Naja atra
(Chinese cobra)

Scientific classification

Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Order: Squamata
Suborder: Serpentes
Family: Elapidae
Genus: Naja
Species: N. atra
Binomial name
Naja atra
Cantor, 1842
Synonyms
Naja nigra Gray

The Chinese Cobra (Naja atra) or the Taiwan Cobra is a type of cobra species found in China and some other Asian countries. It is one of the most common and famous Chinese venomous snakes. The Chinese Cobra has potent venom and has caused many snake bite cases.

Contents
1 Characteristics
1.1 Scalation
1.2 Identification
2 Distribution
3 Behavior
4 Reproduction
5 vEnOm

Characteristics

This medium snake, usually 1.2-1.5 m long, reaches a maximum length of 1.94 m (male) and 1.64 m (female). Large specimens of 2.3 m in length have been reported . The dorsal color of the Chinese Cobra is usually brown, grey or black, with or without narrow, light transverse lines at irregular intervals which are especially prominent in juveniles. The hood mark shape of the snake is highly variable: spectacle, mask, horseshoe or O-shape;sometimes linking to light throat area. It has clearly defined throat area usually with a black transverse band and 2 black spots above the band.

Scalation

23-29 scale rows around hood (usually 25-27) ; 19-21 just ahead mid-body(usually 21); ventral scales 161-180(usually 171 in males, 173 in females); subcaudal scales 37-51 pairs (usually 48 in males, 46 in females).

Identification

The Chinese Cobra is easily confused with the Monocled Cobra (Naja kaouthia). But it is most easily distinguished by virtue of having lower ventral and subcaudal scale counts, particular when sex is taken into account.

Distribution

This species is found in the southeastern China, including Hong Kong, Hainan and Taiwan, northern Laos and northern Vietnam.It inhabits in different kinds of land habitats such as woodlands, shrublands, grasslands and mangroves often hiding beneath objects.

Behavior

The Chinese Cobra has a characteristic defensive behavior. When threatened, this snake rises one third of the fore body, hissing loudly and the characteristic hood on the neck is expanded. The Chinese Cobra usually escapes to avoid confrontation with humans. However, strikes are readily if provoked. The Chinese Cobra mainly preys on rodents, frogs, toads and other snakes. It is active during both the day and night.

Reproduction

It is Oviparous.

vEnOm

The Chinese Cobra is highly venomous. Its venom consists mainly of cobratoxin (neurotoxin), hemotoxin and cardiotoxin. The LD50 is 0.53 mg/kg to mice. The average venom yield from this snake is about 250.8 mg and it is enough to kill 10 people. Some individuals (mostly the specimens from Guizhou Province) might spit venom towards the enemy with a distance of two meters. Local symptoms of victims caused by Chinese cobra are: wound darkening, localized redness and swelling, pain, insensibility, and always accompanied by blisters and necrosis. Necrosis is a serious problem in case of bites by cobra as it may last a long period of many years after recovery of the victim. The following systemic symptoms may occur: chest uncomfortable, fever, sore-throat, difficulty in swallowing, loss of voice, weak feeling in limbs, walking haltingly, general ache, lockjaw, and difficult breathing. Fatality occasionally occurs. The anti-venom is widely available nowadays and deaths are being much rare.

RATTLE SNAKE

Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Order: Squamata
Suborder: Serpentes
Family: Viperidae
Subfamily: Crotalinae
Genera

Crotalus Linnaeus, 1758
Sistrurus Garman, 1883
Rattlesnakes are a group of venomous snakes, genera Crotalus and Sistrurus. They belong to the subfamily of venomous snakes known as Crotalinae (pit vipers).

Contents

1 Overview
2 Prey
3 Reproduction
4 Rattle
5 Safety and identification
6 Bites
6.1 vEnOm
6.2 First aid
7 Human consuption
8 Captivity

Overview

There are approximately thirty species of rattlesnake, with numerous subspecies. They receive their name for the rattle located at the end of their tails. The rattle is used as a warning device when threatened. The scientific name Crotalus derives from the Greek, κρόταλον, meaning "castanet". The name Sistrurus is the Latinized form of the Greek word for "tail rattler" (Σείστρουρος, Seistrouros) and shares its root with the ancient Egyptian musical instrument, the sistrum, a type of rattle. Most rattlesnakes mate in the spring. All species give live birth, rather than laying eggs. The young are self-sufficient from birth. Since they do not need their mother after birth, the mother does not remain with her young. However, at least one captive study has demonstrated that females and their neonates show some level of affinity for each other's company and will cross barriers to reunite if separated.[citation needed]
Contrary to popular myth, rattlesnakes are not deaf. In fact, the structure of their inner ears is very much like that of other reptiles. They do, however, lack external ears. Sound (whether from air or ground vibration) is transmitted to the snake's inner ear via bone and muscle.

Prey

Rattlesnakes consume mice, rats, small birds and other small animals. They subdue their prey quickly with a venomous bite as opposed to constricting. The venom will immediately stun or kill typical prey. Rattlesnake venom can kill in 20 seconds, but a rattlesnake will follow prey that does not quickly succumb to the venom and attempts to escape. Rattlers are known to strike at distances up to two-thirds their body length.

Reproduction

Although many kinds of snakes are oviparous (lay eggs), rattlesnakes are ovoviviparous – the female retains the eggs in her body and they hatch as they are laid or soon afterwards; or viviparous (give birth to live young). Baby snakes are ready to go as soon as they are hatched or born. There is little to no parental care of the newborn snakes.

Rattlesnake rattle

The rattle is composed of a series of nested, hollow beads which are actually modified scales from the tail tip. Each time the snake sheds its skin, a new rattle segment is added. They may shed their skins several times a year depending on food supply and growth rates. Newborn rattlesnakes (pre-button) do not have functional rattles; it is not until after they have shed their skin for the first time that they gain an additional bead, which beats against the first bead, known as the button, to create the rattling sound. Adult snakes may lose their rattles on occasion, but more appear at each molting. If the rattle absorbs enough water in wet weather, it will not make noise.

Safety and identification

Young rattlesnake warming itself on the pavement - Del Valle Regional Park, Livermore, CA
Juvenile Southern Pacific Rattlesnake in California
Different species of rattlesnake vary significantly in size, territory, markings, and temperament. If the rattlesnake is not cornered or imminently threatened, it will usually attempt to flee from encounters with humans, but will not always do so. Bites often occur when humans startle the snake or provoke it. Those bitten while provoking rattlesnakes have usually underestimated the range (roughly two-thirds of its total length) and speed with which a coiled snake can strike (literally faster than the human eye can follow). Heavy boots and long pants reinforced with leather or canvas are recommended for hikers in areas known to harbor rattlesnakes.
Guides are available through booksellers, libraries, and local conservation and wildlife management agencies that aid hikers and campers in identifying rattlesnakes. The advice given is to avoid contact with rattlesnakes by remaining observant and not approaching the animals. Hikers are advised to be particularly careful when negotiating fallen logs or boulders and when near rocky outcroppings and ledges where rattlesnakes may be hiding or sunning themselves. However, snakes will occasionally sun themselves in the middle of a trail, so such areas are not the only places where they are encountered. When encountering a rattlesnake on a trail, hikers are advised to keep their distance and allow the snake room to retreat.

A rattlesnake warning sign

Rattlesnakes are born with fully functioning fangs capable of injecting venom and can regulate the amount of venom they inject when biting. Generally they deliver a full dose of venom to their prey, but may deliver less venom or none at all when biting defensively. A frightened or injured snake may not exercise such control. Young snakes are also dangerous, because their venom is actually more potent than that of adults.

vEnOm

Most species of rattlesnakes have hemotoxic venom, destroying tissue, degenerating organs and causing coagulopathy (disrupted blood clotting). Some degree of permanent scarring is very likely in the event of a venomous bite, even with prompt, effective treatment, and a severe envenomation, combined with delayed or ineffective treatment, can lead to the loss of a limb or death. Thus, a rattlesnake bite is always a potentially fatal injury. Untreated rattlesnake bites, especially from larger species, are very often fatal. However, antivenom, when applied in time, reduces the death rate to less than 4%. It is estimated that between 7,000 and 8,000 people are bitten by venomous snakes in the United States each year, and about five of those die.About 72% of those bitten by rattlesnakes are male.
Some rattlesnakes, especially the tropical species, have neurotoxic venom. A bite from these snakes can interfere with or shut down parts of the nervous system. In the U.S. the Mojave Rattlesnake (Crotalus scutulatus) in Arizona and parts of California has a neurotoxic venom component known as Mojave Type A toxin. The current antivenom, (FDA-approved in October, 2000) known as CroFab, contains antibodies to Mojave A and B toxins as well as the toxins of most other U.S. pit vipers. Mojave A toxin has been identified present in the venoms of other species of rattlesnakes on occasion. Neurotoxins cause neurological symptoms, paralysis and could result in death due to respiratory paralysis. In the U.S., Central and South America there are another group of neurotoxic snakes known as the Coral Snakes, not related to rattlesnakes but more closely related to the cobra family of Africa and Asia. These snakes can also cause death due to respiratory paralysis if not properly treated.
The Common Kingsnake (Lampropeltis getula), a constrictor, is famous for being largely immune to the venom of rattlesnakes and other vipers, and therefore rattlesnakes form part of this snake's natural diet in the wild.

First aid

When a bite occurs, the amount of venom injected cannot be gauged easily. Symptoms and swelling may occur quickly, and may cause death easily but in some cases hours may pass before serious effects appear.
Experienced health workers typically gauge envenomation in stages ranging from 0, when there is no evident venom, to 5, when there is a life-threatening amount of venom present. The stages reflect the amount of bruising and swelling around the fang marks and the speed with which that bruising and swelling progresses. In more severe envenomation cases (stage 4 or 5) there may also be proximal symptoms, such as lip-tingling, dizziness, bleeding, vomiting, or shock. Difficulty breathing, paralysis, drooling, and massive haemorrhaging are also common symptoms.
Quick medical attention is critical, and treatment typically requires antivenin/antivenom to block the tissue destruction, nerve effects, and blood-clotting disorders common with rattlesnake venom. Most medical experts recommend keeping the area of the bite below the level of the heart. It is important to keep a snake bite victim calm in order to avoid elevating their heart rate and accelerating the circulation of venom within the body. Untrained individuals should not attempt to make incisions at or around bite sites, or to use tourniquets, as either treatment may be more destructive than the envenomation itself.
Any bite from a rattlesnake should be regarded as a life-threatening medical emergency that requires immediate hospital treatment from trained professionals.

Human consumption

Rattlesnakes are also a popular food in some southeastern and southwestern American cuisines and are sometimes sold in specialty meat shops. The flavor has been characterized by one vendor as "delicate" and "resembling chicken"; and by journalist Alistair Cooke as "just like chicken, only tougher." Others have compared the flavor to a wide range of other meats, including veal, frog, tortoise, quail, fish, rabbit, and even canned tuna.

Captivity

There are fairly obvious risks with private ownership of rattlesnakes. A bite can cause death or permanent disability. Even a nonfatal bite can lead to very high costs for emergency medical care.Some jurisdictions outlaw the possession of venomous snakes. Where it is legal, some form of license or insurance policy may be required.

CORAL SNAKE

Coral snake (Micrurus sp.)
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Order: Squamata
Suborder: Serpentes
Family: Elapidae
Genus: Leptomicrurus
Calliophis
Micrurus
Micruroides
Species


The Distribution of the US Coral Snakes, some species range father south
The coral snakes are a large group of elapid snakes that can be subdivided into two distinct groups, Old World coral snakes and New World coral snakes. There are 11 species of Old World coral snake in one genus (Calliophis), and over 65 recognized species of New World coral snakes in three genera (Leptomicrurus, Micruroides, and Micrurus).

Contents
1 North American Coloration Patterns
2 Behavior
3 Distribution
4 vEnOm

Coral snakes are most notable for their red, yellow/white, and black colored banding. (Several nonvenomous species have similar coloration, however, including the Scarlet Kingsnake, the Milk Snake, and the Chionactis occipitalis annulata.) In some regions, the order of the bands distinguishes between the non-venomous mimics and the venomous coral snakes, inspiring some folk rhymes — "Red on yellow, kill a fellow; red on black, friend of Jack" (for similar looking Milk Snakes). However, this only reliably applies to coral snakes native to North America: Micrurus fulvius (Eastern or common), Micrurus tener (Texas), and Micruroides euryxanthus (Arizona), found in the southern and eastern United States. Coral snakes found in other parts of the world can have distinctly different patterns, have red bands touching black bands, have only pink and blue banding, or have no banding at all.
Most species of coral snake are small in size. North American species average around 3 feet (91 cm) in length, but specimens of up to 5 feet (150 cm) or slightly larger have been reported. Aquatic species have flattened tails, to act as a fin, aiding in swimming.

Behavior

Coral snake showing typically reclusive behavior of hiding under rotting wood. This one was over 30 inches long, but less than an inch across.
Coral snakes vary widely in their behavior, but most are very elusive, fossorial snakes which spend the vast majority of their time buried beneath the ground or in the leaf litter of a rainforest floor, only coming to the surface during rains or during breeding season. Some species, like Micrurus surinamensis are almost entirely aquatic and spend most of their lives in slow-moving bodies of water that have dense vegetation.
Like all elapid snakes, coral snakes use a pair of small fangs fixed in the front of their top jaw to deliver their venom. They feed on smaller snakes, lizards, frogs, and nestling birds and rodents etc. The venom takes time to fully take effect.
Coral snakes have a tendency to hold on to a victim when biting, unlike vipers which have retractable fangs and tend to prefer to strike and let go immediately. Coral snakes are not aggressive or prone to biting however, and account for less than one percent of the number of snake bites each year in the United States. Most coral snake bites in the United States are legitimate occurring because of accidental contact with the snake while engaged in an outdoor activity such as gardening.

Distribution

Eastern Coral Snake, Micrurus fulvius
New World coral snakes exist in the southern range of many temperate U.S. states.
Coral Snakes are found in scattered localities in the southern Coastal Plain from North Carolina to Louisiana, including all of Florida. They can be found in pine and scrub oak sandhills habitats in parts of this range but sometimes inhabit hardwood areas and pine flatwoods that undergo seasonal flooding.
There is controversy about the classification of the very similar Texas coral snake as a separate species. Its habitat, in Texas, Louisiana, and Arkansas, is separated from the eastern habitat by the Mississippi River. The map here shows the denser population in the southeast United States but coral snakes have been spotted as far north as Kentucky.
The Arizona coral snake, clearly a separate species, is found in central and southern Arizona, extreme southwestern New Mexico and southward to Sinaloa in western Mexico. It occupies arid and semiarid regions in many different habitat types including thornscrub, desert-scrub, woodland, grassland and farmland. It is found in the plains and lower mountain slopes from sea level to 5800 feet (1768 m); often found in rocky areas.

vEnOm

New World coral snakes possess the second most potent venom of any North American snake, behind some rattlesnake species. However, few bites are recorded due to their reclusive nature and the fact they generally inhabit sparsely populated areas. When confronted by humans, coral snakes will almost always attempt to flee, and bite only as a last resort. In addition, coral snakes have short fangs (proteroglyph dentition) that cannot penetrate thick leather clothing. Any skin penetration, however, is a medical emergency that requires immediate attention. Coral snakes have a powerful neurotoxin that paralyzes the breathing muscles; mechanical or artificial respiration, along with large doses of antivenom, are often required to save a victim's life. There is usually only mild pain associated with a bite, but breathing difficulties and ptosis can occur within hours.
The bite of a coral snake may soon become increasingly more dangerous, ironically because of the relatively few bites each year. Production of coral snake antivenom in the United States has ceased because it is not profitable. The current antivenom stock is scheduled to expire in 2010, after two consecutive expiration date extensions approved by the FDA. Foreign pharmaceutical manufacturers have produced coral snake antivenoms such as Coralmyn, but the costs associated with licensing them in the United States have stalled availability.

KING COBRA

This article is about the snake. For other uses, see King Cobra (disambiguation).

King Cobra

Conservation status

Least Concern (IUCN 3.1)
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Order: Squamata
Suborder: Serpentes
Family: Elapidae
Genus: Ophiophagus
Species: O. hannah
Binomial name
Ophiophagus hannah
Cantor, 1836

Distribution of the King Cobra
Synonyms
Genus-level:
Hamadryas Cantor, 1838 (non Hübner, 1804: preoccupied)
The King Cobra (Ophiophagus hannah) is the world's longest venomous snake, with a length up to 5.6 m (18.5 ft).[1] This species is widespread throughout Southeast Asia and parts of India, and is found mostly in forested areas. The King Cobra is fierce, agile, and can deliver a large quantity of highly potent venom in a single bite. It is one of the most dangerous and feared Asiatic snakes.
Contents
1 Profile
2 Characteristics
2.1 Identification
2.2 Scalation
3 Habitat
4 Behavior
4.1 Defense
5 Diet
6 Venom
7 Reproduction
8 Other culture
9 Related species
10 Gallery
11 References

Profile

The King Cobra is a large and powerful snake, averaging 3.6–4 m (12–13 feet) in length and typically weighing about 6 kg (13.2 lb). A particularly large specimen was kept captive at the London Zoo and grew to 5.7 m (18.8 ft) before being euthanized upon the outbreak of World War II. Despite their large size, King Cobras are fast and agile.

Characteristics

The skin of this snake is either olive-green, tan, or black and it has faint, pale yellow cross bands down the length of the body. The belly is cream or pale yellow, and the scales are smooth. Juveniles are shiny black with narrow yellow bands(can be mistaken for a Banded Krait but readily identified with its expanded hood). The head of a mature snake can be quite massive and bulky in appearance, though like all snakes, they can expand their jaws to swallow large prey items. It has proteroglyph dentition, meaning it has two short, fixed fangs in the front of the mouth which channel venom into the prey like hypodermic needles. The male is larger and thicker than the female. The average lifespan of a King Cobra is about 20 years.

Identification

The King Cobra is the sole member of genus Ophiophagus, while most other cobras are members of the genus Naja. It can be identified from other cobras by its size and its hood mark. King cobras are larger than other cobras, and the stripe on its neck is like the symbol "^" instead of a double or single eye(s) shape that may be seen in most of the other cobras.

Scalation

Dorsal scales: midbody 15 rows; Ventral scales: Males 235-250, females 239-265; Tail: Sub-caudal scales single or paired in each row, 83-96 in males and 77-98 in females.

Habitat

The King Cobra is distributed across South and South-east Asia, but is not common. It lives in dense highland forests,[1][4], preferring areas dotted with lakes and streams. King Cobra populations have dropped in some areas of its range because of the destruction of forests, but despite this the snake is not listed by the IUCN as in danger of becoming extinct. It is, however, listed as an Appendix II Animal within CITES


Scalation of the King Cobra

Behavior

King Cobras, like other snakes, receive chemical information (“smell”) via their forked tongues, which pick up scent particles and transfer them to a special sensory receptor (Jacobson's Organ) located in the roof of its mouth. When the scent of a meal has been detected, the snake will flick its tongue to gauge the prey's direction (the twin forks of the tongue acting in stereo); it will also rely on its keen eyesight (King Cobras are able to detect moving prey almost 100 m [300 feeT>away), intelligenceand sensitivity to earth-borne vibration to track its prey.[7] Following envenomation, the King Cobra will begin to swallow its struggling prey while its toxins begin the digestion of its victim.King Cobras, as with all other snakes, do not have rigidly fixed jaws. Instead, the jaw bones are connected by extremely pliable ligaments, enabling the lower jaw bones to move independently of each other.Like other snakes, the King Cobra does not chew its food, instead it swallows its prey whole. The expansion of the jaw enables the snake to swallow prey much larger than its head.
King Cobras are able to hunt at all times of day, although it is rarely seen at night, leading most herpetologists to classify it as a diurnal species.

Defense

The King Cobra is regarded as a fierce and highly aggressive snake. When threatened, the King Cobra raises up the anterior portion of its body, flattening the neck, showing the fangs and hissing loudly. It is easily irritated by closely approaching objects or sudden movements. The King cobra attacks quickly and the strike distance is about 7 feet, people can easily misjudge the safe distance. The King Cobra may deliver multiple bites in a single attack or bite and hold on.Although the King Cobra is undoubtedly a very dangerous snake, it prefers to escape unless it is cornered or provoked.
If a King Cobra encounters a natural predator, such as the mongoose, which has some resistance to the neurotoxins,[11] the snake generally tries to flee. If unable to do so, it forms the distinctive cobra hood and emits a high-pitched hiss, sometimes with feigned closed-mouth strikes. These efforts usually prove to be very effective, especially since the King Cobra is more dangerous than other mongoose prey as well as being much too large for the small mammal to kill with ease.

Diet

King cobra's genus name, Ophiophagus, literally means "snake-eater", and its diet consists primarily of other snakes, including rat snakes, sizeable pythons and even other venomous snakes (including kraits, cobras and smaller members of its own species). When food is scarce, King Cobras may also feed on other small vertebrates such as lizards, birds, and rodents. In some cases, the cobra may “constrict” its prey, like birds and larger rodents using its muscular body, though this is uncommon.After a large meal the snake may live for many months without another one because of its slow metabolic rate. The King Cobra's most common meal is the Ratsnake. This leads King Cobras near human settlements.

vEnOm

The venom of King Cobra is primarily neurotoxic but also contains cardiotoxic compounds. It is composed mostly of proteins and polypeptides. During a bite, venom is forced through the snake's half-inch (1.25 cm) fangs and into the wound, and quickly attacks the victim's central nervous system and induces severe pain, blurred vision, vertigo, drowsiness, and paralysis.Envenomation progresses to cardiovascular collapse, and the victim falls into a coma. Death soon follows due to respiratory failure.
In the past, the LD50 of King Cobra’s venom was treated as 1.6 mg/kg-1.8 mg/kg (which is one of the least toxic elapids). However, the recent toxicology study shows that the LD50 of Chinese King Cobra venom is 0.34 mg/kg.This proves that actually the King Cobra can be more venomous than most of the other species with its range, like the Chinese Cobra. The King Cobra is also capable of delivering larger quantities of venom than most other venomous snakes, injecting a 380-600 mg dose in a single bite. This quantity is enough to kill 20-40 grown men or even an adult elephant. One bite from a King Cobra can cause the death of a healthy adult human within 15 minutes,but death usually occurs between 30–45 minutes.The mortality rate from a bite can be over 75%, or only 33%, depending upon treatment details. It is regarded as one of the deadliest snakes in the world.
There are two types of antivenom made specifically to treat King Cobra envenomations. The Red Cross in Thailand manufactures one, and the Central Research Institute in India manufactures the other; however, both are made in small quantities and are not widely available.Ohanin, a protein component of the venom, causes hypolocomotion and hyperalgesia in mammals. Other components have cardiotoxic, cytotoxic and neurotoxic effects.

Reproduction

The female King Cobra is a very dedicated parent. Before she is ready to lay her eggs, she uses the coils of her long body to gather a big mound of leaf litter. She deposits 20–40 eggs into the mound, which acts as an incubator. The female stays with her eggs and guards the mound tenaciously, rearing up into a threat display if any large animal gets too close.
Inside the mound that the female has built the eggs are incubated at a steady 28 °C (82 °F). When the eggs start to hatch, instinct causes her to leave the nest and find prey to eat so that she does not eat her young. The baby King Cobras can have a length of 45 to 55 centimeters (18 to 22 in). They are highly aggressive and have already developed potent venom which is as deadly as that of an adult.

Other culture

In Burma, King Cobras are often used by female snake charmers.The charmer is usually tattooed with three pictograms using an ink mixed with snake venom; superstition holds that it protects the charmer from the snake. The charmer kisses the snake on the top of its head at the end of the show.

Related species

The King Cobra belongs to the family Elapidae. There are over 200 species of elapid found around the world, except Antarctica and Europe. All are venomous and have short, fixed fangs (proteroglyphs), but may differ widely in habits, behaviour and appearance. Four better known species of the Elapidae are the Coral Snake, Death Adder, Black mamba, and of course, the King Cobra.

BLACK MAMBA

Scientific classification

Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Order: Squamata
Suborder: Serpentes
Family: Elapidae
Genus: Dendroaspis
Species: D. polylepis
Binomial name
Dendroaspis polylepis

The black mamba (Dendroaspis polylepis) is the longest venomous snake in Africa, averaging around 2.5 meters (8.2 ft), and sometimes growing up to 4.3 meters (14 ft). Apart from being considered one of the world's deadliest snakes,the black mamba is also one of the most feared snakes in Africa due to its potent venom, large size, and the ferocity of its attacks.Its name is derived from the black coloration inside the mouth; the actual color of the skin varies, from dull yellowish-green to a gun-metal gray. It is the fastest snake in the world, capable of moving at 4.5 to 5.4 meters per second (16–20 km/h, 10–12 mph).

Contents


* 1 Taxonomy
* 2 Etymology
* 3 Description
* 4 Distribution
* 5 Habitat
o 5.1 Environmental Encroachment
* 6 Behavior
o 6.1 Hunting and Prey
* 7 Venom
* 8 Predators
* 9 Gallery
* 10 References
* 11 External links


Taxonomy

The eastern green mamba, Dendroaspis angusticeps, and the black mamba, Dendroaspis polylepis were recognized as one species, until 1946 when Fitzsimon split them into separate species

Etymology

The snake's scientific name is Dendroaspis polylepis: Dendroaspis meaning "tree asp" and Polylepis meaning "many scaled." The name "black mamba" is given to the snake not because of its body color but because of its ink-black mouth.It displays this physical attribute when threatened
Description

The black mamba's back skin color is olive, brownish, gray, or sometimes khaki in color.The adult black mamba's length is on average 2.5 meters (8.2 ft),but some specimens have reached lengths of 4.3 to 4.5 meters (14 to 15 ft).[5] Black mambas weigh on average about 1.6 kilograms (3.5 lb).The black mamba is the second longest venomous snake in the world, which is only exceeded in length by the King Cobra. The snake also has an average life span of 11 years in the wild.

Distribution

The black mamba lives in Africa, occupying the following range: Northeast Zaire, southwestern Sudan to Ethiopia, Eritrea, Somalia, Kenya, Eastern Uganda, Tanzania, southwards to Mozambique, Malawi, Zambia, Zimbabwe and Botswana to Natal in South Africa, and Namibia; then northeasterly through Angola to southeastern Zaire.The black mamba is not commonly found above altitudes of 1000 meters (3280.8 feet), although the distribution of black mamba does reach 1800 meters (5905.5 feet) in Kenya and 1650 meters (5413.3 feet) in Zambia.The black mamba was also 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, has not been noted and thus the snake's distribution there is inconclusive.The black mamba’s 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 anti-venom

Habitat

The black mamba has adapted to a variety of climates ranging from savanna, woodlands, rocky slopes, dense forests and even humid swamps of Africa.The grassland and savanna woodland/shrubs that extend through central and western Africa are the black mamba’s typical habitat.The black mamba prefers more arid environments such as light woodland, rocky outcrops, and semi-arid dry bush country.

Environmental Encroachment

The sugarcane fields that dominate the habitat of the black mamba.

The black mamba's environment is rapidly diminishing. In Swaziland alone, 75% of the population is employed by subsistence farming.Because of agricultural encroachment on the black mamba's habitat, the snake is commonly found in sugarcane fields. The black mamba will climb to the top of the sugarcane to bask in the sun and possibly wait for prey. The majority of human attacks occur in the sugarcane fields as thousands of workers must plow the fields by hand. This encroachment on the snake's territory contributes to potentially dangerous human contact with these venomous snakes.Nearly 20,000 people die of snake bites each year, and the residents of Swaziland and southern Africa have suffered for generations.

Behavior

The black mamba uses its incredible speed to escape threats, not to hunt prey.It is known to be capable of reaching speeds of around 20 kilometers per hour (12 mph), traveling with up to a third of its body raised off the ground.Over long distances the black mamba travels 11 to 19 kilometers per hour (6.8 to 12 mph), but in short bursts the it can reach a speed of 23 kilometers per hour (14 mph),making it the fastest land snake.It is shy and secretive; it always seeks to escape when confronted.When a black mamba is cornered it mimics a cobra by spreading a neck-flap, exposing its black mouth, and hissing.If this attempt to scare away the attacker fails, the black mamba will strike repeatedly, injecting gratuitous amounts of venom.The black mamba is a diurnal snake. Although its scientific name seems to be indicative of tree climbing, the black mamba is rarely an arboreal snake.

Hunting and Prey

As stated, the black mamba is diurnal. It is an ambush predator that waits for hapless prey to get too close.If the prey attempts to escape, the black mamba will follow up its initial bite with a series of strikes.When hunting, the black mamba has been known to raise a large portion (approximately 48 centimeters or 18 inches) of its body off the ground.The black mamba will release larger prey after biting it, but smaller prey, such as birds or rats, are held onto until the prey's muscles stop moving. Black mambas have been known to prey on bushbabies, bats, and small chickens.

vEnOm

The venom of the black mamba consists mainly of neurotoxins with an LD50 of 0.25 mg/kg.Its bite delivers about 100–120 mg of venom on average; however, it can deliver up to 400 mg. The mortality rate is nearly 100%, unless the snakebite victim is promptly treated with antivenom.Black mamba bites can potentially kill a human within 20 minutes, but death usually occurs after 30–60 minutes, sometimes taking up to three hours (depending on the health, size, age, psychological state of the human, the penetration of one or both fangs from the snake, amount of venom injected, location of the bite, and proximity to major blood vessels.The health of the snake and the interval since it last used its venom mechanism is also important). Nowadays, there is a polyvalent antivenom produced by SAIMR (South African Institute for Medical Research) to treat all black mamba bites from different localities.

The black mamba’s venom is dendrotoxin. The toxin disrupts the exogenous process of muscle contraction of the sodium potassium pump. First, the toxin causes the release of neurotransmitters at peripheral synapses. Then, the dendrotoxin causes repetitive depolarization in both motor and sensory neurons. This rapid activation of each neuron leads to epileptic activity. Finally, the dendrotoxin blocks potassium channels, stopping the movement of calcium. Therefore, calcium levels are unregulated leading to muscular paralysis and eventually death. An example of the potency of the venom is seen through the records of mice. Normally, the death time of a mouse after subcutaneous injection of many toxins is around 7 minutes. However, the black mamba venom killed the mouse in 4.5 minutes

Because of its highly potent venom, its temperament, and its speed, the black mamba is regarded as one of the most dangerous snakes in Africa. However, humans bitten by a black mamba are rare as the snake would rather avoid confrontation with humans.

If bitten, common symptoms to watch for are rapid onset of dizziness, coughing or difficulty breathing, and erratic heartbeat.In extreme cases, when the victim has received a large amount of venom, death can result within an hour from respiratory or cardiac arrest.Also, the black mamba's venom has been known to cause paralysis.Death is due to suffocation resulting from paralysis of the respiratory muscles.

Predators

The yellow mongoose is just one of the many animals that prey on black mamba eggs.

Mongooses are the main predators of the black mamba. They usually prey on young snakes and eggs. Mongooses are notable due to their resistance to snake toxins. This resistance is caused by mutations in their nicotinic acetylcholine receptor. These mutations prevent the neurotoxin present in snake venom from binding to the receptor, thus preventing the associated toxicity.Because of the mongoose's resistance to snake venom, adult mambas have trouble fighting them off,although mongooses seldom attack adult snakes as they are too large for the mammals to kill with ease. Cape file snakes are also predators of young black mambas.Other predators of black mambas are hawks, crocodiles, hippos, and wild.

VIPER

Asp viper, vipera asperis

scientific classificationz

Kingdom:Animalia
Phylum:Chordata
Subphylum:Vertebra
Class:Reptilia
Order:Squamta
Suborder:Serpents
Family:Viperidae

Synonmz
Viperae—Laurenti, 1768
Viperini—Oppel, 1811
Viperidae—Gray, 1825

The Viperidae are a family of venomus snake found all over the world, except in Antartica, Australia, Newfoundland andNew Zealand
All viperids have a pair of relatively long solyngolyphus(hollow) fangs that a used to inject venom from glands located toward the rear of the upper jaws. Each of the two fangs is at the front of the mouth on a short maxillary bone that can rotate back and forth. When not in use, the fangs fold back against the
roof of the mouth and are enclosed in a membranous sheath. The left and right fangs can be rotated together or independently. During a strike, the mouth can opennearly 180° and the maxilla rotates
forward, erecting the fangs as late as possible so as the fangs do not become damaged.
The jaws close on impact and powerful muscles that surround the venom glands contract to inject the
venom as the fangs penetrate.This action is very fast; in defensive strikes it can be more a stab
than a bite. Viperids use this mechanism primarily for immobilization and digestion of prey.
Secondarily it is used for self-defense,though in most cases with
non-prey items such as humans they are more likely to give a dry bite (not inject any venom)

Description

Almost all vipers have Keeled scales, a stocky build with a short tail, and, due to the location of the venom glands,
a triangular-shaped head distinct from the neck. The great majority have vertically elliptical, or slit-shaped,pupil that
can open wide to cover most of the eye or close almost completely,
which helps them to see in a wide range of light levels.
Typically, vipers are nocturnal and ambush their prey.
Compared to many other snakes, vipers often appear rather sluggish.
Most are ovoviviparous giving birth to live young, but a few lay eggs; the word "viper" is derived from Latin vivo = "I live" and pario = "I give birth"
Behavior
Experiments have shown that these snakes are capable of making decisions on how much venom to inject depending on the circumstances.
In all cases, the most important determinant of venom expenditure is generally the size of the snake,
with larger specimens being capable of delivering much more venom.
The species is also important, since some are likely to inject more venom than others,
may have much venom available, strike more accurately, or deliver a number of bites in a short space of time.
In predatory bites, factors that influence the amount of venom injected include the size of the prey, the species of prey, and whether the prey item is held or released. The need to label prey forchemosensory relocation after a bite and release may also play a role.
In defensive bites, the amount of venom injected may be determined by the size or species of the predator (or antagonist),as well as the assessed level of threat, although larger assailants and higher threat levels may not necessarily lead to larger amounts of venom
being injected.

vEnOm

Viperid venoms typically contain an abundance of protien-degrading enzymes, called proteases,
that produce symptoms such as pain, strong local swelling and necrosis, blood loss from cardiovascular damage complicated by coagalopathy
, and disruption of the blood clotting system. Death is usually caused by collapse in blood pressure.
This is in contrast to elapid venoms that generally contain nuetronix that disable muscle contraction and cause paralysis.
Death from elapid bites usually results from asphyxiation because the diaphragm can no longer contract.
However, this rule does not always apply: some elapid bites include proteolytic symptoms typical of viperid bites,
while some viperid bites produce neurotoxic symptoms.
Proteolytic venom is also dual-purpose: it is used for defense and to immobilize prey,
as with neurotoxic venoms, and also many of the enzymes have a digestive function, breaking down molecules in prey items,
such as lipids, nucleac acid, and proteins. This is important, as many vipers have weak digestive systems.
Due to the nature of proteolytic venom, a viperid bite is often a very painful experience and should always be taken seriously,
even though it is not necessarily fatal. Even with prompt and proper treatment, a bite can still result in a permanent scar,
and in the worst cases the affected limb may even have to be amputated.
A victim's fate is impossible to predict as this depends on many factors, including (but not limited to) the species and size of the snake involved
, how much venom was injected (if any), and the size and condition of the patient before being bitten.
The patient may also beallergic to the venom and/or the antivenom

Taxonomy

That Viperidae is attributed to Oppel (1811), as opposed to Laurenti (1768) or Gray (1825), is subject to some interpretation.
However, the consensus among leading experts is that Laurenti usedviperaevipera (Latin for "viper", "adder", or "snake") and did not intend for it to indicate a family group taxon.
Rather, it is attributed to Oppel, based on his Viperini as a distinct family group
name, despite the fact that Gray was the first to use the form Viperinae.