis p. polylepis venom. This toxin consists of 60 amino acids with four disulfide bonds. Calciseptine specifically blocks L-type calcium channels, but not other voltage-dependent Ca²⁺ channels such as N-type and T-type channels.

The coastal taipan, or common taipan, is a species of extremely venomous snake in the family Elapidae. Described by Wilhelm Peters in 1867, the species is native to the coastal regions of northern and eastern Australia and the island of New Guinea. The second-longest venomous snake in Australia, the coastal taipan averages around 2.0 m (6.6 ft) long, with the longest specimens reaching 2.9 m (9.5 ft) in length. It has light olive or reddish-brown upperparts, with paler underparts. The snake is considered to be a least-concern species according to the International Union for Conservation of Nature.

Jameson's mamba is a species of highly venomous snake in the family Elapidae. The species is native to equatorial Africa. A member of the mamba genus, Dendroaspis, it is slender with dull green upper parts and cream underparts and generally ranges from 1.5 to 2.2 m in total length. Described by Scottish naturalist Thomas Traill in 1843, it has two recognised subspecies. The nominate subspecies is found in central and western sub-Saharan Africa, and the eastern black-tailed subspecies is found eastern sub-Saharan Africa, mainly western Kenya.

The Papuan black snake is a highly venomous snake of the family Elapidae native to New Guinea. Reaching around 2 m in length, it is a predominantly black snake coloured grey underneath.

Most snakebites are caused by non-venomous snakes. Of the roughly 3,700 known species of snake found worldwide, only 15% are considered dangerous to humans. Snakes are found on every continent except Antarctica. There are two major families of venomous snakes, Elapidae and Viperidae. 325 species in 61 genera are recognized in the family Elapidae and 224 species in 22 genera are recognized in the family Viperidae, In addition, the most diverse and widely distributed snake family, the colubrids, has approximately 700 venomous species, but only five genera—boomslangs, twig snakes, keelback snakes, green snakes, and slender snakes—have caused human fatalities.

References

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↑ Jan Knappert (1 January 1985). Myths and Legends of Botswana, Lesotho, and Eswatini. Brill Archive. pp. 53–. ISBN 90-04-07455-4.
↑ Alfred Burdon Ellis (1887). South African Sketches. Chapman and Hall, Limited. also at:
1 2 3 O'Shea, Mark (2005). VENOMOUS SNAKES OF THE WORLD. multiple places: US and Canada: Princeton University Press; Europe: New Holland (UK) Ltd. pp. 78–79. ISBN 978-0-691-15023-9. ...in common with other snakes they prefer to avoid contact;...Of the three species of green mambas...;...from 1957 to 1963...including all seven black mamba bites - a 100 per cent fatality rate
1 2 The new encyclopedia of Reptiles (Serpent). Time Book Ltd. 2002.
↑ "Neurotoxins in Snake Venom" . Retrieved 2019-12-26.
↑ van Aswegen G, van Rooyen JM, Fourie C, Oberholzer G (May 1996). "Putative cardiotoxicity of the venoms of three mamba species". Wilderness & Environmental Medicine. 7 (2): 115–21. doi: 10.1580/1080-6032(1996)007[0115:PCOTVO]2.3.CO;2 . PMID 11990104.
1 2 WHO Expert Committee on Biological Standardization. "Guidelines for the production, control and regulation of snake antivenom immunoglobulins" (PDF). WHO Technical Report Series, No. 964. pp. 224–226. Retrieved 1 January 2019.
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↑ Harvey AL, Robertson B (2004). "Dendrotoxins: structure-activity relationships and effects on potassium ion channels". Curr. Med. Chem. 11 (23): 3065–72. doi:10.2174/0929867043363820. PMID 15579000.
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↑ Séan Thomas & Eugene Griessel – Dec 1999. "LD50 (Archived)". Archived from the original on 1 February 2012.{{cite web}}: CS1 maint: numeric names: authors list (link)
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↑ Nhachi, Charles FB; Kasilo, Ossy M. (1994). "Snake poisoning in rural Zimbabwe – A prospective study". Journal of Applied Toxicology . 14 (3): 191–193. doi:10.1002/jat.2550140308. PMID 8083480. S2CID 40171925.
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↑ "Definition of "aspis" - Collins English Dictionary". collinsdictionary.com. Retrieved 15 February 2015.
↑ "aspis, asp". Dictionary.com Unabridged. Random House. Retrieved 4 March 2014.
↑ "Dendroaspis". Integrated Taxonomic Information System . Retrieved 9 December 2013.
↑ Brongersma, Leo Daniel (1936). "Herpetological note XIII". Zoo. Mededeel. 19: 135.
↑ Mertens, Robert (1962). "Dendraspis Fitzinger, 1843 (Reptilia, Serpentes); Proposed Suppression under the Plenary Powers. Z.N. (S.) 1500" (PDF). Bulletin of Zoological Nomenclature. 19: 189–190.
1 2 3 "Dendroaspis". Integrated Taxonomic Information System. Archived from the original on 12 March 2009. Retrieved 5 July 2013.
↑ Ainsworth, Stuart; Petras, Daniel; Engmark, Mikael; Süssmuth, Roderich D.; Whiteley, Gareth; Albulescu, Laura-Oana; Kazandjian, Taline D.; Wagstaff, Simon C.; Rowley, Paul; Wüster, Wolfgang; Dorrestein, Pieter C.; Arias, Ana Silvia; Gutiérrez, José M.; Harrison, Robert A.; Casewell, Nicholas R.; Calvete, Juan J. (2018). "The medical threat of mamba envenoming in sub-Saharan Africa revealed by genus-wide analysis of venom composition, toxicity and antivenomics profiling of available antivenoms". Journal of Proteomics . 172: 173–189. doi:10.1016/j.jprot.2017.08.016. hdl: 10261/279110 . PMID 28843532. S2CID 217018550.
↑ Figueroa, A.; McKelvy, A. D.; Grismer, L. L.; Bell, C. D.; Lailvaux, S. P. (2016). "A species-level phylogeny of extant snakes with description of a new colubrid subfamily and genus". PLOS ONE. 11 (9): e0161070. Bibcode:2016PLoSO..1161070F. doi: 10.1371/journal.pone.0161070 . PMC 5014348 . PMID 27603205.