Dendroaspis polylepis

- THOMPSON M,
Dendroaspis polylepsis
Natural history
Allen hunter
When herpetologists are asked "What's the world's most dangerous snake?", most would probably state that Africa's Black mamba (Dendroaspis polylepis) and Australia's Taipan (Oxyuranus scutellatus) as the two top contenders. These members of the Elapidae family of venomous snakes grow to large size, are similar in habits, and both have uncertain tempers coupled with copious amounts of exceedingly potent neurotoxic venom. Legends surrounding the Black mamba regarding it's speed, agility, ferocity and deadliness of it's venom are often greatly exaggerated, but do hold some basis in fact. It's listed in the Guinness Book of World Records as ' The World's Fastest Snake', and indeed, it is extremely fast and difficult to control when spooked. Although Africa has a few other speed demons such as the various sand snakes (Psammophis ssp.), Gold's tree cobra (Pseudohaje goldi) and the Forest cobra (Naja melanoleuca), none have achieved the status of the Black mamba (except to herpers!).
Distribution
South Africa (Pondoland, Natal,Transvaal), Botswana, Namibia, Zimbabwe, Zambia, Malawi, Mozambique, Angola, Zaire, East Africa. A subspecies, the Northern Black mamba (D. p. antinori) occurs in Northern Kenya, north-eastern Uganda, Eritrea, Somalia and Ethiopia. This subspecies differs from the nominate race only in a variation in head-shields and a higher average number of scale rows.
Description
SIZE: Averages 8-9ft., 10-12ft. specimens are not uncommon and the record is 14ft. Supposedly, females grow larger than males. This is the world's second longest venomous snake next to the King cobra (Ophiophagus hannah).
APPEARANCE: Long slender elapid with an aptly described 'coffin' shaped head, face paler than the body with gray or greenish-brown medium size eyes. Mid-body scale count is 23-25 rows with body color generally from olive-brown in the northern/western parts of it's range to a slate/gunmetal gray in the southern and humid coastal areas. There is often black speckling along the back half of the body. Belly color is grayish/greenish white. The young are olive to greenish-gray at hatching, but attain adult coloration at about 3-4ft. in length. Despite it's common name, it's never actually black but derives it's name from the color of the inside of it's mouth, which is purple-black and will gladly show you during it's impressive threat display when angered.
RELATED SPECIES: The Eastern Green mamba (D. angusticeps), Western Green mamba (D. viridis), and Jameson's mamba (D. jamesoni) are all highly arboreal species with bright green coloration to a greater or lesser degree, are smaller (average 6-7ft.) and have a more timid disposition (although I also work with D. angusticeps and agree with this, I'm told that D. jamesoni doesn't take much to anger).
Habitat
The Black mamba inhabits lower-altitude areas in savannas, semi-arid bush country, open woodlands and rocky outcrops. Of the four species of mambas, it is the most terrestrial but will occasionally ascend trees in search of prey, bask, or to escape predators. As homes they will often utilise unused termite mounds, tree hollows, rock crevices or mammal burrows, sometimes using the same home base for years unless unduly disturbed by predators, habitat destruction or nervy snake collectors! ;-)
Behaviour
A truly anti-social reptile (unlike the green mambas, which are often found in pairs or groups in the trees) , the Black mamba is shy and extremely nervous, taking flight at the first sign of human encroachment and rarely allowing an approach of less than 75ft. If cornered or an attempt to capture it are made, the Black mamba will (when angered, which doesn't take much) give a threat display as follows: raise the front body and head well off the ground (3-4ft. in large specimens), spread a flat narrow hood while shaking the head, gaping the mouth showing the purple-black interior and emitting a long hollow-sounding hiss that is thoroughly convincing. When confronted with an angry mamba displaying as such, FREEZE! Be forewarned; unlike most cobras this snake doesn't bluff, and will not hesitate to attack - usually delivering quick multiple bites while dashing for freedom past the victim. The very large size attained by these snakes give them the ability to strike from a long way out and up (4-6ft. away and upper body bites). With patience by the would-be victim, the mamba will slowly and cautiously retreat, allowing it's escape. Black mambas are diurnal (active by day), and usually emerge from their home base (see Habitat) in the early morning to bask and then forage for prey, which mostly consists of small mammals such as rats, mice, squirrels, voles, bushbabies; and various small to medium sized birds (a killed 12 ft. mamba was found to have a parrot in it's stomach, and another large mamba was witnessed consuming an adult Forest cobra!).The Black mamba lays between 6 and 17 eggs (averaging 12) usually down moist unused mammal burrows, and take 90-96 days to hatch with the young measuring 18-24 inches.
Venom
The venom of the Black mamba is a highly potent neurotoxin and cardiotoxin with an average adult yield of 100-120 mg. The approx. lethal dose for an average-sized human is 10-15 mg. About 2 full drops is fatal, so it can be appreciated how serious and urgent a bite (or even a scratch from a fang) must be treated. Mambas, along with Taipans and Death adders, have the longest fangs of all elapids, which have generally short fixed fangs. Why mambas evolved with such long fangs is uncertain, but it's presumed to be for penetrating the feathers of birds. Collapse following a mamba bite in under 15 minutes is uncommon, but not unheard of. In most fatal cases, the average time from bite to death is approx. 4 hours. If systemic symptoms appear within 10-15 mins., it can be presumed a lethal dose has been injected. Initial first-aid utilising 'The Extractor' suction device quickly followed by the pressure bandage/immobilization technique are recommended. For more detailed first-aid and bite management, go to the Snakebyte Emergency Web page. Severe envenomations by mambas will often produce a suite of symptoms such as tightening of the chest and throat muscles, drooling caused by gradual paralysis of the facial muscles, slurred speech, drooping eyelids, mental confusion, blurred vision and dilated pupils, flaccid paralysis of all muscle groups and loss of tendon reflex, then respiratory distress. The victim struggles to breathe, the chest feels tight and painful, the lungs eventually stop functioning, convulsions and coma precede death. The cardiotoxin (Dendrotoxins I and K) present in mamba venom causes the heart to beat wildly and erratically. Patients should be closely monitored for possible delayed relapse, even though the treatment and recovery seemed successful. Before the advent of mamba antivenins in the mid-1960's, bites by black mambas were 100% fatal. Antivenin is essential in treating mamba bites, and unless there was little or no venom injected, the victim will probably not survive without it. Much antivenin may be necessary in serious cases, as much as 100ml (approx. 10 vials) or more may be required. Mamba antivenins are available in trivalent specific and polyvalent forms from S.A. I.M. R. in South Africa, Pasteur in France and Behringwerk in Germany
Q: How fast are black mambas?
A: Many wild and totally exaggerated tales surround the black mamba. Such stories of them chasing bicycles, galloping horses and even cars (!) are pure rubbish. I suppose the next stage in mamba evolution will have them sprouting wings and breathing fire! (grin) Please! Seriously, black mambas are indeed among the fastest of snakes, and even the Guinness Book of World Records has them listed as the fastest. But fast is a relative term, and the mamba has been actually clocked at approx. 12mph. In a confined area, or up close, this may seem much quicker. In areas such as dense brush or tall grass where a person cannot move quickly, yes the mamba has the speed advantage. But on open ground, a fully-grown adult will have little trouble out-running an attacking mamba.
Q: I've heard of almost instantaneous death from mamba venom. Is this true?
A: Well, mamba venom is indeed very toxic, but I know of not a single case of "instant" death from a bite. Generally, the 'average' time from a serious bite to death is approximately 4 hours. This is provided that the victim received little/no antivenin and/or proper and knowledgeable hospital treatment. Really, the only feasible way I can see someone dying almost instantly from any venomous snakebite(and this is a truly freak accident), would be that a fang hit and injected venom directly into a vein or artery. Then yes, you'd be toast in a minute or so! Another possible explanation for a quick demise, is the victim being allergic to the venom and immediately going into anaphylactic shock. Without immediate injections of adrenaline, the victim would die in a few minutes. Sadly, this happened to a friend of mine that was bitten by an Egyptian cobra, and died in 12 minutes on the front lawn waiting for an ambulance. Truly a tragedy
Q: How much antivenin is needed to treat a black mamba bite?
A: Much antivenin can be required. At the first signs of envenomation, a *minimum* of five 10ml vials should be administered as an *initial* dose, adding more when or if symptoms increase. As a general rule, on average, most bites require by severity: Mild} 5-10 vials, Moderate } 10-15 vials, Severe } 15-20 vials, Life-threatening } 20+ vials. I've heard of really bad bites where as much as 30+ vials were used, and the victim ended up dying anyway! Food for thought! :-(
Mambas, genus dendroaspis
Mambas are restricted to subsaharan Africa, where four species are known. They are large, agile, slender, diurnal elapid snakes with long, flat-sided head, a medium-sized eye and a round pupil. Their scales are smooth and narrow, in 13-25 rows at midbody. Three species are confined to forest or woodland, but the black mamba (Dendroaspis polylepis) occurs in savannah. All except the black mamba are arboreal. All lay eggs. They are the most feared of African snakes, but their reputation is largely unjustified and based mostly on legend. They are not aggressive and they do not attack people. However, the black mamba is the biggest venomous snake in Africa, reaching a length of 3.5 m (possibly more!), is widespread in savannah and is willing to bite. Mambas have a neutrotoxic venom, and victims need prompt and thorough treatment.

Comments

Popular posts from this blog

Homeopathic Remedies for Over Sensitive to Noise&Tinnitus

The Effective treatment of Urethral stricture with Homeopathy

Dr.Devendra Kumar Munta MD Homeo,International Homeopathic Consultant