Western green mamba | |
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Scientific classification ![]() | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Reptilia |
Order: | Squamata |
Suborder: | Serpentes |
Family: | Elapidae |
Subfamily: | Elapinae |
Genus: | Dendroaspis |
Species: | D. viridis |
Binomial name | |
Dendroaspis viridis | |
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Dendroaspis viridis range | |
Synonyms [3] [4] | |
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The western green mamba (Dendroaspis viridis) 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.
The western green mamba is a shy and agile snake that lives mainly in the coastal tropical rainforest, thicket, and woodland regions of western Africa. Its venom is a highly potent mixture of rapid-acting presynaptic and postsynaptic neurotoxins (dendrotoxins), cardiotoxins and fasciculins. Some consider this species not to be a particularly aggressive snake, but others have suggested that they are extremely nervous and are prone to attack aggressively when cornered. Conflict with humans is low compared to some other species found in the region. Bites to people by this species are quite uncommon. Their mortality rate, however, is high; many of the recorded bites have been fatal. Rapid progression of severe, life-threatening symptoms are hallmarks of mamba bites. Bites with envenomation can be rapidly fatal.
The western green mamba was first described by the American herpetologist and physician Edward Hallowell in 1844 as Leptophis viridis, from a specimen collected in Liberia. [5] The specific name viridis is the Latin adjective "green". [6] In 1852, Hallowell described Dinophis hammondii from two specimens of western green mambas collected in Liberia, naming it for his friend Ogden Hammond of South Carolina. [7] These were later deemed by Belgian-British zoologist George Albert Boulenger to be the same species. [3]
The genus was misspelt as Dendraspis by Dumeril in 1856, and generally uncorrected by subsequent authors. In 1936, Dutch herpetologist Leo Brongersma pointed the correct spelling was Dendroaspis. [8] Analysis of the components of the venom of all mambas places the western green mamba as sister species to Jameson's mamba. [9] In addition to being called the western green mamba, this species is also commonly known as the West African green mamba, [10] and formerly Hallowell's green mamba. [11]
Analysis of the components of the venom of all mambas places the western green mamba sister to Jameson's mamba (Dendroapsis j. jamesoni and j. kaimosae), as shown in the cladogram below. [12]
The western green mamba has a long and slender body with a long tapering tail. The average length of an adult is between 1.4 metres (4.6 ft) and 2.1 metres (7 ft), with large approaching 2.4 metres (8 ft) long. [13] The long thin head has a distinct canthus above the medium-sized eyes, which have round pupils and yellowish brown irises. [14] When threatened or otherwise aroused, the western green mamba is capable of flattening its neck area into a slight hood. [15] The snake is bright green fading to yellow or orange towards the tail. Its scales have prominent black margins, giving the species a networked pattern. [16]
The western green mamba can be mistaken for similar species such as green bushsnakes of the genus Philothamnus or the boomslang (Dispholidus typus). [17]
The number and pattern of scales on a snake's body are a key element of identification to species level. [18] The western green mamba has 13 rows of long and thin dorsal scales at midbody, fewer than any similar species. Each is double the length of the ventral scales. There are 211 to 225 ventral scales, 105 to 128 divided subcaudal scales, and a divided anal scale. [lower-alpha 1] Its mouth is lined with 7 to 9 supralabial scales above, the fourth and sometimes fifth one located under the eye, and 9–10 sublabial scales below. [16]
The western green mamba is native to West Africa from Gambia and southern Senegal to Benin, including the intervening countries (from west to east) Guinea-Bissau, Guinea, Sierra Leone, Liberia, Côte d'Ivoire (Ivory Coast), Ghana, and Togo. [1] It is common in Togo, found as far north as the Alédjo Wildlife Reserve, though may theoretically be found in Sarakawa and Djamdé forests in the Kara Region. [20] Records from Nigeria are dubious, [1] and reports from the Central African Republic are more likely to be misidentification of Jameson's mamba. [21]
Western green mambas live mainly in the coastal tropical rainforest, thicket, and woodland regions of western Africa. [13] The majority of records of the western green mamba are from within the continuous forest, but the Gambia and Guinea-Bissau records are from isolated forests. The species persists in areas where the tree cover has been removed, providing that sufficient hedges and thicket remain. Found in some suitably vegetated suburbs and towns and parklands therein. [13] It is largely confined to areas where rainfall exceeds 1,500 millimetres (60 in). [22] In Togo, however, its range extends into the drier open forests of the north, the Guinean savannas of the west, and the littoral zone. [20]
This species is classified as Least Concern (LC) on the IUCN Red List of Threatened Species (v3.1, 2011). The conservation status of this species was last assessed in July 2012 and published in 2013, and it was classed as such due to a wide distribution, fairly generalist habits, stable population and the lack of major threats. However, its habitat and population is highly fragmented. [1] Despite not being listed in the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES), the western green mamba is collected and sold internationally, and is one of the more expensive African snake species. [23]
Mostly diurnal, the western green mamba spends most of its time in the forest canopy, at times at considerable height, though on occasion commonly go to the ground. When it wants to sleep it seeks out tree branches that offer dense cover. It generally retreats if encountered. [24] The oldest recorded western green mamba was a captive specimen that lived 18.7 years. [25]
The species lays a clutch of 6 to 14 eggs. [24]
The western green mamba generally hunts in trees though can also hunt on the ground. It preys on birds and small mammals, including rodents and squirrels. [24]
The western green mamba is classified as a snake of medical importance in western SubSaharan Africa by the World Health Organization, [lower-alpha 2] [26] although bites from this species are rare as it is rarely encountered. [13] When bitten, symptoms rapidly begin to manifest, usually within the first 15 minutes or less. The extraordinary speed with which the venom spreads through tissue and produces rapid manifestations of life-threatening symptoms is unique to mambas. Common symptoms of a bite from a western green mamba include local pain and swelling, although uncommon, local necrosis can be moderate, ataxia, headache, drowsiness, difficulty breathing, vertigo, hypotension (low blood pressure), diarrhea, dizziness, and paralysis. Left untreated, new and more severe symptoms rapidly progress. All symptoms worsen and the victim eventually dies due to suffocation resulting from paralysis of the respiratory muscles. Bites with envenomation can be rapidly fatal, which can be possible in 30 minutes. [14] [27]
Similar to the venom of most other mambas, the western green mamba's contains predominantly three-finger toxin agents. The exception is the black mamba, whose venom lacks the potent alpha-neurotoxin as well. It is thought this may reflect the species' preferred prey—small mammals for the mainly land-dwelling black mamba, versus birds for the other predominantly arboreal mambas. Unlike that of many snake species, the venom of mambas has little phospholipase A2. Overall, the venom of the western green mamba is more potent than that of the eastern green mamba, similar or slightly less potent than that of Jameson's mamba, and much less potent than that of the black mamba. [9]
The venom consists mainly of both pre-synaptic and post-synaptic neurotoxins, cardiotoxins, [27] and fasciculins. The toxicity of the venom can vary tremendously depending on various factors including diet, geographical location, age-dependent change, and other factors. The SC and IV LD50 for this species is 0.79 mg/kg and 0.71 mg/kg, respectively (Christensen and Anderson (1967)). [14] One study determined the LD50 of the venom administered to mice via the intraperitoneal (IP) route was 0.33 mg/kg. [28] In another test using mice that were administered the western green mamba's venom via the intraperitoneal (IP) route the LD50 was 0.045 mg/kg. [29] Another experimental IV LD50 toxicity of 0.5 mg/kg has been reported, with an average wet venom yield of 100 mg. [13] Like other mamba species, western green mamba venom is among the most rapid-acting venom of snakes. [30]
The speed of onset of envenomation means that urgent medical attention is needed. [24] Standard first aid treatment for any bite from a suspectedly venomous snake is the application of a pressure bandage, minimisation of the victim's movement, and rapid conveyance to a hospital or clinic. Due to the neurotoxic nature of green mamba venom, an arterial tourniquet may be beneficial. [31] Tetanus toxoid is sometimes administered, though the main treatment is the administration of the appropriate antivenom. [32]
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.
Mambas are fast-moving, highly venomous snakes of the genus Dendroaspis 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.
Acanthophis is a genus of elapid snakes. Commonly called death adders, they are native to Australia, New Guinea and nearby islands, and are among the most venomous snakes in the world. Despite their common name, they are not adders at all and belong to the Elapidae family. The name of the genus derives from the Ancient Greek akanthos/ἄκανθος ('spine') and ophis/ὄφις ('snake'), referring to the spine on the death adder's tail.
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 boomslang is a highly venomous snake in the family Colubridae. The species is native to Sub-Saharan Africa.
The inland taipan, also commonly known as the western taipan, small-scaled snake, or fierce snake, is a species of extremely venomous snake in the family Elapidae. The species is endemic to semiarid regions of central east Australia. Aboriginal Australians living in those regions named the snake dandarabilla. It was formally described by Frederick McCoy in 1879 and then by William John Macleay in 1882, but for the next 90 years, it was a mystery to the scientific community; no further specimens were found, and virtually nothing was added to the knowledge of this species until its rediscovery in 1972.
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, but rather describes 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 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 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.
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.
Micrurus fulvius, commonly known as the eastern coral snake, common coral snake, American cobra, and more, is a species of highly venomous coral snake in the family Elapidae.The Elapidae family also contains the cobras and sea snakes. The species is endemic to the southeastern United States. It should not be confused with the scarlet snake or scarlet kingsnake, which are harmless mimics. No subspecies are currently recognized.
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.
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.
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.
Naja christyi, commonly known as the Congo water cobra or Christy's water cobra, is a species of venomous snakes belonging to the family Elapidae. The species is native to Sub-Saharan Africa.
Aspidelaps lubricus, commonly known as the Cape coral snake, Cape coral cobra or coral shield cobra, is a species of venomous snake in the family Elapidae. The species is endemic to southern Africa.
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