DEADLY VENOMOUS BIG FOUR SNAKES IN PAKISTAN
A symbol of both terror and fascination in the history of humans, snakes are legless, elongated reptiles belonging to the suborder Serpentes. In many cultures, snakes have been considered as signs of evil. Snakes range in size from the tiny threadlike snakes (10cm) to the python of up to 7.67 meters (25.2 feet) in length. Snakes kill 125,000 people every year. Due to their deadly poisonous venom, they are taken as a symbol of terror. However, only a few types of snakes are too poisonous to cause death. Ophidiophobia is the abnormal fear of snakes. Snakes are found on every continent except Antarctica and the New Zealand islands. There is an Island in Brazil where people are forbidden to go because it has up to 5 snakes per square meter. Pakistan is the host of sixty-seven snake species consisting of the commonly harmless non-venomous colubrids to the deadly vipers, cobras, kraits, pythons, thread snakes and sea snakes. The 4 venomous species of snake responsible for most cases of snake bites and deaths on the Indian Subcontinent (Pakistan, Sri Lanka, Bangladesh, Nepal, Bhutan, Maldives, and India etc. are collectively termed as the “Big Four”. This includes Saw-scaled viper, Russell’s viper, Indian cobra, and Common Krait.
Habitat and Description
Saw-scaled viper locally in Pakistan, termed as Lundi, Khappra, Astola khappra, Waziristan khappra and Sindh khappra is common in Asia. It is found in Pakistan, Bangladesh, Sri Lanka Northern India, Iraq, United Arab Emirates, Oman, Tadzhikistan, Turkmenistan, Uzbekistan, Afghanistan. In Pakistan, it is found in Cholistan and Thar deserts in Sind and Punjab and also Astola Island off the Markan coast in Baluchistan Province. Mostly, it is an inhabitant of sandy, rocky, moderately thick grass and scrubs forest areas.
Carpet viper having slender to moderately plump body reaches the average length of 0.4 to 0.6 meters. It has a short head with an arrow-shaped mark, and is distinctly wider than the neck. There is a pale strip from both eyes to the angle of the mouth. The topside of the saw-scaled viper is tan to olive brown with dark-edged white spots alongside the backbone. The tail is short, which is about 10% of the entire body length.
Behavior and feeding
This snake is primarily nocturnal in summer (may be active at dusk) and is sometimes diurnal (active during daytime) in winters. It can be found basking in the early morning in bushes more than two meters above the ground. It basks openly during the winter season, but mostly below rocks or stalks of the dead plant. It can conceal itself in the sand with only the head exposed. It can quickly move in a side zigzag movement. It can become easily aggressive and excited. But it is likely to flee when encountered, also has been reported to run after victims violently. Upon threatening it assumes a self-protective C-coil shape, rubbing exaggerated body loops to make a typical sizzling hiss-like rasp sound like water on the hot plate.
Saw-scaled viper is ovoviviparous, breeding season extending from mid-February to late April. Viviparous vipers give birth to six to twenty-eight young, while oviparous lay almost as many white eggs having unbreakable shells. It may feed on birds, small mammals, toads, frogs, centipedes, scorpions, locusts, spiders, beetles, slugs, worms, and reptiles (including other snakes).
It is considered to be the world’s most dangerous snake because of its very poisonous venom, easily excitable nature and its abundance near cultivated areas. It produces on average about 18 mg/weight of dry venom, with a recorded highest of 72 mg. It may inject about 12 mg, while the lethal dose for an adult is expected to be merely 3-5 mg.
Its symptoms comprise inflammation and soreness, which appear within just few minutes of a snake bite. In severe cases the inflammation may affect the whole limb within 12–24 hours and blisters appear on the skin. More dangerous symptoms include hemorrhage (bleeding), hematemesis (vomiting of blood), and epistaxis (bleeding from nose). The mortality rate from their bites is about 20%, and due to availability of anti-venom, now deaths are rare.
Habitat and Description
Russel’s viper known locally as Koriwala in Pakistan is also responsible for most snakebite incidents and deaths. It is habitually found in grassy areas, scrub forests and farmlands. It is most common in hilly, coastal areas and plains of suitable habitat. Humid environments, such as rainforests, swamps, and marshes are avoided. Due to the attraction for rodents, it is also found in vastly urbanized settlements. The chain viper is found in Pakistan from India-Pakistan border to Indus Valley in Sind and Punjab provinces. It extends from Karachi to Rawalpindi, at low altitudes. Commonly it attains the length of 0.7 to 1.3 meters and the highest length of 1.7 meters. The triangular head is quite long which to some extent is distinct from neck. It has large Fangs and the short striped tail. Its color may vary from dark brown and brownish-yellow to brownish-gray. Spots in the central row may merge together to form zig-zag model. 2 rows of oval spots run along each side of the body. 3 detached semi-triangular spots on the head are positioned to shape triangle with the peak between the eyes.
Behavior and Feeding
This snake is also nocturnal and sluggish during the day. However, it can be active during the day in the winter season. Upon threatening, it forms a sequence of S-loops, raises the first 3rd of the entire body and produces a hissing sound that is evidently louder than that of any other snake. Its diet includes small mammals such as birds, mice, and rats.
This can spray lethal venom from two to three times. An adult snake can yield venom ranging from 130–250 mg to 150–250 mg to 21–268 mg. For adult humans, its lethal dose is about 40–70 mg. Its symptoms include pain at the bitten site, instantly followed by inflammation. Bleeding especially from urine and the gums is a familiar symptom showing blood signs within twenty minutes after the bite. Blisters occur at the bitten site and the blood pressure drops with the fall in heart rate. Facial swelling and vomiting occur in approximately 1/3 of all cases. In 20-30% untreated cases kidney failure also occurs.
Habitat and Description
Cobra locally in Pakistan known as Kala Nag and sheesh Nag in addition to Pakistan, is found in Bangladesh, Bhutan, Nepal, Sri Lanka, and India. It is also reported for most snake bites. It is an inhabitant of plains, dense forests, farming lands, wetlands, rocky territory, and densely populated urban regions. It is not present in true desert areas. The Indian cobra is mostly found in the locality of water. It preferably hides in holes, tree hollows, and piles of rock. Having body color from yellow and dark brown to black it attains an average length of 1.9 meters, reaching the highest 2.4 meters in length. Male cobras are usually heavier and shorter than females with longer tails.
Overgrazing and deforestation are the major threats to the cobra snake in Pakistan. Also for their skin, thousands of cobras are killed every year. Snake charmers also capture cobras to stage fights with mongoose as well as the street performance of snakes by using pungi (Been or Murli). Although the snakes lack the external ear which makes them unable to perceive music. They just respond and follow the pungi movement held by snake charmer which is taken as a threat by the snake. Herbal practitioners use cobras in their recipes. Due to continuous human intervention and unsystematic cobras killing, there is quick depletion of cobras all over Pakistan.
Behavior and Feeding
This cobra is diurnal and is active during morning and early evening. Usually, it is not considered aggressive, particularly shy of humans and avoids confrontation. At a chance of coming across, its 1st priority is to run away unnoticed. However upon threatening it lifts the front part of its body to impress the enemy and fixes its eyes to the source of frustration and keenly follows its activities. However, if it finds a chance to avoid confrontation, it rapidly slips away. Cobras are known for lifetime pairing. Its breeding activity is observed during April to July. About twelve to thirty eggs are laid in rat holes and female stays close awaiting hatching. Its prey usually comprises poultry, nesting birds, frogs, and mice. Mostly, it becomes an inhabitant of rat holes after eating its dweller.
Cobra’s venom is highly toxic, generally containing an influential cardiotoxin and neurotoxin. Its average venom yield/bite ranges between 169 and 250 mg. Symptoms of snake bite initiate about eight minutes after the bite. Victims feel anxiety, irregular pulse rate, and also may fall into a deep coma. Its mortality rate is around 20–30% but according to a study when timely medical treatment was provided, the mortality rate was reduced to 9%.
Indian or Sind Krait (Bungares Caeruleus)
Habitat and Description
Indian or Sind Krait locally in Pakistan known as Sung choor is an inhabitant of Pakistan, Afghanistan, Sri Lanka, India, and Nepal etc. In Pakistan, it has been reported from throughout Punjab, KPK, Sind, Azad Kashmir, and southern Baluchistan. It is mainly widespread in Indus Valley. It is generally an occupant of holes in the ground, heaps of debris, cut foliage and bricks etc. It can also be found in wet and moist regions like tanks or wells containing water. It is mostly found close to or in human dwellings. It normally attains 1 m (3 ft) to 1.8 m (6 ft) length. They have egg-shaped head and have fine white bands on the body, however, bands can vary from yellow to grey. Young kraits contain white spots on 1/3 part of the body instead of bands.
Behavior and Feeding
This snake is nocturnal. When disturbed, it hisses loudly, coils up and makes bouncy movements by lifting its tail. It is hesitant to bite, bites occasionally and in one study 77% of victims died. It is the most dangerous of Bunguarus species. This snake feeds on mice, lizards, frogs, toads, frogs, and other snakes. Young krait snakes are known to consume arthropods.
Its venom is extremely poisonous comprising powerful neurotoxins, which may cause muscle paralysis. It yields an average of 10 mg/dry weight venom. Mostly bite incidents take place at night. Often, its bite feels like a bit of a mosquito or an ant causing slight or no pain and this can provide fake reassurance to the sufferer. If bitten by krait during sleep, a victim cannot realize this and may die without waking up. Normally, victims experience an inability to see or talk, severe abdominal cramps, followed by paralysis. After about 4-8 hours of krait bite, the death may occur due to suffocation caused by respiratory failure. According to a clinical toxicology study, if untreated, the mortality rate is about 70-80%.
Treatment of “Big Four” bite
A polyvalent serum that has all of Big Four snakes’ venom neutralizing effect is widely available to save lives.