What Species of Snake are Venomous?

Western Diamondback
Boston Science Museum, 2010

If you are attempting to decide whether or not a snake is venomous, it is important to remember that not all venomous snakes are easily recognized. There are thousands of species of snakes on the planet and hundreds of these species are venomous. It is also important to note that some venomous snake species closely resemble their non venomous cousins and vice-versa. If you are planning to attempt to handle a snake, you should seek an education in the handling and identification of these animals. You should never, under any circumstances, handle a wild snake that you don’t positively recognize to be harmless, unless you are an experienced snake handler.

The only way to be sure a snake is venomous is to be aware of what the species looks like. There is no universal red flag that tells you a snake is venomous, so be careful. There are four families of snakes that include venomous species. These are the Colubridae, Viperidae, Elapids and Hydrophiidae. Here we will discuss some of the characteristics of each family and some of the venomous species found within these families.

Hydrophiidae

Hydrophiidae are more widely known as Sea Snakes. Every species of Hydrophiidae that has been found thus far is highly venomous. These snakes are very dangerous to humans, so do not disturb them. Usually they would rather not bite you, but they will if they are threatened. It is relatively easy to recognize a Hydrophiidae because they all live in salt water and have flattened tails for swimming.

Colubridae

Colubridae make up around 75% of the world's snake population and it has been estimated that around 20% of them are venomous.  Twenty percent may not seem like a lot, but that is hundreds of species of venomous Colubrids. These snakes are found all over the world, so it is a good idea to educate yourself on the Colubrids in your area so that you can tell the difference between a harmless garter snake and a venomous Colubrid.

Viperidae

Every snake species that belongs to the Viperidae family is venomous. They have hinged fangs that fold back when they close their mouths, but inspecting a snake’s teeth is an impractical way to decide if it is venomous. However, many of these species have triangular heads and slender necks. This is not a surefire way to tell if a snake is venomous, but if you see a snake does have this triangular shape to its head, it is a good idea to leave the area carefully.

Species of Viperidae include all rattlesnakes, cottonmouths, the bushmaster, and of course vipers. Pit vipers are recognizable for the pits that appear between their nostrils and eyes.  There is one on each side. However, these cannot be seen from a distance. Rattlesnakes are recognizable for the rattles that appear on their tails. Thankfully, they shake these when threatened and it makes a distinctive noise. Unfortunately, young rattlesnakes can deliver a venomous bite, but they only have one rattle and therefore can’t make the telltale sound. Cottonmouths can be recognized when they open their jaws, which they do when they are threatened. The insides of their mouths are white, hence the name.

Elapids

All species of the Elapid family are also venomous. They tend to have shorter fangs that are fixed rather than hinged. This group contains some of the most notorious of the venomous snake species, such as cobras, mambas, kraits, taipans and coral snakes. It is very difficult to tell the difference between a coral snake and the harmless kingsnake, because they both have yellow, black and red bands over the entire length of their bodies. A good way to remember the difference between the two is to use this rhyme, “if red touches yellow, kill a fellow, if red touches black, friend of Jack.”

If you plan to spend time outdoors, pick up a field guide on snakes in that area before venturing into snake territory. If you are unfamiliar with the snakes in an area and come across one, you should treat it as if it were venomous. This means leaving the snake alone and allowing it to wander off or, if the snake is aggressive, you can leave the area immediately, being careful not to step on any other snakes.

Try to bring a friend with you whenever you wander outside; this can be helpful if you are bitten. The unafflicted person should try to remember what the snake looks like so they can describe it to a doctor. Ideally the doctor would like to see the snake, but if you cannot catch the snake safely, don’t try. It is also important to know that recently deceased snakes can still deliver venomous bites.

Sources

Stillwell, Steven E., Snake Mystique, retrieved 7/4/09, buckmasters.com/bm/resources/articles/tabid/135/articleType/ArticleT-d/919/Snake-mystique.aspx

Abby, Michael, “Viperidae” A Dictionary of Zoology 1999, retrieved 7/4/09, encyclopedia.com/doc/108-Viperidae.html

Colubrids:Colubridae-Physical Characteristic, Habitat, Diet, Behavior and reproduction, Colubrids and People, Conservation, staus-GEOGRAPHIC RANGE</a7>,retrieved 7/4/09, http//animals.jrank.org/pages/3893/Colubrids-Colubridae.htm 

Garamone, Jim, Dealing with That Snake in the Grass, retrieved 7/4/09, defenselink.mil/news/newsarticle.aspx?id=45207

Spitting Cobras Aim To Kill

Equatorial spitting cobra
looking fierce

Cool, terrifying, whatever you want to call them, spitting cobras are unarguably fascinating. They are a group of cobra species that have the ability to “spit” their venom from their fangs. They are similar to other cobra species, aside from this odd defense mechanism. They have similar eating and mating habits and are also alike in appearance. It's tough to tell the difference, but it's good to avoid cobras whether they prefer to spit or bite, anyway.

There are currently eleven known species of spitting cobras on Earth. Their color, markings and size differ greatly between the species. The difference in size can be several feet. Some spitting cobras are only a few feet long, while the largest spitting cobra ever found was more than nine feet in length. Spitting cobras can be red, brown or black, with or without markings. However, they do have one feature in common; all spitting cobras are hooded, like the king cobra.

An interesting fact about spitting cobras is that they do not actually spit their venom; technically it is sprayed out of their fangs. After the snake uses its muscles to force the venom into its fangs, it uses a burst of air from its lungs to propel the venom out of its mouth. They do this mainly as a way to defend themselves, and they can aim their venom rather accurately when threatened. The venom that is expelled from the snakes fangs can travel up to ten feet.

Most spitting cobras are equipped with hemotoxic and neurotoxic venom. This venom is harmless if it lands on unbroken skin. However, you should be careful not to touch or spread the venom and to wash it off carefully. If the venom enters the blood stream through broken skin, it can be deadly. A spitting cobra will often aim for the eyes, which can be a problem if it hits its target. The venom can cause complete and permanent blindness if it isn’t treated properly.

Spitting cobras are also capable of delivering their venom through a bite. They will typically use this method for prey only, but the bite is dangerous for the unlucky who are on the receiving end. The large brown spitting cobra is particularly dangerous as it can potentially deliver more venom per bite than any other snake species on Earth.

The large brown spitting cobra is the most recent discovery among spitting cobra species. It is also the biggest and most deadly. Its venom is not as toxic as the king cobra, but far more can be delivered in one bite. There may be even more spitting cobras out there, just waiting to be discovered, but it is doubtful that any can deliver as much venom as the large brown.

Ways That Snakes Defend Themselves

Eastern Diamondback Rattlesnake

Snakes are highly efficient predators. They are stealthy, they are fast and some of them are even packing lethal venom. It is hard to imagine that such skilled hunters would need defense mechanisms, but obviously they do. No animal on Earth is exempt from becoming prey. Snakes may be preyed upon by predatory birds, other snakes, small mammals and more. Lucky for them, most snake species have evolved with instinctual defensive behaviors and/or physical attributes that aid in their defense. Here are just a few of the more common ways that snakes can defend themselves.

Ways That Snakes Defend Themselves: Warnings

When a member of some species of snakes is startled by something that it feels may be a threat, it may attempt to scare the creature off by giving it a warning. The most well known of these snake warnings is the rattle. Rattlesnakes will use their rattle as a way of saying “If you get close, I’m going to bite you.” This can be effective against animals that know the sound comes from a very dangerous snake. Other ways that snakes may warn potential predators are to hiss, puff themselves up so they look larger or to open their mouths wide as if to strike.

Ways That Snakes Defend Themselves: Balling

A very popular snake to keep as a pet is known as the Ball Python. This snake is thus named because of its habit of wrapping its body around its head when it is threatened. This is called balling. They are not the only snakes that do this to protect their head from damage, but they are the only species that are nicknamed for it.

Ways That Snakes Defend Themselves: Tail Loss

There are at least three species of snakes that are capable of ridding themselves of their tails. They do this when a predator has them by the tail. This way, the more important half of their body can escape to safety while their attacker munches on their tail.

Ways That Snakes Defend Themselves: Play Dead

There are several species of snakes that will pretend they are dead when confronted by a predator. Some will roll over on their back and let their mouth hang open. Others will go one step further by giving off a nasty scent that mimics the smell of decomposition. However, this isn’t very effective when they meet with a predator that doesn’t mind eating a dead snake.

Ways That Snakes Defend Themselves: Camouflage

Snakes can camouflage themselves in many ways. This is a great defense mechanism because it makes it very difficult for a predator to spot them. Some snakes can blend into their surroundings really well by hiding in leaf litter or holding very still so they look like a branch or a vine.

Ways That Snakes Defend Themselves: Venom

Now, most venomous snakes rarely resort to using their venom as a defense. They prefer to use their venom to kill prey. Nonetheless, they will not hesitate when need be. Spitting cobras (which don’t actually ‘spit’) spray their perceived threat with venom strictly as a warning. They never use their ‘venom spit’ to kill prey. Of course, a venomous snake without this ability will bite if they have to. They don’t want to, but they will, with the exception of a scant few highly aggressive venomous snake species. They do want to bite you and will if you get close enough.

So you see, snakes are not only very good at causing the rest of the animal kingdom to go on the defensive, they are actually quite good at playing defense themselves. Remember, if you see a snake displaying any of these behaviors, they are threatened by you. The best thing you can do is to leave them alone and walk away. They’ll eventually calm down and go about their business. Also, if you will be walking outdoors, know the snake species in the area, if possible. Some snakes are very territorial–not many, but some. The best defense against the smaller species of this category is high boots.

Sources

Chris Mattison, Snake, p. 26-29, DK Publishing, INC. 1999

King Cobras: The Planet's Biggest Venomous Snakes

A gorgeous King Cobra photographed by
Michael Allen Smith

King Cobras are the largest venomous snakes on Earth. They are recognizable for the telltale hood that spreads out behind their heads when threatened. They can be found in the forests and grasslands of Southern Asia.

An average adult King Cobra is about 12 feet long and weighs around 13 pounds. Larger specimens have been recorded, but they are rare. King Cobras can be tan, olive green or black. They have yellow bands that appear on the entire length of their bodies. The underside of these snakes is a light, yellowish color. The King Cobra’s most distinguishing feature is its hood. The hood is actually a set of ribs that can be stretched out giving the animal its formidable appearance.

King Cobras subsist mainly on other snakes. When pressed for food they will eat lizards, rodents and birds. Like all other snakes, King Cobras have hinged jaws and eat their prey by swallowing it whole. They hunt for their food by using a snake’s unique sense of smell and by interpreting vibrations. These snakes can go for months at a time without eating.

Female King Cobras lay clutches of 20-40 eggs in nests of leaves. These eggs incubate for roughly three months. The mother abandons the nest as soon as her young start hatching. She instinctively does this so that she will not eat her babies.

Adult King Cobras shed up to five times a year. Adolescents shed once a month. These snakes are able swimmers and can readily climb trees. They have an average lifespan of 20 years.

King Cobras are extremely dangerous. One bite is sufficient to kill an adult elephant if administered in the right spot. The generally accepted mortality rate for these bites is 75%–not good odds. The venom of a King Cobra is neurotoxic, meaning that it attacks the central nervous system. This venom is less potent than that of some other snake species. However, because of the King Cobra’s size it can produce more venom per bite, so it is no less deadly.

Victims of the King Cobras bite will experience a myriad of symptoms. These may include blurry vision, severe pain, cardiovascular complications and vertigo. There are many other possible symptoms as the symptoms may be different for some individuals and symptoms like necrosis may appear if the victim survives long enough. Respiratory failure is usually the cause of death for individuals who have been bitten by a King Cobra.

King Cobras are magnificent creatures, but they are extremely deadly. People traveling in Southern Asia should be aware of these snakes and their habits. As antivenin for their bites is not always readily available, the best defense against them is avoidance.

Sources

King Cobra, retrieved 5/18/09, reference.com/browse/king+cobra&fromAsk=true

Green Anacondas: The Biggest Snakes in the World

Green anaconda in captivity
Photo by LA Dawson

Green anacondas (Eunectes murinus) are boa constrictors that can be found in marshy or swampy areas, as well as near slow moving rivers and streams. They are commonly found in the tropical rainforests of the Amazon and Orinoco basins. Because they are semi-aquatic and far more graceful in the water than on land, they are never too far from a water source. They are also known as the common anaconda. Not only are they common, but they are also the largest of the four anaconda species. In fact, they are the largest of all snakes.

Adult green anacondas are 20 feet in length, on average. However, they can grow up to 29 feet in length, or more. Reticulated pythons can grow to be longer than the green anaconda, but they are nowhere near as heavy. Adult green anacondas weigh an average of 330 pounds and can grow to weigh up to 550 pounds, or more. It’s no wonder that many humans are afraid that these massive beasts could eat them. In truth, they are capable of eating humans that are not too large. However, anaconda attacks on humans are rare and no fatal cases have been proven.

These snakes mate in a very interesting way. The female, which is significantly larger than the male, will lie in wait for males during the later months of the dry season. Several males, anywhere between two and twelve, will coil around the female in a “‘breeding ball” for several weeks. Once the female has mated with her partners, she will go up to seven months without eating. Gestating for roughly six months, she will retain her eggs, which incubate for eight to twelve weeks. She gives birth to dozens of live young that are roughly 1-2 feet in length. They are completely independent from birth and can be expected to live about ten years in the wild. However, green anacondas have been known to live up to thirty years in captivity.

Green anacondas feed on a variety of mammals, reptiles, amphibians, fish and birds. They can eat rather large prey, such as wild pigs, capybara, jaguars and deer. They coil around their prey and squeeze it until it can no longer breathe and subsequently dies. They then swallow their prey whole. Like many snakes, they can go for a long time without eating, depending on the size of their most recent meal. It is extremely rare for an adult green anaconda to be consumed by another animal. However, adolescents of the species may be preyed upon by some mammals, birds and reptiles.

Despite their obviously formidable appearance, green anacondas are quite beautiful. They are commonly dark green in color with black, oval-shaped markings. These markings have yellowish centers on the sides of the snake. They can be admired from afar in several zoos and aquariums. This may be the best way to catch a glimpse of these awesome creatures.

Sources

Green Anaconda, retrieved 11/17/09, seaworld.org/animal-info/Animal-Bytes/animalia/eumetazoa/coelomates/deuterostomes/chordata/craniata/reptilia/squamata/green-anaconda.htm#top

Green Anaconda, retrieved 11/17/09, neaq.org/animals_and_exhibits/animals/anaconda/index.php

Soomro, A. 2001 “Eunictus murinus,” Animal Diversity Web, retrieved 11/17/09, animaldiversity.ummz.umich.edu/site/accounts/information/Eunectes_murinus

Some Cool Creatures With Deadly Venom

Gorgeous and extraordinarily
deadly box jellyfish
Photo is in the public domain
in the United States.

Venom is a toxin or combination of toxins that a creature injects through biting or stinging. There are countless animals on Earth that are capable of delivering venoms to humans that range from slightly irritating to deadly. Despite their deadly venom, many of these creatures do not pose a significant threat to humans because they are shy and reclusive. Others that possess deadly venom are made even more deadly for the fact that they are aggressive and are not intimidated by humans. Others still are deadly because humans happen upon them by chance and are envenomed before the creature or the human can make a choice to stay or go. Below are creatures of all these groups that have one thing in common. They possess extremely deadly venom.

Very Deadly Venom: Blue-Ringed Octopus

Blue-ringed octopi are so named because of the vivid blue rings that appear on their skin when they are threatened. Otherwise, they are typically brown in color. They are very small creatures (about the size of a golf ball when fully grown). Therefore, if you are walking in a Pacific tidal pool from Australia to Japan or a little west and you see a small brown blob or a golf-ball with blue rings, leave immediately. Stepping on one of these beautiful, but deadly, creatures can quickly lead to your death.

It is thought that blue-ringed octopi deliver their venom through a bite. It may also deliver through the skin, in which case it would be a poison rather than venom. Whatever the case, you do not want to be on the receiving end. Their venom contains maculotoxin and tetrodotoxin (think pufferfish) It causes paralysis, namely of the respiratory system. Unless someone begins breathing for you almost immediately, you will die. They also need to start massaging your heart soon after. If this is accomplished and continued for the next 24 hours, you will survive without any long-term complications. If you are alone or with someone who does not know to start CPR, a dose of this venom will get you a one-way ticket to a coffin. There is no antivenin.

Very Deadly Venom: Inland Taipan

The inland taipan is a 6-8 foot snake that lives in the dry plains of eastern and southern Australia. They change color with the seasons, being lightest (brown) in summer and black in winter. Their heads are often darker than the rest of their bodies. They are reclusive and do not often encounter humans. They would rather hide if they do. Nonetheless, they will still bite when provoked.

The inland taipain is often said to be the most venomous snake in the world. Its venom is the deadliest of all snakes found on land and it can deliver enough to kill you in roughly 45 minutes. Its venom contains powerful neurotoxins and procoagulants. This means it can paralyze you and affect the blood clotting process. Bleeding is a serious concern. Their bites can also cause renal failure. Thankfully, there is an antivenin, if you can get to it in time.

Very Deadly Venom: Australian Box Jellyfish

The Australian box jellyfish is an extremely feared sea creature and with good reason. Its body is box-shaped and it has up to 60 tentacles that can grow up to 10 feet long. Each tentacle contains 5,000 nematocysts (the things they sting you with). They are transparent light blue, making them nearly impossible to see, if you are not looking for them. You should be on the lookout for them off the northern coast of Australia and in the Indo-Pacific area.

The venom of Australian box jellyfish is cardiotoxic, neurotoxic and dermatonecrotic. That means it attacks your heart, rots tissue and attacks your nervous system. The sting of this creature is so painful that victims often go into shock instantly. A large sting (many stinging cells make contact) can cause a victim to go into cardiac arrest within minutes. Little stings are not as bad, but a big sting spells certain death if you are alone.

Necrosis sets in at the site of the sting, leaving telltale scars. The tentacles stick to the victim and need to be removed before the damage worsens. The only way to do this is by pouring vinegar on them and then removing them. (Do not handle with your bare hands)

These animals should be avoided at all times. Seeking them out or keeping them as pets (as people often do with blue-ringed octopi) is foolhardy. Just because you will not certainly die, does not mean you will not regret it if you are envenomed. Other animals that should be avoided because of their venom are the Brazilian wandering spider (bite causes priapism, which needs to be treated immediately) and the death stalker scorpion (aggressive animal), the bite and sting of these animals causes excruciating pain.

Sources

Blue-Ringed Octopus, retrieved 11/10/10, marinebio.org/species.asp?id=403

Facts About Inland Taipan, retrieved 11/10/10, lifestyle.iloveindia.com/loounge/facts-about-inland-taipan-7433.html

Box Jellyfish, retrieved 11/10/10