If you are a long time reader of Listverse you will remember that we have previously had two lists on snakes: 10 lesser known venomous snakes and10 unusual and amazing snakes. Surprisingly, we have not published a list of the most venomous snakes – and so, today, we fill that void with the following list. This is probably also a good time to point out (which we have done on a previous list) that something is venomous when it injects you with venom, and something is poisonous when it harms you through touch or eating.
Popular species :
Venomous snakes are species of the suborder Serpentes that are capable of producing venom, which is used primarily for immobilizing prey and defense mostly via mechanical injection by fangs. Common venomous snakes include the families Elapidae, Viperidae, Atractaspididae, and some of the Colubridae. The toxicity of them is mainly indicated by murine LD50, while multiple factors are considered to judge their potential danger to humans.
The evolutionary history of venomous snakes can be traced back to as far as 25 million years ago. Snake venom is actually modified saliva used for prey immobilization and self-defense and is usually delivered through highly specialized teeth, hollow fangs, directly into the bloodstream or tissue of the target. Evidence has recently been presented for the Toxicofera hypothesis, but venom was present (in small amounts) in the ancestors of all snakes (as well as several lizard families) as 'toxic saliva' and evolved to extremes in those snake families normally classified as venomous by parallel evolution. The Toxicofera hypothesis further implies that 'nonvenomous' snake lineages have either lost the ability to produce venom (but may still have lingering venom pseudogenes), or actually do produce venom in small quantities, likely sufficient enough to help capture small prey but causing no harm to humans when bitten.
There is no a single or special taxonomic group for venomous snakes which comprise species from different families. This has been interpreted to mean venom in snakes originated more than once as the result of convergent evolution. Around a quarter of all snake species are identified as being venomous.
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. It is, for example, harmless to drink snake venom as long as there are no lacerations inside the mouth or digestive tract. The two exceptions are: the Rhabdophis keelback snakes have glands that secrete poison they ingest from eating poisonous toads, and similarly, certain garter snakes from Oregon retain toxins in their livers from ingesting rough-skinned newts. This ability to sequester toxins and store them for defense renders these certain snakes both poisonous and venomous.
LD50, mostly on rodents, is a common indicator of snakes' toxicity with a smaller resultant value indicating a higher level of toxicity. There have been numerous studies on snake venom with a variability of potency estimates. There are four methods in which the LD50 test is conducted, which are injections to subcutis (SC), vein (IV), muscle (IM or IC), and peritoneum (IP). The former (SC) is most applicable to actual bites as only
The world's most venomous snake, based onLD50, is the inland taipan.
vipers with large fangs, such as large Bitis, Bothrops, Crotalus or Daboia specimens, would be able to deliver a bite that is truly intramuscular, and snakebites rarely cause IV envenomation. Testing using dry venom mixed with 0.1% bovine serum albumin in saline, gives more consistent results than just saline alone.
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 Ernst and Zug's published book "Snakes in Question: The Smithsonian Answer Book" from 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 LD50 (recorded only intramuscularly) is 0.24 mg/kgand 0.155 mg/kg,. Studies on mice and human cardiac cell culture shows that venom of the inland taipan, drop by drop, is the most toxic among all snakes.
Most venomous snakes of the world
Other factors :
Toxicity of snake venom (based on laboratory tests conducted on Mice) is sometimes used to gauge the extent of their 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 LD50 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.
2- Eastern Brown Snake
Top 10 Most Venomous Snakes
courtesy to : listverse.com/2011/03/30/top-10-most-venomous-snakes/
IAKHOVAS MARCH 30, 2011
The Big Four snakes responsible for most fatal bites in India
For the external links , refrences click here to read the full wikipedia article
The only snake from the Americas on the list, the Rattlesnake is easily identifiable by the tell tale rattle on the end of its tail. They are actually a part of the Pit Viper family, and are capable of striking at up to 2/3rd their body length. The Eastern Diamondback in considered the most venomous species in North America. Surprisingly, juveniles are considered more dangerous than adults, due to their inability to control the amount of venom injected. 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 can lead to the loss of a limb or death. Difficulty breathing, paralysis, drooling and massive hemorrhaging are also common symptoms. Thus, a rattlesnake bite is always a potentially fatal injury. Untreated rattlesnake bites, especially from larger species, are very often fatal. However, antivenin, when applied in time, reduces the death rate to less than 4%
9- Death Adder
The appropriately named Death Adder is found in Australia and New Guinea. They actually hunt and kill other snakes, including some on this list, usually via ambush. Death Adders look quite similar to vipers, in that they have triangular shaped heads and short, squat bodies. They typically inject around 40-100mg of venom with an LD of 0.4mg-0.5mg/kg. An untreated Death Adder bite is one of the most dangerous in the world. The venom is a neurotoxin. A bite causes paralysis and can cause death within 6 hours, due to respiratory failure. Symptoms generally peak within 24-48 hours. Antivenin is very successful in treating a bite from a Death Adder, particularly due to the relatively slow progression of symptoms, but before its development, a Death Adder bite had a fatality rate of 50%. With the quickest strike in the world, a Death Adder can go from strike position to striking and back again within 0.13 of a second.
Vipers are found throughout most of the world, but arguably the most venomous is the Saw Scaled Viper and the Chain Viper, found primarily in the Middle East and Central Asia, particularly India, China and South East Asia. Vipers are quick tempered and generally nocturnal, often active after rains. They are also very fast. Most of these species have venom that cause symptoms that begin with pain at the site of the bite, immediately followed by swelling of the affected extremity. Bleeding is a common symptom, especially from the gums. There is a drop in blood pressure and the heart rate falls. Blistering occurs at the site of the bite, developing along the affected limb in severe cases. Necrosis is usually superficial and limited to the muscles near the bite, but may be severe in extreme cases. Vomiting and facial swelling occurs in about one-third of all cases. Severe pain may last for 2-4 weeks. Often, local swelling peaks within 48-72 hours, involving the affected limb. Discoloration may occur throughout the swollen area as red blood cells and plasma leak into muscle tissue. Death from septicaemia, respiratory or cardiac failure may occur 1 to 14 days post-bite, or even later.
7- Philippine Cobra
Most species of Cobra would not make this list; however the Philippine Cobra is the exception. Drop for drop, its venom is the most deadly of all the Cobra species, and they are capable of spitting it up to 3 metres. The venom is a neurotoxin which affects cardiac and respiratory function, and can cause neurotoxicity, respiratory paralysis and death in thirty minutes. The bite causes only minimal tissue damage. The neurotoxins interrupt the transmission of nerve signals by binding to the neuro-muscular junctions near the muscles. The symptoms might include headache, nausea, vomiting, abdominal pain, diarrhea, dizziness, collapse and convulsions.
6- Tiger Snake
Found in Australia, the Tiger snake has a very potent neurotoxic venom. Death from a bite can occur within 30 minutes, but usually takes 6-24 hours. Prior to the development of antivenin, the fatality rate from Tiger snakes was 60-70%. Symptoms can include localized pain in the foot and neck region, tingling, numbness and sweating, followed by a fairly rapid onset of breathing difficulties and paralysis. The Tiger snake will generally flee if encountered, but can become aggressive when cornered. It strikes with unerring accuracy.
5- Black Mamba
The feared Black Mamba is found throughout many parts of the African continent. They are known to be highly aggressive, and strike with deadly precision. They are also the fastest land snake in the world, capable of reaching speeds of up to 20km/h. These fearsome snakes can strike up to 12 times in a row. A single bite is capable of killing anywhere from 10-25 adults. The venom is a fast acting neurotoxin. Its bite delivers about 100–120 mg of venom, on average; however, it can deliver up to 400 mg. If the venom reaches a vein, 0.25 mg/kg is sufficient to kill a human in 50% of cases. The initial symptom of the bite is local pain in the bite area, although not as severe as snakes with hemotoxins. The victim then experiences a tingling sensation in the mouth and extremities, double vision, tunnel vision, severe confusion, fever, excessive salivation (including foaming of the mouth and nose) and pronounced ataxia (lack of muscle control). If the victim does not receive medical attention, symptoms rapidly progress to severe abdominal pain, nausea and vomiting, pallor, shock, nephrotoxicity, cardio toxicity and paralysis. Eventually, the victim experiences convulsions, respiratory arrest, coma and then death. Without antivenin, the mortality rate is nearly 100%, among the highest of all venomous snakes. Depending on the nature of the bite, death can result at any time between 15 minutes and 3 hours.
Another entry from Australia, the venom in a Taipan is strong enough to kill up to 12,000 guinea pigs. The venom clots the victim’s blood, blocking arteries or veins. It is also highly neurotoxic. Before the advent of an antivenin, there are no known survivors of a Taipan bite, and death typically occurs within an hour. Even with successful administration of antivenin, most victims will have an extensive stay in intensive care. It has been likened to the African Black Mamba in morphology, ecology and behavior.
3- Blue Krait
The Malayan or Blue Krait is, by far, the most deadly of this species. Found throughout South East Asia and Indonesia, 50% of bites from the deadly Blue Krait are fatal, even with the administration of antivenin. Kraits hunt and kill other snakes, even cannibalizing other Kraits. They are a nocturnal breed, and are more aggressive under the cover of darkness. However, overall they are quite timid and will often attempt to hide rather than fight. The venom is a neurotoxin, 16 times more potent than that of a Cobra. It quickly induces muscle paralysis by preventing the ability of nerve endings to properly release the chemical that sends the message to the next nerve. This is followed by a period of massive over excitation (cramps, tremors, spasms), which finally tails off to paralysis. Fortunately, bites from Kraits are rare due to their nocturnal nature. Before the development of antivenin, the fatality rate was a whopping 85%. Even if antivenin is administered in time, you are far from assured survival. Death usually occurs within 6-12 hours of a Krait bite. Even if patients make it to a hospital, permanent coma and even brain death from hypoxia may occur, given potentially long transport times to get medical care.
While I did say that I would not include multiple sub-species in this list, the incredible Inland Taipan deserves a spot of its own. It has the most toxic venom of any land snake in the world. The maximum yield recorded for one bite is 110mg, enough to kill about 100 humans, or 250,000 mice! With an LD/50 of 0.03mg/kg, it is 10 times as venomous as the Mojave Rattlesnake, and 50 times more than the common Cobra. Fortunately, the Inland Taipan is not particularly aggressive and is rarely encountered by humans in the wild. No fatalities have ever been recorded, though it could potentially kill an adult human within 45 minutes.
Don’t let the innocuous name of this snake fool you, 1/14,000 of an ounce of its venom is enough to kill an adult human. Coming in a variety of species, the Eastern Brown snake is the most venomous. Unfortunately, its preferred habitat is also along the major population centers of Australia. The Brown snake is fast moving, can be aggressive under certain circumstances and has been known to chase aggressors and repeatedly strike at them. Even juveniles can kill a human. The venom contains both neurotoxins and blood coagulants. Fortunately for humans, less than half of bites contain venom and they prefer not to bite if at all possible. They react only to movement, so stand very still if you ever encounter one in the wild. [Image Source]
1- Fierce Snake or Inland Taipan
1- Belcher’s Sea Snake
The most venomous snake known in the world, a few milligrams is strong enough to kill 1000 people! Less than 1/4 of bites will contain venom, and they are relatively docile. Fisherman are usually the victims of these bites, as they encounter the species when they pull nets from the ocean. Found throughout waters off South East Asia and Northern Australia.