115-596: The black mamba ( Dendroaspis polylepis ) 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 (6 ft 7 in) and commonly grow to 3 m (9.8 ft). Specimens of 4.3 to 4.5 m (14 to 15 ft) 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
230-423: A mutation–selection balance . It is predicted that a viral quasispecies at a low but evolutionarily neutral and highly connected (that is, flat) region in the fitness landscape will outcompete a quasispecies located at a higher but narrower fitness peak in which the surrounding mutants are unfit, "the quasispecies effect" or the "survival of the flattest". There is no suggestion that a viral quasispecies resembles
345-480: A polyvalent antivenom that had no effect on black mamba venom, and 15 of 35 people who received the antivenom died. A mamba-specific antivenom was introduced in 1962, followed by a fully polyvalent antivenom in 1971. Over this period, 5 of 38 people bitten by black mambas and given antivenom died. A census in rural Zimbabwe in 1991 and 1992 revealed 274 cases of snakebite, of which 5 died. Black mambas were confirmed in 15 cases, of which 2 died. The peak period for deaths
460-408: A threat display , the black mamba usually opens its inky-black mouth, spreads its narrow neck-flap and sometimes hisses. It is capable of striking at considerable range and may deliver a series of bites in rapid succession. Its venom is primarily composed of neurotoxins that often induce symptoms within ten minutes, and is frequently fatal unless antivenom is administered. Despite its reputation as
575-400: A "classical" method of determining species, such as with Linnaeus, early in evolutionary theory. However, different phenotypes are not necessarily different species (e.g. a four-winged Drosophila born to a two-winged mother is not a different species). Species named in this manner are called morphospecies . In the 1970s, Robert R. Sokal , Theodore J. Crovello and Peter Sneath proposed
690-424: A 'smallest clade' idea" (a phylogenetic species concept). Mishler and Wilkins and others concur with this approach, even though this would raise difficulties in biological nomenclature. Wilkins cited the ichthyologist Charles Tate Regan 's early 20th century remark that "a species is whatever a suitably qualified biologist chooses to call a species". Wilkins noted that the philosopher Philip Kitcher called this
805-413: A black mamba can cause collapse in humans within 45 minutes. Without appropriate antivenom treatment, symptoms typically progress to respiratory failure , which leads to cardiovascular collapse and death. This typically occurs in 7 to 15 hours. In 2015, the proteome (complete protein profile) of black mamba venom was assessed and published, revealing 41 distinct proteins and one nucleoside . The venom
920-593: A black tail, while central and western examples typically have a pale green or yellow tail. The thin fangs are attached to the upper jaw and have a furrow running down their anterior surface. The number and pattern of scales on a snake's body play a key role in the identification and differentiation at the species level. Jameson's mamba has between 15 and 17 rows of dorsal scales at midbody, 210 to 236 ( Subsp. ) jamesoni ) or 202 to 227 ventral scales ( Subsp. kaimosae ), 94 to 122 ( Subsp. jamesoni ) or 94 to 113 ( Subsp. kaimosae ) divided subcaudal scales, and
1035-440: A child dying within 30 minutes. With an average intravenous murine median lethal dose (LD 50 ) of 0.53 mg/kg, the venom of the eastern subspecies kaimosae is more than twice as potent as that of the nominate subspecies jamesoni at 1.2 mg/kg. The reason for this is unclear as the venom compositions are similar between the two subspecies, though kaimosae has higher concentrations of the potent neurotoxin-1. Similarly to
1150-428: A connected series of neighbouring populations, each of which can sexually interbreed with adjacent related populations, but for which there exist at least two "end" populations in the series, which are too distantly related to interbreed, though there is a potential gene flow between each "linked" population. Such non-breeding, though genetically connected, "end" populations may co-exist in the same region thus closing
1265-432: A different species from its ancestors. Viruses have enormous populations, are doubtfully living since they consist of little more than a string of DNA or RNA in a protein coat, and mutate rapidly. All of these factors make conventional species concepts largely inapplicable. A viral quasispecies is a group of genotypes related by similar mutations, competing within a highly mutagenic environment, and hence governed by
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#17327979118451380-502: A divided anal scale . Its mouth is lined with 7 to 9 (usually 8) supralabial scales above and 8 to 10 (usually 9) sublabial scales below, the fourth ones located over and under the eye. Its eyes have three preocular , three postocular and one subocular scale. Jameson's mamba occurs mostly in Central Africa and West Africa , and in some parts of East Africa . In Central Africa it can be found from Angola northwards to
1495-510: A formidable and highly aggressive species, the black mamba attacks humans only if it is threatened or cornered. It is rated as least concern on the International Union for Conservation of Nature (IUCN)'s Red List of Threatened Species . The first formal description of the black mamba was made in 1864 by German-born British zoologist Albert Günther . A single specimen was one of many species of snake collected by John Kirk ,
1610-508: A genetic boundary suitable for defining a species concept is present. DNA barcoding has been proposed as a way to distinguish species suitable even for non-specialists to use. One of the barcodes is a region of mitochondrial DNA within the gene for cytochrome c oxidase . A database, Barcode of Life Data System , contains DNA barcode sequences from over 190,000 species. However, scientists such as Rob DeSalle have expressed concern that classical taxonomy and DNA barcoding, which they consider
1725-465: A lineage should be divided into multiple chronospecies , or when populations have diverged to have enough distinct character states to be described as cladistic species. Species and higher taxa were seen from the time of Aristotle until the 18th century as categories that could be arranged in a hierarchy, the great chain of being . In the 19th century, biologists grasped that species could evolve given sufficient time. Charles Darwin 's 1859 book On
1840-492: A misnomer, need to be reconciled, as they delimit species differently. Genetic introgression mediated by endosymbionts and other vectors can further make barcodes ineffective in the identification of species. A phylogenetic or cladistic species is "the smallest aggregation of populations (sexual) or lineages (asexual) diagnosable by a unique combination of character states in comparable individuals (semaphoronts)". The empirical basis – observed character states – provides
1955-676: A naturalist who accompanied David Livingstone on the 1858–1864 Second Zambesi expedition . This specimen is the holotype and is housed in the Natural History Museum, London . The generic name of the species is derived from the Ancient Greek words dendron ( δένδρον ), "tree", and aspis ( ἀσπίς ) " asp ", and the specific epithet polylepis is derived from the Ancient Greek poly ( πολύ ) meaning "many" and lepis ( λεπίς ) meaning "scale". The term "mamba"
2070-449: A particular species, including which genus (and higher taxa) it is placed in, is a hypothesis about the evolutionary relationships and distinguishability of that group of organisms. As further information comes to hand, the hypothesis may be corroborated or refuted. Sometimes, especially in the past when communication was more difficult, taxonomists working in isolation have given two distinct names to individual organisms later identified as
2185-400: A perfect model of life, it is still a useful tool to scientists and conservationists for studying life on Earth, regardless of the theoretical difficulties. If species were fixed and clearly distinct from one another, there would be no problem, but evolutionary processes cause species to change. This obliges taxonomists to decide, for example, when enough change has occurred to declare that
2300-431: 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. Tetanus toxoid is sometimes administered, though the main treatment is the administration of the appropriate antivenom. Trivalent and monovalent antivenoms for the black, eastern green, and Jameson's mambas became available in
2415-569: A purplish sheen. Individuals occasionally display dark mottling towards the posterior, which may appear in the form of diagonal crossbands. Black mambas have greyish-white underbellies. The common name is derived from the appearance of the inside of the mouth, dark bluish-grey to nearly black. Mamba eyes range between greyish-brown and shades of black; the pupil is surrounded by a silvery-white or yellow colour. Juvenile snakes are lighter in colour than adults; these are typically grey or olive green and darken as they age. The number and pattern of scales on
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#17327979118452530-400: A short way of saying that something applies to many species within a genus, but not to all. If scientists mean that something applies to all species within a genus, they use the genus name without the specific name or epithet. The names of genera and species are usually printed in italics . However, abbreviations such as "sp." should not be italicised. When a species' identity is not clear,
2645-500: A snake's body are a key element of identification to species level. The black mamba has between 23 and 25 rows of dorsal scales at midbody, 248 to 281 ventral scales, 109 to 132 divided subcaudal scales , and a divided anal scale . Its mouth is lined with 7–8 supralabial scales above, with the fourth and sometimes also the third one located under the eye, and 10-14 sublabial scales below. Its eyes have 3 or occasionally 4 preocular and 2–5 postocular scales . The black mamba inhabits
2760-404: A specialist may use "cf." before the epithet to indicate that confirmation is required. The abbreviations "nr." (near) or "aff." (affine) may be used when the identity is unclear but when the species appears to be similar to the species mentioned after. With the rise of online databases, codes have been devised to provide identifiers for species that are already defined, including: The naming of
2875-523: A species as groups of actually or potentially interbreeding natural populations, which are reproductively isolated from other such groups. It has been argued that this definition is a natural consequence of the effect of sexual reproduction on the dynamics of natural selection. Mayr's use of the adjective "potentially" has been a point of debate; some interpretations exclude unusual or artificial matings that occur only in captivity, or that involve animals capable of mating but that do not normally do so in
2990-400: A species as determined by a taxonomist. A typological species is a group of organisms in which individuals conform to certain fixed properties (a type), so that even pre-literate people often recognise the same taxon as do modern taxonomists. The clusters of variations or phenotypes within specimens (such as longer or shorter tails) would differentiate the species. This method was used as
3105-491: A species. All species definitions assume that an organism acquires its genes from one or two parents very like the "daughter" organism, but that is not what happens in HGT. There is strong evidence of HGT between very dissimilar groups of prokaryotes , and at least occasionally between dissimilar groups of eukaryotes , including some crustaceans and echinoderms . The evolutionary biologist James Mallet concludes that there
3220-685: A species. Generally the term includes the unknown element of a distinct act of creation. Many authors have argued that a simple textbook definition, following Mayr's concept, works well for most multi-celled organisms , but breaks down in several situations: Species identification is made difficult by discordance between molecular and morphological investigations; these can be categorised as two types: (i) one morphology, multiple lineages (e.g. morphological convergence , cryptic species ) and (ii) one lineage, multiple morphologies (e.g. phenotypic plasticity , multiple life-cycle stages). In addition, horizontal gene transfer (HGT) makes it difficult to define
3335-441: A study of seven black mambas found an average weight of 1.03 kg (2.3 lb), ranging from 520 g (18 oz) for a specimen of 1.01 m (3 ft 4 in) total length to 2.4 kg (5.3 lb) for a specimen of 2.57 m (8 ft 5 in) total length. Specimens vary considerably in colour, including olive, yellowish-brown, khaki and gunmetal but are rarely black. The scales of some individuals may have
3450-462: A tail which typically accounts for 20 to 25% of its total length. The total length (including tail) of an adult snake is approximately 1.5–2.2 m (4 ft 11 in – 7 ft 3 in). It may grow as large as 2.64 m (8 ft 8 in). The general consensus is that the sexes are of similar sizes, although fieldwork in southeastern Nigeria found that males were significantly larger than females. Adults tend to be dull green across
3565-528: A taxonomic decision at the discretion of cognizant specialists, is not governed by the Codes of Zoological or Botanical Nomenclature, in contrast to the PhyloCode , and contrary to what is done in several other fields, in which the definitions of technical terms, like geochronological units and geopolitical entities, are explicitly delimited. The nomenclatural codes that guide the naming of species, including
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3680-517: A traditional biological species. The International Committee on Taxonomy of Viruses has since 1962 developed a universal taxonomic scheme for viruses; this has stabilised viral taxonomy. Most modern textbooks make use of Ernst Mayr 's 1942 definition, known as the Biological Species Concept as a basis for further discussion on the definition of species. It is also called a reproductive or isolation concept. This defines
3795-447: A variation on the morphological species concept, a phenetic species, defined as a set of organisms with a similar phenotype to each other, but a different phenotype from other sets of organisms. It differs from the morphological species concept in including a numerical measure of distance or similarity to cluster entities based on multivariate comparisons of a reasonably large number of phenotypic traits. A mate-recognition species
3910-515: A variety of reasons. Viruses are a special case, driven by a balance of mutation and selection , and can be treated as quasispecies . Biologists and taxonomists have made many attempts to define species, beginning from morphology and moving towards genetics . Early taxonomists such as Linnaeus had no option but to describe what they saw: this was later formalised as the typological or morphological species concept. Ernst Mayr emphasised reproductive isolation, but this, like other species concepts,
4025-495: A wide range in sub-Saharan Africa ; its range includes Burkina Faso , Cameroon , Central African Republic , Democratic Republic of the Congo , South Sudan , Ethiopia , Eritrea , Somalia , Kenya , Uganda , Tanzania , Burundi , Rwanda , Mozambique , Eswatini , Malawi , Zambia , Zimbabwe , Botswana , South Africa , Namibia , and Angola . The black mamba's distribution in parts of West Africa has been disputed. In 1954,
4140-438: Is "an entity composed of organisms which maintains its identity from other such entities through time and over space, and which has its own independent evolutionary fate and historical tendencies". This differs from the biological species concept in embodying persistence over time. Wiley and Mayden stated that they see the evolutionary species concept as "identical" to Willi Hennig 's species-as-lineages concept, and asserted that
4255-430: 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 (4.9 to 7.2 ft) in total length. Described by Scottish naturalist Thomas Traill in 1843, it has two recognised subspecies . The nominate subspecies
4370-400: Is a group of sexually reproducing organisms that recognise one another as potential mates. Expanding on this to allow for post-mating isolation, a cohesion species is the most inclusive population of individuals having the potential for phenotypic cohesion through intrinsic cohesion mechanisms; no matter whether populations can hybridise successfully, they are still distinct cohesion species if
4485-458: Is a set of organisms adapted to a particular set of resources, called a niche, in the environment. According to this concept, populations form the discrete phenetic clusters that we recognise as species because the ecological and evolutionary processes controlling how resources are divided up tend to produce those clusters. A genetic species as defined by Robert Baker and Robert Bradley is a set of genetically isolated interbreeding populations. This
4600-412: Is agile and can move quickly. In the wild, black mambas seldom tolerate humans approaching more closely than about 40 metres (130 ft). When it perceives a threat, it retreats into brush or a hole. When confronted, it is likely to engage in a threat display, gaping to expose its black mouth and flicking its tongue. It also is likely to hiss and spread its neck into a hood similar to that of the cobras in
4715-436: Is an adaptable species; it persists in areas where there has been extensive deforestation and human development. It is often found around buildings, town parks, farmlands and plantations. Jameson's mamba is a highly arboreal snake, more so than its close relatives the eastern green mamba and western green mamba, and significantly more so than the black mamba . Jameson's mamba is a highly agile snake. Like other mambas it
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4830-468: Is both terrestrial and arboreal . On the ground, it moves with its head and neck raised, and typically uses termite mounds, abandoned burrows, rock crevices and tree cracks as shelter. Black mambas are diurnal ; in South Africa, they are recorded to bask between 7 and 10 am and again from 2 to 4 pm. They may return daily to the same basking site. Skittish and often unpredictable, the black mamba
4945-414: Is called speciation . Charles Darwin was the first to describe the role of natural selection in speciation in his 1859 book The Origin of Species . Speciation depends on a measure of reproductive isolation , a reduced gene flow. This occurs most easily in allopatric speciation, where populations are separated geographically and can diverge gradually as mutations accumulate. Reproductive isolation
5060-412: Is called the specific name or the specific epithet (in botanical nomenclature , also sometimes in zoological nomenclature ). For example, Boa constrictor is one of the species of the genus Boa , with constrictor being the species' epithet. While the definitions given above may seem adequate at first glance, when looked at more closely they represent problematic species concepts. For example,
5175-464: Is capable of flattening its neck in mimicry of a cobra when it feels threatened, and its body shape and length give an ability to strike at significant range. Generally not aggressive, it will typically attempt to escape if confronted. In Nigeria males fight each other for access to females (and then breed) over the dry season of December, January and February; mating was recorded in September in
5290-509: Is composed of two main families of toxic agents, dendrotoxins (I and K) and (at a slightly lower proportion) three-finger toxins . Dendrotoxins are akin to kunitz -type protease inhibitors that interact with voltage-dependent potassium channels , stimulating acetylcholine and causing an excitatory effect, and are thought to cause symptoms such as sweating. Members of the three-finger family include alpha-neurotoxin , cardiotoxins , fasciculins and mambalgins . The most toxic components are
5405-464: Is derived from the Zulu word " imamba ". In Tanzania, a local Ngindo name is ndemalunyayo ("grass-cutter") because it supposedly clips grass. In 1873, German naturalist Wilhelm Peters described Dendraspis Antinorii from a specimen in the museum of Genoa that had been collected by Italian explorer Orazio Antinori in what is now northern Eritrea . This was subsequently regarded as a subspecies and
5520-403: Is described formally, in a publication that assigns it a unique scientific name. The description typically provides means for identifying the new species, which may not be based solely on morphology (see cryptic species ), differentiating it from other previously described and related or confusable species and provides a validly published name (in botany) or an available name (in zoology) when
5635-564: Is exaggerated; it is usually provoked by perceived threats such as the blocking of its movements and ability to retreat. The species' reputed speed has also been exaggerated; it cannot move more quickly than 20 km/h (12 mph). The black mamba's breeding season spans from September to February, following the drop in temperature which occurs from April to June. Rival males compete by wrestling, attempting to subdue each other by intertwining their bodies and wrestling with their necks. Some observers have mistaken this for courtship. During mating,
5750-603: Is found in central and western sub-Saharan Africa , and the eastern black-tailed subspecies is found eastern sub-Saharan Africa, mainly western Kenya . Predominantly arboreal , Jameson's mamba preys mainly on birds and mammals. Its venom consists of both neurotoxins and cardiotoxins . Symptoms of envenomation in humans include pain and swelling at the bite site, followed by swelling, chills, sweating, abdominal pain and vomiting, with subsequent slurred speech, difficulty breathing and paralysis. Fatalities have been recorded within three to four hours of being bitten. The venom of
5865-671: Is further weakened by the existence of microspecies , groups of organisms, including many plants, with very little genetic variability, usually forming species aggregates . For example, the dandelion Taraxacum officinale and the blackberry Rubus fruticosus are aggregates with many microspecies—perhaps 400 in the case of the blackberry and over 200 in the dandelion, complicated by hybridisation , apomixis and polyploidy , making gene flow between populations difficult to determine, and their taxonomy debatable. Species complexes occur in insects such as Heliconius butterflies, vertebrates such as Hypsiboas treefrogs, and fungi such as
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#17327979118455980-726: Is hard or even impossible to test. Later biologists have tried to refine Mayr's definition with the recognition and cohesion concepts, among others. Many of the concepts are quite similar or overlap, so they are not easy to count: the biologist R. L. Mayden recorded about 24 concepts, and the philosopher of science John Wilkins counted 26. Wilkins further grouped the species concepts into seven basic kinds of concepts: (1) agamospecies for asexual organisms (2) biospecies for reproductively isolated sexual organisms (3) ecospecies based on ecological niches (4) evolutionary species based on lineage (5) genetic species based on gene pool (6) morphospecies based on form or phenotype and (7) taxonomic species,
6095-525: Is located, as well as in Uganda, Rwanda, and the adjacent Democratic Republic of the Congo. It is a relatively common and widespread snake, particularly across its western range. Fieldwork in Nigeria indicated the species is sedentary . Found in primary and secondary rainforests , woodland , forest- savanna and deforested areas at elevations of up to 2,200 metres (7,200 ft) high, Jameson's mamba
6210-403: Is no easy way to tell whether related geographic or temporal forms belong to the same or different species. Species gaps can be verified only locally and at a point of time. One is forced to admit that Darwin's insight is correct: any local reality or integrity of species is greatly reduced over large geographic ranges and time periods. The botanist Brent Mishler argued that the species concept
6325-554: Is no longer held to be distinct. In 1896, Belgian-British zoologist George Albert Boulenger combined the species Dendroaspis polylepis as a whole with the eastern green mamba ( Dendroaspis angusticeps ), a lumping diagnosis that remained in force until 1946 when South African herpetologist Vivian FitzSimons again split them into separate species. A 2016 genetic analysis showed the black and eastern green mambas are each other's closest relatives, and are more distantly related to Jameson's mamba ( Dendroaspis jamesoni ), as shown in
6440-547: Is not commonly found at altitudes above 1,000 m (3,300 ft), although its distribution does include locations at 1,800 m (5,900 ft) in Kenya and 1,650 m (5,410 ft) in Zambia. It is rated as a species of least concern on the International Union for Conservation of Nature (IUCN)'s Red List of endangered species, based on its huge range across sub-Saharan Africa and no documented decline. The black mamba
6555-478: Is not valid, notably because gene flux decreases gradually rather than in discrete steps, which hampers objective delimitation of species. Indeed, complex and unstable patterns of gene flux have been observed in cichlid teleosts of the East African Great Lakes . Wilkins argued that "if we were being true to evolution and the consequent phylogenetic approach to taxa, we should replace it with
6670-833: Is predominantly neurotoxic , and symptoms often become apparent within 10 minutes. Early neurological signs that indicate severe envenomation include a metallic taste , drooping eyelids ( ptosis ) and gradual symptoms of bulbar palsy . Other neurological symptoms include miosis (constricted pupils), blurred or diminished vision, paresthesia (a tingling sensation on the skin), dysarthria (slurred speech), dysphagia (difficulty swallowing), dyspnea (shortness of breath), difficulty handling saliva, an absent gag reflex , fasciculations (muscle twitches), ataxia (impaired voluntary movement), vertigo , drowsiness and loss of consciousness, and respiratory paralysis. Other more general symptoms include nausea and vomiting, abdominal pain, diarrhea, sweating, salivation, goosebumps and red eyes. The bite of
6785-586: Is similar to Mayr's Biological Species Concept, but stresses genetic rather than reproductive isolation. In the 21st century, a genetic species could be established by comparing DNA sequences. Earlier, other methods were available, such as comparing karyotypes (sets of chromosomes ) and allozymes ( enzyme variants). An evolutionarily significant unit (ESU) or "wildlife species" is a population of organisms considered distinct for purposes of conservation. In palaeontology , with only comparative anatomy (morphology) and histology from fossils as evidence,
6900-581: Is sometimes administered, though the main treatment is the administration of the appropriate antivenom. A polyvalent antivenom produced by the South African Institute for Medical Research is used to treat black mamba bites, and a new antivenom was being developed by the Universidad de Costa Rica 's Instituto Clodomiro Picado . Species A species ( pl. : species) is a population of organisms in which any two individuals of
7015-424: Is sometimes an important source of genetic variation. Viruses can transfer genes between species. Bacteria can exchange plasmids with bacteria of other species, including some apparently distantly related ones in different phylogenetic domains , making analysis of their relationships difficult, and weakening the concept of a bacterial species. Jameson%27s mamba Jameson's mamba ( Dendroaspis jamesoni )
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#17327979118457130-455: Is swallowed. The snake's potent digestive system has been recorded to fully digest prey in eight to ten hours. Adult mambas have few natural predators aside from birds of prey . Brown snake eagles are verified predators of adult black mambas, of up to at least 2.7 m (8 ft 10 in). Other eagles known to hunt or at least consume grown black mambas include tawny eagles and martial eagles . Young snakes have been recorded as prey of
7245-558: Is the longest species of venomous snake in Africa and the second-longest venomous snake species overall, exceeded in length only by the king cobra . The black mamba is a proteroglyphous (front-fanged) snake, with fangs up to 6.5 mm (0.26 in) in length, located at the front of the maxilla . The tail of the species is long and thin, the caudal vertebrae making up 17–25% of its body length. The body mass of black mambas has been reported to be about 1.6 kg (3.5 lb), although
7360-411: Is the species' breeding season from September to February, during which black mambas are most irritable. Bites are very rare outside Africa; snake handlers and enthusiasts are the usual victims. Unlike many venomous snake species, black mamba venom does not contain protease enzymes. Its bites do not generally cause local swelling or necrosis , and the only initial symptom may be a tingling sensation in
7475-625: Is thought to use a sit-and-wait strategy, which has been reported for the eastern green mamba. The bulk of its diet is made up of birds and tree-dwelling mammals, such as cisticolas , woodpeckers, doves, squirrels, shrews and mice. Smaller individuals of under 100 cm (40 in) in length have been recorded feeding on lizards such as the common agama , and toads. There is no evidence they have adapted to hunting terrestrial rodents such as rats, though they have been recorded eating rodents in Kenya, and have accepted them in captivity. The main predators of this species are birds of prey , including
7590-594: Is threatened by hybridisation, but this can be selected against once a pair of populations have incompatible alleles of the same gene, as described in the Bateson–Dobzhansky–Muller model . A different mechanism, phyletic speciation, involves one lineage gradually changing over time into a new and distinct form (a chronospecies ), without increasing the number of resultant species. Horizontal gene transfer between organisms of different species, either through hybridisation , antigenic shift , or reassortment ,
7705-517: The Cape file snake . Mongooses , which have some resistance to mamba venom and are often quick enough to evade a bite, will sometimes harass or take a black mamba for prey, and may pursue them in trees. The similarly predatory honey badger also has some resistance to mamba venom. The mechanism in both mammals is thought to be that their muscular nicotinic acetylcholine receptors do not bind snake alpha-neurotoxins. Black mambas have also been found amongst
7820-673: The Democratic Republic of the Congo , Republic of the Congo , Central African Republic , and as far north as the Imatong Mountains of South Sudan . In West Africa it ranges from Ghana eastwards to Togo , Nigeria, Cameroon , Equatorial Guinea and Gabon . In East Africa it can be found in Uganda , Kenya, Rwanda , Burundi and Tanzania . The subspecies D. jamesoni kaimosae is endemic to East Africa and chiefly found in western Kenya, where its type locality
7935-530: The ICZN for animals and the ICN for plants, do not make rules for defining the boundaries of the species. Research can change the boundaries, also known as circumscription, based on new evidence. Species may then need to be distinguished by the boundary definitions used, and in such cases the names may be qualified with sensu stricto ("in the narrow sense") to denote usage in the exact meaning given by an author such as
8050-482: The Kakamega Forest in Kenya. Jameson's mamba is oviparous ; the female lays a clutch of 5–16 eggs; in Nigeria laying was recorded from April to June, and most likely soon after November in Uganda. Egg clutches have been recovered from abandoned termite colonies. Jameson's mamba has been difficult to study in the field due to its arboreal nature and green coloration. It has not been observed hunting but
8165-663: The Transvaal area of South Africa , almost all recorded prey was rather small, largely consisting of rodents and similarly sized small or juvenile mammals as well as passerine birds, estimated to weigh only 1.9–7.8% of the mamba's body mass. Nonetheless, anecdotes have indicated that large black mambas may infrequently attack large prey such as the rock hyrax or dassie, and in some tribal languages, its name even means "dassie catcher". The black mamba does not typically hold onto its prey after biting; rather it releases its quarry and waits for it to succumb to paralysis and death before it
8280-401: The chronospecies since fossil reproduction cannot be examined. The most recent rigorous estimate for the total number of species of eukaryotes is between 8 and 8.7 million. About 14% of these had been described by 2011. All species (except viruses ) are given a two-part name , called a "binomial". The first part of a binomial is the genus to which the species belongs. The second part
8395-408: The cladogram below. king cobra ( Ophiophagus hannah ) Jameson's mamba – western subspecies ( Dendroaspis j. jamesoni ) Jameson's mamba – eastern subspecies ( Dendroaspis j. kaimosae ) western green mamba ( Dendroaspis viridis ) eastern green mamba ( Dendroaspis angusticeps ) black mamba ( Dendroaspis polylepis ) Jameson's mamba is a long and slender snake with smooth scales and
8510-399: The fly agaric . Natural hybridisation presents a challenge to the concept of a reproductively isolated species, as fertile hybrids permit gene flow between two populations. For example, the carrion crow Corvus corone and the hooded crow Corvus cornix appear and are classified as separate species, yet they can hybridise where their geographical ranges overlap. A ring species is
8625-406: The genus Dendroaspis , designating Jameson's mamba as the type species . The generic name is derived from the Ancient Greek words δένδρον ( dendron , 'tree') and ἀσπίς ( aspis ' asp '). The genus was misspelt as Dendraspis by French zoologist Auguste Duméril in 1856, and went generally uncorrected by subsequent authors. In 1936, Dutch herpetologist Leo Brongersma corrected
8740-507: The jaguar ( Panthera onca ) of Latin America or the leopard ( Panthera pardus ) of Africa and Asia. In contrast, the scientific names of species are chosen to be unique and universal (except for some inter-code homonyms ); they are in two parts used together : the genus as in Puma , and the specific epithet as in concolor . A species is given a taxonomic name when a type specimen
8855-739: The martial eagle , bateleur , and the Congo serpent eagle . Other predators may include the honey badger , other snakes, and species of mongoose . Jameson's mamba is classified as a Snake of Medical Importance in Sub-Saharan Africa by the World Health Organization , although there are few records of snakebites. Field observations over a 16-year period in the Niger Delta in southern Nigeria found that both humans and snakes were most active in rural areas during
8970-406: The "cynical species concept", and arguing that far from being cynical, it usefully leads to an empirical taxonomy for any given group, based on taxonomists' experience. Other biologists have gone further and argued that we should abandon species entirely, and refer to the "Least Inclusive Taxonomic Units" (LITUs), a view that would be coherent with current evolutionary theory. The species concept
9085-626: The Origin of Species explained how species could arise by natural selection . That understanding was greatly extended in the 20th century through genetics and population ecology . Genetic variability arises from mutations and recombination , while organisms themselves are mobile, leading to geographical isolation and genetic drift with varying selection pressures . Genes can sometimes be exchanged between species by horizontal gene transfer ; new species can arise rapidly through hybridisation and polyploidy ; and species may become extinct for
9200-405: The abbreviation "sp." in the singular or "spp." (standing for species pluralis , Latin for "multiple species") in the plural in place of the specific name or epithet (e.g. Canis sp.). This commonly occurs when authors are confident that some individuals belong to a particular genus but are not sure to which exact species they belong, as is common in paleontology . Authors may also use "spp." as
9315-442: The adults. The black mamba is recorded to live up to 11 years and may live longer. The black mamba usually hunts from a permanent lair, to which it will regularly return if there is no disturbance. It mostly preys on small vertebrates such as birds , particularly nestlings and fledglings, and small mammals like rodents , bats , hyraxes and bushbabies . They generally prefer warm-blooded prey but will also consume other snakes. In
9430-429: The alpha-neurotoxins, which bind nicotinic acetylcholine receptors and hence block the action of acetylcholine at the postsynaptic membrane and cause neuromuscular blockade and hence paralysis. Fasciculins are anticholinesterase inhibitors that cause muscle fasciculation. The venom has little or no haemolytic , haemorrhagic or procoagulant activity. Mambalgins act as inhibitors for acid-sensing ion channels in
9545-570: The amount of hybridisation is insufficient to completely mix their respective gene pools . A further development of the recognition concept is provided by the biosemiotic concept of species. In microbiology , genes can move freely even between distantly related bacteria, possibly extending to the whole bacterial domain. As a rule of thumb, microbiologists have assumed that members of Bacteria or Archaea with 16S ribosomal RNA gene sequences more similar than 97% to each other need to be checked by DNA–DNA hybridisation to decide if they belong to
9660-404: The appropriate sexes or mating types can produce fertile offspring , typically by sexual reproduction . It is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity . Other ways of defining species include their karyotype , DNA sequence, morphology , behaviour, or ecological niche . In addition, paleontologists use the concept of
9775-418: The area of the bite. The snake tends to bite repeatedly and let go, so there can be multiple puncture wounds. Its bite can deliver about 100–120 mg of venom on average; the maximum recorded dose is 400 mg. The murine median lethal dose (LD 50 ) when administered intravenously has been calculated at 0.32 and 0.33 mg/kg. Bites were often fatal before antivenom was widely available. The venom
9890-422: The back, blending to pale green towards the underbelly with scales generally edged with black. The neck, throat and underparts are typically cream or yellowish in colour. Jameson's mamba has a narrow and elongated head containing small eyes and round pupils. Like the western green mamba, the neck may be flattened. The subspecies D. jamesoni kaimosae , which is found in the eastern part of the species' range, features
10005-474: The biological species concept, "the several versions" of the phylogenetic species concept, and the idea that species are of the same kind as higher taxa are not suitable for biodiversity studies (with the intention of estimating the number of species accurately). They further suggested that the concept works for both asexual and sexually-reproducing species. A version of the concept is Kevin de Queiroz 's "General Lineage Concept of Species". An ecological species
10120-505: The biological species concept, a cladistic species does not rely on reproductive isolation – its criteria are independent of processes that are integral in other concepts. Therefore, it applies to asexual lineages. However, it does not always provide clear cut and intuitively satisfying boundaries between taxa, and may require multiple sources of evidence, such as more than one polymorphic locus, to give plausible results. An evolutionary species, suggested by George Gaylord Simpson in 1951,
10235-483: The black mamba was recorded in the Dakar region of Senegal . This observation, and a subsequent observation that identified a second specimen in the region in 1956, has not been confirmed and thus the snake's distribution in this area is inconclusive. The species prefers moderately dry environments such as light woodland and scrub, rocky outcrops and semi-arid savanna. It also inhabits moist savanna and lowland forests. It
10350-428: The boundaries between closely related species become unclear with hybridisation , in a species complex of hundreds of similar microspecies , and in a ring species . Also, among organisms that reproduce only asexually , the concept of a reproductive species breaks down, and each clone is potentially a microspecies. Although none of these are entirely satisfactory definitions, and while the concept of species may not be
10465-416: The central and peripheral nervous system, causing a pain-inhibiting effect. There is research interest in their analgesic potential. The composition of black mamba venom differs markedly from those of other mambas, all of which contain predominantly three-finger toxin agents. It is thought this may reflect the preferred prey items – small mammals for the mainly land-dwelling black mamba versus birds for
10580-552: The cladogram below. Ophiophagus hannah Dendroaspis j. jamesoni Dendroaspis j. kaimosae Dendroaspis viridis Dendroaspis angusticeps Dendroaspis polylepis The black mamba is a long, slender, cylindrical snake. It has a coffin-shaped head with a somewhat pronounced brow ridge and a medium-sized eyes. The adult snake's length typically ranges from 2 to 3 m (6 ft 7 in to 9 ft 10 in) but specimens have grown to lengths of 4.3 to 4.5 m (14 ft 1 in to 14 ft 9 in). It
10695-539: 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 species is both terrestrial (ground-living) and arboreal (tree-living); it inhabits savannah , woodland , rocky slopes and in some regions, dense forest. It is diurnal and is known to prey on birds and small mammals. Over suitable surfaces, it can move at speeds up to 16 km/h (10 mph) for short distances. Adult black mambas have few natural predators. In
10810-433: The concept of a chronospecies can be applied. During anagenesis (evolution, not necessarily involving branching), some palaeontologists seek to identify a sequence of species, each one derived from the phyletically extinct one before through continuous, slow and more or less uniform change. In such a time sequence, some palaeontologists assess how much change is required for a morphologically distinct form to be considered
10925-601: The eastern subspecies is around twice as potent as that of the nominate subspecies. Jameson's mamba was first described as Elaps jamesoni in 1843 by Thomas Traill , a Scottish doctor, zoologist and scholar of medical jurisprudence . The specific epithet is in honour of Robert Jameson , Traill's contemporary and the Regius Professor of Natural History at the University of Edinburgh where Traill studied. In 1848, German naturalist Hermann Schlegel created
11040-435: The evidence to support hypotheses about evolutionarily divergent lineages that have maintained their hereditary integrity through time and space. Molecular markers may be used to determine diagnostic genetic differences in the nuclear or mitochondrial DNA of various species. For example, in a study done on fungi , studying the nucleotide characters using cladistic species produced the most accurate results in recognising
11155-451: The genus Naja . During the threat display, any sudden movement by the intruder may provoke the snake into performing a series of rapid strikes, leading to severe envenomation . The size of the black mamba and its ability to raise its head a large distance from the ground enables it to launch as much as 40% of its body length upwards, so mamba bites to humans can occur on the upper body. The black mamba's reputation for being ready to attack
11270-403: The male will slither over the dorsal side of the female while flicking his tongue. The female will signal her readiness to mate by lifting her tail and staying still. The male will then coil himself around the posterior end of the female and align his tail ventrolaterally with the female's. Intromission may last longer than two hours and the pair remain motionless apart from occasional spasms from
11385-448: The male. The black mamba is oviparous ; the female lays a clutch of 6–17 eggs. The eggs are elongated oval in shape, typically 60–80 mm (2.4–3.1 in) long and 30–36 mm (1.2–1.4 in) in diameter. When hatched, the young range from 40–60 cm (16–24 in) in length. They may grow quickly, reaching 2 m (6 ft 7 in) after their first year. Juvenile black mambas are very apprehensive and can be deadly like
11500-483: The numerous fungi species of all the concepts studied. Versions of the phylogenetic species concept that emphasise monophyly or diagnosability may lead to splitting of existing species, for example in Bovidae , by recognising old subspecies as species, despite the fact that there are no reproductive barriers, and populations may intergrade morphologically. Others have called this approach taxonomic inflation , diluting
11615-475: The other predominantly arboreal mambas. Unlike many snake species, black mamba venom has little phospholipase A2 content. Standard first aid treatment for any suspected bite from a venomous snake is the application of a pressure bandage to the bite site, minimisation of movement of the victim and conveyance to a hospital or clinic as quickly as possible. The neurotoxic nature of black mamba venom means an arterial tourniquet may be of benefit. Tetanus toxoid
11730-593: The paper is accepted for publication. The type material is usually held in a permanent repository, often the research collection of a major museum or university, that allows independent verification and the means to compare specimens. Describers of new species are asked to choose names that, in the words of the International Code of Zoological Nomenclature , are "appropriate, compact, euphonious, memorable, and do not cause offence". Books and articles sometimes intentionally do not identify species fully, using
11845-674: The person who named the species, while the antonym sensu lato ("in the broad sense") denotes a wider usage, for instance including other subspecies. Other abbreviations such as "auct." ("author"), and qualifiers such as "non" ("not") may be used to further clarify the sense in which the specified authors delineated or described the species. Species are subject to change, whether by evolving into new species, exchanging genes with other species, merging with other species or by becoming extinct. The evolutionary process by which biological populations of sexually-reproducing organisms evolve to become distinct or reproductively isolated as species
11960-583: The rainy season, April to August, hence rendering this a peak period for snakebite. As well as succumbing to snakebites, workers were reported to have perished from falling from trees after encountering Jameson's mambas in the canopy of trees in palm oil plantations. Snake bites are rare in cities but more common in forested areas in countries such as the Democratic Republic of the Congo; the country's poor infrastructure and lack of facilities render access to antivenom difficult. Like other mambas,
12075-487: The result of misclassification leading to questions on whether there really are any ring species. The commonly used names for kinds of organisms are often ambiguous: "cat" could mean the domestic cat, Felis catus , or the cat family, Felidae . Another problem with common names is that they often vary from place to place, so that puma, cougar, catamount, panther, painter and mountain lion all mean Puma concolor in various parts of America, while "panther" may also mean
12190-586: The ring. Ring species thus present a difficulty for any species concept that relies on reproductive isolation. However, ring species are at best rare. Proposed examples include the herring gull – lesser black-backed gull complex around the North pole, the Ensatina eschscholtzii group of 19 populations of salamanders in America, and the greenish warbler in Asia, but many so-called ring species have turned out to be
12305-508: The same species. This concept was narrowed in 2006 to a similarity of 98.7%. The average nucleotide identity (ANI) method quantifies genetic distance between entire genomes , using regions of about 10,000 base pairs . With enough data from genomes of one genus, algorithms can be used to categorize species, as for Pseudomonas avellanae in 2013, and for all sequenced bacteria and archaea since 2020. Observed ANI values among sequences appear to have an "ANI gap" at 85–95%, suggesting that
12420-529: The same species. When two species names are discovered to apply to the same species, the older species name is given priority and usually retained, and the newer name considered as a junior synonym, a process called synonymy . Dividing a taxon into multiple, often new, taxa is called splitting . Taxonomists are often referred to as "lumpers" or "splitters" by their colleagues, depending on their personal approach to recognising differences or commonalities between organisms. The circumscription of taxa, considered
12535-506: The species concept and making taxonomy unstable. Yet others defend this approach, considering "taxonomic inflation" pejorative and labelling the opposing view as "taxonomic conservatism"; claiming it is politically expedient to split species and recognise smaller populations at the species level, because this means they can more easily be included as endangered in the IUCN red list and can attract conservation legislation and funding. Unlike
12650-513: The spelling to the original. In 1936, British biologist Arthur Loveridge described a new subspecies D. jamesoni kaimosae , from a specimen collected from the Kaimosi Forest in western Kenya , observing that it had fewer subcaudal scales and a black (rather than green) tail. Analysis of the components of the venom of all mambas places Jameson's mamba as sister species to the western green mamba (Dendroaspis viridis) , as shown in
12765-705: The stomach contents of Nile crocodiles . Young mambas in the Serengeti are known to fall prey to southern ground hornbills , marsh owls and hooded vultures . The black mamba is the most feared snake in Africa because of its size, aggression, venom toxicity and speed of onset of symptoms following envenomation, and is classified as a snake of medical importance by the World Health Organization . A survey in South Africa from 1957 to 1979 recorded 2,553 venomous snakebites, 75 of which were confirmed as being from black mambas. Of these 75 cases, 63 had symptoms of systemic envenomation and 21 died. Those bitten before 1962 received
12880-399: The venom of mambas has little phospholipase A2 . Although cardiotoxins have been isolated in higher proportions from its venom than other mamba species, their role in toxicity is unclear and probably not prominent. The speed of onset of envenomation means that urgent medical attention is needed. Standard first aid treatment for any bite from a suspected venomous snake is the application of
12995-509: The venom of most other mambas, Jameson's mamba's contains predominantly three-finger toxin agents as well as dendrotoxins . Other toxins of the three-finger family present include alpha-neurotoxin , cardiotoxins and fasciculins . Dendrotoxins are akin to kunitz -type protease inhibitors that interact with voltage-dependent potassium channels , stimulating acetylcholine and causing an excitatory effect, and are thought to cause symptoms such as sweating. Unlike that of many snake species,
13110-465: The venom of the Jameson's mamba is highly neurotoxic . Symptoms of envenomation by this species include pain and swelling of the bite site. Systemic effects include generalised swelling, chills, sweating, abdominal pain and vomiting, with subsequent slurred speech, difficulty breathing, and paralysis. Death has been recorded within three to four hours of being bitten; there is an unconfirmed report of
13225-540: The wild. It is difficult to define a species in a way that applies to all organisms. The debate about species concepts is called the species problem. The problem was recognised even in 1859, when Darwin wrote in On the Origin of Species : I was much struck how entirely vague and arbitrary is the distinction between species and varieties. He went on to write: No one definition has satisfied all naturalists; yet every naturalist knows vaguely what he means when he speaks of
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