Before we get to our list of the world’s most venomous animals, we'd like to make a
distinction between poisonous and venomous.
A poisonous animal carries and can secrete toxins, however a human has to ingest, inhale
or touch the animal to be poisoned.
If you bite it and you die, it’s poisonous.
Venomous means that the animal actively seeks to deliver toxins through a bite, sting, stab
or spit usually as defense or in the pursuit of prey.
If it bites you and you die, it’s venomous.
Also this list of the most venomous animals aren’t necessarily the most deadly or dangerous
venomous animals for humans.
There are some animals whose venom is far less deadly, but more humans are injured and
killed by them each year simply because humans come into contact with them more frequently.
We’ve taken a number of factors in consideration for creating this list such as how much venom
the animal tends to deliver during an attack, how quickly death occurs and the LD50 or median
lethal dose rating of the animal.
The LD50 provides an estimation of how dangerous a particular venom or toxin as determined
by how much venom is needed to kill 50 percent of a test population of lab test animals,
usually mice.
Even if you disagree with our rankings, you can agree that every animal listed is lethal.
On with the list:
10) Brazilian Wandering Spider Number 10 on our list is the Brazilian Wandering
Spider, a nomadic, nocturnal arachnid which got its name because it travels from place
to place to find food rather than building a web.
It’s also known as the banana spider because of its propensity for hiding in the yellow
fruit.
It can be found in South and Central American countries--occasionally it ends up in England
or America, showing up as a horrid surprise for someone purchasing a bunch of bananas.
While the Brazilian Wandering Spider nest on the ground in the forest, they also like
hiding in dark, moist places such as piled logs, garages, shoes and closets.
As a defense mechanism, Brazillian wandering spiders stand on their hind legs and swing
side to side in warning before attacking.
A bite from this spider causes severe pain at the site of the wound, often with inflammation.
Within about 30 minutes systemic envenomation occurs, characterized by symptoms such as
hypertension or hypotension, arrhythmia, nausea, cramping, hypothermia, vertigo, blurred vision,
convulsions and paralyzation.
If the spider injects enough venom when it bites you, you can die within an hour from
respiratory complications.
However, in most cases bites from Brazillian wandering spiders don’t contain enough venom
to require antivenom.
However, victims should immediately seek medical treatment.
Even if the spider didn’t deliver a fatal does of venom, it can cause tissue necrosis.
0.006mg (0.00000021 oz) of its venom is enough to kill a mouse.
Interestingly, the venom of the Brazillian wandering spider contains a toxin called Tx2-6
that causes priapism or long, painful erections in males lasting several hours which can lead
to impotence or enhanced potency, depending on the victim.
9) King cobra Native to South and Southeast Asia, theese
typically 10-15 foot King Cobras are the largest venomous snakes in the world.
The largest King Cobra ever found was just over 19 feet.
Generally their prey is other smaller snakes and lizards which they invenomate and then
use their flexible jaws to swallow their paralyzed prey whole.
Typically King Cobras are non aggressive and shy, but as their highland forests home is
encroached on, they are coming into contact with humans more and more.
In humans, the risk of death from a King Cobra bite is somewhere around 75%.
The painful bite can cause the death of a healthy adult human within 15 minutes, although
it generally takes 30-45 minutes.
The King Cobra is even capable of killing a full-grown Asian Elephant within 3 hours
if the pachyderm is bitten in a vulnerable area such as the trunk.
Seven milliliters- or slightly less than one and one-half teaspoons- of a king cobra’s
venom can kill 20 human adults or one elephant.
The King Cobra’s venom attacks the victim's central nervous system, resulting in agonizing
pain, blurred vision, vertigo, and eventually paralysis.
If the envenomation is serious, it progresses to failure of the circulatory system and the
victim falls into a coma, then dies.
Antivenom is available is small doses.
A traditional Ayurvedic cocotion of turmeric and alcohol has also had some success in treating
King Cobra bite sufferers.
8) Sydney funnel-web spider The Sydney funnel-web spider is Number 8 on
our list of the most venomous animals in the world.
It belongs to a family of approximately 35 spiders native to Australia.
Six spiders of the species are venomous, considered dangerous and are known to cause grave injuries
to humans.
The male Sydney funnel-web spider most likely to come in contact with humans as it travels
to search for a mate.
This spider delivers a painful bite with its large fangs and the wound often bleeds.
The spider doesn’t always inject its victims with venom, but when it does watch out!
The venom contains a neurotoxin which attacks the nervous system and organs in a human.
Fatality can occur anywhere from 15 minutes in small children to 3 days for a healthy
adult.
The venom of this spider is reputedly 60 times as potent as cyanide.
Symptoms of envenomation present almost immediately.
Early symptoms include sweating, twitching, elevated heart rate, and elevated blood pressure.
As the venom spreads throughout the body symptoms include nausea, vomiting, muscle spasms, pulmonary
oedema , metabolic acidosis, and extreme hypertension.
Often victims fall into a coma before death.
7) Boomslang The Boomslang is a tree snake native to Sub-Saharan
Africa.
Described as shy and pretty with large eyes and with bright, light green color in males
and brown in females, Boomslangs are ‘rear-fanged’ snakes.
Their fangs are far back in their mouths behind other teeth, which means to envenomate, they
have to open their mouths really wide - up to 170 degrees to grab a chunk of flesh and
stab.
When venomously bitten by a boomslang, a victim experiences several symptoms such as headache,
nausea, and sleepiness.
However, the most dangerous aspect of Boomslang venom is that it’s a hemotoxin with anti-coagulating
properties.
In addition to destroying red blood cells, loosening blood clotting and tissue degeneration,
victims suffer extensive muscle and brain haemorrhaging.
Death happens via progressive internal bleeding, and is a slow, excruciating process, taking
anywhere between 3 to 5 days.
It can also be messy and embarrassing, as blood leaks out of every orifice.
Since Boomslang venom is slow acting and symptoms may take several hours to set in after a venomous
bite, in the past victims have been lulled into a false sense of security that the bite
was dry or not serious.
Symptoms may be counteracted with an antivenom and also blood transfusions, depending on
the amount of time between the bite and the victim seeking medical attention.
6) Coastal taipan The coastal taipan or common taipan is native
to New Guinea and also the coastal regions of northern and eastern Australia.
Adult coastal taipans typically range in size from 4.9 to 6.6 feet (1.5 to 2.0 m) and tend
to live in logs, piles of vegetation and have even been found in trash heaps.
Bite victims may experience a wide variety of symptoms including headache, vomiting,
convulsions, paralysis, internal bleeding and kidney failure.
In cases of severe envenomation, depending on the health of the victim, death can occur
within 30 minutes of being bitten, but on average takes 2.5 hours.
The venom of a coastal taipan contains a potent neurotoxin which affects the nervous system
and the blood's ability to clot.
Medical attention must be sought immediately, untreated bites have a mortality rate of 100%
as the coastal taipan always delivers a fatal dose of venom.
The average bite delivers 10-12x the dose needed to kill a human adult male.
5) Irukandji jellyfish Irukandji jellyfish primarily live in the
ocean off the coast of northern Australia.
They are the smallest jellyfish in the world, with an adult being a single cubic centimeter
(1 cm3).
For being so tiny, they are incredibly dangerous.
They can shoot stingers into their victim, causing symptoms collectively known as Irukandji
syndrome.
While a single sting tends to be only mildly painful--apparently it feels similar to a
mosquito bite, victims are usually struck with multiple barbs and the venom effects
aren’t immediate.
In anywhere from 5 to 120 minutes, with 30 minutes being the average, a victim begins
to experience symptoms, including severe headache, muscle pains, vomiting, sweating, paranoia,
hypertension, tachycardia and pulmonary edema.
Thankfully, while often severely painful Irukandji syndrome is not necessarily fatal, depending
on the dose delivered.
Symptoms generally improve in four to 30 hours, but it may take up to two weeks for a patient
to make a full recovery.
With fatal doses, victims often expire within 24 hours of the attack due to brain hemorrhages.
Since Irukandji jellyfish are so tiny and delicate they have proven hard to study in
the hopes of creating a targeted antivenom.
Current treatment is symptomatic, such as antihistamines and anti-hypertensive drugs
used to control inflammation and hypertension.
Pain management can be problematic as in some cases morphine has had little effect.
4) Blue-ringed octopus The typical adult blue ringed octopus is about
the size of a golf ball and lives off the coasts of Australia and Southeast Asia.
Though usually non aggressive, when provoked, it delivers debilitating and deadly venom
for which there is no antidote.
The average adult blue ringed octopus carries enough venom to kill 26 male adults, and it’s
10, 000 times more potent than cyanide.
Before it attacks, the octopus usually issues a warning by turning an intense blue color.
While the bite is generally painless, with 10 minutes a victim can go into respiratory
failure and expire within half an hour.
In some victims, symptoms may occur hours late.
The blue ringed octopus’s venom contains neurotoxins which cause muscular weakness
and numbness, followed by respiratory failure and ultimately death.
3) Inland Taipan The inland taipan or fierce snake inhabits
semi-arid regions of central east Australia and is considered the world's most venomous
snake.
It’s estimated that one bite is enough of a lethal dose to kill at least 100 male adults
or about 250,000 mice.
Its venom is considered at least 200 – 400 times more toxic than a common cobra.
Even worse, the inland taipan has extreme accuracy when attacking, often striking multiple
times in the same attack, and it nearly always injects venom rather than delivering a dry
bite.
Victims should seek medical treatment immediately, if left untreated, an inland taipan bite can
kill a human in 30 to 45 minutes.
Aside from pain and inflammation at the site of a bite, symptoms include headache, nausea,
vomiting, abdominal pain and diarrhea.
The victim then collapses or goes into convulsions leading to major organ failure and finally
death.
Fortunately there have been no documented human fatalities from an inland taipan bite;
all known bite victims have been successfully treated with anti-venom.
2) Cone snail.
The second most venomous animal in the world is the Cone snail.
The name ‘cone snail’ encapsulates a family of several hundred species of marine gastropods.
All of them are extremely venomous and dangerous to humans.
They typically live in tropical seas in the sand or among coral reefs and rocks.
They move slowly--their venom is used to capture prey.
Fortunately, they can easily be avoided.
If you’re foolish enough to pick up a live cone snail, you may be courting death.
They shoot harpoon like sharp teeth from their mouths to sting and then pump venom into their
victims via muscular contraction..
The harpoon of larger cone snails can even penetrate wetsuits.
Intense pain at the site of the sting is often immediately felt, followed by swelling, numbness,
tingling and vomiting.
Severe cases rapidly cause muscle paralysis, changes in vision and respiratory failure
that can lead to death.
The venom of larger cone snails can potentially kill a human in 4 minutes, though it generally
takes longer.
A venom dose fatal to humans is incredibly small; it’s thought that the venom in one
cone snail is enough to kill 20 adults.
Researchers are studying some species of cone snail in order to harness the toxins to create
various pharmaceutical drugs.
A chemical extracted from the venom of the magical cone snail is a painkiller, 1,000
times more potent than morphine.
1) Australian Box Jellyfish
The world’s most venomous animal title goes to the Australian Box Jelly.
It’s also one of the world’s most deadly animals as humans fairly frequently come into
contact with them.
Since Jellyfish aren’t really fish, biologists have dropped the “fish” part from its
name.
No matter what you call it, if an Australian Box Jelly stings you, you’re having a really
bad day.
It carries enough venom to kill 60 adults.
This species of box jelly can primarily be found in the oceans around Asia and Australia.
Box jellies are virtually transparent in the water.
Adults can measure up to about 12 inches (30 cm) in diameter in the ‘box’ or bell shaped
core body, and the tentacles can grow up to nearly 10 feet (3 m in) length.
Each box jelly has around 15 tentacles on each corner of its box.
Each tentacle has about 5,000 nematocysts or microscopic harpoon-shaped barbs that inject
venom into a victim.
Within minutes of envenomation, the victim experiences extreme pain, paralysis, delirium,
skin necrosis and may even go into cardiac arrest.
Box jelly venom is so excruciatingly painful, that human victims often go straight into
shock, and drown or die of heart failure before even reaching shore.
Despite some recent controversial studies which think the remedy causes more damage
than good, box jelly stings should be treated immediately with an application of vinegar
for at least 30 seconds.
The acetic acid in vinegar neutralizes the box jelly’s nematocysts that have not yet
discharged into the bloodstream.
Any stray tentacles should be removed.
After that, the victim should be immersed in hot water, which will help reduce the intensity
and duration of pain.
More minor stings can be treated with ice packs, topical and oral pain medications.
Whether a box jelly attack is lethal or not depends upon how much venom is injected into
the victim.
The vast majority of victims survive stings, and the odds of survival are almost 100% if
the victim makes it through the first 10 minutes after the attack.
Around 50 people are killed annually by box jellyfish, however that number maybe grossly
underreported because death certificates are not required in many countries within the
range of box jellies.
In the spring of 2019, scientists announced headway in making a possible antidote which
could be life saving if administered within 15 minutes of a victim being stung.
Have you ever come into contact with a venomous animal?
What happened?
Let us know in the comments!
Now go watch Why Spinosaurus Was The Greatest Predator Ever!
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