What is the most venomous snake in the world?
Venomous snake
Belcher's sea snake ("Hydrophis belcheri"), which many times is mistakenly called the hook-nosed sea snake ("Enhydrina schistosa"), has been erroneously popularized as the most venomous snake in the world, due to the first edition of Ernst and book, "Snakes in Question: The Smithsonian Answer Book", published in 1996.
Prominent venom expert Associate Professor Bryan Grieg Fry has clarified the error: "The hook nosed myth was due to a fundamental error in a book called "Snakes in Question". In there, all the toxicity testing results were lumped in together, regardless of the mode of testing (e.g., subcutaneous vs. intramuscular vs. intravenous vs. intraperitoneal). As the mode can influence the relative number, venoms can only be compared within a mode. Otherwise, it's apples and rocks." Belcher's sea snake's actual LD (recorded only intramuscularly) is 0.24 mg/kg and 0.155 mg/kg. Studies on mice and human cardiac cell culture show that venom of the inland taipan, drop by drop, is the most toxic among all snakes.
List of dangerous snakes
The Egyptian cobra ("Naja haje") is another species of cobra which causes a significant amount of bites and human fatalities throughout its range. The venom of the Egyptian cobra consists mainly of neurotoxins and cytotoxins. The average venom yield is 175 to 300 mg in a single bite, and the murine subcutaneous value is 1.15 mg/kg. This species has large fangs and can produce large quantities of venom. Envenomation by this snake is a very serious medical emergency.
Eastern brown snake
The eastern brown snake is considered to be the second-most venomous terrestrial snake in the world, behind only the inland taipan of central east Australia. It is the most commonly encountered dangerous snake in Adelaide, and is also found in Melbourne, Canberra, Sydney, and Brisbane. Clinically, the venom of the eastern brown snake is known to cause diarrhea, dizziness, collapse or convulsions, renal failure, paralysis, and cardiac arrest.
Without medical treatment, bites can be fatal. As this species tends to initiate its defence with nonfatal bites, the untreated mortality rate in most snakebite cases reported is 10–20%, a relatively low figure.
Venomous snake
Venomous snakes are often said to be poisonous, but poison and venom are not the same thing. Poisons must be ingested, inhaled or absorbed, while venom must be injected into the body by mechanical means. While unusual, there are a few species of snake which are actually poisonous. "Rhabdophis" keelback snakes are both venomous and poisonous – their poisons are stored in nuchal glands and are acquired by sequestering toxins from poisonous toads the snakes eat. Similarly, certain garter snakes from Oregon can retain toxins in their livers from ingesting rough-skinned newts.
List of medically significant spider bites
The Australian funnel-web spiders, such as the Sydney funnel-web spider "Atrax robustus" (a mygalomorph spider not to be confused with the araneomorph funnel-weaver or grass spiders) are regarded as among the most venomous in the world. They react vigorously to threats and, reputedly, will more often attempt to bite than run away. "A. robustus", a large black spider, is found within a radius of about 100 km from Sydney. Its venom contains a compound known as atracotoxin which is highly toxic to primates. Approximately 10% of bites lead to serious symptoms for a total of 3-4 severe envenomations annually.
Epidemiology of snakebites
There are also venomous colubrids in Africa, although of these only two arboreal genera, the boomslang and the twig snakes, are likely to inflict life-threatening bites. Of the Atractaspididae, "Atractaspis" is the species involved in the majority of bites. Since these snakes are nocturnal and fossorial, living in burrows underground, bites remain rare, peaking at 1 to 3% in certain areas of the Sudanian savanna. However, there is no antivenom or other effective therapy for "Atractaspis" envenomation, and the case fatality rate remains approximately 10%, with death typically occurring quickly.
Crotalus tigris
Although tiger rattlesnakes are reluctant to strike, they are highly venomous and cantankerous, so pose a potential threat to humans. Their venom contains a neurotoxin and a myotoxin known to cause muscle necrosis. Although production is low compared to other rattlesnakes, their venom is the third most toxic of any snake in the Western Hemisphere. The combination of toxins in their venom makes them extremely dangerous to humans.
Megalania
Along with other varanid lizards, such as the Komodo dragon and the Nile monitor lizard, megalania belongs to the proposed clade Toxicofera, which contains all known reptile clades possessing toxin-secreting oral glands, as well as their close, venomous and non-venomous relatives, including Iguania, Anguimorpha, and snakes. Closely related varanids use a potent venom found in glands inside the jaw. The venom in these lizards have been shown to be a hemotoxin. The venom would act as an anticoagulant and would greatly increase the bleeding the prey received from its wounds. This would rapidly decrease the prey's blood pressure and lead to systemic shock. Being a member of Anguimorpha, megalania may have been venomous and if so, would be the largest venomous vertebrate known.
List of dangerous snakes
The Black desert cobra ("Walterinnesia aegyptia") is a highly venomous snake found in the Middle East. The subcutaneous for the venom of this species is 0.4 mg/kg. For comparison, the Indian cobra's ("naja naja") subcutaneous is 0.80 mg/kg, while the Cape cobra's ("naja nivea") subcutaneous is 0.72 mg/kg. This makes the black desert cobra a more venomous species than both. The venom is strongly neurotoxic and also has mild hemotoxic factors. Envenomation usually causes some combination of local pain, swelling, fever, general weakness, headache, & vomiting. This is not a typically aggressive snake, but it will strike and hiss loudly when provoked. It can strike at a distance of ⅔ of its body length. It does not usually spread a hood nor hold up its body up off the ground like true cobras do. Envenomation by this species should be considered a serious medical emergency. Reports of human fatalities due to envenomation by this species has been reported.
List of dangerous snakes
It is estimated that only 10 to 15 mg will kill a human adult; however, its bites deliver about 120 mg of venom on average, although they may deliver up to 400 mg of venom in a single bite. If bitten, severe neurotoxicity invariably ensues rapidly. This is because of several factors that include the high potency of their venom, the unusual composition of synergistic toxins contained within the venom which bring on severe symptoms of envenomation and death much faster than any other venomous snake in the world. In addition, the species itself possesses the most advanced, evolved, and efficient venom delivery apparatus among all venomous snakes, and the most advanced and evolved dentition of all elapids. Black mambas possess the longest fangs of any elapid, averaging around , but may grow as long as . Another feature that distinguishes the dentition and venom delivery apparatus of this species from all other elapids, as well as other species of venomous snake including those of the family Viperidae, is the fact that its fangs are positioned well forward at the most-anterior position possible in its mouth - right up in the front of its upper jaw. The proteins in black mamba venom are of low molecular weight, low viscosity, and the venom's high activity in terms of hyaluronidases, which is also essential in facilitating dispersion of venom toxins throughout tissue (spreading the venom through the body) by catalyzing the hydrolysis of hyaluronan, a constituent of the extracellular matrix (ECM), hyaluronidase lowers the viscosity of hyaluronan, and Dendroaspin natriuretic peptide (DNP), a newly discovered component of mamba venom, is the most-potent natriuretic peptide and it's unique to the genus "Dendroaspis", or mambas. It 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, thereby increasing tissue permeability. These advanced and highly evolved physical and biological features combined with this species' large size, explosive aggression, and quickness make the black mamba a terrifying adversary. Neurological, respiratory, and cardiovascular symptoms rapidly begin to manifest, usually within less than ten minutes. Common symptoms are rapid onset of dizziness, drowsiness, headache, 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 severe abdominal pain. Local tissue damage appears to be relatively infrequent and of minor severity in most cases of black mamba envenomation. Edema is typically minimal. Acute renal failure has been reported in a few cases of black mamba bites in humans as well as in animal models. The venom of this species has been known to cause permanent paralysis in some cases. Death is due to suffocation resulting from paralysis of the respiratory muscles. Untreated black mamba bites have a mortality rate of 100%. Antivenom therapy is the mainstay of treatment for black mamba envenomation. A polyvalent antivenom produced by the South African Institute for Medical Research (SAIMR) is used to treat all black mamba bites from different localities. Because of the availability of antivenom, a bite from a black mamba no longer results in certain death, but in order for the antivenom therapy to be successful, vigorous treatment and large doses of antivenom must be administered rapidly post-envenomation. In case studies of black mamba envenomation, respiratory paralysis has occurred in less than 15 minutes. Envenomation by this species invariably causes severe neurotoxicity because black mambas often strike repeatedly in a single lunge, biting the victim up to 12 times in extremely rapid succession. Such an attack is fast, lasting less than one second, and so it may appear to be a single strike and single bite. With each bite, the snake delivers anywhere from 100 to 400 mg of a rapid-acting and virulently toxic venom. As a result, the doses of antivenom required are often massive (10–30+ vials) for bites from this species. Although antivenom saves many lives, mortality due to black mamba envenomation is still at 14%, even with antivenom treatment. In addition to antivenom treatment, endotracheal intubation and mechanical ventilation are required for supportive therapy.
Vermicella
Vermicella is a genus of venomous snakes of the family Elapidae, commonly known as bandy-bandies or hoop snakes. The best known species is the bandy-bandy ("V. annulata").
Rattlesnake
The venom is hemotoxic, destroying tissue, causing necrosis and coagulopathy (disrupted blood clotting). In the U.S., the tiger rattlesnake ("C. tigris") and some varieties of the Mojave rattlesnake ("C. scutulatus") also have a presynaptic neurotoxic venom component known as Mojave type A toxin, which can cause severe paralysis. Although it has a comparatively low venom yield, the venom toxicity of "C. tigris" is considered to be among the highest of all rattlesnake venoms, and among the highest of all snakes in the Western Hemisphere based on studies conducted on laboratory mice. "C. scutulatus" is also widely regarded as producing one of the most toxic snake venoms in the Americas, based on studies in laboratory mice.
Conus geographus
The geography cone is highly dangerous; live specimens should be handled with extreme caution. "C. geographus" has the most toxic sting known among "Conus" species and is responsible for more than thirty human fatalities. Yoshiba estimated an LD70 value (in humans) of 0.001-0.003 mg/kg. In two cases of envenomation, only 0.0002-0.0005 mg resulted in severe paralysis. Other figures estimate LD50 values of 0.012-0.03 mg/kg. These estimates make the geographic cone snail the most venomous animal in the world. The venom is a complex mix of hundreds of different toxins that is delivered through toxoglossan radula, a harpoon-like tooth propelled from an extendable proboscis. There is no antivenom for a cone snail sting, and treatment consists of keeping victims alive until the toxins wear off.
Among the compounds found in cone snail venom are proteins which, when isolated, have great potential as pain-killing drugs. Research shows that certain component proteins of the venom target specific human pain receptors and can be up to 10,000 times more potent than morphine without morphine's addictive properties and side-effects.
Lachesis
"Lachesis" is a genus of pit vipers sometimes called bushmasters. It includes the largest venomous snake in the Western Hemisphere.
List of dangerous snakes
The Rinkhals ("Hemachatus haemachatus") is a not a true cobra in that it does not belong to the genus "Naja". However, it is closely related to the true cobras and is considered to be one of the true spitting cobras. The venom of this species is less viscous than that of other African elapids, naturally, as thinner fluid is naturally easier to spit. However, the venom of the rinkhals is produced in copious amounts. Average venom yield is 80–120 mg and the murine is 1.1-1.6 mg/kg SC with an estimated lethal dose for humans of 50–60 mg. Actual bites from this species are fairly rare, and deaths in modern times are so far unheard of. Local symptoms of swelling and bruising is reported in about 25% of cases. General symptoms of drowsiness, nausea, vomiting, violent abdominal pain and vertigo often occur, as does a mild pyrexial reaction. Neurotoxic symptoms are however rare and have only included diplopia and dyspnoea. Ophthalmia has been reported, but has not caused as severe complications as in some of the spitters in the genus "Naja" (especially "N. nigricollis" and "N. mossambica").
Venomous mammal
The definition of venom by Fry et al. (see Definitions) regards the feeding secretions of hematophagous (blood eating) specialists as a particular subtype of venom. In this context, the subfamily Desmodontinae represents the venomous mammals from the order Chiroptera. This group comprises the most well known venomous bat, the common vampire bat ("Desmodus rotundus") and two other rare species, the hairy-legged vampire bat ("Diphylla ecaudata") and the white-winged vampire bat ("Diaemus youngi"). These bats produce toxic saliva with anticoagulant properties and have a series of anatomical and physiological adaptations to allow nourishment based solely on blood. The majority of their prey do not perish from the attack or contact with the venom.
Acanthophis
Acanthophis is a genus of elapid snakes. Commonly called "death adders", they are native to Australia, New Guinea and nearby islands, and are among the most venomous snakes in the world. The name of the genus derives from the Ancient Greek "acanthos"/ἄκανθος ('spine') and "ophis"/ὄφις ('snake'), referring to the spine on the death adder's tail.
Twig snake
The twig snakes (genus Thelotornis), also commonly known as bird snakes or vine snakes, are a genus of rear-fanged venomous snakes in the family Colubridae. The genus is native to Africa. All species in the genus have a slender and elongated profile, a long tail, a narrow head, and a pointed snout. The eye of all species has a horizontal pupil, shaped like a keyhole, which gives twig snakes binocular vision. Twig snakes are greyish-brown with faint light and dark markings. When threatened, they inflate the throat to display bold black markings between the scales. Twig snakes are considered to be very dangerous because the venom is haemotoxic, affecting the blood clotting mechanism and causing uncontrolled bleeding. Bites by twig snakes can cause death in humans; famous herpetologist Robert Mertens died after being bitten by his pet Savanna vine snake ("Thelotornis capensis").
List of dangerous snakes
The Puff adder ("Bitis arietans") is responsible for more fatalities than any other African snake. This is due to a combination of factors, including its wide distribution, common occurrence, large size, potent venom that is produced in large amounts, long fangs, their habit of basking by footpaths and sitting quietly when approached. The venom has cytotoxic effects and is one of the most toxic of any vipers based on LD50 studies. The values in mice vary: 0.4–2.0 mg/kg IV, 0.9–3.7 mg/kg IP, 4.4–7.7 mg/kg SC. Mallow et al. (2003) gives a LD range of 1.0–7.75 mg/kg SC. Venom yield is typically between 100–350 mg, with a maximum of 750 mg. Brown (1973) mentions a venom yield of 180–750 mg. About 100 mg is thought to be enough to kill a healthy adult human male, with death occurring after 25 hours. In humans, bites from this species can produce severe local and systemic symptoms. Based on the degree and type of local effect, bites can be divided into two symptomatic categories: those with little or no surface extravasation, and those with hemorrhages evident as ecchymosis, bleeding and swelling. In both cases there is severe pain and tenderness, but in the latter there is widespread superficial or deep necrosis and compartment syndrome. Serious bites cause limbs to become immovably flexed as a result of significant hemorrhage or coagulation in the affected muscles. Residual induration, however, is rare and usually these areas completely resolve. The fatality rate depends on the severity of the bites and some other factors. Deaths are rare and occur in less than 10% of all untreated cases (usually in 2–4 days from complications following blood volume deficit and a disseminated intravascular coagulopathy), although some reports show that very severe envenomations have a 52% mortality rate. Most fatalities are associated with bad clinical management and neglect.
Collett's snake
The venom produced by Collett's snake is similar to the Papuan black snake's and mulga snake's venom. The venom is cytotoxic and has haemolytic activity. Neurotoxins may also be found in its venom as well. "P. colletti" produces about 30 milligrams of venom in one strike. Black snake or tiger snake anti-venom can be administered. It is the world's nineteenth most venomous snake.
Venom
Some 450 species of snake are venomous. Snake venom is produced by glands below the eye (the mandibular gland) and delivered to the victim through tubular or channeled fangs. Snake venoms contain a variety of peptide toxins, including proteases, which hydrolyze protein peptide bonds, nucleases, which hydrolyze the phosphodiester bonds of DNA, and neurotoxins, which disable signalling in the nervous system. Snake venom causes symptoms including pain, swelling, tissue necrosis, low blood pressure, convulsions, hemorrhage (varying by species of snake), respiratory paralysis, kidney failure, coma and death. Snake venom may have originated with duplication of genes that had been expressed in the salivary glands of ancestors.
List of dangerous snakes
The Sharp-nosed pit viper or hundred pacer ("Deinagkistrodon acutus") is another Asian species of pitviper that is medically important. This species is considered dangerous, and fatalities are not unusual. According to the U.S. Armed Forces Pest Management Board, the venom is a potent hemotoxin that is strongly hemorrhagic. Bite symptoms include severe local pain and bleeding that may begin almost immediately. This is followed by considerable swelling, blistering, necrosis, and ulceration. Brown (1973) mentions a venom yield of up to 214 mg (dried) and values of 0.04 mg/kg IV, 4.0 mg/kg IP and 9.2-10.0 mg/kg SC. The envenomation rate is up to 80% and the untreated mortality rate is very low (1-10%). Antivenom is produced in China and Taiwan.
Sydney funnel-web spider
The lethal dose of venom in humans is not known. The lethal dose of venom from male Sydney funnel-web spiders for the crab-eating macaque ("Macaca fascicularis") is 0.2 mg/kg. Higher figures were found for other experimental animals, such as 1.5 mg/kg for two-day-old mice. The average venom yield for a male is 176 mg. "Guinness World Records" has ranked the Sydney funnel-web as the world's most venomous spider, defining the term "most venomous" as "having the venom most toxic to humans", although it has also given this title to the Brazilian wandering spider.
Mamushi
This species and the Okinawan habu are the most venomous snakes in Japan. Every year, 2000–3000 people in Japan are bitten by a mamushi. Bitten victims typically require one week of treatment in a hospital. Severe bites require intensive care, and approximately 10 victims die annually.
Rough-scaled snake
The rough-scaled snake is a highly venomous snake. Its venom is a fast acting powerful neurotoxin that is both presynaptic and post-synaptic. It has potent post-synaptic neurotoxins as well as potent pre-synaptic neurotoxins. It also has potent coagulants as well as myotoxins. It will readily bite and is known for its foul disposition and defensive nature. Several fatalities have occurred due to this species and it will strike rapidly in defense.
Timber rattlesnake
The timber rattlesnake, canebrake rattlesnake or banded rattlesnake ("Crotalus horridus"), is a species of venomous pit viper endemic to the eastern United States. This is the only rattlesnake species in most of the populous northeastern United States and is second only to the related prairie rattlesnake as the most northerly distributed venomous snake in North America. No subspecies are currently recognized.
Boiga dendrophila melanota
The mangrove snake is one of biggest cat snake species in Asia. It is a shiny bluish black in colour, marked with 40-50 yellow stripes. The mouth and throat area are yellows, whereas the ventral part of the body is yellowish black. The eyes are greyish in colour. It is categorised as a mildly venomous snake.
Bitis nasicornis
"Bitis nasicornis" is considered to be one of the most dangerous snakes in Africa. Small doses of the snake's primarily hemotoxic venom can be deadly. This is unlike the Gaboon viper, the largest of the vipers, which uses a considerably larger amount of venom. "Bitis nasicornis" has both neurotoxic, as well as hemotoxic venom, as do most other venomous snakes. The hemotoxic venom in rhinoceros vipers is much more dominant. This venom attacks the circulatory system of the snake's victim, destroying tissue and blood vessels. Internal bleeding also occurs. When not in use, the rhino viper's fangs are folded up into the roof of the snake's mouth. The snake has the ability to control the movement of its fangs. Simply because the rhino viper may open its mouth does not mean that the fangs will flip down into place. These fangs penetrate deep into the victim and the small doses of venom flow through the hollow fangs into the wound.
List of dangerous snakes
The cobras ("Naja spp") are a medically important group of snakes due to the number of bites and fatalities they cause across their geographical range. The genus "Naja" consists of 20 to 22 species, but has undergone several taxonomic revisions in recent years, so sources vary greatly. They range throughout Africa (including some parts of the Sahara where "Naja haje" can be found), Southwest Asia, Central Asia, South Asia, East Asia, and Southeast Asia. The most recent revision, listed 28 species after the synonymisation of "Boulengerina" and "Paranaja" with "Naja". But unlike some other members of the family Elapidae (the species of the genus "Bungarus", genus "Oxyuranus", genus "Pseudohaje", and especially genus "Dendroaspis"), half of the bites by many species of both African and Asian origin of the genus "Naja" are "dry bites" (a dry bite is a bite by a venomous snake in which no venom is released). Roughly 45-50% of bites by most cobra species are dry bites and thus don't cause envenomation. Some of the species which are known and documented to deliver dry bites in a majority of cases (50% +) include: "Naja naja", "Naja kaouthia", "Naja sputatrix", "Naja siamensis", "Naja haje", "Naja annulifera", "Naja anchietae" and "Naja nigricollis". Some species will inject venom in the majority of their bites, but still deliver high number of dry bites (40-45%) include: "Naja sumatrana", "Naja melanoleuca", "Naja atra", "Naja mossambica" and "Naja katiensis". Within this genus, there are a few species in which dry bites are very rare. Envenoming occurs in at least 75-80% of bite cases involving these species. The species which typically cause envenomation in the majority of their bites include some of the more dangerous and venomous species of this genus: "Naja oxiana", "Naja philippinensis", "Naja nivea", and "Naja samarensis". There are many more species within the genus which have not yet been subject to much research and studies, and as a result, very little is known about their behaviour, venom, diet, habitat and general temperaments. Some of these species include "Naja sagittifera", "Naja annulata", "Naja christyi" and many others.
List of dangerous snakes
The Asian Monocled cobra ("Naja kaouthia") is a medically important species as it is responsible for a considerable amount of bites throughout its range. The major toxic components in the Monocled cobras venom are postsynaptic neurotoxins, which block the nerve transmission by binding specifically to the nicotinic acetylcholine receptor, leading to flaccid paralysis and even death by respiratory failure. The major α-neurotoxin in "Naja kaouthia" venom is a long neurotoxin, α-cobratoxin; the minor α-neurotoxin is different from cobrotoxin in one residue. The neurotoxins of this particular species are weak. The venom of this species also contains myotoxins and cardiotoxins. The median lethal dose () is 0.28-0.33 mg per gram of mouse body weight. In case of IV the is 0.373 mg/kg, and 0.225 mg/kg in case of IP. The average venom yield per bite is approximately 263 mg (dry weight). The monocled cobra causes the highest fatality due to snake venom poisoning in Thailand.
Envenomation usually presents predominantly with extensive local necrosis and systemic manifestations to a lesser degree. Drowsiness, neurological and neuromuscular symptoms will usually manifest earliest; hypotension, flushing of the face, warm skin, and pain around bite site typically manifest within one to four hours following the bite; paralysis, ventilatory failure or death could ensue rapidly, possibly as early as 60 minutes in very severe cases of envenomation. However, the presence of fang marks does not always imply that envenomation actually occurred.
Vespa luctuosa
In addition to being the most venomous known wasp, "Vespa luctuosa" has one of the highest recorded toxicities of any known insect venom. Only harvester ant venom from the genus "Pogonomyrmex" (especially "Pogonomyrmex maricopa"), as well as the unrelated ant "Ectatomma tuberculatum", are known to be more toxic.
Eastern brown snake
The eastern brown snake ("Pseudonaja textilis"), often referred to as the common brown snake, is an extremely venomous snake of the family Elapidae, native to eastern and central Australia and southern New Guinea. Considered the world's second-most venomous land snake after the Inland Taipan and based on its value (subcutaneous) in mice, it is responsible for about 60% of snake-bite deaths in Australia. First described by André Marie Constant Duméril in 1854, the adult eastern brown snake is a slender snake up to 2 m (7 ft) long with variable upperparts that can be various shades of brown, ranging from pale brown to almost black. Its underside is pale cream-yellow, often with orange or grey splotches.
Walterinnesia aegyptia
"W. aegyptia" is highly venomous. The subcutaneous for the venom of "W. aegyptia" is 0.4 mg/kg. For comparison, the Indian cobra's ("Naja naja") subcutaneous is 0.80 mg/kg, while the Cape cobra's ("Naja nivea") subcutaneous is 0.72 mg/kg. This makes "W. aegyptia" (the desert black snake) a more venomous snake than both. Like many elapid snakes, the venom is primarily neurotoxic and effects of envenenomation are from systemic circulation of the toxins rather than from local effect on tissue near the site of injection.
Crete
There are four species of snake on the island and these are not dangerous to humans. The four species include the leopard snake (locally known as Ochendra), the Balkan whip snake (locally called Dendrogallia), the dice snake (called Nerofido in Greek), and the only venomous snake is the nocturnal cat snake which has evolved to deliver a weak venom at the back of its mouth to paralyse geckos and small lizards, and is not dangerous to humans.
List of dangerous snakes
Spitting cobras are another group of cobras that belong to the genus "Naja". Spitting cobras can be found in both Africa and Asia. These cobras have the ability to eject venom from their fangs when defending themselves against predators. The sprayed venom is harmless to intact skin. However, it can cause permanent blindness if introduced to the eye and left untreated (causing chemosis and corneal swelling). The venom sprays out in distinctive geometric patterns, using muscular contractions upon the venom glands. These muscles squeeze the glands and force the venom out through forward-facing holes at the tips of the fangs. The explanation that a large gust of air is expelled from the lung to propel the venom forward has been proven wrong. When cornered, some species can "spit" their venom a distance as great as . While spitting is typically their primary form of defense, all spitting cobras are capable of delivering venom through a bite as well. Most species' venom exhibit significant hemotoxic effects, along with more typical neurotoxic effects of other cobra species.
List of dangerous snakes
The most medically important species of snake bites in Central Asia is the Caspian cobra ("Naja oxiana"). It is the most venomous species of cobra in the world, slightly ahead of the Philippines cobra based on a toxinological study from 1992 found in the Indian Journal of Experimental Biology, in which this species produced the highest potency venom among cobras. The venom of this species has the most potent composition of toxins found among any cobra species known. It is made up of primarily highly potent neurotoxins but it also has cytotoxic activity (tissue-death, necrosis) and cardiotoxins. Two forms of "cytotoxin II" (cardiotoxin) were found in the venom of this species. The crude venom of this species produced the lowest known lethal dose (LCLo) of 0.005 mg/kg, the lowest among all cobra species, derived from an individual case of poisoning by intracerebroventricular injection. A 1992 extensive toxinology study gave a value of 0.18 mg/kg (range of 0.1 mg/kg - 0.26 mg/kg) by subcutaneous injection. According to Brown (1973), the subcutaneous value is 0.4 mg/kg, while Ernst and Zug "et al." list a value of 0.21 mg/kg SC and 0.037 mg/kg IV. Latifi (1984) listed a subcutaneous value of 0.2 mg/kg. In another study, where venom was collected from a number of specimens in Iran, the IV in lab mice was 0.078 mg/kg. Average venom yield per bite for this species is between 75 and 125 mg (dry weight), but it may yield up to 590 mg (dry weight) in a single bite. The bite of this species may cause severe pain and swelling, along with severe neurotoxicity. Weakness, drowsiness, ataxia, hypotension, and paralysis of throat and limbs may appear in less than one hour after the bite. Without medical treatment, symptoms rapidly worsen and death can occur rapidly after a bite due to respiratory failure. An adult woman bitten by this species in northwestern Pakistan suffered severe neurotoxicity and died while en route to the closest hospital nearly 50 minutes after envenomation. Between 1979 and 1987, 136 confirmed bites were attributed to this species in the former Soviet Union. Of the 136, 121 received antivenom, and only four died. Of the 15 who did not receive antivenom, 11 died. This species is an abundant snake in northeastern Iran and is responsible for a very large number of snakebite mortalities. Antivenom is not as effective for envenomation by this species as it is for other Asiatic cobras within the same region, like the Indian cobra ("Naja naja") and due to the dangerous toxicity of this species' venom, massive amounts of antivenom are often required for patients. As a result, a monovalent antivenom serum is being developed by the Razi Vaccine and Serum Research Institute in Iran. The untreated mortality rate for this species is 70-75%, which is the highest among all cobra species of the genus "Naja".
List of dangerous snakes
The Forest cobra ("Naja melanoleuca") is the largest true cobra of the genus "Naja" and is a very bad-tempered, aggressive, and irritable snake when cornered or molested as handled in captivity. According to Brown (1973) this species has a murine IP value of 0.324 mg/kg, while the IV value is 0.6 mg/kg. Ernst and Zug "et al." 1996 list a value of 0.225 mg/kg SC. The average venom yield per bite is 571 mg and the maximum venom yield is 1102 mg. The forest cobra is one of the least frequent causes of snake bite among the African cobras, this is largely due to its forest-dwelling habits. It is the largest of the "Naja" cobras and the venom is considered highly toxic. If the snake becomes cornered or is agitated, it can quickly attack the aggressor, and if a large amount of venom is injected, a rapidly fatal outcome is possible. Clinical experience with forest cobras has been very sparse, and few recorded bites have been documented. However, in 2008, around the area of Friguiagbé in Guinea, there were 375 bites attributed to the forest cobra and of those 79 were fatal. Most of the fatal bites were patients who received no medical treatment. Deaths from respiratory failure have been reported, but most victims will survive if prompt administration of antivenom is undertaken as soon as clinical signs of envenomation have been noted.
List of dangerous snakes
The Jararaca ("Bothrops jararaca") is a species that is often abundant within its range, where it is an important cause of snakebite. It is the best-known venomous snake in the wealthy and heavily populated areas of southeastern Brazil, where it was responsible for 52% (3,446 cases) of snakebites between 1902 and 1945, with a 0.7% mortality rate (25 deaths). The average venom yield is with a maximum of of dried venom. The venom is slightly more toxic than that of the terciopelo or fer-de-lance ("B. asper"). In mice, the median lethal dose () is 1.2-1.3 mg/kg IV, 1.4 mg/kg IP and 3.0 mg/kg SC. For humans, the LD is estimated to be subcutaneous.
Pseudohaje goldii
"Pseudohaje goldii" venom is one of the most toxic and deadly of all African snakes. Venom of this species is primarily a neurotoxin, like most Elapidae. It is quick acting and extremely potent, easily killing a person. Moreover, there is no known specific antivenom made. Bite symptoms include swelling and stinging pain around the bite wound, numbness of limbs and lip, severe difficulty in breathing, sweating profusely and blurred vision. Victims may die of respiratory failure. A number of people are killed by this species.
Isthmian-Atlantic moist forests
The common chunk-headed snake is also called the blunthead snake. It is supposedly the thinnest snake in the world. It is native to South America and can be found in all the countries that the Isthmian-Atlantic moist forest covers. Although slightly venomous, the venom is mostly restricted the back teeth to aid the tree snake in eating prey such as small lizards.
Queen Saovabha Memorial Institute
The snake farm houses thousands of some of the most venomous snakes in the world, such as the king cobra and all sorts of vipers. Visitors can see handlers interact with pythons, and venom extractions can be seen. There is also a museum, and lectures are given.
Chironex fleckeri
Chironex fleckeri, commonly known as the sea wasp, is a species of extremely venomous box jellyfish found in coastal waters from northern Australia and New Guinea north to the Philippines and Vietnam. It has been described as "the most lethal jellyfish in the world", with at least 63 known deaths in Australia from 1884 to 1996.
Venomous fish
There are at least 1200 species of venomous fish. There are more venomous fish than venomous snakes and indeed more than the combined total of all other venomous vertebrates. Venomous fish are found in almost all habitats around the world, but mostly in tropical waters. They injure over 50,000 people every year.
Spectral bat
The spectral bat ("Vampyrum spectrum"), also called the great false vampire bat or Linnaeus's false vampire bat, is a large, carnivorous leaf-nosed bat found in Mexico, Central America, and South America.
It is the only member of the genus Vampyrum; its closest living relative is the big-eared woolly bat.
It is the largest bat species in the New World, as well as the largest carnivorous bat: its wingspan is .
It has a robust skull and teeth, with which it delivers a powerful bite to kill its prey.
Birds are frequent prey items, though it may also consume rodents, insects, and other bats.
Toxicofera
The world's largest venomous lizard and the largest species of venomous land animal is the Komodo dragon.
List of dangerous snakes
The Australian King brown snake or Mulga snake ("Pseudechis australis") is the second longest species of venomous snake in Australia. The venom of this snake is relatively weak compared to many other Australian species. The LD is 2.38 mg/kg subcutaneous. However, these snakes can deliver large amounts of venom when they bite, compensating for the lower venom potency. Average venom yield is 180 mg and they have a maximum yield of 600 mg. The venom of this species contains potent myotoxins and anticoagulants, that can inhibit blood clotting. The neurotoxic components are weak. This snake can cause severe envenomation of humans. They are a moderately common cause of snakebites and uncommonly to rarely cause snakebite deaths in Australia at present. Envenomation can cause anticoagulation coagulopathy, renal damage or renal failure (kidney failure). They do not cause significant neurotoxic paralysis (muscle weakness, respiratory failure), though rarely they may cause ptosis (drooping of the upper eyelids). Bites can also cause myolysis (rhabdomyolysis, muscle damage) which can be very severe and is the major effect of bites. Rate of envenomation is 40-60%, while untreated mortality rate is 30-40%.
Mamba
Black mambas live in the savannas and rocky hills of southern and eastern Africa. They are Africa’s longest venomous snake, reaching up to 14 feet in length, although 8.2 feet is more the average. They are also among the fastest snakes in the world, slithering at speeds of up to 12.5 miles per hour.
List of dangerous snakes
The Many-banded krait ("Bungarus multicinctus") is the most venomous krait species known based on toxinological studies conducted on mice. The venom of the many-banded krait consists of both pre- and postsynaptic neurotoxins (known as α-bungarotoxins and β-bungarotoxins, among others). Due to poor response to antivenom therapy, mortality rates are very high in cases of envenomation - up to 50% of cases that receive antivenom are fatal. Case fatality rates of the many-banded krait envenoming reach up to 77%–100% without treatment. The average venom yield from specimens kept on snake farms was between 4.6—18.4 mg per bite. In another study, the average venom yield was 11 mg (Sawai, 1976). The venom is possibly the most toxic of any "Bungarus" (krait) species and possibly the most toxic of any snake species in Asia, with values of 0.09 mg/kg—0.108 mg/kg SC, 0.113 mg/kg IV and 0.08 mg/kg IP on mice. Based on several studies, the many-banded krait is among the most venomous land snakes in the world. The Taiwan National Poison Control Center reports that the chief cause of deaths from snakebites during the decade (2002-2012) was respiratory failure, 80% of which was caused by bites from the many-banded krait.
List of fatal snake bites in the United States
It has been estimated that 7,000–8,000 people per year receive venomous snake bites in the United States, and about five of those people die. Most fatal bites are attributed to the eastern diamondback rattlesnake and the western diamondback rattlesnake. The copperhead accounts for more cases of venomous snake bite than any other North American species; however, its venom is the least toxic, so its bite is seldom fatal.
Desert death adder
The desert death adder ("Acanthophis pyrrhus") is a species of snake native to Australia and is one of the most venomous land snakes in the world. The desert death adder is under threat due to the destruction of habitat.
Naja ashei
Naja ashei, commonly known as Ashe's spitting cobra or the giant spitting cobra, is a species of venomous snake in the family Elapidae. The species is native to Africa. It is the world's largest species of spitting cobra.
Palm Springs, California
The Sonoran Desert has more species of rattlesnakes (11) than anywhere else in the world. The most common species is the extremely venomous Mojave rattler, which is considered the world's most dangerous rattlesnake. The largest rattle snake species here is the Western diamondback rattlesnake, while other species include the Black-tailed rattlesnake, Tiger rattler and Sidewinder rattler. Palm Springs is home to Tarantulas and various Scorpion species, including the Vinegaroon.
Fauna of South Africa
Many species of snake, both venomous and non-venomous, make South Africa their home. The largest is the African rock python, a non-venomous snake that kills its prey, which includes creatures up to the size of an antelope, by constriction. A much smaller species that also kills by constriction is the mole snake; as its name suggests, this snake preys on small mammals, most often rodents such as mole-rats.
Many venomous snakes occur, some of which include famous examples such as the black mamba (one of the most deadly snakes in the world), eastern green mamba, boomslang, Cape cobra and rinkhals. Though human fatalities can occur, these snakes are normally timid and prefer to avoid humans. Snakes, both venomous and non-venomous, are important in controlling rodent populations.
Kaziranga National Park
Two of the largest snakes in the world, the reticulated python and rock python, as well as the longest venomous snake in the world, the king cobra, inhabit the park. Other snakes found here include the Indian cobra, monocled cobra, Russell's viper, and the common krait.
Monitor lizard species found in the park include the Bengal monitor and the Asian water monitor. Other reptiles include fifteen species of turtle, such as the endemic Assam roofed turtle and one species of tortoise, the brown tortoise. 42 species of fish are found in the area, including the "Tetraodon".
Crotalus scutulatus
All rattlesnake venoms are complex cocktails of enzymes and other proteins that vary greatly in composition and effects, not only between species, but also between geographic populations within the same species. "C. scutulatus" is widely regarded as producing one of the most toxic snake venoms in the New World, based on studies in laboratory mice. Their potent venom is the result of a presynaptic neurotoxin composed of two distinct peptide subunits. The basic subunit (a phospholipase A) is mildly toxic and apparently rather common in North American rattlesnake venoms. The less common acidic subunit is not toxic by itself, but in combination with the basic subunit, produces the potent neurotoxin called “Mojave toxin”. Nearly identical neurotoxins have been discovered in five North American rattlesnake species besides "C. scutulatus". However, not all populations express both subunits. The venom of many Mojave rattlesnakes from south-central Arizona lacks the acidic subunit and has been designated “venom B,” while Mojave rattlesnakes tested from all other areas express both subunits and have been designated “venom A” populations.
List of fatal snake bites in the United States
The United States has about 20 species of venomous snakes, which include 16 species of rattlesnakes, two species of coral snakes, one species of cottonmouth (or water moccasin), and one species of copperhead. At least one species of venomous snake is found in every state except Alaska and Hawaii.
Inland taipan
Although extremely venomous and a capable striker, in contrast to the rather aggressive coastal taipan, the inland taipan is usually quite a shy and reclusive snake, with a placid disposition, and prefers to escape from trouble. However, it will defend itself and strike if provoked, mishandled, or prevented from escaping. Because it lives in such remote locations, the inland taipan seldom comes in contact with people; therefore it is not considered the most deadly snake in the world overall, especially in terms of disposition and human deaths per year. The word "fierce" from its alternative name describes its venom, not its temperament.
Pseudonaja
Pseudonaja is a genus of venomous elapid snakes native to Australia. Species of this genus are known commonly as brown snakes and are considered to be some of the most dangerous snakes in the world; even young snakes are capable of delivering a fatal envenomation to a human.
Mulga snake
The mulga snake ("Pseudechis australis") is a species of venomous snake found in Australia. It is one of the longest venomous snakes in the world, and is the second-longest in Australia (surpassed only by the coastal taipan). Its alternative common name is king brown snake, although it is a species in the genus "Pseudechis" (black snakes) and only distantly related to true brown snakes.
Mamushi
The venom of this species varies very little among Japan, China, and Korea in terms of both its potency and its effects. According to Yoshimitsu (2005), this species and the Okinawan habu, another pitviper, are the most venomous snakes in Japan. The venom's lethality as measured by LD in mice following intraperitoneal injection is in the range 0.3 mg/kg to 1.22 mg/kg. The venom mostly contains haemolytic toxins, but it also has two neurotoxins—an alpha-toxin that is a post-synaptic inhibitor and a beta-toxin that is a pre-synaptic inhibitor. Because the beta-toxin acts pre-synaptically, its effects cannot be blocked or treated by anticholinesterases. The venom contains an anticoagulant, mamushi L-amino-acid oxidase (M-LAO). It also contains the peptide ablomin which is highly similar in amino acid sequence to that of the venom, helothermine, of the beaded lizard ("Heloderma horridum").
List of dangerous snakes
Russell's viper ("Daboia russelii") produces one of the most excruciatingly painful bites of all venomous snakes. Internal bleeding is common. Bruising, blistering and necrosis may appear relatively quickly as well. The Russell's viper is irritable, short-tempered and a very aggressive snake by nature and when irritated, coils tightly, hisses, and strikes with lightning speed. This species is responsible for more human fatalities in India than any other snake species, causing an estimated 25,000 fatalities annually. The in mice, which is used as a possible indicator of snake venom toxicity, is as follows: 0.133 mg/kg intravenous, 0.40 mg/kg intraperitoneal, and about 0.75 mg/kg subcutaneous. For most humans, a lethal dose is approximately 40–70 mg. However, the quantity of venom produced by individual specimens is considerable. Reported venom yields for adult specimens range from 130–250 mg to 150–250 mg to 21–268 mg. For 13 juveniles with an average length of 79 cm, the average venom yield was 8–79 mg (mean 45 mg).
List of dangerous snakes
Mortality (often determined by measured toxicity on mice) is a commonly used indicator to determine the danger of any given venomous snake, but important too are its efficiency of venom delivery, its venom yield and its behavior when it encounters humans. Many snake experts have cited the black mamba and the coastal taipan as the world's most dangerous, albeit not the most venomous snakes. Both species are elapids, and in several aspects of morphology, ecology and behaviour, the coastal taipan is strongly convergent with the black mamba. Black mamba and coastal taipan bites require very rapid and vigorous antivenom therapy as without such intervention they are almost always fatal. The venoms of both species are exceptionally quick acting.
Coral Sea
Seventeen species of sea snake, including "Laticauda colubrina" (pictured), live on the GBR in warm waters up to deep and are more common in the southern than in the northern section; none of them are endemic or endangered. The venom of many of these snakes is highly toxic; for example, "Aipysurus duboisii" is regarded as the world's most venomous sea snake.
List of dangerous snakes
The Indochinese spitting cobra ("Naja siamensis") is a venomous spitting cobra whose venom consists of postsynaptic neurotoxins, metalloproteinases, powerful cardiotoxins, with cytolytic activity, and Phospholipase A with a diversity of activities. The of its venom is 1.07-1.42 mg/gram of mouse body weight. Cranial palsy and respiratory depression are reported to be more common after bites by Naja siamensis than by Naja kaouthia. Indochinese spitting cobras will use their venom for self-defense with little provocation, and as the name implies, are capable of spitting venom when alarmed, often at the face and eyes of the animal or human threatening them. A case report in the literature describes pain and irritation of the eyes, bilateral redness, excessive tear production and whitish discharge, with superficial corneal opacity but normal acuity.
List of dangerous snakes
The Cape cobra ("Naja nivea") is regarded as one of the most dangerous species of cobra in Africa, by virtue of its potent venom and frequent occurrence around houses. The venom of this snake tends to be thick and syrupy in consistency and dries into shiny pale flakes, not unlike yellow sugar. The Cape cobras venom is made up of potent postsynaptic neurotoxins and might also contain cardiotoxins, that affect the respiratory system, nervous system, and the heart. The mouse SC for this species' venom is 0.72, while the IV and IP values are 0.4 mg/kg and 0.6 mg/kg, respectively. The average venom yield per bite is 100 to 150 mg according to Minton. The mortality rate for untreated bites is not exactly known, but is thought to be high. This can be because of various factors including the amount of venom injected, psychological state of the bitten subject and the penetration of one or both fangs. Mechanical ventilation and symptom management is often enough to save a victim's life, but cases of serious Cape cobra envenomation will require antivenom. When death does occur, it normally takes anywhere from an hour (in severe cases) to ten hours (or more) and it is often as a result of respiratory failure, because of the onset of paralysis. The antivenom used in case of a bite is a polyvalent antivenom produced by the South African Institute of Medical Research (SAIMR).
Giant garter snake
The giant garter snake is the largest species of garter snake, with the adult snakes ranging from in length. As with many snakes, the female giant garter snakes tend to be longer and larger than the males. The snakes have keeled scales, with a yellow dorsal stripe against a black or dark grey background, and two additional yellow stripes on either side that run the length of its body. Although, some unstriped checkered patterns have been observed. It is venomous, but harmless to humans; it possesses a very mild neurotoxic venom that helps subdue its prey. A bite to a human will at most give a red itchy rash around the area of the bite.
Epidemiology of snakebites
Most snakebites are caused by non-venomous snakes. Of the roughly 3,700 known species of snake found worldwide, only 15% are considered dangerous to humans. Snakes are found on every continent except Antarctica. There are two major families of venomous snakes, Elapidae and Viperidae. Three hundred twenty five species in 61 genera are recognized in the family Elapidae and 224 species in 22 genera are recognized in the family Viperidae, In addition, the most diverse and widely distributed snake family, the colubrids, has approximately 700 venomous species, but only five genera—boomslangs, twig snakes, keelback snakes, green snakes, and slender snakes—have caused human fatalities.
List of dangerous snakes
The Rhinoceros viper ("Bitis nasicornis") is a large species of viper that is similar to the Gaboon viper, but not as venomous, smaller and with a less dangerous bite. They are slow moving, but like other "Bitis" species, they're capable of striking quickly, forwards or sideways, without coiling first or giving a warning. Holding them by the tail is not safe; as it is somewhat prehensile, they can use it to fling themselves upwards and strike. They have been described as generally placid creatures, not as bad-tempered as the Puff adder. When approached, they often reveal their presence by hissing, said to be the loudest hiss of any African snake—almost a shriek. Relatively little is known about the toxicity and composition of the venom, but it has very minor neurotoxic, as well as hemotoxic venom, as do most other venomous snakes. The hemotoxic venom in rhinoceros vipers is much more dominant. This venom attacks the circulatory system of the snake's victim, destroying tissue and blood vessels. Internal bleeding also occurs. In mice, the intravenous is 1.1 mg/kg. The venom is supposedly slightly less toxic than those of the Puff adder and the Gaboon viper. The maximum wet venom yield is 200 mg. In only a few detailed reports of human envenomation, massive swelling, which may lead to necrosis, had been described. In 2003, a man in Dayton, Ohio, who was keeping a specimen as a pet, was bitten and subsequently died. At least one antivenom protects specifically against bites from this species: India Antiserum Africa Polyvalent.
Snake venom
The bite of all the proteroglyphous elapids, even of the smallest and gentlest, such as the coral snakes, is, so far as known, deadly to humans. However, there are still some mildly venomous elapids such as the hooded snakes (Parasuta), bandy-bandies (Vermicella), etc.
Arizona bark scorpion
The bark scorpion is the most venomous scorpion in North America, and its venom can cause severe pain (coupled with numbness, tingling, and vomiting) in adult humans, typically lasting between 24 and 72 hours. Temporary dysfunction in the area stung is common; e.g. a hand or possibly arm can be immobilized or experience convulsions. It also may cause loss of breath for a short time. Due to the extreme pain induced, many victims describe sensations of electrical jolts after envenomation.
Pholcus phalangioides
An urban legend states that Pholcidae are the most venomous spiders in the world but that it is nevertheless harmless to humans because its fangs cannot penetrate human skin. Both of these claims have been proven untrue. Recent research has shown that pholcid venom has a relatively weak effect on insects. In the "MythBusters" episode "Daddy Long-Legs" it was shown that the spider's fangs (0.25 mm) could penetrate human skin (0.1 mm), but that only a very mild burning feeling was felt for a few seconds.
List of dangerous snakes
The Saw-scaled viper ("Echis carinatus") is small, but its unpredictability, aggressive temper, and lethal venom potency make it very dangerous. This species is one of the fastest striking snakes in the world, and mortality rates for those bitten are very high. In India alone, the saw-scaled viper is responsible for an estimated 5,000 human fatalities annually. However, because it ranges from Pakistan, India (in rocky regions of Maharashtra, Rajasthan, Uttar Pradesh and Punjab), Sri Lanka, parts of the Middle East and Africa north of the equator, is believed to cause more human fatalities every year than any other snake species. In drier regions of the African continent, such as sahels and savannas, the saw-scaled vipers inflict up to 90% of all bites. The rate of envenomation is over 80%. The saw-scaled viper also produces a particularly painful bite. This species produces on the average of about 18 mg of dry venom by weight, with a recorded maximum of 72 mg. It may inject as much as 12 mg, whereas the lethal dose for an adult human is estimated to be only 5 mg. Envenomation results in local symptoms as well as severe systemic symptoms that may prove fatal. Local symptoms include swelling and intense pain, which appear within minutes of a bite. In very bad cases the swelling may extend up the entire affected limb within 12–24 hours and blisters form on the skin. Of the more dangerous systemic symptoms, hemorrhage and coagulation defects are the most striking. Hematemesis, melena, hemoptysis, hematuria and epistaxis also occur and may lead to hypovolemic shock. Almost all patients develop oliguria or anuria within a few hours to as late as 6 days post bite. In some cases, kidney dialysis is necessary due to acute renal failure (ARF), but this is not often caused by hypotension. It is more often the result of intravascular hemolysis, which occurs in about half of all cases. In other cases, ARF is often caused by disseminated intravascular coagulation.
Pogonomyrmex maricopa
Pogonomyrmex maricopa, the Maricopa harvester ant, is one of the most common species of harvester ant found in the U.S. state of Arizona, but it is also known from California, Colorado, New Mexico, Nevada, Texas and Utah, and the Mexican states of Baja California, Chihuahua, Sinaloa and Sonora. Its venom is believed to be the most toxic insect venom in the world.
List of dangerous snakes
The Big Four are the four venomous snake species responsible for causing the most snake bite cases in South Asia (mostly in India). The Big Four snakes cause far more snakebites because they are much more abundant in highly populated areas. They are the Indian cobra ("Naja Naja"), common krait ("Bungarus caeruleus"), Russell's viper ("Daboia russelii") and the Saw-scaled viper ("Echis carinatus").
List of dangerous snakes
The Common death adder ("Acanthophis antarcticus") is a highly venomous snake species with a 50-60% untreated mortality rate. It is also the fastest striking venomous snake in the world. A death adder can go from a strike position, to strike and envenoming their prey, and back to strike position again, in less than 0.15 seconds. The SC value is 0.4 mg/kg and the venom yield per bite can range anywhere from 70–236 mg. Unlike other snakes that flee from approaching humans crashing through the undergrowth, common death adders are more likely to sit tight and risk being stepped on, making them more dangerous to the unwary bushwalker. They are said to be reluctant to bite unless actually touched.
List of dangerous snakes
The King cobra ("Ophiophagus hannah") is the longest venomous snake in the world, and it can inject very high volumes of venom in a single bite. The venom is 1.80 mg/kg SC according to Broad et al. (1979). The mean value of subcutaneous of five wild-caught king cobras in Southeast Asia was determined as 1.93 mg/kg. Between 350 and 500 mg (dry weight) of venom can be injected at once (Minton, 1974). In another study by (Broad et al., 1979), the average venom quantity was 421 mg (dry weight of milked venom). The maximum venom yield is approximately 1000 mg (dry weight). The king cobra has a fearsome reputation. When annoyed, it spreads a narrow hood and growls loudly, but some scientists claim that their aggressiveness is grossly exaggerated. In most of the local encounters with live, wild king cobras, the snakes appear to be of rather placid disposition, and they usually end up being killed or subdued with hardly any hysterics. These support the view that wild king cobras generally have a mild temperament, and despite their frequent occurrence in disturbed and built-up areas, are adept at avoiding humans. Naturalist Michael Wilmer Forbes Tweedie felt that "this notion is based on the general tendency to dramatise all attributes of snakes with little regard for the truth about them. A moment’s reflection shows that this must be so, for the species is not uncommon, even in populated areas, and consciously or unconsciously, people must encounter king cobras quite frequently. If the snake were really habitually aggressive records of its bite would be frequent; as it is they are extremely rare." Mortality rates vary sharply depending on many factors. In cases where envenomation is severe, death can be rapid.
Gaboon viper
The snake's cytotoxic venom itself is not considered particularly toxic based on tests conducted in mice. In mice, the is 0.8–5.0 mg/kg IV, 2.0 mg/kg IP and 5.0–6.0 mg/kg SC. However, the venom glands are enormous and each bite produces the largest quantities of venom of any venomous snake; this is partially due to the fact that, unlike many African vipers such as the Puff Adder, the Gaboon viper does not release after a bite, which enables it to inject larger amounts of venom. Yield is probably related to body weight, as opposed to milking interval. Brown (1973) gives a venom yield range of 200–1000 mg (of dried venom), A range of 200–600 mg for specimens 125–155 cm in length has also been reported. Spawls and Branch (1995) state from 5 to 7 ml (450–600 mg) of venom may be injected in a single bite.
List of dangerous snakes
Green mambas (Western, Eastern, and Jameson's) are all highly venomous snakes that can be highly aggressive and unpredictable in disposition. They can suddenly go from a state of relative calm to an extremely agitated and dangerous state. All three species have a tendency to strike repeatedly with little provocation, although they are generally much less aggressive than their larger cousin, the Black mamba. All three species of green mamba are highly arboreal, alert, extremely quick, and agile. Although the potency of their venom is similar to the more venomous cobra species, mamba venom is much more rapid-acting and the dendrotoxins contained in mamba venom is generally more devastating in nature to the central nervous system, causing more severe neurotoxicity in more rapid fashion.
List of dangerous snakes
The Samar cobra ("Naja samarensis") is a highly venomous species of spitting cobra that is found in the southern islands of the Philippines. Although it is a spitting cobra, this species only rarely spits its venom. It is considered to be an extremely aggressive snake that strikes with little provocation. The venom of this species is not well studied, but is known to be an extremely potent postsynaptic neurotoxin that also contains cytotoxic agents. According to Ernst & Zug et al. the murine SC value is 0.21 mg/kg, making it one of the most venomous true cobra species (genus "Naja") in the world. Severe envenomation is likely in case of a bite and envenomation rate is high. The untreated mortality rate is not known, but is thought to be high (~60%). Envenomation results in marked local effects such as pain, severe swelling, bruising, blistering, and necrosis. Other effects include headache, nausea, vomiting, abdominal pain, diarrhea, dizziness, collapse or convulsions. There may also be moderate to severe flaccid paralysis and renal damage. Cardiotoxicity is possible, but rare.
Rat snake
Rat snakes (or ratsnakes) are members – along with kingsnakes, milk snakes, vine snakes and indigo snakes – of the subfamily Colubrinae of the family Colubridae. They are medium to large constrictors and are found throughout much of the Northern Hemisphere. They feed primarily on rodents and birds. With some species exceeding 2.5 m (8 ft) in total length, they can occupy top levels of some food chains. Many species make attractive and docile pets and one, the corn snake, is one of the most popular reptile pets in the world. Other species can be very skittish and sometimes aggressive, but bites are rarely serious. Like nearly all colubrids, rat snakes pose no threat to humans. Rat snakes were long believed to be completely nonvenomous, but recent studies have shown that some Old World species do possess small amounts of venom, though the amount is negligible relative to humans.
Epidemiology of snakebites
Mambas, cobras, and some larger puff adder species may claim territories of up to , which are used by the snakes for hunting and reproduction. These snakes are large enough to defend their territory from intruders, including humans. The black mamba, in particular, is among the most venomous snakes in the world and one of the most aggressive. It is the longest snake on the continent and is able to move at , making it unusually dangerous. Although black mambas cause only 0.5-1% of snakebites in South Africa, they produce the highest mortality rate and the species is responsible for many snake bite fatalities. The black mamba is the species with the highest mortality rate in every single nation in which it occurs, despite not being responsible for the most numerous snakebites. It is also the species which has the highest mortality rate worldwide.
Epidemiology of snakebites
Of the 120 known indigenous snake species in North America, only 20 are venomous to human beings, all belonging to the families Viperidae and Elapidae. However, in the United States, every state except Maine, Alaska, and Hawaii is home to at least one of 20 venomous snake species. Up to 95% of all snakebite-related deaths in the United States are attributed to the western and eastern diamondback rattlesnakes. Further, the majority of bites in the United States occur in the southwestern part of the country, in part because rattlesnake populations in the eastern states are much lower.
Russell's viper
Russell's viper ("Daboia russelii") is a species of venomous snake in the family Viperidae. of venomous Old World vipers. The single member species, "D. russelii", is found in Asia throughout the Indian subcontinent, much of Southeast Asia, southern China and Taiwan. The species is named for Patrick Russell (1726–1805), a Scottish herpetologist who first described many of India's snakes, and the name of the genus is from the Urdu word meaning "that lies hid", or "the lurker". In Bengali this snake is called chandroborha (চন্দ্রবোড়া) since it carries lenticular or more precisely lunar marks all over its body. Apart from being a member of the big four snakes in India, "Daboia" is also one of the genera responsible for causing the most snakebite incidents and deaths among all venomous snakes on account of many factors, such as their wide distribution, generally aggressive demeanor, and frequent occurrence in highly populated areas.
List of amphibians and reptiles of Montana
The prairie rattlesnake "(Crotalus viridis viridis, Salish: X̣eʔulexʷ )" is a venomous pitviper species native to the western United States, southwestern Canada, and northern Mexico. In Montana, this is the only venomous snake in the state but it is common and widespread.
List of medically significant spider bites
The Brazilian wandering spider (a ctenid spider) is a large brown spider similar to North American wolf spiders in appearance, although somewhat larger. It has a highly toxic venom and is regarded (along with the Australian funnel-web spiders) as among the most dangerous spiders in the world.
Based on one of the few pharmacological studies performed in the 1970s, "Phoneutria"'s venom toxicity was more virulent than both "Atrax" and "Latrodectus".
Takshaka
Takshaka is known in Chinese and Japanese mythology as being one of the "eight Great Dragon Kings" (八大龍王 Hachi Ryuu-ou), they are the only snakes which can fly and also mentioned as the most venomous snakes,amongst Nanda (Nagaraja), Upananda, Sagara (Shakara), Vasuki, Balavan, Anavatapta and Utpala.
List of dangerous snakes
The Gaboon viper ("Bitis gabonica"), although generally docile and sluggish, has the longest fangs of any venomous snake and their venom glands are enormous and each bite produces the largest quantities of venom of any venomous snake. Yield is probably related to body weight, as opposed to milking interval. Brown (1973) gives a venom yield range of 200–1000 mg (of dried venom), A range of 200–600 mg for specimens 125–155 cm in length has also been reported. Spawls and Branch (1995) state from 5 to 7 ml (450–600 mg) of venom may be injected in a single bite. Based on how sensitive monkeys were to the venom, Whaler (1971) estimated 14 mg of venom would be enough to kill a human being: equivalent to 0.06 ml of venom, or 1/50 to 1/1000 of what can be obtained in a single milking. Marsh and Whaler (1984) wrote that 35 mg (1/30 of the average venom yield) would be enough to kill a man of . A study by Marsh and Whaler (1984) reported a maximum yield of 9.7 ml of wet venom, which translated to 2400 mg of dried venom. They attached "alligator" clip electrodes to the angle of the open jaw of anesthetized specimens (length 133–136 cm, girth 23–25 cm, weight 1.3–3.4 kg), yielding 1.3–7.6 ml (mean 4.4 ml) of venom. Two to three electrical bursts within a space of five seconds apart were enough to empty the venom glands. The snakes used for the study were milked seven to 11 times over a 12-month period, during which they remained in good health and the potency of their venom remained the same. In addition, Gaboon vipers produce the most painful bite of any venomous snake in the world. A bite causes very rapid and conspicuous swelling, intense pain, severe shock and local blistering. Other symptoms may include uncoordinated movements, defecation, urination, swelling of the tongue and eyelids, convulsions and unconsciousness. Blistering, bruising and necrosis is often very extensive. There may be sudden hypotension, heart damage and dyspnoea. The blood may become incoagulable with internal bleeding that may lead to haematuria and haematemesis. Local tissue damage may require surgical excision and possibly amputation. Healing may be slow and fatalities during the recovery period are not uncommon.
List of dangerous snakes
The South American bushmaster ("Lachesis muta muta") is the longest species of venomous snake in the Western Hemisphere and the longest pit viper in the world. It is native to parts of South America, especially the equatorial forests east of the Andes. They are active at dusk or after dark and so they are very secretive and elusive. This species is large, fast and has a reputation for being particularly aggressive when cornered. Some reports suggest that this species produces a large amount of venom that is weak compared to some other vipers. Others, however, suggest that such conclusions may not be accurate. These animals are badly affected by stress and rarely live long in captivity. This makes it difficult to obtain venom in useful quantities and good condition for study purposes. For example, Bolaños (1972) observed that venom yield from his specimens fell from 233 mg to 64 mg while they remained in his care. As the stress of being milked regularly has this effect on venom yield, it is reasoned that it may also affect venom toxicity. This may explain the disparity described by Hardy and Haad (1998) between the low laboratory toxicity of the venom and the high mortality rate of bite victims. However, wild specimens have an average venom yield per bite of 280–450 mg (dry weight) (U.S. Dept. Navy, 1968). According to (Sanchez et al., 1992), who used wild specimens from Pará, Brazil, the average venom yield per bite was 324 mg, with a range of 168–552 mg (dry weight). Brown (1973) gives the following values for mice: 1.5 mg/kg IV, 1.6–6.2 mg/kg IP, 6.0 mg/kg SC. He also notes a venom yield of 200–411 mg. Human envenoming by this species, although infrequent, can be rather severe due to the large volumes of venom injected. Envenomation is characterized by pronounced local tissue damage and systemic dysfunctions, including massive internal bleeding.
Venomous snake
The toxicity of snake venom (based on laboratory tests conducted on mice) is sometimes used to gauge the extent of danger to humans, but this is not enough. Many venomous snakes are specialized predators whose venom may be adapted specifically to incapacitate their preferred prey. A number of other factors are also critical in determining the potential hazard of any given venomous snake to humans, including their distribution and behavior. For example, while the inland taipan is regarded as the world's most venomous snake based on LD tests on mice, it is a shy species and rarely strikes, and has not caused any known human fatalities. On the other hand, India's Big Four (Indian cobra, common krait, Russell's viper, and saw-scaled viper), while less venomous than the inland taipan, are found in closer proximity to human settlements and are more confrontational, thus leading to more deaths from snakebite. In addition, some species, such as the black mamba and coastal taipan, occasionally show some aggression, generally when alarmed or in self-defence, and then may deliver fatal doses of venom, resulting in high human mortality rates.
Sea snake
Like their relatives in the family Elapidae, the majority of the sea snakes are highly venomous; however, when bites occur, venom injection is rare, so envenomation symptoms usually seem nonexistent or trivial. For example, "Hydrophis platurus" has a venom more potent than any terrestrial snake species in Costa Rica based on LD, but despite its abundance in the waters off its western coast, few human fatalities have been reported.
Epidemiology of snakebites
In Australia, there are many more annual cases of spiderbite and jellyfish envenomation than snakebite; however, when considering the number of fatal cases, snakebite is the most serious type of envenoming. Australia is unique in that it is the only continent where venomous snakes constitute the majority of species. Nearly all venomous species in Australia are elapids, as vipers are absent from the continent.
Chrysopelea
Chrysopelea, more commonly known as the flying snake or gliding snake, is a genus that belongs to the family Colubridae. Flying snakes are mildly venomous, though the venom is dangerous only to their small prey. Their range is in Southeast Asia (the mainland (Vietnam, Cambodia, and Laos), Greater and Lesser Sundas, Maluku, and the Philippines), southernmost China, India, and Sri Lanka.
Deathstalker
The deathstalker is one of the most dangerous species of scorpions. Its venom is a powerful mixture of neurotoxins, with a low lethal dose. While a sting from this scorpion is extraordinarily painful, it normally would not kill a healthy adult human. However, young children, the elderly, or infirm (such as those with a heart condition and those who are allergic) are at much greater risk. Any envenomation runs the risk of anaphylaxis, a potentially life-threatening allergic reaction to the venom. A study from Israel shows a high rate of pancreatitis following envenomation. If a sting from "Leiurus quinquestriatus" does prove deadly, the cause of death is usually pulmonary edema.
Colubrinae
Colubrine snakes are extremely morphologically and ecologically diverse. Many are terrestrial, and there are specialized fossorial (e.g. "Tantilla") and arboreal (e.g. "Oxybelis") groups, but no truly aquatic groups. Some of the most powerful constrictors (e.g. "Pantherophis", "Pituophis", "Lampropeltis") are members of this group, as are a few snakes that have strong enough venom to kill humans (i.e. boomslangs ["Dispholidus"] and twigsnakes ["Thelotornis"]).
Helen Springs Station
In 2008 a nine-year-old boy was bitten by a King Brown Snake, one of the most venomous snakes in the world. The boy had picked up the snake and swung it around his head before it bit him on the arm. The Royal Flying Doctor Service medivacced the boy to Alice Springs Hospital. He received anti-venine and survived the bite.
List of venomous animals
Strictly speaking, all spiders and scorpions possess venom, though only a handful are dangerous to humans. Spiders typically deliver their venom with a bite from piercing, fang-like chelicerae; scorpions sting their victims with a long, curved stinger mounted on the telson.Of more than a thousand known species of scorpion, only a few dozen have venom that is dangerous to humans, most notably the bark scorpions, including:
Caspian cobra
The Caspian cobra is the most venomous species of cobra in the world, slightly ahead of the Philippine cobra, based on a 1992 toxinological study reported in the Indian Journal of Experimental Biology. A number of small nonenzymatic proteins are found in the venom, including neurotoxins and members of the cytotoxin family, which have been shown to cause cell death through damage to lysosomes.
Red-bellied black snake
The red-bellied black snake ("Pseudechis porphyriacus") is a species of elapid snake native to Australia. Described by George Shaw in 1794, it is one of eastern Australia's most commonly encountered snakes. Averaging around in length, it has glossy black upperparts, bright red or orange flanks and a pink or dull red belly. It is not an aggressive species and generally retreats from encounters with people, but can attack if provoked. Although its venom is capable of causing significant illness, no deaths have been recorded from its bite, which is less venomous than other Australian elapid snakes. The venom contains neurotoxins, myotoxins, coagulants and has haemolytic properties; victims can also lose their sense of smell.
Enhydrina schistosa
Enhydrina schistosa, commonly known as the beaked sea snake, (), hook-nosed sea snake, common sea snake, or the Valakadyn sea snake, is a highly venomous species of sea snake common throughout the tropical Indo-Pacific. This species is implicated in more than 50% of all bites caused by sea snakes, as well as the majority of envenomings and fatalities.
Opiliones
An urban legend claims that the harvestman is the most venomous animal in the world, but possesses fangs too short or a mouth too round and small to bite a human, so is not dangerous (the same myth applies to "Pholcus phalangioides" and the cranefly, which are both also called a 'daddy longlegs'). This is untrue on several counts. None of the known species of harvestmen has venom glands; their chelicerae are not hollowed fangs but grasping claws that are typically very small and not strong enough to break human skin.
List of dangerous snakes
The Neotropical rattlesnake or Cascabel ("Crotalus durissus") is a medically important species due to its venom toxicity and the human fatalities it is responsible for. The IP value is 0.17 mg/kg with an average venom yield between 20–100 mg/kg per bite. Bite symptoms are very different from those of Nearctic species due to the presence of neurotoxins (crotoxin and crotamine) that cause progressive paralysis. Bites from "C. d. terrificus" in particular can result in impaired vision or complete blindness, auditory disorders, ptosis, paralysis of the peripheral muscles, especially of the neck, which becomes so limp as to appear broken, and eventually life-threatening respiratory paralysis. The ocular disturbances, which according to Alvaro (1939) occur in some 60% of "C. d. terrificus" cases, are sometimes followed by permanent blindness. Phospholipase A neurotoxins also cause damage to skeletal muscles and possibly the heart, causing general aches, pain, and tenderness throughout the body. Myoglobin released into the blood results in dark urine. Other serious complications may result from systemic disorders (incoagulable blood and general spontaneous bleeding), hypotension, and shock. Hemorrhagins may be present in the venom, but any corresponding effects are completely overshadowed by the startling and serious neurotoxic symptoms. Subcutaneous venom for this species is 0.193 mg/kg. The neotropical rattlesnake in Brazil is of special importance because of the high incidence of envenoming and mortality rates. Clinically, venom of this snake does not usually cause local effects at the bite site and is usually painless. However, the etiology progresses to systemic neurotoxic and myalgic symptoms, with frequent renal failure accompanied by acute tubular necrosis. The huge area of distribution, potent venom in fairly large quantities and a definite willingness to defend themselves are important factors in their dangerousness. In Brazil and probably also in other countries in their area of distribution, this species is probably the most dangerous rattlesnake. After the fer-de-lance ("Bothrops asper"), it is the most common cause of snake envenoming. In the first half of the 20th century as well as in the 1950s and 1960s, 12% of treated cases ended fatally. Untreated cases apparently had a mortality rate of 72% in the same period, but this was due to the fact that there was no antivenom, poor medical care and neglect (Rosenfeld, 1971). In more recent times, an average of 20,000 snakebites are registered each year in Brazil, almost 10% of them caused by the neotropical rattlesnake. The mortality rate is estimated at 3.3% and is thus much lower than in the past (Ribeiro, 1990b). A study from southeastern Brazil documented only one fatality from 87 treated cases (Silveira and Nishioka, 1992).