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Crawly creepy creatures. Big eyes and protruding tongues. Hissing sounds and hoods in ready to attack poses.

What would people do if they come across such things? Take a stick and hit them repeatedly till they get killed! Fed on a diet of folk stories, they fear these animals so much that they think getting rid of them is the best thing to save themselves and everybody around.

That is the human instinct because they associate snakes with danger and feel getting them out of the way is the best thing to do.

But if I say, when I faced similar situations twice, I didn't kill the snakes and just let them go, you would think I did a foolish thing! And I insist that I did not for what I did was the right thing to do! Moreover, I tell people not to kill snakes. Because, snakes have a very important role to play in our ecosystems and killing them would cause imbalances in the natural environment. Nature doesn't evolve living beings without purposes.

Effective hunters and ambush predators, snakes use their highly-developed senses of sight, taste, hearing and touch to locate, recognize and track their prey. Some snakes use a lethal dose of venom, a modified saliva, to paralyze and kill their prey while others use their powerful muscular bodies to squeeze their prey to death.

When threatened by you, they use the same methods to protect themselves from you. It is their defensive mechanism. But that is where the conflict begins between human beings and these reptiles as they both fear each other. Snakes usually prefer to retreat when encountered but can become defensive if threatened. Most snake bites are received by people who try to capture or kill a snake or disturb them in some way. When left alone, snakes present little or no danger to people.

Some snake species have become threatened due to land clearing for agriculture, urban development and through the introduction of animals such as domestic pets. Maintaining a high level of biodiversity is important to all life on Earth, including humans, and snakes are an important part of that biodiversity. Snakes and other reptiles make up a significant proportion of the middle-order predators that keep our natural ecosystems working. Without them the numbers of prey species would increase to unnatural levels and the predators that eat snakes struggle to find food. They serve as a food source for larger predators such as hawks, owls, herons, and carnivorous mammals such as bobcats. Some snakes consume other snakes if given the opportunity. Immune to the poisonous venom, king snakes will readily make a meal of a rattlesnake that they might encounter.

Snakes are a key component in the balance of nature.Their presence or removal from an area directly impacts the health of an ecosystem.

Do you know that snakes kill the rats, mice and the bandikoots that eat farm products and destroy crops? They also eat insects that are harmful to crops. Without snakes, most of the crops will be ruined by rodents. Without snakes, we would be completely overrun by these nuisance rodents.

Moreover, not all snakes are venomous. Only a few species of them are. Then how to recognize harmful snakes?

There is no hard-and-fast rule to distinguish a dangerous snake from a harmless one. For the untrained observer in particular, it can often be difficult to make a positive identification of different types of snakes. The general rule is always to be cautious and avoid coming into contact with any snake.

Different types of snakes do exhibit certain distinguishing features and behaviours that can be used to tell them apart. If you live in or are visiting an area where snakes are common, it is generally a good idea to become familiar with the characteristics of the different snakes you may encounter. This will help you become more aware of the common snakes you might expect to see and allow you to react appropriately if you encounter them.

Not all snake bites are harmful. Pythons do not have venom and colubrids (rear-fanged snakes) either have a weak venom or lack venom altogether. Bites from venomous elapids (front-fanged snakes) should be taken seriously and treated appropriately.

Snake venoms contain species-specific proteins with widely varying toxicological features. A list of venomous snakes in the Indian sub-continent:

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Cobra: The subcontinent harbors many varieties of cobras but the primarily identified species are binocled or spectacled cobra, monocled cobra, black cobra, and albino cobra. No marked variation in their venom has been observed by any research group. Cobra can deliver 60 mg of venom in a single bite, which is five times its fatal dose. The venom consists of three types of proteins: cardiotoxin ( causes heart electrophysiology dysfunction or muscle damage. The heart becomes weaker and is not as efficient in pumping and therefore circulating blood), neurotoxin (harmful to nervous system), and phospholipase A2 (PLA2). Severe inflammation and necrosis in the affected tissue area may be due to the cardiotoxins and/or PLA2 .

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Kraits: In the subcontinent, there is a variety of kraits which vary in size, color and toxicity, but the common krait is considered the most aggressive species. It has small fangs and therefore indistinct bite marks. The common krait has small and fixed front fangs. Its bite may not be painful and the local symptoms are barely detectable, but systemic symptoms and abdominal pain are the distinctive features of a krait envenomation, along with hypokalemia (deficiency of potassium in the bloodstream). The neurotoxins (harmful to nervous ssytem) in the krait venom are prominently pre-synaptic and prevent release of acetylcholine at the neuromuscular junctions. Krait venom has a fatal dose of 6 mg with an average deliverable dose of 20 mg.

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Russell's Viper: It is a large and thick viper with one chain of rings on the vertebrae and two more dorsal chains symmetrically placed on either side. It has aggressive tendencies and may bite under provocations. The venom causes local and hemotoxic (destroy red blood cells that is, cause hemolysis, disrupt blood clotting, and/or cause organ degeneration and generalized tissue damage) manifestations with distinctive blister formation on the affected limb. Hematuria (blood in the urine), renal (kidney) failure, hyper edema (swelling from excessive accumulation of watery fluids in cells, tissues or cavities), hemorrhage ( an escape of blood from a ruptured blood vessel) and anemia are other typical features in Russell's viper envenomation. This snake has a fatal dose of 15 mg and the average venom yield per bite is 63 mg.

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Saw-Scaled Viper: It accounts for more than two-third of the venomous bites in the region. This small snake camouflages in the background, therefore the victim often fails to sight it, particularly in the dark. It is aggressive and coils in the shape of "8" with a sound of a saw cutting wood by rubbing its scale. Ecchymosis (a discoloration of the skin resulting from bleeding underneath, typically caused by bruising), rise in CT/BT, hematological (blood-related) complications, local pain and edema can help in identifying an Echis bite. Untreated Echis envenomation may involve multiple organs and the patient may suffer from hematuria, melena (black faeces because of gatro-intestinal bleeding), renal failure, hemorrhage, anemia and hypotension (low BP). No cases of any significant cardiotoxins have been reported by any research group but some case reports have indicated myocardial ischemia (blood flow to the heart is reduced, preventing it from receiving enough oxygen) following viper bites.

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Bamboo Pit Viper: It is a green-colored, yellow-bellied snake, which often camouflages in the leaves and therefore causes frequent envenomation to the forest dwellers. It has a fatal dose of 100 mg but the maximum extractable venom dose is only about 14 mg. The bites are never alarmingly toxic and no mortality has been reported. However, PLA2, 14kDa, is one of its main constituents, with a number of isoforms, and shows moderate anti-platelet activities, edema, mild anti-coagulating and myotoxicity resulting in local swelling, dizziness and morbidity.

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King Cobra: The largest venomous snake found in the Indian subcontinent, it has some aggressive tendencies. Its venom is functionally much similar to that of cobras, with limited variations like serine proteinase blood coagulation factor X activator. A unique protein toxin (CM55 - LD50 28 mg/20 g in albino mice) found in the venom has cardiotoxic and hemorrhagic characteristics, whereas the crude venom has a reported fatal dose of 12 mg. However, it may contain and deliver venom many times the fatal dose because of its large venom glands.

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Common Sea Snake: It is the most commonly encountered estuarine species. This snake is one of the most venomous and is found in the coastal aquaculture and river deltas. However, it is not aggressive towards human beings and its bites are very rare. Its venom possesses potent post-synaptic neurotoxic activity with a fatal dose of 0.6 mg for a 60-kg body . It is reported that nearly 80% of sea snake bites fail to produce significant envenomation, and bites may be inconspicuous, painless, and free of edema, but severe envenomation may cause neurological complications, oliguria (the production of abnormally small amounts of urine), and hyperkalemic (elevated concentration of the electrolyte potassium (K+) in the blood. Extreme hyperkalemia is a medical emergency, due to the risk of potentially fatal abnormal heart rhythms or arrhythmia) cardiac arrest .

Snakes usually live in semi-urban, desert and forest areas. If you destroy their eco-systems, they might come to urban areas. They are often attracted to yards and houses, when food and shelter are unknowingly provided by the human inhabitants. Some snakes eat rodents and are attracted to garden or farm sheds to hunt rats and mice. Some eat birds and eggs and so enter poultry farms and aviaries to prey on the occupants. Common tree snakes actively hunt frogs during the day and are often seen around the house and garden where frogs occur.

Houses and yards can also be used by snakes for shelter. They are regularly found curled up in ceilings, enjoying the security and warmth. A variety of snake species is often encountered in places such as timber piles and under sheets of corrugated iron. If there are holes in the walls of your house or in the soil surrounding your home, they are likely to make these holes their homes. Therefore, you can take measures to reduce the attractiveness of your yard or house to snakes. If you have a rock wall or other structure that has the potential to house frogs and rats, and in turn attract snakes, discourage these animals by blocking holes. Avoid creating habitat for snakes by keeping a tidy, well-maintained yard and shed. Actively discourage rats and mice, and snake-proof your aviaries and poultry farms.

Ensure that the yard is tidy with shrubs and gardens kept away from the house. Snakes will shelter in houses, under shrubs and in timber stacks to avoid the hottest parts of the day. It is also important to ensure that food scraps are disposed of properly to discourage rats and mice as snakes are attracted to places where they can obtain food. Bird owners should also discourage rodents by ensuring that aviaries are kept clean and hygienic and that the mesh is small enough to stop snakes entering.

Blocking off as many potential access points as possible can significantly reduce the chance of snakes entering your house. Install screens on doors and windows. Block any holes around the house including those between the roof and ceiling. Extra care should be taken during summer when the snakes are most active. In areas that experience flooding, snakes will move to higher ground during a flood. Take extra precautions at these times.

If there is a chance that a snake could find its way into your home, you should have the phone number or address of a snake catcher on hand. Even, NGOs such as friends of snake societies catch them and leave them in forests if you call them. Relocating them is the best policy. It is important to remember that snakes are an important part of the environment and the relocated snake is often replaced by another living nearby. The best approach is to snake-proof your house.

It is important that you never try to kill the snake. Not only is it making injustice to the eco-system to kill a native animal, but it places you at a higher risk of being bitten if you force the snake to defend itself.

Close the internal doors in the house and open the external doors and windows. Block the gaps underneath internal doors with rolled up towels or papers. Place chairs and boxes under windows to make it easier for snakes to climb out. Keep everyone well clear of the snake.

If the snake is in a place away from electricity and valuable items, try directing a gentle jet of water from the garden hose or squirt bottle towards the snake to encourage it to move away. Remember that snakes on the move will naturally try to find shelter, so hosing the snake may not always work.

Snake activity patterns change dramatically over the course of a year. Throughout the cool months, snakes and other reptiles are relatively inactive. Reptiles gain body warmth using external heat sources, either by basking in the sun or in warm places including rocks, near roads and even under the fridge!

All aspects of a snake's life rely on this external heat to function, whether it is to feed, find a mate, fight off disease and infection, or even just to pump blood around its body. As a result, they are not very active during winter.

As the months become warmer, particularly around summer, snakes become active and are frequently encountered by people. This is the breeding and feeding season for snakes. A good guide to when a snake is likely to be active is if the species that it feeds on are active and abundant at that particular time and place. For example, frog-eating snakes are likely to be active on warm, humid nights near streams when frogs are breeding.

The fastest snake in the world is the black mamba of Africa and it can travel at around 12km/hr. Humans can easily run faster than this. Snakes soon tire, as moving rapidly uses their stored energy. The likelihood that a snake will give a persistent chase is small.

If you encounter a snake on your way home, don't panic. Back away to a safe distance and allow the snake to move away. Snakes often want to escape when disturbed. Most snakes have the potential to bite a human, but will generally only bite as a last resort.

Snakes sense the vibration of approaching footsteps and tend to flee into the undergrowth.

If you see a snake, the best way to avoid being bitten is simply to leave the snake alone.

You can also take these following precautions if you are visiting snake-infested areas:

Wear boots and trousers or gaiters when walking in a bushy area. Do not wear sandals or thongs.
Be aware of where you are placing your feet.
Do not put hands or feet in or under logs, rocks, hollows, crevices or debris without checking first that there is no snake there.
When in the bush, check inside your shoes, clothes and sleeping bag before using them.
Use a torch when walking around campsites or in the forest at night.
Do not interfere with a snake if pets or other people have already provoked it.
Do not handle injured snakes. A hurt animal is a much more dangerous animal, as it is fighting for its life.
Know appropriate first aid for treating snake bites.
First aid for snake bites
If you are bitten by a snake, here is what you should and should not do. Assume ALL snakes are venomous, and take the following action:

Do not panic. Try to remain calm, lie down and immobilise the bitten area. It is unlikely that the bite will be life-threatening.
Apply a bandage but do not block circulation. Take a broad bandage and bind along the limb starting at the bite area, at the same pressure as for a sprain. Then bandage down the limb and continue back up the entire limb over and above the bite area. This will help prevent the spread of the venom through the body. Do not remove the bandage. It is often easier to go over the top of clothing such as jeans rather than remove clothing. In an emergency, strips of clothing or pantyhose can be used instead of a bandage.
Immobilise the limb with a splint. Lie down and keep the limb completely still until help arrives. Do not elevate the limb or attempt to walk or run. Movement will encourage the spread of the venom through the body.
Do not attempt to catch the snake. All too often, the snake will bite again if an attempt is made to catch it. Identification of the snake species can be obtained through samples of the patient's blood or urine, and from venom around the bite area. If the species of snake still remains uncertain, a poly-antivenene may be used, which is suitable for treatment of all venomous snake bites.
Do not wash the wound. Venom left on the skin will help doctors identify the snake and administer the appropriate antivenene.
Do not cut or bite into the wound. This will spread the venom into the bloodstream and can cause more serious injuries than the snake bite itself.
Seek medical help. Find a doctor immediately who can treat snake bites. An anti-venum  may be required.

Now you know enough to respect these creatures. You also know how to protect yourself from them. Killing snakes should not be an option for you when you encounter these important eco-system organisms now. Live and let live!

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Synthetic Biology Bites Back at Global Snake Antivenom Shortage

Lab-made antibodies could produce high-volume, high-quality snakebite treatments 

http://www.scientificamerican.com/article/synthetic-biology-bites-b...

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Researchers from India have identified what makes the venom from the saw-scaled viper (Echis carinatus) so destructive: the involvement of cells known as neutrophils. Their findings, published in Nature Communications, could lead to therapies to prevent the devastating tissue damage and amputation that often results from snakebites.

In an attempt to understand the mechanism of venom-induced tissue destruction, a team led by Professor Kempaiah Kemparaju from the University of Mysore studied the effect of the venom on various immune cells. “Initially, we suspected that macrophages played a key role and intended to find out the effect of E. carinatus venom on macrophage differentiation into M1 and M2 subtypes,” Kemparaju explained. “However, the macrophage isolation protocol invariably results in isolation of neutrophils as well. Since neutrophils were available in plenty, out of curiosity, we also tested the effect of venom on neutrophils.” The decision to study neutrophils proved to be serendipitous. Kemparaju and his team found that saw-scale viper venom not only caused the neutrophils to die but also induced the release of neutrophil extracellular traps (NETs), a sticky web of DNA designed to prevent the spread of bacteria. “When we started digging for more information on neutrophils, we found out that several pathogenic bacteria were able to degrade NETs-DNA by secreting the enzyme DNase, using this as an efficient strategy to escape from the NETs and reach the blood circulation,” Kemparaju said. Interestingly, they found that saw-scaled viper venom lacked DNase activity, unlike cobra venom which is highly lethal and neurotoxic. “This finding led us to reason that E. carinatus venom will induce massive NETs formation, not only blocking the blood vessels but also trapping venom toxins at the bite site. Eventually, the tissue suffers from starvation due to a lack of blood supply, and in addition, the trapped venom toxins (especially extracellular matrix degrading enzymes) degrade the tissue in its vicinity,” he added. Working in mice, the team found that tail vein injection of the venom did not lead to tissue damage if the mice lacked neutrophils. Similarly, when the venom was co-injected with DNase, tissue damage was greatly reduced, although the mice also died faster. The researchers hypothesize that the lack of NETs allowed the saw-scaled viper venom to behave more like cobra venom, rapidly entering the circulation and leading to lethal systemic toxicity. “Our results suggest that even if you administer DNase three hours after E. carinatus venom injection or a natural bite, you can prevent the loss of limb. However, co-injection of DNase with venom was highly fatal. Delayed administration of DNase enzyme, on the other hand, was not fatal and prevents tissue damage 100 percent,” Kemparaju said. The team next plans to find out more about the molecular mechanisms underlying tissue damage caused by other types of vipers and colubrid snakes, as well as chronic conditions such as diabetic gangrene.

http://www.nature.com/ncomms/2016/160419/ncomms11361/full/ncomms113...

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