10 . Yellow Sac Spider
The beautiful Yellow sac spider is one of the least venomous in our list –
but is still a seriously poisonous proposition. Yellow sac spiders are likely to
make the drag line webs of the type you might get rid of with a broom or vacuum
cleaner, but thankfully they rarely get near humans to bite. One of the dangers
of their bite is a close connection with MRSA infections, which can be very
serious; however the level of toxicity itself is disputed, even though the bite
can leave necrotic – or dead tissue – lesions.
The beautiful Yellow sac spider is one of the least venomous in our list –
but is still a seriously poisonous proposition. Yellow sac spiders are likely to
make the drag line webs of the type you might get rid of with a broom or vacuum
cleaner, but thankfully they rarely get near humans to bite. One of the dangers
of their bite is a close connection with MRSA infections, which can be very
serious; however the level of toxicity itself is disputed, even though the bite
can leave necrotic – or dead tissue – lesions.
9. Fringed Ornamental Tarantula
The Fringed ornamental tarantula is quite a venomous spider, with cases of
coma reported in the tropics as a result of its bite. Not a lot is known about
this spider's venomosity. It is known, however, that almost all tarantulas have
large fangs, and even though most are harmless, in this case the bite can cause
serious harm, not to mention intense pain!
The Fringed ornamental tarantula is quite a venomous spider, with cases of
coma reported in the tropics as a result of its bite. Not a lot is known about
this spider's venomosity. It is known, however, that almost all tarantulas have
large fangs, and even though most are harmless, in this case the bite can cause
serious harm, not to mention intense pain!
8. Chinese Bird Spider
The Chinese bird spider is a large tarantula with a legspan as large as eight
inches. Much research has been done on this large spider's venom as it is an
aggressive creature and can bring down small mammals with tiny doses. Found in
Southeast Asia, at least one infant death has been recorded. It only takes
0.70mg/kg to cause death in 50 percent of test cases using lab mice. Not a
tarantula to mess with.
The Chinese bird spider is a large tarantula with a legspan as large as eight
inches. Much research has been done on this large spider's venom as it is an
aggressive creature and can bring down small mammals with tiny doses. Found in
Southeast Asia, at least one infant death has been recorded. It only takes
0.70mg/kg to cause death in 50 percent of test cases using lab mice. Not a
tarantula to mess with.
7. Mouse Spider
The Mouse spider is found in Australia. The female is all black, while the
Red-headed mouse spider male has red jaws (the other species has a red head as
well but bright red). Despite their demure-sounding name, these spiders are
considered to be as dangerous as the Funnel-web spider (see below); however,
there are fewer cases of bites, perhaps because the Mouse spider has been known
to often give "dry" bites – that is without releasing its venom. The venom
itself is similar to the Funnel-web's, and the same antivenom works to treat the
Mouse spider's bite. It has the potential to kill a human being, although so far
it seems that a combination of fast emergency treatment and the spider's habit
of keeping hold of its venom has resulted in no loss of life. Thank heavens!
The Mouse spider is found in Australia. The female is all black, while the
Red-headed mouse spider male has red jaws (the other species has a red head as
well but bright red). Despite their demure-sounding name, these spiders are
considered to be as dangerous as the Funnel-web spider (see below); however,
there are fewer cases of bites, perhaps because the Mouse spider has been known
to often give "dry" bites – that is without releasing its venom. The venom
itself is similar to the Funnel-web's, and the same antivenom works to treat the
Mouse spider's bite. It has the potential to kill a human being, although so far
it seems that a combination of fast emergency treatment and the spider's habit
of keeping hold of its venom has resulted in no loss of life. Thank heavens!
6. Brown and Chilean Recluse Spider
The Brown recluse spider and a sister species, the Chilean recluse, are
extremely venomous. However, on the plus side, they have small fangs and can't
penetrate clothing easily. They are also, well, recluses, which means there are
not as many bites as there might be due to their habit of hiding.
Some of the most dangerous symptoms of their bites are necrosis – the dying
of tissue at the site of the bite – and the potential for the wound to grow to
10 inches and become gangrenous. About 14 percent of the symptoms are systemic,
meaning an infection is caused throughout the body. The Chilean recluse spider
is even more toxic, with some systemic infections resulting in kidney failure.
One study in Chile showed that 3-4 percent of all bites ended in death. The
lethal dose of the Chilean recluse's venom in tests on lab mice in 50% of the
victims – its LD-50 – is 1.45mg/kg, so this is definitely a spider to steer
clear of.
The Brown recluse spider and a sister species, the Chilean recluse, are
extremely venomous. However, on the plus side, they have small fangs and can't
penetrate clothing easily. They are also, well, recluses, which means there are
not as many bites as there might be due to their habit of hiding.
Some of the most dangerous symptoms of their bites are necrosis – the dying
of tissue at the site of the bite – and the potential for the wound to grow to
10 inches and become gangrenous. About 14 percent of the symptoms are systemic,
meaning an infection is caused throughout the body. The Chilean recluse spider
is even more toxic, with some systemic infections resulting in kidney failure.
One study in Chile showed that 3-4 percent of all bites ended in death. The
lethal dose of the Chilean recluse's venom in tests on lab mice in 50% of the
victims – its LD-50 – is 1.45mg/kg, so this is definitely a spider to steer
clear of.
5. Redback Spider
Redback spiders are part of the same family as Black widows (see below) and
are also very toxic. They are found in Australia and have a prominent red stripe
down their back as well as a striped or hourglass figure on their abdomen.
Before an antivenom was developed, 14 people had died as a result of Redback
bites. Most people suffer less severe symptom, from localized skin infection to
others such as swollen lymph nodes, headache, fever, nausea and tremors. More
significant, though thankfully rarer, symptoms include seizures, coma and
respiratory failure. It's easy to see why these critters have a bad reputation
Down Under.
Redback spiders are part of the same family as Black widows (see below) and
are also very toxic. They are found in Australia and have a prominent red stripe
down their back as well as a striped or hourglass figure on their abdomen.
Before an antivenom was developed, 14 people had died as a result of Redback
bites. Most people suffer less severe symptom, from localized skin infection to
others such as swollen lymph nodes, headache, fever, nausea and tremors. More
significant, though thankfully rarer, symptoms include seizures, coma and
respiratory failure. It's easy to see why these critters have a bad reputation
Down Under.
4. Black Widow Spider
Who among us hasn't heard of the Black widow, a spider that is not only
extremely venomous but eats its mate for an after-sex snack! Its bite causes a
condition called Latrodectism, which causes severe muscle spasms and sometimes
temporary spinal or cerebral paralysis, but rarely death. All species of Black
widow spiders display the bright red hourglass on their abdomen, while some also
have other red markings on their body – a warning to those that spot them!
Before antivenom was available, 5 percent of those bitten would die. Its LD-50
is 0.002 mg/kg. This means it doesn't take much venom to do the job!
Who among us hasn't heard of the Black widow, a spider that is not only
extremely venomous but eats its mate for an after-sex snack! Its bite causes a
condition called Latrodectism, which causes severe muscle spasms and sometimes
temporary spinal or cerebral paralysis, but rarely death. All species of Black
widow spiders display the bright red hourglass on their abdomen, while some also
have other red markings on their body – a warning to those that spot them!
Before antivenom was available, 5 percent of those bitten would die. Its LD-50
is 0.002 mg/kg. This means it doesn't take much venom to do the job!
3. Sydney Funnel-Web
Sydney funnel-web spiders are among the most venomous on earth. They have
large fangs and unlike some of the other very venomous spiders invariably
deliver a full dose of venom instead of dry bites. They are also are more likely
to bite than run away and will strike multiple times. Nasty! A compound in the
Sydney funnel-web's venom called atracotoxin is very dangerous to all primates –
including us! One child died within 15 minutes, but that was before the
discovery of an antivenom. The funnel-web's LD-50 is just 0.16mg/kg.
Sydney funnel-web spiders are among the most venomous on earth. They have
large fangs and unlike some of the other very venomous spiders invariably
deliver a full dose of venom instead of dry bites. They are also are more likely
to bite than run away and will strike multiple times. Nasty! A compound in the
Sydney funnel-web's venom called atracotoxin is very dangerous to all primates –
including us! One child died within 15 minutes, but that was before the
discovery of an antivenom. The funnel-web's LD-50 is just 0.16mg/kg.
2. Six-Eyed Sand Spider
The Six-eyed sand spider is another of the most venomous spiders in the
world, but luckily it lives in areas where it has little contact with humans and
is not aggressive. A cousin of the recluses, it is found in Africa and South
Asia, but its venom is many times the strength of the Brown recluse, according
to one study. There is no antivenom for it, and apart from localized necrosis,
it can also cause disseminated intravascular coagulation (DIC), which results in
clots throughout the skin as well as bleeding from the skin and orifices, and
can lead to death. That should be warning enough.
The Six-eyed sand spider is another of the most venomous spiders in the
world, but luckily it lives in areas where it has little contact with humans and
is not aggressive. A cousin of the recluses, it is found in Africa and South
Asia, but its venom is many times the strength of the Brown recluse, according
to one study. There is no antivenom for it, and apart from localized necrosis,
it can also cause disseminated intravascular coagulation (DIC), which results in
clots throughout the skin as well as bleeding from the skin and orifices, and
can lead to death. That should be warning enough.
1. Brazilian Wandering Spider
In 2010, the Brazilian wandering spider was named in the Guinness World
Records as the most venomous spider in the world. It is also aggressive,
obviously making the chance of a bite from it more likely. It has a highly
potent neurotoxin that can lead to breathing problems then asphyxiation and
death in those bitten. Another effect of its venom is priapism, meaning
erections that last a long time – hours to days – and can result in permanent
impotence. However, the venom is being studied as a possible fix for erectile
dysfunction. The spider only needs to inject 6 ug of its venom to kill a 20-gram
mouse, and a full venom load is 1.069 mg. Death in humans has been known to
occur even after antivenom has been administered.
In 2010, the Brazilian wandering spider was named in the Guinness World
Records as the most venomous spider in the world. It is also aggressive,
obviously making the chance of a bite from it more likely. It has a highly
potent neurotoxin that can lead to breathing problems then asphyxiation and
death in those bitten. Another effect of its venom is priapism, meaning
erections that last a long time – hours to days – and can result in permanent
impotence. However, the venom is being studied as a possible fix for erectile
dysfunction. The spider only needs to inject 6 ug of its venom to kill a 20-gram
mouse, and a full venom load is 1.069 mg. Death in humans has been known to
occur even after antivenom has been administered.