The 'Top Ten' most poisonous snakes on earth.

The Fierce Snake: The most poisonous snake on earth.
A Snake that is 68 times as poisonous as the King Cobra and 740 times as poisonous as the Western Diamondback Rattlesnake.
The other 9 of the 'Top Ten' most poisonous snakes on earth are also found only in Australia.

The Fierce Snake, otherwise known as the Inland Taipan or Small-Scaled Snake, can reach an average length of about 2 metres (6.5 ft) with a maximum of about 2.7 m ( 8.8 ft).
The upper surface of the snake can vary from dark brown to a light straw colour.
Dramatic seasonal colour changes also take place, with a dark winter and light summer phases.

Distribution
The Inland Taipan lives in the far west and southwest of Queensland, extending through the far west of New South Wales into the northeast corner of South Australia, and into the southeast of the Northern Territory.

This distribution includes the drainage systems of the Cooper and Diamantina Rivers, as well as the Bulloo, Paroo, Warrego and lower Darling. Few people live in this remote, hot, dry country, and the Inland Taipan is rarely encountered.

To escape the blistering heat of this open country, the Inland Taipan shelters in abandoned animal burrows, deep fissures in cracked ground, rock crevices and sink holes.

The only Victorian specimens were collected near the junction of the Murray and Darling rivers in 1857. It lives in areas of cracking soils of river overflows, flood plains or on gibber plains.
No fatalities have been attributed to this species, and all known bites have been to people who keep them in captivity or actively seek them out in the wild

Diet
The diet is almost solely composed of small mammals, particularly native rats, which, at times, reach plague proportions in this region. The prey is subdued with a rapid, accurate strike, injecting the extremely toxic venom deep into the prey item. The venom is unequalled in toxicity amongst any snake anywhere in the world.

The Taipan Venom.
The most deadly component is a neurotoxin that immobilises by paralysis. It essentially scrambles the body's communication lines - the nerves that carry electrical signals around the body.

The taipan neurotoxin acts at the point where nerves join to muscles, called the neuro-muscular junction.
The toxin binds to the ends of the nerves, blocking electrical activity and shutting down communication between the brain and muscles.

As the poison spreads the victim experiences headache, nausea, vomiting, pain in the abdomen and dizziness.
Blurred vision follows, sometimes accompanied by convulsions and, in severe cases, coma.

The neurotoxin (like many other snake venoms) is also a myotoxin, meaning it eats away at muscle tissue. The urine of a bite victim often turns reddish-brown as their muscles dissolve and are passed through the kidneys.
In fact, the kidneys are often badly damaged by filtering so much tissue debris out of the blood and kidney failure is a common complication in serious snake-bites and a frequent cause of death.

Internal bleeding is the other major complication of taipan bites. The snake's second main toxin is a procoagulant which prevents blood-clotting by removing the body's supply of its natural blood clotting agent, fibrinogen.
This causes persistent bleeding from the bite site and can lead to more serious - sometimes fatal - internal haemorrhaging, especially in the brain.

In Australia, around half of all deaths from snakebite involve brown snakes. However, this does not necessarily mean that brown snakes are the "most venomous".
In fact, on a world scale, deaths from brown snake are negligible compared to deaths from cobras, kraits or vipers.

A large number of deaths associated with a specific species of venomous snake is often related to the snake's population size, its habitat and its nature.
Those species found in large numbers in highly populated areas are more likely to cause envenomation because of the greater number of possible victims.
Also a species which is aggressive and does not move away when approached is more likely to bite than a species which is shy and not aggressive

In Australia Brown snakes are the primary cause of snake bite death and the Tiger snake was the second most common cause.

The Australian venomous snakes of major medical importance are the:

• Brown Snakes: Eastern or common brown snake (Pseudonaja textilis), western brown snake or gwardar (P. nuchalis), the dugite (P. affinis)

• Tiger snakes: Common or mainland tiger snake (Notechis scutatus), black or island tiger snakes (N. ater)

• Taipan: Common or coastal taipan (Oxyuranus scutellatus)

• Fierce snake: also called small scaled snake, inland taipan, western taipan (Oxyuranus microlepidotus)

• Black snakes: Red-bellied black snake (Pseudechis porphyriacus), king brown snake, also called mulga snake (P. australis), spotted or blue-bellied black snake (P. guttatus), Papuan black snake (P. papuanis)

• Death Adders: Acanthophis spp.

• Copperhead: Austrelaps spp.

• Rough scaled snake: also called Clarence River snake (Tropidechis carinatus)

• Sea snakes: Family Hydrophiidae, multiple species

Snakes of lesser medical importance include the Stephen's banded snake (Hoplocephalus stephensi), pale-headed snake (H. bitorquatus), broad-headed snake (H. bungaroides), and small-eyed snake (Cryptophis nigrescens)

More than 400,000 people are poisoned by snakebites worldwide each year and 20,000 of them die, with most cases occurring in the poorest countries, researchers say.

While Australia has over 100 different species of land snakes, 12 whose bite is deadly, it does not make the list of countries with high snakebite rates.

In an article published in United States-based open access Public Library of Science Medicine, the researchers said the burden from snakebites was highest in South and South East Asia and sub-Saharan Africa.

They said, according to a conservative estimate, there are 421,000 cases of envenoming, or venom delivered through biting, each year and which lead to at least 20,000 deaths.

But the actual figures could be several times higher.

"These figures may be as high as 1,841,000 envenomings and 94,000 deaths," the team wrote.

"Based on the fact that envenoming occurs in about one in every four snakebites, between 1.2 million and 5.5 million snakebites could occur annually."

India has the highest figures, with 81,000 envenomings and 11,000 deaths each year, followed by Sri Lanka with 33,000 envenomings, Vietnam and Brazil with 30,000 each, Mexico with 28,000 and Nepal with 20,000.
Source.  A.B.C  News  Nov 4, 2008

LD₅₀ (mg/kg) in saline by subcutaneous injection in mice

Reference.  A cited list, from "Australian Animal Toxins" (Sutherland and Tibballs, 1983),
Handbook of Clinical Toxicology of Animal Venoms and Poisons" by Meier and White (eds) 1995.
Snakbite  http://www.avru.org/compendium/biogs/A000084b.htm
Australian Zoo.  http://www.australiazoo.com.au/
Great Australian Bites  http://www.abc.net.au/science/slab/shorter/story.htm