|A black mamba in a defensive posture|
The black mamba (Dendroaspis polylepis), also called the common black mamba or black-mouthed mamba, is a highly venomous snake of the Mamba (Dendroaspis), and is endemic to the Sub-Saharan Africa. It was first described in 1864 by Albert Günther, a German-born British zoologist, ichthyologist, and herpetologist. Soon after, a subspecies was identified, Dendroaspis polylepis antinorii (Peters, 1873), but this is no longer accepted as distinct. It is the longest species of venomous snake in Africa and the second longest venomous snake in the world, averaging around 2.2 to 2.7 m (7.2 to 8.9 ft) in length, and sometimes growing close to lengths of 4 m (13 ft). The longest recorded black mamba was 4.3 m (14 ft).
Black mambas are one of the most feared snake species in the world, and certainly the most feared in Africa. Its combination of speed, unpredictable aggression, and potent venom make it an extremely dangerous species. It is the fastest snake in the world, capable of moving at 4.32 to 5.4 metres per second (11–19 km/h, 10–12 mph) for short distances. The black mamba has a reputation for being very aggressive, but like most snakes, it usually attempts to flee from humans unless threatened.
It has one of the most highly potent and rapid-acting venom of any snake, and there is capable of killing an adult human in 20 minutes. This is documented in the medical literature. Black mamba venom can kill a mouse after 4.5 minutes, the shortest time among all known venomous snakes. Without rapid and vigorous antivenom therapy, a bite from a black mamba is almost always fatal. Many experts regard this as the world's most dangerous snake.
- 1 Etymology
- 2 History
- 3 Biology
- 4 Distribution and habitat
- 5 Behaviour and ecology
- 6 Venom
- 7 Relationship with humans
- 8 References
- 9 Further reading
Dendroaspis polylepis has been the name of the black mamba's binomial name since 1864. The generic name, Dendroaspis, is derived from Ancient Greek words – Dendro, which means "tree", and aspis (ασπίς) or "asp", which' is understood to mean "shield", but it also designate "cobra" or simply "snake". In old text, aspis or asp was used to refer to Naja haje (in reference with the hood, like a shield). Thus, "Dendroaspis" literally means tree snake, which refers to the arboreal nature of most of the species within the genus. Schlegel used the name Dendroaspis, significant tree cobra. The specific name polylepis, is also derived from the Greek words - poly or polus, simply means "many" or "more" and lepis, also Greek in origin, means "scales", therefore "polylepis" literally means "many-scales". This refers to the black mambas size and the many scales it has. The name "black mamba" is given to the snake not because of its body colour but because of the ink-black colouration of the inside of its mouth, which it displays when threatened.
Evolution and taxonomy
The black mamba is classified under the genus Dendroaspis of the family Elapidae. The genus was described by the German ornithologist and herpetologist Hermann Schlegel in 1848. Initially, they were grouped within the Naja genus, but later removed due to the fact that they don't belong to the "cobra group". Parsimony analysis of phylogenetic relationships among elapines was found to be divided into two clades: coral snakes vs cobras, Bungarus, Elapsoidea, and Dendroaspis. The term cobra has traditionally been applied to the genera Aspidelaps, Boulengerina, Hemachatus, Naja, Ophiophagus, Paranaja, Pseudohaje, and Walterinnesia, a mostly African group generally characterized by the ability to flatten the neck into a hood when threatened. The African mambas (Dendroaspis) also have the ability to spread a hood when threatened, albeit more weakly than many members of the aforementioned group. Studies found significant bootstrap support for a core cobra group consisting of Naja, Boulengerina, Paranaja, Aspidelaps, Hemachatus, and Walterinnesia. Oddly, the Asian king cobra (Ophiophagus hannah), was not part of this clade, clustering instead with a group including Dendroaspis and Bungarus on the most-parsimonious tree or with Elapsoidea on the maximum-likelihood tree. This result calls into question the monophyly of cobras and underscores the uncertainty of the homology of the hood spreading behavior in cobras and mambas. The relationships of Dendroaspis, Ophiophagus, and Bungarus differed between the parsimony and likelihood analyses, suggesting that more work is necessary to resolve the relationships of these problematic taxa.
The black mamba is one of four species in the African snake genus Dendroaspis that are known as mambas. The species was first described in 1864 by Albert Günther, a German-born British zoologist, ichthyologist, and herpetologist. Soon after, a subspecies was identified, Dendroaspis polylepis antinorii (Peters, 1873), but this is no longer accepted as distinct. In 1896, zoologist George Albert Boulenger combined the species (Dendroaspis polylepis) as a whole with the eastern green mamba, (Dendroaspis angusticeps), and they were considered a single species from 1896, until 1946, when Dr. Vivian FitzSimons split them into separate species.
The adult black mamba's back skin colour is olive, brownish, gray, or sometimes khaki. A young snake is lighter, but not light enough to be confused with the different species of green mamba. Its underbody is cream-coloured, sometimes blended with green or yellow. Dark spots or blotches may speckle the back half of the body, and some individuals have alternating dark and light scales near the posterior, giving the impression of lateral bars. The inside of the mouth is dark blue to inky black. The head is large but narrow and elongated, with the shape of a coffin. It is a proteroglyphous snake, meaning it has immovable, fixed fangs at the front of the maxilla. The eyes are dark brown to black, with a silvery-white to yellow edge on the pupils. As they age, their colouration tends to get darker.
The species is the second-longest venomous snake in the world, exceeded in length only by the king cobra. Not all scientific sources agree on the range of lengths for this species, but adult specimens are 2.2 to 2.7 m (7.2 to 8.9 ft) in length on average, with a range of 2.0 to 3.8 m (6.6 to 12 ft). Some sources report maximum lengths of 4.3 to 4.5 m (14 to 15 ft). In the 1950s, a black mamba measuring 4.3 m (14 ft), known as "the King of the Mambas" in African Wildlife, was shot in Natal, South Africa. There is no real sexual dimorphism, and both male and female snakes of this species have a similar appearance and tend to be similar in size. Information regarding the lifespan of snakes in the wild is sparse; the longest recorded lifespan of a captive black mamba is 14 years, but actual maximum lifespans could be much greater.
|Dorsal at midbody||Ventral||Subcaudal||Anal plate||Upper labials||Upper labials to eye||Preoculars||Postoculars||Lower labials||Temporal|
|23-25 (rarely 21)||248–281||109–132 (paired)||Divided||7-10||4th (or 3rd to 4th)||3-4 (2-5)||3 (can be 4)||11-13 (10-14)||2+3 (variable)|
Like all snakes, black mambas need to maintain the characteristics of their inner environment within the limits that are compatible with their survival. They are ectotherms, and so their internal temperature depends on that of their external environment. When at rest, they expend litle energy. Black mambas can carry out most of their functions only at high tempertatures. However, they mmust also avoid extremely high temperatures, which could be fatal to them. This necessitates a thermoregulating activity, at least during certain seasons, which allows them maintain their internal temperature at a level compatible with their survival. Unlike birds or mammals who are capable of producing heat, black mambas (and snakes in general) adapt behvaiourally, mostly by searching for the right thermic conditions. Their vital functions more or less depend on temperature, but they also possess various mechanisms to help cope with changes in ionic and retain internal fluids.
Black mambas breed only once a year. The breeding season begins in the spring, which occurs around the month of September in the African regions where these snakes occur, as much of sub-Saharan Africa is in the Southern Hemisphere. In this period, the males fight over females. Agonistic behaviour for black mambas involves wrestling matches in which opponents attempt to pin each other's head repeatedly to the ground. Fights normally last a few minutes, but can extend to over an hour. The purpose of fighting is to secure mating rights to receptive females nearby during the breeding season. Beyond mating, males and females do not interact. Males locate a suitable female by following a scent trail. Upon finding his mate, he will thoroughly inspect her by flicking his forked tongue across her entire body. Males are equipped with two hemipenes. After a successful and prolonged copulation, the eggs develop in the female's body for about 60 days. During this period, the female seeks a suitable place to lay the eggs. Females prefer using abandoned termite mounds as nests. Mature females lay between 15 and 25 eggs, which they hide very well and guard very aggressively. The eggs incubate for about 60 days before hatching. The hatchlings are about 50 centimetres (20 in) in length and are totally independent after leaving the eggs, hunting and fending for themselves from birth. Young hatchlings are as venomous as the adults, but do not deliver as much venom per bite as an adult snake would. Unlike adults who carry about 8-16 ml of venom in their glands, young hatchlings carry only 1–2 ml of venom in their venom glands, which is sufficient quantity for a lethal effect on a human.
No specific information was available for this species regarding the hatchlings development, but some general assumptions can be made. Black mambas are oviparous. Young incubate inside the eggs for 2 to 3 months after being deposited. They break through the shell with an "egg-tooth". Upon hatching, young are fully functional and can fend for themselves. They have fully developed venom glands (that carry 1-2 ml of venom, which is sufficient to kill an adult human), and are dangerous just minutes after birth. The yolk of the egg is absorbed into the body and can nourish the young for quite some time.
Distribution and habitat
Although it is a large diurnal snake, the distribution of the black mamba is the subject of much confusion in research literature, indicating the poor status of African herpetological zoogeography. However, the distribution of the black mamba in eastern Africa and southern Africa is well documented. Pitman (1974) gives the following range for the species' total distribution in Africa: northeastern Democratic Republic of the Congo, southwestern Sudan, South Sudan to Ethiopia, Eritrea, Somalia, southern Kenya, eastern Uganda, Tanzania, southwards to Mozambique, Swaziland, Malawi, Zambia, Zimbabwe and Botswana to KwaZulu-Natal in South Africa, and into Namibia; then northeasterly through Angola to the southeastern part of the Democratic Republic of Congo. According to WHO, the species is also found in Rwanda. The black mamba is not commonly found above altitudes of 1,000 metres (3,300 ft), although the distribution of black mamba does reach 1,800 metres (5,900 ft) in Kenya and 1,650 metres (5,410 ft) in Zambia. The black mamba was recorded in 1954 in West Africa in the Dakar region of Senegal. However, this observation, and a subsequent observation that identified a second specimen in the region in 1956, have not been confirmed and thus the species' distribution in West Africa is inconclusive. The black mamba's western distribution contains gaps within the Central African Republic, Chad, Nigeria and Mali. These gaps may lead physicians to misidentify the black mamba and administer an ineffective antivenom. West of Ethiopia, it has a curious distribution, with few records. There is a single record from the Central African Republic, two from Burkina Faso, and as mentioned two unconfirmed sightings from Senegal, one from the Gambia, and a possible sighting in Cameroon. These sightings may indicate improper documentation, remaining populations from what was once a larger range, or new populations, indicating a growing range.
The black mamba has adapted to a variety of climates, ranging from savanna, woodlands, farmlands, rocky slopes, dense forests and humid swamps. The grassland and savanna woodland/shrubs that extend all the way from southern and eastern Africa to central and western Africa are the black mamba's typical habitat. The snake prefers more arid environments, such as semiarid, dry bush country, light woodland, and rocky outcrops. This species likes areas with numerous hills, as well as riverine forests. Black mambas often make use of abandoned termite mounds and hollow trees for shelter, which it goes back to everynight. The abandoned termite mounds are especially used when the snake is looking for somewhere to cool off, as the mounds are sort of a "natural air-conditioning" system. The structure of these mounds is very complex and elaborate. They have a network of holes, ducts, and chimneys that allow air to circulate freely, drawing heat away from the nest during the day – though without taking too much valuable moisture – while preventing the nest cooling too much at night. As a species which maintains a permanent home range throughout its entire life, the black mamba will always return to its lair at night within this home range if left undisturbed.
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 June 2009 and published in 2010, and it was classed as such due to its very large distribution. Besides its very large geographical distribution, the species has no specific threats that have been reported, and this species is not undergoing significant population declines. This species is regarded as common in sub-Saharan Africa, it has been found as far north as Senegal and as far south as northeast South Africa. Trape (2005) reports this species as far west as Senegal and Guinea. The black mamba is reported to be widespread in locations with suitable habitats. In areas with few records this can be attributed to undercollecting rather than low abundance. It is unlikely that any major threat is impacting this species across its full range. Black mambas prefer to stay away from humans. Human population expansion into its habitat could therefore constitute a potential threat to this species. However, the extent of its range throughout much of Africa means that this should not be considered a serious threat. There are no known species-specific conservation measures in place for this species, however, in places its distribution coincides with protected areas. No conservation measures are required for this species.
Behaviour and ecology
Though they prefer traveling on the ground, and they are considered to be a terrestrial species of snake, they are also arboreal. Black mambas maintain a home range, but are not considered highly territorial, preferring to flee from danger when threatened. Unless disturbed, black mambas will remain in the same home range for years or even their entire lifespan. They have a favoured home or lair usually in an abandoned termite mound, an aardvark burrow, a hollow tree or log, a rock crevice or sometimes even the roof of a home. They prefer to avoid confrontation and will often attempt to retreat to their lair, attacking anything that gets in its way. This usually results when an threat or predator blocks the snake's direct path to its lair or refuge. A cornered black mamba will raise its head far off the ground, open its mouth, expand a narrow hood, flick its tongue and hiss before striking. If the attempt to scare away the attacker fails, it will strike repeatedly. Strikes will be numerous and rapid, and are often fatal to humans. If the threat slowly moves away from the mamba, the snake will usually retreat. Black mambas spend much of their time basking and will return often to a favoured sunny spot. A diurnal species, the black mamba is usually active from a few hours after sunrise until about an hour before dusk. In short bursts and over short distances, the black mamba can travel 11 to 19 km/h (6.8 to 12 mph), making it the fastest land snake in the world. Besides the relatively high speed with which it moves, the black mamba can strike accurately in any direction, even while moving fast. In striking, it throws its head upward from the ground for about two-fifths the lengths of its body.
Many snake experts have cited the black mamba as the world's most aggressive snake, noting tendency to attack without provocation. It can show an incredible amount of tenacity, fearlessness, and aggression when cornered, during breeding season, or when defending its territory. According to Swaziland-born snake handler and snake expert Thea Litschka-Koen:
Black mambas will kill a dog or several dogs if threatened and it happens quite often. We also find dead cows and horses! We were called by the frantic family late one evening. When we arrived minutes later, two small dogs had already died and two more were showing severe symptoms of envenomation. Within 15 minutes we had found and bagged the snake. By this time the other two dogs were also dead. The snake must have been moving through the garden when it was attacked by the dogs. It would have struck out defensively, biting all the dogs that came within reach. The snake was bitten in several places on its body as well and died about a week later.
— Thea Litschka-Koen
Communication and perception
Black mambas show little deviation from the common methods of communication and perception found in snakes. They primarily rely on their eyesight, their tongue, and ability to sense vibration to gather information from their environment. Their eyes are large and they have excellent eyesight which is used to detect motion, to view surroundings, and to help them carefully navigate and move about in their environment. Detection of quick or sudden movements will cause them to strike immediately. The vomeronasal organ (Jacobson's organ), a chemosensory organ located on the roof of their mouth, is involved in the black mambas social chemical communication and in hunting prey. They collect environment stimuli, such as molecules from the air and nearby objects by extending their forked tongue from their mouth. These chemical elements are then deposited in the vomeronasal organ when the tongue is retracted. They lack external auditory structures and cannot hear airborne sounds, but the part of their body in direct contact with the ground is very sensitive to vibrations; thus they are able to sense other animals approaching by detecting faint vibrations in the air and on the ground. Like many snakes, when threatened, they will become defensive and aggressive, displaying a set of warning signals of a possibility of attack.
Hunting and prey
Black mambas are opportunistic predators. They generally seem to prefer larger sized prey, but will take small prey items as well. Although they mainly feed on warm-blooded mammals and birds, they have also been said to take other snakes. Juvenile black mambas will readily take skinks and lizards. A 2 m (6.6 ft) black mamba has even been observed feeding on flying termite alates. When hunting, the black mamba is often seen travelling with its head raised well above ground level, quickly moving forward in search of prey. Once prey is detected, the black mamba freezes before hurling itself forward and issuing several quick bites, swiftly killing its prey. If the prey attempts to escape, the black mamba will follow up its initial bite with a series of strikes. It will release larger prey after biting it, but smaller prey, such as birds or rats, are held until the prey's muscles stop moving. Black mambas feed on a variety of prey, especially mammals, including Rock hyraxes (dassies), rats, mice, young Cane rats, Common mole rats, squirrels, bats, bushbabies and elephant shrews. They have also been known to prey on birds and small chickens, as well as other snakes, such as the puff adder and Cape cobra. A large specimen has even been recorded eating a young blue duiker (Philantomba monticola). Although rare, predation on primates by larger sized snakes does occur. In one incident, a black mamba predated on a Sykes monkey (Cercopithecus albogularis albogularis). After ingestion, powerful acids digest the prey, sometimes within 8 to 10 hours.
There are no specific predators of the black mamba, but snakes in general tend to have many. Large adult black mambas have no specific predators other than humans. Humans do not usually consume black mambas; they often kill them out of fear. Other predators will often target eggs or very young mambas, and known predators are large reptiles such as crocodiles or monitors, mongooses, foxes or jackals, and birds of prey. Mamba eggs are also susceptible to being eaten by many types of scavengers. Juvenile mambas are also subject to predation from Cape file snakes.
Like many snakes, the venom toxicity (LD50) of individual specimens can show considerable variation which can be due to geographical region, seasonal variation, diet, habitat, and age-dependent change. The venom of the black mamba is a protein of low molecular weight and displays very high activity in terms of hyaluronidases, which is also essential in facilitating propagation of venom components throughout tissue (spreading the venom through the body), as a result the venom is able to spread extraordinarily rapidly within the bitten tissue. It is considered to be the most rapid-acting snake venom. In a study, a mouse injected with an overodse of black mamba toxins subcutaneously, died in 4.5 minutes. Such short death times have never been seen with any other snake venom toxins. The shortest death time for any other snake was in the range of 7–8 minutes. and consists mainly of highly potent pre-synaptic and post-synaptic neurotoxins; it also contains cardiotoxins, fasciculins, and calciseptine. Median lethal dose LD50 values for this species' venom varies tremendously from one toxinological study to the next. Ernst and Zug et al. 1996 listed a value of 0.02 mg/kg for intravenous injection and 0.05 mg/kg for subcutaneous injection, One study showed the intraperitoneal injection LD50 in mice was very toxic: 0.01 mg/kg. In the study, seizure threshold was significantly lowered and the mice went through convulsions. Significant changes in motor activity were observed and there were changes in structure or function of salivary glands. Spawls & Branch and Minton & Minton both listed the SC LD50 at 0.28 mg/kg and Brown lists a murine value of 0.12 mg/kg SC. Brown also conducted venom toxicity studies on monkeys, who were given subcutaneous injections of venom. The results indicated that black mamba venom was the most toxic to monkeys, ranking first among all snake venoms that were tested. It was more toxic than the Inland taipan, Eastern brown snake, and Coastal taipan. In the same study on monkeys, the Coastal taipan and Many-banded krait were also elevated above both the Inland taipan and Eastern brown snake in the toxicity of their venoms, ranking second and third behind the black mamba, respectively.
It is estimated that only 10 to 15 milligrams (0.15 to 0.23 gr) will kill a human adult, and its bites delivers about 120 milligrams (1.9 gr) of venom on average, although they may deliver up to 400 milligrams (6.2 gr) of venom in a single bite. The black mamba's venom glands contain approximately 8–16 ml of liquid venom. In the freshly hatched young, the amount is 1–2 ml of venom, which is sufficient quantity for a lethal effect on a human. Its bite is often called "the kiss of death" because, before antivenom was widely available, the mortality rate from a bite was 100% since this species always delivers fatal dosage of venom during every envenomation. The fatality duration and rate depends on various factors, such as the health, size, age, and psychological state of the victim, the penetration of one or both fangs from the snake, the amount of venom injected, the pharmacokinetics of the venom, the location of the bite, and its proximity to major blood vessels. The health of the snake and the interval since it last used its venom mechanism is important, as well. Severe black mamba envenomation can kill a person in 30 minutes, but sometimes it takes up to 2–3 hours, depending upon many factors.
If bitten, severe neurotoxicity invariably ensues. Their venom contains neurotoxically acting nicotinic acetylcholine receptor antagonists analogical to the postsynaptic neurotoxins of other elapids classified as α, β, γ and δ neurotoxins. Mambas carry powerful and efficient pre-synaptic neurotoxins called dendrotoxins (DTX) - peptides causing inhibition by blocking voltage channeled by potassium for the re-polarization of neurons, thus causing extension of the process. This way, the substances support muscular paralysis, either at a central level or by exhausting neuromuscular junctions by super-threshold stimulation. The effect of DTX is very probably manifest on the vegetative nerves as well. The DTX I subtype of the black mamba is the most rapid-acting and efficient venoms of all known snake venom toxins. A number of peptides isolated from mamba's venom potentiate neurotransmission in the central nervous system as well as in peripheral nerves. They are limited only to the mamba's venom outfit. The peptides, acting as muscarinic acetylcholine receptor ligands, may probably cause activation in the central nervous system. Fasciculins are peptide acetylcholinesterase inhibitors increasing the intrasynaptic amount of acetylcholine, which results in fasciculation of muscles. Dendroaspin natriuretic peptide (DNP) is a polypeptide analogous to the human atrial natriuretic peptide; it is responsible for causing diuresis through natriuresis and dilating the vessel bloodstream, which results in, among other things, acceleration of venom distribution in the body of the victim. Mamba venom has powerful cardiotoxic components as well. The venom displays relatively high activity in terms of hyaluronidases, which is also essential in facilitating propagation of venom components throughout tissue.
Local symptoms of envenoming by this species is minimal. Bleeding might occur from the bite wound. Minor redness and minor localized edema might appear around the bitten site. Pain is minimal and may last up to a week. Local tissue damage appears to be relatively infrequent and of minor severity in most cases of black mamba envenomation. Edema is typically minimal. Systemic symptomology, even highly serious, will often manifest very early on - within 10 minutes, or less. Common symptoms are rapid onset of dizziness, drowsiness, coughing or difficulty breathing, convulsions, and an erratic heartbeat. Other common symptoms which come on rapidly include neuromuscular symptoms, shock, loss of consciousness, hypotension, pallor, ataxia, excessive salivation (oral secretions may become profuse and thick), limb paralysis, nausea and vomiting, ptosis, fever, and very severe abdominal pain. Myocardial infarctions (heart attacks), although rare, have been reported in black mamba envenomation. Death is due to suffocation resulting from paralysis of the respiratory muscles.
Clinical cases and antivenom
- Dangerousness of bite: Severe Envenoming likely, high lethality potential.
- Rate of Envenoming: >95%.
- Untreated Lethality Rate: 100%.
In a case of 10 envenomations in South Africa all ten received medical treatment but only five lived. One developed respiratory paralysis in ten minutes, and all other patients were showing signs of neurotoxicity upon arrival at the hospital. Symptoms initially included mild swelling at bite site, confusion, excessive sweating, urinary incontinence, fecal incontinence, loss of coordination, ptosis, erratic heartbeat, drowsiness, and breathing difficulties. Out of the 10 patients, five were fatal despite prompt hospitalization and induction of medical treatment. One patient died in just under 30 minutes. The four other patients all died within 3–8 hours post-envenomation. The other five patients survived but all of them required massive amounts of antivenom and assisted mechanical ventilation for a prolonged period. Three of the patients were on mechanical ventilation for 10 days, while the other two required assisted mechanical ventilation for 16 days. Cases of this nature are not at all uncommon among cases of envenomation by the black mamba.
Envenomation by this species invariably causes very severe neurotoxicity due to the fact that black mambas often strike repeatedly in a single lunge, biting the victim many times extremely rapid succession. Such an attack is very fast, lasting less than one second and so it appears to be a single strike and single bite. With each bite the snake delivers anywhere from 100 to 400 milligrams (1.5 to 6.2 gr) of a rapid-acting and highly toxic venom. As a result, the doses of antivenom required for successful treatment are often massive (10–20+ vials) for bites from this species. It is not unusual to use 30+ vials in extremely severe cases. In addition to antivenom therapy, endotracheal intubation and mechanical ventilation are required for supportive therapy.
A polyvalent antivenom produced by the South African Institute for Medical Research (SAIMR) is used to treat all black mamba bites from different localities. Due to antivenom, a bite from a black mamba is no longer a certain death sentence. But in order for the antivenom therapy to be successful, vigorous treatment and large doses of antivenom must be administered very rapidly post-envenomation. In case studies of black mamba envenomation, respiratory paralysis has occurred in less than 15 minutes. Due to the nature of the lethality of the venom and the associated 100% fatality rate among black mamba bites stimulated the production of a specific mamba antivenom, and in 1967 Louw reported the first successful treatment of two black mamba bites with a specific antivenom prepared by the South African Institute of Medical Research (SAIMR). This was the first time that any victim of a black mamba bite was scientifically documented to survive envenomation. Although antivenom saves many lives, mortality due to black mamba envenomation is still at 14%, even with antivenom therapy.
Mamba venom is made up mostly of dendrotoxins (dendrotoxin-k – "Toxin K", dendrotoxin-1 – "Toxin 1", dendrotoxin-3 – "Toxin 3", dendrotoxin-7 – "Toxin 7", among others), fasciculins, and calciseptine. Being a protein of low molecular weight, the venom and its constituents are able to spread extraordinarily rapidly within the bitten tissue, so black mamba venom is the most rapid-acting of all snake venoms. The dendrotoxins disrupt the exogenous process of muscle contraction by means of the sodium potassium pump. Toxin K is a selective blocker of voltage-gated potassium channels, and Toxin 1 inhibits the K+ channels at the pre and postsynaptic level in the intestinal smooth muscle. It inhibits Ca2+-sensitive K+ channels from rat skeletal muscle‚ incorporated into planar bilayers (Kd = 90 nM in 50 mM KCl), Toxin 3 inhibits M4 receptors, while Toxin 7 inhibits M1 receptors. The calciseptine is a 60 amino acid peptide which acts as a smooth muscle relaxant and an inhibitor of cardiac contractions. It blocks K+-induced contraction in aortic smooth muscle and spontaneous contraction of uterine muscle and portal vein. The venom is highly specific and virulently toxic. However, black mamba venom can kill a mouse after 4.5 minutes, the shortest time among all known venomous snakes.
Black mamba venom also contains proteins, mambalgins, which in mice act as an analgesic as strong as morphine, but without most of the side-effects. Mambalgins cause much less tolerance than morphine and no respiratory distress. They act through a completely different route, acid-sensing ion channels. Laboratory tests suggest that the pain-killing effect on humans may be similar, but this had not been tested as of October 2012[update]. Researchers were puzzled about the advantage this substance could give the snakes.
Availability of treatment
Venomous snakebites are rampant in sub-Saharan Africa. Although antivenom is now widely available and bite victims can rapidly access adequate treatment in most of Africa's medium to large cities and nearby areas, some severely impoverished African nations do not always have antivenom in stock, as it is very expensive, even by Western standards. Most of those bitten by a venomous African snake species require 5 vials of antivenom as an initial dose. A single vial of antivenom can cost anywhere from USD $160–$200, and black mamba envenomation is the costliest to treat, as 10-12 vials of antivenom are often required as an initial starting dose and more than 20 vials are often required for effective treatment. As a result of the severe nature of black mamba bites and the cost of antivenom required to treat such a bite, deaths due to black mamba envenomation are very common in Swaziland and the rate of mortality is close to 100%. Other contributing factors besides the lack of antivenom are lack of mechanical ventilation equipment, proper envenomation symptom control, and drugs. Some victims will not access medical care, but rather go to a traditional healer or witch doctor. However, Swaziland does have "Antivenom Swazi", a charity whose mission is to raise enough funds to create a "bank" of antivenom for treating snakebites, but they are specifically focused on treating black mamba bite victims in Swaziland. Although bites attributed to this species are less likely compared to most African cobra species and to the puff adder, the mortality rate is significantly higher among those envenomed by black mambas. According black mamba expert and handler, Thea Litschka-Koen, black mambas only cause 10% of the total amount of bites in Swaziland, but cause more fatalities than the Mozambique spitting cobra, which causes 80% of all bites in the same country. In Zimbabwe, the black mamba and green mamba are responsible for 18% of all snake bites, but the number of deaths due to mamba envenomation is equal to the number of deaths among those bitten by cobras, who are responsible for double the amount of bites at 37%. In Tanzania, while the black mamba is second to the puff adder in causing human fatalities, the puff adder bites almost six times the number of people that the black mamba does. A survey of snakebites in South Africa from 1957 to 1963 recorded over 900 venomous snakebites, but only seven of these were confirmed black mamba bites. From the 900 bites, only 21 ended in fatalities, including all seven black mamba bites – a 100% mortality rate.
Relationship with humans
Although respected by the local populations in Africa, the black mamba still faces human persecution because of its fearsome reputation throughout its range. With the increasing amount of its territory being inhabited by humans, the black mamba often finds itself cornered with no escape. In this situation, it will stand its ground and display incredible aggressive behavior. A group of people is usually required to kill it, as it is very fast and agile, striking in all directions while a third of its body is 3–4 feet (0.91–1.2 m) above the ground. The deep fear of this snake stems not only from its reputation for aggression, speed, and venom toxicity, but from stories and legends that have been passed down from generation to generation. throughout sub-Saharan Africa. One such myth sees the mamba bite its tail to make a loop, enabling it to roll down a hill. As it comes to the bottom, it straightens like an arrow and attacks at exceptional speed. Another false perception maintains that the black mamba has superior intelligence enabling it to plan an attack on humans, where it 'ambushes' a car by waiting in the road, then coils itself around the wheel to bite the driver when he reaches his destination. Popular accounts say that the snake can balance itself on the tip of its tail.
- Spawls, S. (2009). "Dendroaspis polylepis". IUCN Red List of Threatened Species. Version 3.1. International Union for Conservation of Nature. Retrieved 13 December 2013.
- "Dendroaspis". Integrated Taxonomic Information System. Retrieved 9 December 2013.
- "Dendroaspis polylepis". Integrated Taxonomic Information System. Retrieved 12 December 2013.
- Uetz, Peter. "Dendroaspis polylepis GÜNTHER, 1864". Reptile Database. Zoological Museum Hamburg. Retrieved 2 December 2011.
- "Dendroaspis polylepis – General Details, Taxonomy and Biology, Venom, Clinical Effects, Treatment, First Aid, Antivenoms". WCH Clinical Toxinology Resource. University of Adelaide. Retrieved 2 December 2011.
- Spawls, Stephen; Branch, Bill (1995). The dangerous snakes of Africa: natural history, species directory, venoms, and snakebite. Dubai: Oriental Press: Ralph Curtis-Books. pp. 49–51. ISBN 0-88359-029-8.
- Phelps, Tony (2002). "A study of the Black Mamba (Dendroaspis polylepis) in KwaZulu-Natal, South Africa, with particular reference to long-term-refugia". Herpetological Bulletin 80: 7–19. Retrieved 16 November 2013.
- FitzSimons, Vivian FM (1970). A field guide to the snakes of Southern Africa. Canada: HarperCollins. p. 221. ISBN 0-00-212146-8.
- Burton, Robert (2002). International Wildlife Encyclopedia: Leopard – marten. USA: Marshall Cavendish. p. 3168. ISBN 0-7614-7277-0.
- Branch, Bill (1988). Branch's Field Guide Snakes Reptiles Southern Africa. Curtis Publishing, Ralph. ISBN 978-0-88359-023-2.
- Guinness World Records (2013). Guinness World Records 2014 : Officially Amazing. Guinness Publishing. ISBN 978-1-897553-28-2.
- Capstone Press (2005). Mambas. Compass Point Books. p. 13. ISBN 978-0-7368-2137-7.
- O'Shea, Mark (2005). Venomous Snakes of the World. United Kingdom: New Holland Publishers. p. 78. ISBN 0-691-12436-1. "... in common with other snakes they prefer to avoid contact; ... from 1957 to 1963 ... including all seven black mamba bites - a 100 per cent fatality rate"
- Strydom, Daniel (1972). "Snake Venom Toxins". The Journal of Biological Chemistry 247 (12): 4029–4042. PMID 5033401.
- Mitchell, Deborah (September 2009). The Encyclopedia of Poisons and Antidotes. New York, USA: Facts on File, Inc. p. 324. ISBN 0-8160-6401-6.
- "IMMEDIATE FIRST AID for bites by Black Mamba (Dendroaspis polylepis polylepis)". Toxicology. University of California, San Diego. Retrieved 3 December 2013.
- Rauchenberger, Mary (18 May 1988). "A New Species of Allodontichthys (Cyprinodontiformes: Goodeidae), with Comparative Morphometrics for the Genus". Copeia – American Society of Ichthyologists and Herpetologists 2: 433–441. doi:10.2307/1445884. Retrieved 2 December 2011.
- Hardy Fern Library – polylepis etymology. Hardyfernlibrary.com. Retrieved on 2012-07-08.
- Bauchot, Roland (2006). Snakes: A Natural History. Sterling. pp. 41, 76. ISBN 978-1-4027-3181-5.
- Broadley, Donald (1983). "9". In Fitzsimmons, VFM. Fitzsimmons' Snakes of Southern Africa (Reprint, revised ed.). Johannesburg, South Africa: Delta Books, LTD. ISBN 978-0-908387-04-5.
- Greene; Fogden, Harry W.; Michael (2000). Snakes: The Evolution of Mystery in Nature. United States: University of California Press. p. 351. ISBN 0-520-22487-6.
- Slowinski, JB; Knight A, Rooney AP (December 1997). "Inferring species trees from gene trees: A phylogenetic analysis of the Elapidae (Serpentes) based on the amino acid sequences of venom proteins". Molecular Phylogenetics and Evolution 8 (3): 349–62. doi:10.1006/mpev.1997.0434. PMID 9417893. Retrieved 9 December 2013.
- Günther, Albert. "Report on a collection of reptiles and fishes made by Dr. Kirk in the Zambesi and Nyassa Regions". Proceedings of the Zoological Society of London 1864: 303–314 [310–311].
- "Dendroaspis polylepis". Catalogue of Life. Retrieved 12 December 2013.
- Boulenger, GA (1896). Catalogue of the Snakes in the British Museum (Natural History), Volume III (Revised, 2010 ed.). London: Nabu Press. ISBN 978-1-176-56979-9.
- Loveridge, A. "The Green and Black Mambas of East Africa". Museum of Comparative Zoology, Cambridge, Mass. Retrieved 12 December 2013.
- Marais, Johan (2004). A Complete Guide to the Snakes of Southern Africa. Cape Town, South Africa: Struik Nature. pp. 95–97. ISBN 1-86872-932-X.
- Broadley; Doria; Wigge, DG; CT; J (2003). Snakes of Zambia: An Atlas and Field Guide. Frankfurt am Main, Germany: Edition Chimaira. p. 280. ISBN 978-3-930612-42-0.
- Mattison, Chris (1987-01-01). Snakes of the World. New York: Facts on File, Inc. p. 164. ISBN 0-8160-1082-X.
- "Black Mamba Fact File". Perry's Bridge Reptile Park. Snakes-Uncovered. Retrieved 2 December 2011.
- Valenta, Jiri (2010). Venomous Snakes: Envenoming, Therapy. Nova Science Publishers. pp. 108–111. ISBN 978-1-60876-618-5.
- Závada, J.; Valenta J., Kopecký O., Stach Z., Leden P (2011). "Black Mamba Dendroaspis Polylepis Bite: A Case Report". Prague Medical Journal 112 (4): 298–304. PMID 22142525. Retrieved 3 December 2013.
- Håkansson, Thomas; Madsen, Thomas (1983). "On the Distribution of the Black Mamba (Dendroaspis polylepis) in West Africa". Journal of Herpetology 17 (2): 186–187. doi:10.2307/1563464.
- "Central Sub-Saharan Africa - Rwanda - Dendroaspis polylepis". Venomous snakes and antivenoms search interface. World Health Organization. Retrieved 14 December 2013.
- Pitman, Charles R.S. (1974). A Guide to the Snakes of Uganda. United Kingdom: Wheldon & Wesley. p. 290. ISBN 0-85486-020-7.
- Marais, Johan (1992). A Complete Guide to the Snakes of Southern Africa. Southern Book Publishers. ISBN 978-1-86812-380-3.
- Maina, J.N (December 1989). "The morphology of the lung of the black mamba Dendroaspis polylepis". The Journal of Anatomy 167: 31–46. PMC 1256818. PMID 2630539.
- Smith, BW (2005). Venomous Snakes in Captivity: Safety and Husbandry. United States: Lulu.com. p. 147. ISBN 1-4116-2949-3.
- Haji, R. "Venomous snakes and snake bite". Zoocheck Canada Inc. Retrieved 2 December 2011.
- Zug, George R. (1996). Snakes in Question: The Smithsonian Answer Book. Washington D.C., USA: Smithsonian Institution Scholarly Press. ISBN 1-56098-648-4.
- Koen, Thea Litschka. "Black Mamba Snake Handler: Thea Litschka-Koen Answers Your Questions". PBS Nature. Retrieved 13 December 2011.
- Cogger, Harold; Zweifel, Richard (1992). Reptiles & Amphibians. Sydney: Weldon Owen. ISBN 0-8317-2786-1.
- Branch, W.R. (1991). "Unusual Herpetological observations in Kruger National Park". African Herpetological News 19: 39–40.
- Richardson, Adele (2004). Mambas. Mankato, Minnesota: Capstone Press. p. 25. ISBN 978-0-7368-2137-7. Retrieved 2010-05-19.
- Foerster, S. (October 2008). "Two incidents of venomous snakebite on juvenile blue and Sykes monkeys (Cercopithecus mitis stuhlmanni and C. m. albogularis)". Journal of Primatology 49 (4): 300–3. doi:10.1007/s10329-008-0098-x. PMID 18704624. Retrieved 5 December 2013.
- Haagner, GV; Morgan, DR (January 1993). "The maintenance and propagation of the Black mamba Dendroaspis polylepis at the Manyeleti Reptile Centre, Eastern Transvaal". International Zoo Yearbook 32 (1): 191–196. doi:10.1111/j.1748-1090.1993.tb03534.x. Retrieved 14 December 2013.
- Chippaux, JP; Williams V, White J (1991). "Snake venom variability: methods of study, results and interpretation". Toxicon 29 (11): 1279–303. doi:10.1016/0041-0101(91)90116-9. PMID 1814005. Retrieved 1 December 2013.
- Chippaux, Jean-phillipe (2006). Snake Venoms and Envenomations. United States: Krieger Publishing Company. p. 300. ISBN 1-57524-272-9.
- "Sii Polyvalent Anti-Snake Venom Serum (central Africa)". Serum Institute of India. Serum Institute.
- Strydom, Daniel J. (1 October 1976). "Purification and Properties of Low-Molecular-Weight Polypeptides of Dendroaspis polylepis polylepis (Black Mamba) Venom". European Journal of Biochemistry 69 (1): 169–176. doi:10.1111/j.1432-1033.1976.tb10870.x. PMID 991854.
- Barbeito, L.; J. Siciliano, F. Dajas (1990). "Depletion of the Ca++-dependent releasable pool of glutamate in striatal synaptosomes associated with dendrotoxin-induced potassium channel blockade". Journal of Neural Transmission 80 (3): 167–179. doi:10.1007/BF01245118. PMID 1970482. Retrieved 12 December 2013.
- Reed, Tim; Eaton, Katie; Peng, Cathy and Doern, BettyLou. Neurotoxins in Snake Venom. California State University Stanislaus. csustan.edu. Retrieved on 2012-07-08.
- van Aswegen G, van Rooyen JM, Fourie C, Oberholzer G. (1996). "Putative cardiotoxicity of the venoms of three mamba species". Journal of Wilderness and Environmental Medicine 7 (2): 115–21. doi:10.1580/1080-6032(1996)007[0115:PCOTVO]2.3.CO;2. PMID 11990104.
- J R de Weille, H Schweitz, P Maes, A Tartar, and M Lazdunski (15 March 1991). "Calciseptine, a peptide isolated from black mamba venom, is a specific blocker of the L-type calcium channel". Proceedings of the National Academy of Science of the United States of America 88 (6): 2437–2440. doi:10.1073/pnas.88.6.2437. PMC 51247. PMID 1848702.
- Silveira, R.; L. Barbeito, F. Dajas (1988). "Behavioral and neurochemical effects of intraperitoneally injected dendrotoxin". Toxicon 26 (3): 287–292. doi:10.1016/0041-0101(88)90219-X. PMID 3394161.
- Minton, Minton, SA, MR (1969). Venomous Reptiles. USA: New York Charles Scribner's Sons.
- Brown, JH (1973). Toxicology and Pharmacology of Venoms from Poisonous Snakes. Springfield, Illinois: Charles C. Thomas. p. 184. ISBN 0-398-02808-7. LCCN 73–229.
- Visser, Chapman, John, David S (1978). Snakes and Snakebite: Venomous snakes and management of snake bite in Southern Africa. Purnell. ISBN 0-86843-011-0.
- Naidoo, DP; Lockhat HS, Naiker IP (21 March 1987). "Myocardial infarction after probable black mamba envenomation. A case report". South African Medical Journal 71 (6): 388–9. PMID 3563776. Retrieved 1 December 2013.
- Christensen, PA (20 June 1981). "Snakebite and the use of antivenom in southern Africa". South African Medical Journal 59 (26): 934–938. PMID 7244896.
- "Venomous and Poisonous Animals Biology & Clinical Management (Dendroaspis sp)". VAPAGuide. Retrieved 3 December 2013.
- Schmidt, Warren (2006). Reptiles and Amphibians of Southern Africa. Struik Publishers. p. 34. ISBN 978-1-77007-342-5.
- Berndt KD, Güntert P, Wüthrich K. (1993). "[Nuclear magnetic resonance solution structure of dendrotoxin K from the venom of Dendroaspis polylepis polylepis.]". Journal of Molecular Biology 234 (3): 735–50. doi:10.1006/jmbi.1993.1623. PMID 8254670.
- Newitt RA, Houamed KM, Rehm H, Tempel BL. (1991). "[Potassium channels and epilepsy: evidence that the epileptogenic toxin, dendrotoxin, binds to potassium channel proteins.]". Epilepsy Research Supplement 4: 263–73. PMID 1815606.
- Rang, H. P. (2003). Pharmacology. Edinburgh: Churchill Livingstone. p. 139. ISBN 0-443-07145-4.
- Diochot, S.; Baron, A.; Salinas, M.; Douguet, D.; Scarzello, S.; Dabert-Gay, A. S.; Debayle, D.; Friend, V. R.; Alloui, A.; Lazdunski, M.; Lingueglia, E. (2012). "Black mamba venom peptides target acid-sensing ion channels to abolish pain". Nature 490 (7421): 552–555. doi:10.1038/nature11494. PMID 23034652.
- Gallagher, James (3 October 2012). "Black mamba venom is 'better painkiller' than morphine". BBC News Health. BBC. Retrieved 3 October 2012. Describes research by Dr Eric Lingueglia and others, Institute of Molecular and Cellular Pharmacology (Institut de Pharmacologie Moléculaire et Cellulaire), France
- Kasturiratne, A. "Global Snakebite Statistics – Epidemiology". International Society on Toxinology – Global Snakebite Initiative. International Society on Toxinology (IST). Retrieved 13 December 2011.
- "Antivenom Swazi Foundation". Antivenom Swazi Trust Fund. www.antivenomswazi.org. Retrieved 9 December 2011.
- "The Antivenom Crisis in Africa". Global Snakebite Initiative. Retrieved 4 December 2013.
- 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.
- Smith, Roddy. "Black Mamba Myths & Other Snake Stories". Wildlife Conservation – Lower Zambezi National Park, Zambia. The Witness. Retrieved 2 December 2011.
- "Black Mamba Facts". Siyabona Africa. Kruger Park Times. Retrieved 4 December 2013.
- Thorpe, Roger S.; Wolfgang Wüster, Anita Malhotra (1996). Venomous Snakes: Ecology, Evolution, and Snakebite'. Oxford, England: Oxford University Press. ISBN 978-0-19-854986-4
- Roy W.; Jonathan A. Campbell; T'Shaka S. Toure McDiarmid (1999). Snake Species of the World: A Taxonomic and Geographic Reference, Volume 1. Herpetologists' League. ISBN 978-1-893777-01-9
- Spawls, Stephen; Branch, Bill (1995). Dangerous Snakes of Africa: Natural History - Species Directory - Venoms and Snakebite.Ralph Curtis Pub; Revised edition. ISBN 978-0-88359-029-4
- Dobiey, Maik; Vogel, Gernot (2007). Terralog: Venomous Snakes of Africa (Terralog Vol. 15). Aqualog Verlag GmbH.; 1 edition. ISBN 978-3-939759-04-1
- Mackessy, Stephen P. (2009). Handbook of Venoms and Toxins of Reptiles. CRC Press; 1 edition. ISBN 978-0-8493-9165-1
- Greene, Harry W.; Fogden, Michael; Fogden, Patricia (2000). Snakes: The Evolution of Mystery in Nature. University of California Press. ISBN 978-0-520-22487-2
- Spawls, Stephen; Ashe, James; Howell, Kim; Drewes, Robert C. (2001). Field Guide to the Reptiles of East Africa: All the Reptiles of Kenya, Tanzania, Uganda, Rwanda and Burundi Princeton University Press. ISBN 978-0-12-656470-9
- Broadley; Doria; Wigge, DG; CT; J (2003). Snakes of Zambia: An Atlas and Field Guide. Frankfurt am Main, Germany: Edition Chimaira. ISBN 978-3-930612-42-0
- Marais, Johan (2005). A Complete Guide to the Snakes of Southern Africa. Cape Town, South Africa: Struik Nature. ISBN 978-1-86872-932-6
- Engelmann, Wolf-Eberhard (1981). Snakes: Biology, Behavior, and Relationship to Man. Leipzig; English version NY, USA: Leipzig Publishing; English version published by Exeter Books (1982). ISBN 0-89673-110-3
- Minton, Sherman A. (1969). Venomous Reptiles. USA: New York Simon Schuster Trade. ISBN 978-0-684-71845-3
- FitzSimons, Vivian FM (1970). A field guide to the snakes of Southern Africa. Canada: HarperCollins. ISBN 0-00-212146-8
- Department of the Navy Bureau of Medicine and Surgery (2013). Venomous Snakes of the World: A Manual for Use by U.S. Amphibious Forces. Skyhorse Publishing. ISBN 978-1-62087-623-7
- Branch, Bill (1988). Bill Branch's Field Guide to the Snakes and Other Reptiles of Southern Africa (More than 500 Photographs for Easy Identification). Struik Publishers. ISBN 978-0-86977-641-4
- Branch, Bill (1998). Field Guide to the Snakes and Other Reptiles of Southern Africa. Ralph Curtis Publishing. ISBN 978-0-88359-042-3
- Branch, Bill (2005). Photographic Guide to Snakes Other Reptiles and Amphibians of East Africa. Ralph Curtis Books. ISBN 978-0-88359-059-1
- Mara, Wil; Collins, Joseph T; Minton, SA (1993). Venomous Snakes of the World. Tfh Pubns Inc. ISBN 978-0-86622-522-9
- Stocker, Kurt F. (1990). Medical Use of Snake Venom Proteins. CRC Press. ISBN 978-0-8493-5846-3
- Mebs, Dietrich (2002). Venomous and Poisonous Animals: A Handbook for Biologists, Toxicologists and Toxinologists, Physicians and Pharmacists. Medpharm. ISBN 978-0-8493-1264-9
- White, Julian; Meier, Jurg (1995). Handbook of Clinical Toxicology of Animal Venoms and Poisons. CRC Press. ISBN 978-0-8493-4489-3
- Vitt, Laurie J; Caldwell, Janalee P. (2013). Herpetology, Fourth Edition: An Introductory Biology of Amphibians and Reptiles. Academic Press. ISBN 978-0-12-386919-7
- Tu, Anthony T. (1991). Handbook of Natural Toxins, Vol. 5: Reptile Venoms and Toxins. Marcel Dekker. ISBN 978-0-8247-8376-1
- Mattison, Chris (1995). The Encyclopedia of Snakes. Facts on File; 1st U.S. Edition edition. ISBN 978-0-8160-3072-9
- Coborn, John (1991). The Atlas of Snakes of the World TFH Publications. ISBN 978-0-86622-749-0