D.H Lawrence’s brilliant poem “Snake” describes this traditional enemy of the people as one of the lords of life. That’s as may be, but there are a fair number of lords of death out there as well, one of which has revealed an unlikely secret.
Snake venom is a highly developed form of saliva, injected by the snake through hollow fangs. The glands that secrete the venom are usually situated on each side of the snake’s head below and behind the eye. The glands have cavities in which the venom is stored before being conveyed by a duct to the base of channelled or tubular fangs through which it is ejected.
Snake venom has two main functions: the immobilization of prey and its digestion. It is a complex mixture of proteins, enzymes, and various other substances. The proteins are responsible for the toxic and lethal effect of the venom and their function is to immobilize prey. The enzymes play an important role in the digestive process and other substances are responsible for important but non-lethal biological effects. Some of the proteins in snake venom affect biological functions including blood coagulation, blood pressure regulation, and the transmission of nervous or muscular impulses.
None of which goes anywhere near explaining how or why snakes acquired venom. Logic (in true Darwinian style) says that it gave snakes an evolutionary advantage. But what was the first change in a series of miniscule changes that led to the development of venom, the sacs to retain it, and the fangs to inject it? Not even Richard Dawkins seems to know. Writing in The Blind Watchmaker (1986) he remarks, “Many animals bite, and any animal’s spit contains proteins which, if they get into a wound, may cause an allergic reaction. Even so-called non-venomous snakes can give bites that cause a painful reaction in some people. There is a continuous, graded series from ordinary spit to deadly venom.”
Apparently, the ten most venomous snakes in the world are:
(2) The Inland Taipan (Australia) has the most toxic venom of any land snake in the world. It is said to be shy and reclusive, but that probably doesn’t help much if you tread on one.
(3) The Eastern Brown Snake (Australia) is notorious for its speed and aggression and has been known to chase attackers and repeatedly strike at them.
(4) The nocturnal Malayan or Blue Krait is found throughout South East Asia and Indonesia. 50% of bites are fatal, even with the administration of antivenom.
(5) Another entry from Australia, the Coastal Taipan has venom strong enough to kill up to 12,000 guinea pigs. (Not sure how they tested this claim.) The venom clots the victim’s blood, blocking arteries and veins.
(6) The feared Black Mamba is found in many parts of the African continent. It strikes with deadly precision up to 12 times in a row and it is the fastest land snake in the world.
(7) Found in Australia, the Tiger snake has a potent neurotoxic venom. Symptoms can include localized pain in the foot and neck region, tingling, numbness and sweating, followed by rapid onset of breathing difficulties and paralysis.
(8) Drop for drop, the venom of the Philippine Cobra is the most deadly of all the cobra species. Capable of spitting up to 3 metres, the snake’s venom is a neurotoxin affecting cardiac and respiratory functions. It can cause respiratory paralysis and death in thirty minutes.
(9) Vipers are found throughout the world, but arguably the most venomous are the Saw Scaled Viper and the Chain Viper, found primarily in the Middle East, India, China and South East Asia.
(10) The appropriately named Death Adder is found in Australia and New Guinea. It actually hunts and kills other snakes, including some on this list, usually via ambush. The Death Adder can strike in a fraction of a second.
Observant readers will have noted the presence of five of the deadliest land snakes plus the world’s deadliest sea snake in and around Australia; which makes it all the more surprising that anyone in their right mind would want to live there. As Barry Humphries once said, “I love Australia – I think.”
It is ironic, therefore, that a painkiller as powerful as morphine, but without most of its side-effects, has been found in the venom of the Black Mamba. French scientists have named these pain-killing proteins mambalgins. Morphine acts on the brain to cut pain, but it is addictive, causing headaches, nausea and muscle twitching. Mambalgins work by blocking the relaying of pain signals by the central nervous system.
Pharmaceutical companies will doubtless figure out how to use it on people. In the meantime, the advice of W. C. Fields may come in handy: “Always carry a flagon of whiskey in case of snakebite and furthermore always carry a small snake.”