Snake venom and other toxinsí strength is measured using the LD50 (lethal dose 50%) test. It involves dosing several groups of animals with a substance either by mouth (force-feeding), by injection, via the skin or by inhalation. Animals used have included mice, rats, rabbits, cats, dogs, monkeys, fish and birds. The finishing point of the test is when half of the animals in the group have died. The amount of test substance that kills half the animals gives the LD50 figure. LD50 figures are used, in theory, to indicate the standard toxicity value for each chemical.
This test has many downfalls It† has been called "crude and unscientific". LD50 figures for a single chemical can vary enormously according to the species, strain, age, gender and even diet of the animals used in the tested. In one survey, the LD50 figure for the same substance tested by two different laboratories on the same species, varied by three to eleven-fold. Unfortuantly, there is not a more accurate or humane test. The test has to be repeated on more groups of animals and on a variety of species, so that an average LD50 figure can be obtained. The LD50 figure that is used to measure relative toxicities of various snake venoms is conducted using mice. This means the data is not† particularly accurate for estimateing how lethal a snake bite to a human would be. Using the LD50 test for estimating the danger of a particular species to humans is obvoiusly flaured. The snake currently ranking number one on that list has not been the cause of death to a human in any documented case history
The distinction between venomous and poisonous animals is that venomous is applied to a creature that has the ability to secrete or utilise its venom externally, while poisonous includes creatures that contain a poisonous substance. Often poisonous creatures are harmless unless eaten whilst venomous creatures can often use their poison as a weapon. Snake venoms are chemicals made up of enzymes. These chemical can have two effects on the snakeís victims. They can paralyse and incapacitate their victim and ,often but not always, the snake venom helps start digesting the prey.
Dangerous vs Deadly
There is a distinction between dangerous and deadly snakes. Dangerous snakes are the snakes that kill the most people each year whereas the most deadly snake is the snake that has the most deadly venom. The Fierce Snake or Inland Taipan at the top of The Most Deadly Snake List is rare and does not live near people.
This is one version of the Top 10 Deadliest Snake list. Every venom expert has a different top 10. This one takes into account the amount of venom injected in a snake bite and LD50 value.
These rare snakes are virtually unknown in outside of Australia. This list was taken from the http://www.reptilegardens.com which is part of reptile garden South Dakota which holds the largest reptile collection in the world.
1) Fierce Snake or Inland Taipan (Oxyuranus microlepidotus ), Australia. This has the† most toxic venom of any snake. Maximum yield recorded (for one bite) is 110mg. That would probably be enough to kill over 100 people or 250,000 mice.
2) Australian Brown Snake (Pseudonaja textilis ), Australia. One 1/14,000 of an ounce of this venom is enough to kill a person.
3) Malayan Krait (Bungarus candidus ), Southeast Asia and Indonesia. 50% of the bites from this snake are fatal even with the use of antivenin treatment.
4) Taipan (Oxyuranus scutellatus ), Australia. The venom delivered in a single Taipan bite is enough to kill up to 12,000 guinea pigs.
5) Tiger Snake (Notechis scutatus ), Australia. The Tiger snake is a very aggressive snake that kills more people in Australia that any other snake on that continent.
6) Beaked Sea Snake (Enhydrina schistosa ), South Asian waters Arabian Sea to Coral Sea.
7) Saw Scaled Viper (Echis carinatus ), Middle East Asia. Saw Scaled Vipers kill more people in Africa than all the other venomous African snakes combined. Its venom is 5 times more toxic than that of the cobra.
8) Coral Snake (Micrurus fulvius ), North America. Coral Snakes have a very potent venom but many are too small to deliver enough venom to kill a human. It is elapid (relative of the cobras and mambas).
9) Boomslang (Dispholidus typus ), Africa. The Boomslang is the most seriously venomous rear-fanged snake in the world. They have very long fangs and can open their mouths a full 180 degrees to bite.
10) Death Adder (Acanthophis antarcticus ), Australia and New Guinea. A dosage of 10mg of Death Adder venom is enough to kill a human. A good sized Death Adder can deliver up to 180mg in a single bite.
Other snakes that are tied in the #10 position include the Black Mamba, both species of Green Mambas, and the Mojave Rattlesnake.
The inland taipan often regarded as the land snake with the most potent venom in the world. This is an alternative top 10 which does not take into account the amount of venom injected
Species : Hook-nosed seasnake (Enhydrina schistosa) Mouse LD50 (mg/kg) : 0.02 Venom yield per snake (mg) : 7.7-9.0
Species : Russellís viper (Vipera russelii) Mouse LD50 (mg/kg) : 0.03 Venom yield per snake (mg) : 130.0-250.0
Species : Inland taipan (Oxyuranus microlepidotus) Mouse LD50 (mg/kg) : 0.03 Venom yield per snake (mg) : 44.0-110.0
Species : Duboisís reef seasnake (Aipysurus duboisii) Mouse LD50 (mg/kg) : 0.04 Venom yield per snake (mg) : 0.07
Species : Eastern brownsnake (Pseudechis textilis) Mouse LD50 (mg/kg) : 0.05 Venom yield per snake (mg) : 2.0-67.0
Species : Black mamba (Dendroaspis polylepis) Mouse LD50 (mg/kg) : 0.05 Venom yield per snake (mg) : 50.0-100.0
Species : Tiger rattlesnake (Crotalus tigris) Mouse LD50 (mg/kg) : 0.06 Venom yield per snake (mg) : 6.0-11.0
Species : Boomslang (Dispholidus typus) Mouse LD50 (mg/kg) : 0.07 Venom yield per snake (mg) : 1.6-8.0
Species : Yellow-bellied seasnake (Pelamis platurus) Mouse LD50 (mg/kg) : 0.07 Venom yield per snake (mg) : 1.0-4.0
Species : Common Indian krait (Bungarus caeruleus) Mouse LD50 (mg/kg) : 0.09 Venom yield per snake (mg) : 8.0-20.0