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Brazilian Wandering Spider facts

Last updated on July 12th, 2023 at 01:48 pm

When you think of deadly spiders, there are a few names that spring to mind – but none more infamous than the Brazilian Wandering Spider. This species is reputed to have the most toxic venom of any spider, having a bite which causes horrendous side-effects like priapism and convulsions.

What you may not know, however, is that the Brazilian Wandering Spider name is actually used for a few species. The most common, and perhaps the most medically significant in the group are Phoneutria nigriventer and Phoneutria fera .

In this post, I’ll tell you more about these two species, from where they live, to what they eat. To keep things simple, I’ll just refer to them both as the “Brazilian Wandering Spider”, given how similar they are. Let’s dive in…

Quick Facts

To kick things off, here are some fascinating factoids about the Brazilian Wandering Spider:

They belong to the genus ‘Phoneutria’, which translates to ‘murderess’ in Greek.
They are known for their highly potent venom.
Wandering Spiders are nocturnal creatures.
They are also known as ‘banana spiders’ due to their tendency to hide in banana plants.
They are not web-weavers but active hunters. This is called ‘cursorial’ hunting.
It’s considered one of the most dangerous spiders in the world.

Other Common Names

The Brazilian Wandering Spider goes by several other names. The most common is the ‘banana spider’, thanks to their notorious habit of stowing away in banana shipments. In their native Portuguese, they’re known as ‘aranhas-armadeiras’ , translating to ‘armed spiders’ – a reference to their aggressive defense posture.

Brazilian Wandering Spider Venom

Possessing one of the most potent venoms among spiders, the Brazilian Wandering Spider’s bite is a cause for concern. Its venom is a complex cocktail of toxins, proteins, and peptides.

The main component that gets everyone’s attention is the neurotoxin, called PhTx3 , which can interfere with the functioning of our nervous system, leading to a variety of symptoms.

What’s the Benefit of Having Such Strong Venom?

With venom potent enough to kill a human, one might wonder why this spider needs such a powerful weapon. The answer lies in its lifestyle.

Brazilian Wandering Spiders are active hunters and their venom is primarily used to incapacitate prey quickly. The venom’s potency also serves as an effective deterrent against potential predators.

Brazilian Wandering Spider Deaths

Despite the notorious reputation, actual deaths from Brazilian Wandering Spider bites are rare. This is largely due to the rapid medical attention available in areas where these spiders are common. Plus, these spiders don’t always inject venom when they bite – a dry bite can occur.

This actually common in venomous animals, including spiders and reptiles. Occasionally they bite and decide to not inject any venom. The point of this is to conserve it, given that it is energetically costly to produce.

Brazilian Wandering Spider Size

Being quite large and impressive compared to most arachnids, adult Brazilian Wandering Spiders can reach a leg span of up to 7 inches (18 cm) . The body size excluding the legs can be up to 2 inches (5 cm). Their size contributes to their intimidating presence.

If you’d to learn more about why they get so big, check out my article on Brazilian Wandering Spider size for more info!

Brazilian Wandering Spider Location and Habitat

Brazilian Wandering Spiders are native to South America. Here’s a quick rundown of their range and preferred habitats:

Brazilian Wandering Spider Speed

An adept hunter, the Brazilian Wandering Spider can move quickly when chasing prey or evading threats. While exact speed measurements can vary, some sources report that these spiders can achieve speeds up to 1 meter per second.

What Does the Brazilian Wandering Spider Eat?

The Brazilian Wandering Spider’s diet consists mainly of insects, other spiders, and occasionally small amphibians and reptiles. Their potent venom allows them to tackle prey larger than themselves, making them one of the apex micro-predators in their habitat.

Final Thoughts…

While the Brazilian Wandering Spider might seem terrifying to many, as an arachnid enthusiast, I find them to be incredibly fascinating. Their potent venom, hunting prowess, and adaptation to diverse habitats reveal the intricate beauty of the evolutionary process.

Just remember, these spiders, like all creatures, play a vital role in our ecosystem. Respect, not fear, should be our response to these remarkable arachnids.

The truth is that most bites are accidental, but they do occur. The fact that so few deaths occur each year is a testament to the effectiveness of the antivenom that has now become widely available.

FAQ related to the Brazilian Wandering Spider

What happens if you are bitten by a brazilian wandering spider.

Immediately after a bite from a Brazilian Wandering Spider, you will experience localized pain. Then, within 5 to 15 minutes the area around the bite will swell. The swelling can spread to most of a limb, for example. Finally, neurological symptoms like coldness, sweating, and convulsions will set in.

Do wandering spiders jump?

Wandering Spiders are excellent at jumping. They can jump several feet when surprised, and may occasionally use this as a tactic to evade predators. Jumping at you isn’t part of how bites happen though. When faced with humans, Wandering Spiders usually stand their ground and use their threat display of raised legs to warn us away.

Is Brazilian wandering spider friendly?

Wandering Spiders are not friendly. As a general rule, they are relatively calm, but can also be defensive. They tend to see humans as a threat, and will not take to being handled easily. That said, they are not aggressive, and most bites happen when someone accidentally touches one or tries to kill it.

Are Brazilian wandering spiders in Australia?

Brazilian Wandering Spiders are not found in Australia. The only species in Australia that get as large as Wandering Spiders are the Huntsman Spiders. At a distance they may appear relatively similar, but Huntsman Spiders are completely harmless to humans.

Brazilian wandering spiders: Bites & other facts

The spider's name means "murderess" in Greek, which is appropriate for the deadly arachnid.

A closeup-photo of a Brazilian wandering spider, with orange head and black and white-striped legs

Classification/taxonomy

Size & characteristics, bites and venom, additional resources.

The Brazilian wandering spider, also called armed spiders or banana spiders, belongs to the genus Phoneutria , which means "murderess" in Greek. And it's no wonder why — it's one of the most venomous spiders on Earth . Its bite, which delivers neurotoxic venom, can be deadly to humans, especially children, although antivenom makes death unlikely.

Guinness World Records has previously named the Brazilian wandering spider the world's most venomous spider multiple times (though the current record-holder is the Sydney funnel-web spider, Atrax robustus , according to Guinness ). But, as the late Jo-Anne Sewlal, who was an arachnologist at the University of the West Indies in Trinidad and Tobago, told Live Science, "classifying an animal as deadly is controversial," as the amount of damage depends on the amount of venom injected.

Jo-Anne Sewlal was a noted arachnologist from Trinidad and Tobago. While completing her PhD, she received the National Institute of Higher Education, Research, Science and Technology (NIHERST) 2012 Award for Excellence in Science and Technology for Junior Scientist. In 2013, She received a doctorate in zoology from the University of the West Indies. She discovered several species of spiders in her home country, surveyed the arachnids across several countries the Caribbean and appeared as an expert on the topic on The Science Channel. She died of an allergic reaction in January 2020.

There are nine species of Brazilian wandering spider, all of which are nocturnal and can be found in Brazil. Some species also can be found throughout Central and South America, from Costa Rica to Argentina, according to a 2008 article in the journal American Entomologist . Study author Richard S. Vetter, a research associate in the department of entomology at the University of California, Agriculture and Natural Resources, wrote that specimens of these powerful arachnids have been mistakenly exported to North America and Europe in banana shipments. However, Vetter noted, in many cases of cargo infestation, the spider in question is a harmless banana spider (genus Cupiennius ) that is misidentified as a Phoneutria . The two types of spiders look similar.

The taxonomy of Brazilian wandering spiders, according to the Integrated Taxonomic Information System (ITIS) , is:

Kingdom : Animalia Subkingdom : Bilateria Infrakingdom : Protostomia Superphylum : Ecdysozoa Phylum : Arthropoda Subphylum : Chelicerata Class : Arachnida Order : Araneae Family : Ctenidae Genus : Phoneutria

Phoneutria bahiensis
Phoneutria boliviensis
Phoneutria eickstedtae
Phoneutria fera
Phoneutria keyserlingi
Phoneutria nigriventer
Phoneutria pertyi
Phoneutria reidyi
Phoneutria depilata , according to a 2021 study published in the journal ZooKeys , which found that Phoneutria boliviensis actually included two separate species from different habitats.

Brazilian wandering spiders are large, with bodies reaching up to 2 inches (5 centimeters) and a leg span of up to 7 inches (18 cm), according to the Natural History Museum in Karlsruhe, Germany. The species vary in color, though all are hairy and mostly brown and gray, although some species have lightly colored spots on their abdomen. Many species have bands of black and yellow or white on the underside of the two front legs, according to the University of Florida .

A beige Brazilian wandering spider crawls toward a green leaf on a forest floor

These arachnids "are called wandering spiders because they do not build webs but wander on the forest floor at night, actively hunting prey," Sewlal told Live Science in an interview conducted in 2014, before her death. They kill by both ambush and direct attack.

They spend most of their day hiding under logs or in crevices, and come out to hunt at night. They eat insects, other spiders and sometimes, small amphibians, reptiles and mice.

Research into one species of Brazilian wandering spider, Phoneutria boliviensis , revealed that these spiders eat a mix of arthropods and reptiles. DNA metabarcoding, a technique that examines the DNA and RNA in a sample, of the guts of 57 spiders identified 96 prey species, including flies, beetles, butterflies, moths, grasshoppers, locusts and crickets, according to research from the University of Tolima and the University of Ibagué in Colombia . Some of the female spiders also ate lizards and snakes.

While their bites are powerful and painful, "their bites are a means of self-defense and only done if they are provoked intentionally or by accident," Sewlal said.

A gray brazilian wandering spider sits on a green leaf over a large white egg

In the Brazilian wandering spider, just as in most spider species, the female is larger than the male. Males approach females cautiously when attempting to mate, according to the biology department at the University of Wisconsin-La Crosse . Males perform a dance to get females' attention, and males often fight each other over the female. The female can be picky, and she often turns down many males before choosing a mating partner. Once she does pick one, the male needs to watch out; females often attack the males once copulation is finished.

The female then can store the sperm in a separate chamber from the eggs until she is ready to fertilize them. She will lay up to 1,000 eggs at a time, which are kept safe in a spun-silk egg sac.

Brazilian wandering spiders typically live for one or two years.

Brazilian wandering spiders' venom is a complex cocktail of toxins, proteins and peptides, according to the Natural History Museum in Karlsruhe, Germany. The venom affects ion channels and chemical receptors in victims' neuromuscular systems.

After a human is bitten by one of these spiders, he or she may experience initial symptoms such as severe burning pain at the site of the bite, sweating and goosebumps, Sewlal said. Within 30 minutes, symptoms become systemic and include high or low blood pressure , fast or a slow heart rate , nausea, abdominal cramping, hypothermia, vertigo, blurred vision, convulsions and excessive sweating associated with shock. People who are bitten by a Brazilian wandering spider should seek medical attention immediately.

Their venom is perhaps most famous for triggering painful and long-lasting erections . For that reason, in a 2023 study, scientists reported that they were testing the venom in humans as a potential treatment for erectile dysfunction in those for whom Viagra didn't work.

However, these bites are rare, and envenomations, or exposure to these toxins from a spider bite, are usually mild, Vetter said. For instance, a 2000 study in the journal Revista do Instituto de Medicina Tropical de São Paulo found that only 2.3% of people with bites who came to a Brazilian hospital over a 13-year period were treated with antivenom. (The other bites did not contain enough venom to require it.) Most of the bites were from the species P. nigriventer and P. keyserlingi in eastern coastal Brazil. About 4,000 bites reportedly happen each year in Brazil, but only 0.5% of those cases are severe, according to a 2018 study in the journal Clinical Toxinology in Australia, Europe, and Americas . Meanwhile, 15 deaths have been attributed to Phoneutria in Brazil since 1903, the 2018 study reported.

"It is unlikely that the spider would inject all of its venom into you, as this venom is not only needed as a means of defense but to immobilize prey," Sewlal said. "So if it did inject all of its venom, it [would] have to wait until its body manufactured more before it could hunt." That would also leave the spider vulnerable to being attacked by predators.

Furthermore, Sewlal pointed out that venom production requires a lot of a spider's resources and time. "So if the spider were to attack frequently and use up all of its venom, it [would] be safe to assume that it has a ready food supply to replace the energy and resources used. This situation does not exist in the wild."

Learn more about Brazilian wandering spiders from the University of Wisconsin-La Crosse .
Read about several species of Brazilian wandering spiders, including several images of the arachnids at the University of Florida .
Find a spider in your bananas? It may or may not be a deadly species, according to the University of California, Riverside .

This article was originally published on Nov. 20, 2014.

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Jessie Szalay is a contributing writer to FSR Magazine. Prior to writing for Live Science, she was an editor at Living Social. She holds an MFA in nonfiction writing from George Mason University and a bachelor's degree in sociology from Kenyon College.

Laura Geggel Editor

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Brazilian Wandering Spider

The Brazilian Wandering Spider (Phoneutria fera) is an aggressive and highly venomous spider . It was first discovered in Brazil hence its name. However, this genus is known to exist elsewhere in South and Central America .

The Brazilian Wandering spider is a member of the Ctenidae family of wandering spiders.

The Brazilian Wandering spider appeared in the Guinness Book of World Records 2007 for being the most venomous animal .

In this particular genus, there are five known similar species whose members are also highly venomous. They include some of the relatively few species of spiders that present a threat to human beings.

Brazilian Wandering Spider Characteristics

The Brazilian wandering spider can grow to have a leg span of up to 4 – 5 inches. They are large hairy spindly-looking spiders who have eight eyes, two of which are large. Brazilian wandering spiders are fast-moving spiders, their legs are strong and spiny and they have distinctive red jaws which they display when angered.

The Brazilian wandering spider is not a Tarantula . Brazilian wandering spiders are not even in the same family group. Tarantulas are harmless to humans and are mostly ambush killers who wait for prey to come to them. Brazilian wandering spiders are active hunters. Brazilian wandering spiders and Tarantulas do have one thing in common, however, they do not eat bananas.

Brazilian Wandering Spider Habitat and Spider Webs

The Brazilian Wandering spider is so-called because it wanders the jungle floor, rather than residing in a lair or maintaining a web. This is another reason it is considered so dangerous. In densely populated areas, the Brazilian Wandering spider will usually search for cover and dark places to hide during daytime, leading it to hide within houses, clothes, cars, boots, boxes and log piles. This usually causes accidents when people disturb them.

The Brazilian Wandering spider is also called the ‘banana spider’ as it is occasionally found within shipments of bananas. As a result, any large spider appearing in a bunch of bananas should be treated with due care.

Brazilian Wandering Spider Diet

Adult Brazilian Wandering spiders eat crickets, other large insects, small lizards and mice. Spiderlings of this species eat flightless fruit flies and pinhead crickets.

Brazilian Wandering Spider Reproduction

All spiders produce silk, a thin, strong protein strand extruded by the spider from spinnerets most commonly found on the end of the abdomen. Many species use it to trap insects in webs, although there are many species that hunt freely such as the Brazilian Wandering spider. Silk can be used to aid in climbing, form smooth walls for burrows, build egg sacs, wrap prey and temporarily hold sperm, among other applications.

Brazilian Wandering spiders reproduce by means of eggs, which are packed into silk bundles called egg sacs. The male spider must (in most cases) make a timely departure after mating to escape before the females normal predatory instincts return.

Mature male spiders have swollen bulbs on the end of their palps for this purpose and this is a useful way to identify whether the spider is male or female. Once the sperm is inside the female spider, she stores it in a chamber and only uses it during the egg-laying process, when the eggs come into contact with the male sperm for the first time and are fertilized. The Brazilian Wandering spiders life cycle is 1 – 2 years.

Brazilian Wandering Spider Venom

Bites from the Brazilian Wandering spider may result in only a couple of painful pinpricks to full-blown envenomed. In either case, people bitten by this spider or any Ctenid should seek immediate emergency treatment as the venom is possibly life threatening.

The Phoneutria fera and Phoneutria nigriventer (two species of wandering spider) are the two most commonly implicated as the most vicious and deadly of the Phoneutria spiders.

The Phoneutria not only has a potent neurotoxin, but is reported to have one of the most excruciatingly painful envenoms of all spiders due to its high concentration of serotonin. They have the most active venom of any living spiders.

One of their members, the Brazilian Huntsman, is thought to be the most venomous spider in the world. Brazilian wandering spiders are certainly dangerous and bite more people than any other spiders.

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Brazilian Wandering Spider Facts

Brazilian wandering spider profile.

There are more than 50,000 species of spider, and the vast majority are less dangerous than a honeybee. Almost none are aggressive, and of those with medically significant venom, only a small percentage are capable of causing death. So, on the whole, arachnophobes are just being a bit silly.

But there’s one spider that vindicates all of these fears, and few animals are as globally renowned to be a serious threat to human lives as the Brazilian Wandering Spider .

Brazilian Wandering Spiders are actually 9 species of spider in the same genus ‘Phoneutria’, one of which is found in Central America, with the rest in South America.

Brazilian Wandering Spider Facts Overview

These spiders are called wandering spiders because of instead of spinning a web to wait for food, or occupying a lair, they spend their night wandering in the leaf litter of the jungle floor for prey.

The sensitive hairs on its body help detect vibrations of passing prey, and it will feed on insects, lizards, frogs and any animals as large as itself.

During the day they will hide under logs, rocks, or inside termite mounds and banana plants. They will also sometimes wander into urban areas and homes, where they can come into contact with humans.

Brazilian wandering spiders are aggressive , dangerous and frightening. For once, this is an animal you should be wary of.

The females are larger, around 50% heavier than males, and produce more venom, and this might be a clue as to why their Greek name translates to “ Mudress” . These spiders will often stand and fight and have an intimidating threat display.

The potency of their venom is one of the reasons they’re so dangerous, and their ability to hide away in fruit and shoes explains why most bites are on extremities.

Interesting Brazilian Wandering Spider Facts

1. armed spiders.

In Brazilian, these are sometimes known as armed spiders, on account of their elongated front legs.

They can convey quite a bit of information with these legs, and as wandering spiders, use them to get about the forest, looking for food.

2. Banana Spiders

They’re also sometimes called ‘banana spiders’ on account of their status as a stowaway on popular fruit imported from the tropics.

This is becoming less common as stricter regulations ensure there’s less contamination of fruits, but there’s always a chance your next bunch of bananas will have a family of these spiders living inside it.

3. They have the largest venom glands of any spider

Females produce more venom than males, but both sexes have enormous venom glands. These glands are even more impressive when you consider the size of the spider is significantly less than the largest around.

The venom glands of the Brazilian Wandering Spider are over a centimetre long, and this is all housed inside the bright red chelicerae (mouth parts) which they are quick to display whenever they get upset. 1

4. They’re aggressive

These spiders can grow quite large and have long, brightly-coloured legs. Unlike most spiders, they’re known to stand their ground when threatened and are far quicker to bite than many other species.

They’ll still try to scurry away where possible, and they’re not out to get anybody.

But where most other species will flee, the wandering spiders’ aggression does make it more likely to be involved in incidents.

Most bites are on fingers and toes, a sign that they’re being stepped on or grabbed inadvertently. When the spider feels cornered, it’ll rear up on its back legs and waves its colourful arms around as a warning.

Then it’ll sway side to side, beckoning you to have a go. Anything foolhardy enough to call this bluff gets a wealth of envenomation effects. 2 3

Brazilian Wandering Spider threat display with front legs raised

5. They give some men erections

There are ways to accomplish this with fewer side effects, but a bit from a Brazilian wandering spider does come with a certain Viagral quality.

This isn’t as fun as it might sound. Prolonged erections in this manner are likely to harm and destroy muscles and blood vessels in the penis and could cause irreparable damage.

Besides this, the assault on the central nervous system that comes with envenomation by this spider doesn’t sound worth it. 4

6. And some people die

This assault brings with it a whole host of unpleasant symptoms. Seizures, foaming at the mouth, inability to speak, collapse, and a host of other miserable experiences.

Paralysis is possible, as is cardiac shock. Blood vessels can burst in the brain, or anywhere else, and in many cases, this can be enough to kill a person.

This spider has one of the most potent venoms of all, and there are multiple legitimate records of death as a result of bites.

7. But they’re rarely fatal

While the Brazilian wandering spider is potentially one of the most dangerous spiders in the world, there is some evidence to suggest it gives a dry bite, defensively.

This means that despite exceptionally toxic venom, the amount actually injected is less than some of the other contenders, and this is what makes it typically less lethal than the Australian funnel webs.

These spiders are classified as Dangerous Wild Animals and would therefore require a special permit to keep. Bites from wandering spiders are common in South America, but antivenom is often readily available, and they rarely result in death.

In most cases, lethal bites are cases of a very young or very old victim, and few people of healthy age are killed. 5

8. They do invade the UK sometimes

These unquestionably scary spiders show up in supermarkets in the UK on occasion, having hitched a ride on banana shipments.

On more than one occasion they’ve made their way into shoppers’ homes, but it doesn’t appear that there are any cases of them biting people as a result.

These spiders aren’t suited for temperate climates and don’t survive Winter, so there’s no risk of them multiplying.

Brazilian Wandering Spider Fact-File Summary

Scientific classification, fact sources & references.

PeerJ. (2017), “ Dimensions of venom gland of largest venom glands in all spiders ”, Bio Numbers.
Dave Clarke (2010), “ Venomous spider found in Waitrose shopping ‘beautiful but aggressive’” , The Guardian.
“ Phoneutria Perty (Arachnida: Araneae: Ctenidae) ”, UF-IFAS University of Florida
Kátia R.M. Leite (2012), “ Phoneutria nigriventer spider toxin Tx2-6 causes priapism and death: A histopathological investigation in mice ”, Science Direct.
“ Brazilian wandering spiders: Bites & other facts ”, Live Science.

Understanding the Wandering Spider: Quick Essential Facts

Wandering spiders are a group of venomous arachnids found primarily in South America.

Among these, the Brazilian wandering spider is particularly known for its potent venom and unique behavior. They are often referred to as “banana spiders” due to their frequent encounters with humans in banana plantations.

As a reader, you might be interested in learning more about these fascinating creatures, including their habitat, hunting techniques, and the effects of their venom.

In this article, we will delve into the world of wandering spiders and provide you with all the essential information to satisfy your curiosity.

Scientific Classification and Naming

The wandering spider belongs to the genus Phoneutria , which is a part of the Ctenidae family.

These spiders are known for their potent venom and aggressive behavior. Here is the scientific classification of the wandering spider:

Kingdom: Animalia
Phylum: Arthropoda
Subphylum: Chelicerata
Class: Arachnida
Order: Araneae
Family: Ctenidae
Genus: Phoneutria

Within the genus Phoneutria, two species are particularly noteworthy: Phoneutria fera and Phoneutria nigriventer, also known as P. nigriventer . These spiders are primarily found in South America and other tropical regions.

Phoneutria fera and P. nigriventer differ in some aspects. Let’s compare their features using a table:

Some key characteristics of the wandering spiders in the genus Phoneutria include:

Potent venom that can be dangerous to humans
Nocturnal hunters and are active at night
Equipped with long, spiny legs for capturing prey
Aggressive defenders of their territory

By understanding the scientific classification and differences between Phoneutria species, you can better appreciate the diversity and fascinating biology of these wandering spiders.

Identification and Appearance

Color and size.

The wandering spider, also known as the banana spider, has a distinctive appearance that can help you easily identify it in the wild.

They usually have a combination of hairy brown and black colors on their body. Their size can vary, but they are generally considered large spiders. Their size can range from 1 to 2 inches in body length.

When it comes to wandering spider’s leg span, these creatures can have an impressive reach. Their leg span can extend up to 5-6 inches.

Some key characteristics of a wandering spider’s legs include:

Habitat and Distribution

Wandering Spiders are known to inhabit various environments, including rainforests and tropical forests.

These spiders can adapt to different habitats based on their needs and availability of food sources. They prefer warm and humid places, as these conditions suit their growth and reproduction.

Geographical Coverage

Wandering spiders are found in Central and South America .

They live in forests from Costa Rica to Argentina, including Colombia, Venezuela, The Guianas, Ecuador, Peru, Bolivia, Brazil, Paraguay, and Northern Argentina.

They may also be present in some parts of the United States, particularly in the northern part of southern America.

However, they don’t inhabit countries like Australia. In summary, the Wandering Spider is mostly prevalent in the following areas:

South America
Central America
Southern parts of the United States

Types of Wandering Spiders

Here’s a brief description of the major types of wandering spiders.

Brazilian wandering spiders

Also known as armed or banana spiders, these spiders are nocturnal and don’t make webs.

They are known to have been transported outside of South America in banana shipments.

Phoneutria nigriventer

These spiders contain neurotoxins that can cause cerebral changes and breakdown of the blood-brain barrier .

Their venom is medically significant and has been used in manufacturing drugs. Their bites may be fatal to children.

Ctenus captiosus

Also known as the Florida false wolf spider or tropical wolf spider, this species is found in the United States.

Some species of these spiders are large and scary-looking, but they’re only mildly venomous. Their venom is comparable to a bee sting.

Other types of wandering spiders include: Acantheis, Acanthoctenus, Africactenus, and Afroneutria.

Behavior and Diet

Aggression level.

Wandering spiders, as their name suggests, are known for their aggressive behavior .

While they won’t attack without provocation, if they feel threatened, they will not hesitate to defend themselves.

This is especially true during mating season.

Prey and Predators

In their natural habitat, wandering spiders primarily feed on insects and small vertebrates, such as:

Insects like ants and moths
Small amphibians

This diverse diet allows them to thrive in various ecosystems.

However, they are not top predators, as their natural predators include larger birds, mammals, and other spiders.

Nocturnal Activities

Wandering spiders are nocturnal creatures , which means they are active during the night.

During the day, they remain hidden in their retreats, often made from rolled-up leaves or small crevices.

At night, they leave their hiding spots to search for prey using their strong hunting skills.

Venom and Its Effects

Composition of venom.

The venom of the wandering spider is a complex mixture containing several toxic components.

Its main component is a potent neurotoxin, which can have severe effects on your nervous system 1 . Here’s a brief overview of its composition:

Neurotoxins

Symptoms and Severity

A wandering spider’s venomous bite can cause a wide range of symptoms, depending on the severity of envenomation. These symptoms may include 2 :

Mild to moderate pain
Redness and swelling at the bite site
Irregular heartbeat
Difficulty breathing
Blurred vision
High blood pressure

Some severe cases may result in life-threatening complications, such as respiratory failure or even death 2 .

Medical Treatment and Antivenom

If bitten by a wandering spider, it’s crucial to seek immediate medical attention. Treatment often involves the following steps:

Cleaning and immobilizing the affected area
Monitoring and managing the symptoms
Administering antivenom if it’s available and appropriate, depending on the severity of envenomation 3

Antivenom is specific to the venom of the wandering spider and can help neutralize its effects.

However, the availability of antivenom may be limited in some regions 3 .

Always remember that prevention is better than cure: learning how to identify and avoid wandering spiders is the best way to stay safe.

Reproduction and Mating

Mating ritual.

When it’s time for reproduction, the wandering spider undergoes an intriguing mating ritual.

The male spider performs a dance to attract the female by displaying his brightly colored legs and vibrating his body.

During the process, the male also produces a sperm web and transfers his sperm to the female’s reproductive organs using his pedipalps.

Egg Sacs and Offspring

After the mating process, the female wandering spider will create an egg sac to protect her eggs.

The sac consists of silk and can hold hundreds of eggs. She then attaches it to a safe hiding place, usually against a protective surface or within a secure web.

The female often guards the egg sac to ensure the protection of her offspring until they hatch.

Once the spiderlings hatch, they are known to be highly independent.

They disperse quickly and start their own journey, fending for themselves soon after emerging from the egg sac.

As they grow, they’ll go through a series of molts before reaching adulthood and beginning their own reproductive cycle.

Danger and Defense Mechanisms

The Wandering Spider is known to be one of the most dangerous spiders in the world.

Although they can potentially kill humans, fatalities are rare due to their reluctance to bite.

Oddly enough, their venom can cause an involuntary erection in men, alongside other painful symptoms.

Here are some ways the Wandering Spider protects itself and displays its dangerous nature:

Fangs : These spiders are equipped with strong, sharp fangs that can easily pierce human skin, allowing them to inject their venom with ease.
Venom : Their venom is potent and can cause severe pain, inflammation, and other adverse effects. In rare cases, it can even lead to death.

While interacting with Wandering Spiders, be cautious and observe them from a safe distance.

Knowing their defense mechanisms will help you respect their space and avoid any unpleasant encounters.

Remember, it’s essential to be informed and aware when dealing with these fascinating, yet dangerous creatures.

Comparison with Other Dangerous Spiders

Comparison to black widow.

The black widow spider is notorious for its potent venom, but the wandering spider has a stronger venom overall.

Both spiders are capable of causing severe symptoms, but the black widow’s venom is primarily neurotoxic, affecting your nervous system.

In contrast, the wandering spider’s venom can cause both neurotoxic and cytotoxic effects, potentially damaging your nerves and cells.

Potent neurotoxic venom
Red hourglass marking
Stronger venom (neurotoxic and cytotoxic)
No distinct marking

Comparison to Brown Recluse

The brown recluse spider is known for its necrotic venom that can lead to tissue damage and sometimes requires medical intervention.

While both the brown recluse and wandering spider can produce venomous bites, wandering spiders are considered more dangerous due to the potency of their venom and the severity of their bite symptoms.

Necrotic venom
Dark violin-shaped marking

Comparison to Wolf Spider

Wolf spiders are frequently mistaken for more dangerous spiders due to their size and appearance.

Although they can bite, their venom is not particularly potent and generally only causes mild itching, redness, and swelling.

In comparison, the wandering spider’s venom is far more dangerous, and its bite can result in serious symptoms, requiring immediate medical attention.

Large and hairy
Smoother appearance

Comparison to Sydney Funnel-Web Spider

The Sydney funnel-web spider is another highly venomous spider known for its potentially lethal bites.

While both spiders possess powerful venom, the wandering spider has a broader range of symptoms due to the combination of neurotoxic and cytotoxic effects.

In conclusion, wandering spiders are more dangerous than wolf spiders but their venom’s effects are more varied compared to black widows, brown recluses, and Sydney funnel-web spiders.

Be cautious around these spiders and seek medical help if bitten.

Interesting Facts and Guinness World Records

The Wandering Spider, also known as the Brazilian Wandering Spider, is a fascinating creature that has caught the attention of many.

They belong to the genus Phoneutria , which means “murderess” in Greek, giving you an idea of their potency. Let’s explore some interesting facts about this spider and its place in the Guinness World Records.

First, you might be curious about their venom. The Wandering Spider is known for having one of the most potent venoms among spiders.

In fact, it holds the Guinness World Record for the most venomous spider. Their venom contains a potent neurotoxin that can cause severe symptoms, including difficulty breathing, high blood pressure, and intense pain.

Apart from their venom, their behavior is also quite intriguing. These spiders are called “wandering” because they are known for actively hunting their prey rather than spinning webs to catch them.

They are mostly nocturnal creatures and, during the day, can be found hiding in logs or dark crevices.

Here are a few more notable characteristics of the Wandering Spider:

Females are larger than males, with a body length of up to 1.6 inches (4 cm).
They have eight eyes, arranged in two rows, which help them in hunting.
The Wandering Spider is primarily found in Central and South America, particularly in Brazil.
They are known to show aggression when threatened.

While the Wandering Spider is a marvel of the arachnid world, it’s essential to keep a safe distance from them due to their venomous nature.

However, their unique characteristics and record-breaking venom potency make them a fascinating subject for those interested in the natural world.

Prevention and Safety Measures

To protect yourself from wandering spiders, there are some simple safety measures you can take.

Firstly, be cautious in areas where these spiders may live, such as dark and warm spaces. For example, avoid reaching into crevices or lifting piles of wood without inspecting them first.

Always wear appropriate shoes when outdoors, particularly in wooded or grassy areas. This can help prevent bites on your feet or ankles.

Reduce the risk of wandering spiders entering your home by sealing gaps and cracks. This minimizes the chance of the spiders finding a way inside.

Regularly clean your living spaces, paying special attention to dark and hidden areas. By maintaining a clean environment, you’ll discourage wandering spiders from making themselves at home.

When out in nature, avoid disturbing spider habitats like webs or egg sacs. This can prevent agitating wandering spiders, reducing your chance of accidental encounters.

Remember, wandering spiders can be dangerous, but by taking these precautions, you can significantly reduce your risk of encountering them or being bitten. Stay safe and always be aware of your surroundings.

In summary, wandering spiders, particularly those in the genus Phoneutria, are a group of venomous arachnids predominantly found in Central, South America and parts of Southern United States.

These spiders, including the Brazilian wandering spider, are known for their potent venom, nocturnal hunting habits, and aggressive defense mechanisms.

Their venom, containing neurotoxins and other components, can cause severe symptoms in humans, making them one of the most dangerous spider species.

Despite their fearsome reputation, fatalities are rare, and they play a vital role in their ecosystems.

It’s important to respect their space and take preventive measures to avoid encounters. Understanding these spiders’ behavior, habitat, and characteristics can help in appreciating their role in nature while ensuring safety.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2857337/ ↩

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3851068/ ↩ ↩ 2

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6560916/ ↩ ↩ 2

Reader Emails

Over the years, our website, whatsthatbug.com has received hundreds of letters and some interesting images asking us about wandering spiders. Scroll down to have a look at some of them.

Letter 1 – Wandering Spider from Ecuador

Hi Michele, There is a resemblance to the Dolomedes Fishing Spiders, and finding it near a river lends credence to that possibility. Eric Eaton noticed this posting and has this to say: ” Ok, the spiders from Ecuador and Costa Rica: They are most likely NOT wolf spiders, but wandering spiders, either in the family Ctenidae or Sparassidae. They tend to be more common, and even larger than, wolf spiders in the tropics. At least one species, Phoneutria fera, is extremely aggressive, with potentially deadly venom. Do not mess with large spiders in Central and South America! The venomous types are very difficult to distinguish from harmless species, and in any event, a bite is going to be really painful. These spiders sometimes stow away in bananas, houseplants, and other exported goods, so they can show up in odd places. Be careful where you put your hands.”

Update: May 14, 2013 We now have a confirmation that this is a Wandering Spider, Phoneutria fera , and it is a dangerous species. See Encyclopedia Britannica and Animal Corner .

Letter 2 – Brazilian Wandering Spider: Most Venomous Animal

Hi Martin, We are happy you were able to write to us after your encounter with this Brazilian Wandering Spider and are thrilled to be able to post your story and photos to our site. We started to research, and our first hit has a different species name. Phoneutria fera is described as: “The Brazilian Wandering Spider is not for the ‘pet keeper’. Brazilian Wandering Spiders are extremely fast, extremely venomous, and extremely aggressive. These large and dangerous true spiders are ranked among the most venomous spiders known to man. In fact, the Brazilian Wandering Spider is the most venomous spider in the New World! In South America, these true spiders are commonly encountered in peoples’ homes, supposedly hiding in peoples’ shoes, hats, and other clothes. The Brazilian Wandering Spider does not remain on a web, rather, it wanders the forest floor, hence the name.” Our favorite information on Wikipedia is that Phoneutria is Greek for “murderess”. Here is one final tidbit about the effect of the bite of the Brazilian Wandering Spider on the human male .

Letter 3 – Possibly Wandering Spider from Ecuador

Dear Mike, This is really an interesting Spider, but other than to say it appears to be a hunting spider that does not build a web to entrap prey, we aren’t sure about its identity. Many hunting spiders can jump quite well. It looks very much like the spider in a posting in our archives, also from Ecuador, that we identified as possibly a Wandering Spider in the genus Phoneutria, a venomous and potentially dangerous genus . The spotted legs on your individual look like the spotted legs on an individual in an image on Wikipedia of a Wandering Spider in the genus Phoneutria . There are many images of Brazilian Wandering Spiders on Primal Shutter and we believe that might be a correct identification for your individual.

Thank you for the information. After reading more about the spider, I’m glad it didn’t jump! Mike

Letter 4 – Possibly Wandering Spider from Ecuador

Dear Carl, We believe, though we are not certain, that this might be a Wandering Spider in the genus Phoneutria, and you may read more about Wandering Spiders on the Museum für Naturkunde Karlsruhe website where it states: “There is no doubt that the venom of some of the species is quite potent for mammals, including humans.” We eagerly welcome additional opinions on this identification. Perhaps Cesar Crash of Insetologia can provide something. In the future, please submit a single species per submission form as it makes it extremely difficult for us to categorize postings with multiple species.

Letter 5 – Wandering Spider from Belize

Hi Karl, Thanks for allowing us to post your excellent image of a Wandering Spider, Cupiennius salei . The species is pictured on iNaturalist .

Bugman aka Daniel Marlos has been identifying bugs since 1999. whatsthatbug.com is his passion project and it has helped millions of readers identify the bug that has been bugging them for over two decades. You can reach out to him through our Contact Page .

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Piyushi is a nature lover, blogger and traveler at heart. She lives in beautiful Canada with her family. Piyushi is an animal lover and loves to write about all creatures.

8 thoughts on “Understanding the Wandering Spider: Quick Essential Facts”

Hi Michele, I am an Ecuadorian scientist and specialized on spiders, I would like to find one like yours, I can say that, almost without doubt, you found the Phoneutria itself, it is the Phoneutria fera, look at this picture: http://www.google.com/imgres?imgurl=http://4.bp.blogspot.com/-bFH9qzT0F7U/T_2sZuk6xAI/AAAAAAAAAGY/8jnMVcPOcNI/s1600/phoneutria_fera2.jpg&imgrefurl=http://rangerbaiano.blogspot.com/2012/07/animais-peconhentos-e-venenosos.html&usg=__iCWEz7S86xub6RAyvXTER6HBaco=&h=864&w=834&sz=215&hl=es-419&start=6&zoom=1&tbnid=jjOROVO9h-vKXM:&tbnh=145&tbnw=140&ei=99eRUY6xKo2K9QTLvYCoDQ&prev=/search%3Fq%3Dphoneutria%2Bfera%26sa%3DN%26hl%3Des-US%26sout%3D1%26tbm%3Disch%26prmd%3Divns&itbs=1&sa=X&ved=0CDYQrQMwBQ Can you see the similarities?, unfortunately the spider might be in a better life today 🙂 Another thing, when you want identifications you should take a picture in front, the under part, and the upper part, as well as some characteristics about behaviour like how they react when you approach. The Phoneutria is a very agressive one.. best wishes, bye.

Hi Miguel, Thanks so much for the comment. This is a seven year old posting and we did not have the ability to post comments when it was originally posted online. We have made an update on What’s That Bug? and your comment is greatly appreciated.

Ah, there is also needed the size and the picture of its face so we can see the eye arrangement, depending on that it could also be pisauridae, but I stay in Ctenidae..

This is a female Cupiennius sp. wandering spider.

Perhaps surprisingly, this ubiquitous large spider of the Mindo area appears to be undescribed to species level.

Although one is indeed best advised to exercise caution in the presence of large ctenids, members of the genus Cupiennius are not known to be dangerously venomous (Barth, 2002). By way of confirmation, my girlfriend, Shannon Bowley, managed to be bitten by a mature female of this Mindo species in 2013 – she felt only mild effects, equivalent to a bee sting.

Thanks for this valuable information.

I’m planning a trip to Ecuador and I’m fearing these spiders. Do they get in houses? Any tips to keep them out, so I can sleep at night?

Brazilian Wandering (Phoneutria)

The Brazilian Wandering spider is a type of spider from the Phoneutria group. Even though they’re called “Brazilian,” not all of them come from Brazil. They’re known for having strong venom. In this post, we’ll share cool facts about these spiders and help you understand them better.

Scientific Classification

Family: Ctenidae
Genus: Phoneutria

List of Spiders Belonging to This Genus

Physical description and identification.

Size: They are large in size, with their body being 17- 48mm (.67 – 1.89 inches) long and they also have a leg span of 130 – 150 mm (5.1-5.9 inches).
Color: The color may vary from one species to the other, though most of them have a brown hairy body, with black spots on their stomach. Some have bright, red hairs on their mouthparts or chelicerae, while others may lack it, a feature that confuses them with species of another genus, particularly the Cupiennius.
Other characteristics: They often lift their body in an erect posture and hold their frontal legs high to defend themselves against predators.

They are safely placed in a silken sac and the female spiders of this genus are known to lay about 1000 of them in her lifetime.

Spiderlings

They remain with their mother for some time after which they disperse to be on their own. The juvenile spiders are known to consume pin crickets as well as non-volatile fruit flies for their diet.

The spiders of this genus do not build webs but walk on the jungle floor, on the lookout for their prey.

Are Brazilian Wandering Spiders Venomous?

Yes, Brazilian Wandering Spiders have strong venom. They use it to catch their food. It’s one of the reasons they’re pretty famous.

Can Brazilian Wandering Spiders Bite?

Yes, they can bite. While they don’t always want to, they might if they feel scared or threatened by something.

How Fast Can a Brazilian Wandering Spider Kill One?

It has been reported that the bite of species belonging to this genus may result in the victim’s death within one hour after the venom enters the person’s body. However, with effective anti-venom being introduced for treatment in Brazil to combat the toxic effects of these spiders, the incidence of fatalities has been less. In fact, most studies show that death mostly occurs in children below seven years of age. Of all the eight species, P. nigriventer , followed by P. fera, is said to account for most venom intoxications in Brazil.

Ecological Importance and Behavior of the Brazilian Wandering Spider

The Brazilian Wandering Spider, scientifically known as Phoneutria, stands out not just because of its reputation as one of the world’s most venomous spiders , but also due to its ecological significance and unique behavior.

Natural Predator: Despite their fearsome reputation, Brazilian Wandering Spiders are not at the top of the food chain. They fall prey to larger animals and birds. Among their predators are the coatis, certain species of large spiders, and a variety of avian predators.

Prey-Predator Dynamics: The dynamic between the Brazilian Wandering Spider and its prey is a showcase of nature’s balance. While they are efficient hunters, specializing in ambushing their prey, their own survival is constantly under threat from their predators. This cycle ensures that no one species dominates the ecosystem and that biodiversity thrives.

Relationship with Humans: The relationship between humans and the Brazilian Wandering Spider is one of respect and caution. Their venom is potent and can be harmful to humans, although fatal encounters are rare.

Quick Facts

Did You Know

Species of this genus are known for wandering along the jungle floor during the night which is why they are referred to as “wandering spiders”.
They are alternately called “banana spiders”, a name that they also share with other species because members of this genus have often been found in banana shipments. Research in shipments going to North America showed that 7 of the 135 spiders found in such shipments were of the Phoneutria genus.
Phoneutria in Greek means murderess, a name perfectly attributed to its aggressive nature.

Other Spiders in this Family

Wandering spiders.

Phoneutria depilata

Phoneutria boliviensis

Phoneutria fera

Phoneutria nigriventer

Southeastern Wandering (Anahita punctulata)

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Brazilian Wandering Spider: Care, Food, Habitat & Preventions

Mike Wallace

Have you ever heard of or do you know what a Brazilian wandering spider is ? It is a big venomous spider from places like Central and South America, and people sometimes call it the banana spider . Why? Well, we are about to find out!

Table of Contents

These wandering spiders are aggressive hunters who go out on the hunt at night. Their meals include both invertebrates (like insects) and vertebrates (creatures with a backbone, like small animals).

These spiders are super dangerous because their venom is like a powerful potion that can make people really sick or even worse. They usually hang out in tropical rainforests and even in cities, hiding in banana plants.

So, let’s get more information about the world of this sneaky spider to learn the details about its looks, eating habits, where it lives, the venom it carries, and find out if it is genuinely risky. Ready to explore? Keep reading!

Brazilian Wandering Spider Description:

Scientific name and family:.

In Brazil, they are sometimes known as “ armed spiders ” (armadeiras), and they share the name “ banana spiders ” with a few other spiders. They have different names, but they are all talking about the same interesting spider!

Brazilian Wandering-Spider sitting on hand Spiders-Planet

The Brazilian wandering spider, scientifically known as Phoneutria , Maximilian Perty kickstarted the Phoneutria genus in 1833. The name comes from the Greek word φονεύτρια , which means “murderess” and falls under the Animalia kingdom, Arthropoda phylum, and Arachnida class.

Within Arachnida, it is classified in the order Araneae, infraorder Araneomorphae, and Ctenidae family. The genus Phoneutria, described by Perty in 1833, includes the type species Phoneutria fera .

This classification helps us understand where these spiders fit into the larger picture of living organisms.

The following 9 species are accepted by The World Spider Catalog :

Phoneutria bahiensis
Phoneutria boliviensis
Phoneutria eickstedtae
Phoneutria fera
Phoneutria keyserlingi
Phoneutria nigriventer
Phoneutria pertyi
Phoneutria reidyi
Phoneutria depilata

What do Brazilian Wandering Spider look like?

Size range:.

The spiders in the Phoneutria group can get pretty big in size. Their legs can stretch out to be 13 to 18 centimeters (5 to 7 inches) wide, and their bodies can have a range between 17 to 48 millimeters (a little more than half an inch to almost 2 inches) long.

The female Brazilian spiders can get pretty big, reaching up to 15 centimeters (5.9 inches) in length. On the other hand, the males are smaller, usually measuring around 7 centimeters (2.8 inches). They usually weigh up to 0.21 ounces.

They have long, slender legs, and even though some other spiders with different names might have longer legs, the Phoneutria spiders are champions when it comes to having the longest bodies and being the heaviest in their spider gang.

The spider’s body has two main parts. The first is the prosoma, kind of like its “head,” where you will find all eight legs, eyes, fangs (chelicera), and little multitasking arms (pedipalps).

The second part is the opisthosoma, holding the spinnerets for making silk, the back end opening (anal opening), “the lungs,” the heart, and the important bits for making baby spiders (reproductive organs).

So, the prosoma is like the front control center, and the opisthosoma is like the back office, handling things like silk-making and baby-making.

Brazilian spiders come in different colors, with most being hairy and shades of brown and gray. Some species may have lightly colored spots on their abdomen.

A distinctive feature of many species is the presence of bands of black and yellow or white on the underside of their two front legs.

Identification:

To identify a spider from the Phoneutria group, look for a dense brush of fine hairs on their leg parts. They might seem like other spiders, especially Cupiennius , but here is how you can differentiate:

Phoneutria often have a dark line on the front of their palps and a thin black line on top of their head.
Check underneath, too; their legs usually have dark parts and light joints. Sometimes, the belly has black dots or is reddish.
Usually it has been observed that when they are upset, they do a cool defensive move like lifting their front legs high with a distinctive pattern. So, if you see a spider doing that dance, it is probably a Phoneutria!

Brazilian Wandering Spiders live all over the Americas, from Costa Rica to northern Argentina. They are like the residents of the jungle, chilling in forests east of the Andes in countries like Colombia, Venezuela, Ecuador, Peru, Bolivia, Brazil, Paraguay, and the Guianas.

Some, like P. reidyi, P. boliviensis, and P. fera, love the Amazon rainforest, while others prefer the Atlantic Forest in Argentina, Paraguay, and Brazil.

They have also made themselves at home in the Cerrado savanna. But if you head to northeastern Brazil, they are not around. These spiders have even taken trips to Chile and Uruguay.

Why are they called Banana Spiders?

These spiders are linked with bananas. Richard S. Vetter, a researcher at the University of California, found that these powerful spiders sometimes end up in North America and Europe by accident, hitching a ride in banana shipments.

Banana Spider sitting on banana leaf - Spiders Planet

But it is often a case of mistaken identity. Only a few Phoneutria species have been found in banana shipments, and sometimes, other spiders get the blame due to misidentification.

What They Like to Eat or Hunt?

Their food includes flies, beetles, butterflies, moths, grasshoppers, locusts, and crickets. Occasionally, they might even feast on small creatures like amphibians, reptiles, or mice. All these diet or food findings tell us about how diversified eating habits these fascinating spiders have.

Mating and Lifecycle:

Like most spiders, the female spiders are bigger than the males. When the male spider wants to be friends, they do a little dance (vibrating his pedipalps and specialized sensory appendages) to signal his intentions to impress the female, but it is a cautious approach.

The behavior of the female can be choosy, and she might say no to a few before picking the right one.

After the dance, sometimes, the females decide to attack them, or if she is interested, she can store the male’s baby-making material in a special place until she is ready to use it.

Then, she lays a bunch of eggs, up to 1,000 at a time, and keeps them safe in a silk egg sac. Sadly, after laying her eggs, the mom spider says goodbye. It is her way of making sure the new spiders are ready to explore the world on their own.

The lifespan of the banana spider (Phoneutria nigriventer) differs for males and females. Females usually live for 6 to 8 weeks after reaching maturity, while males have a shorter lifespan of 2 to 3 weeks after their last molt.

Certain mammals, like coatis (Procyonidae, which includes raccoons) and other small insectivores, birds are potential predators of large wandering spiders.

These spiders got their name as wandering spiders because of the fact that they are not into web building. Instead, they stroll around the forest floor at night(nocturnal), searching for dinner.

Brazilian Wandering Spiders are active hunters and use both ambush tactics and direct attacks to catch their prey. During the day, they prefer cozy spots like under logs or in crevices, only emerging at night for their hunting adventures. These spiders do not build nests like other spider species.

While wandering spiders are not naturally aggressive towards humans, they won’t hesitate to bite if they feel cornered or threatened. Most bites happen when a spider accidentally gets trapped in clothing or bedding.

Bite and Venom:

The bite of the armed spider is the most dangerous in the world as the venom it carries can be harmful to humans.

The danger is not just about how strong the venom is; it is also about factors like the spider’s likelihood to bite and how close it is to where people live.

These spiders often hide in houses, clothes, and other dark places during the day, making accidental bites more likely.

While their fangs are adapted for small prey, some experts think they might give a “dry” bite in defense to save venom. Studies suggest that not all bites inject venom, and serious cases requiring antivenom are rare.

However, there have been confirmed cases of death, with symptoms appearing quickly, including:

Severe pain
Breathing difficulties
Increased heart rate and blood pressure
In severe cases, paralysis and death

The severity can depend on the spider’s sex, with females generally more dangerous. The spiders produce less venom in colder months, and a small amount can be potent enough to harm.

Fortunately, bites from Brazilian spiders are rare, and when they do occur, the exposure to the toxins is generally mild, as explained by Vetter.

Also Read: What is a Huntsman Spider? (Heteropodidae) – The Ultimate Guide

Banana Spider’s Facts:

Below are essential details about Brazilian wandering spiders:

They hold the title for the world’s largest spiders , boasting leg spans reaching up to 15 centimeters (6 inches).
Their venom packs a powerful punch, capable of inducing severe pain, paralysis, and, in extreme cases, fatal outcomes for humans.
Despite their intimidating reputation, they are generally non-aggressive and resort to biting only when provoked.
These spiders inhabit tropical rainforests and urban areas across Central and South America.
In case someone has been bitten by this spider, he/she needs quick medical treatment to control the effects timely.

Brazilian Wandering Spider sitting on wood -Spiders Planet

Treatment and Preventive Measures:

If bitten by a wandering spider or armed spiders, prompt medical attention is crucial. There is an antivenom for the spider’s venom, but its effectiveness is highest when administered within a few hours of the bite.

To prevent a bite:

Wear protective clothing, use shoes and long pants when in areas where these spiders are found.
Before wearing your clothes and shoes, make sure to check them to ensure no spiders are hiding.
Maintain cleanliness and avoid leaving food or garbage exposed, as this can attract spiders.

These preventive measures are essential for minimizing the risk of encountering and getting bitten by Banana spiders.

Can Brazilian spiders kill humans?

Brazilian wandering spiders (Phoneutria nigriventer) are venomous and can potentially kill a human with a single bite. Their venom contains a potent neurotoxin that can cause severe pain, paralysis, and even death.

Are Brazilian spiders poisonous?

Yes the venom of this spider is poisonous, that can cause death. While Brazilian wandering spiders are potentially dangerous, actual bites are relatively rare.

By adopting preventive measures and promptly seeking medical attention if bitten, the risk of serious complications can be significantly reduced.

Can you keep Brazilian spiders as pets?

It is strongly advised against keeping wandering spiders as pets due to their venomous nature and the potential risk to human safety.

Managing these spiders in captivity demands specialized knowledge and handling procedures to minimize the risk of bites.

Final Thoughts:

The Brazilian wandering spider, banana spider, or armed spider is a large and venomous arachnid found in Central and South America. While their potent venom can be harmful to humans, encounters are rare.

These nocturnal hunters have adopted various habitats, from rainforests to urban areas, and are associated with banana shipments. Understanding their appearance, behavior, and habitat is crucial for minimizing risks.

Seeking immediate medical attention after a bite is essential, as antivenom is available but most effective when administered promptly. Despite their fearsome reputation, the Brazilian spider remains a captivating and potentially dangerous species.

About the author

Spiders Planet is the ultimate source of information about spiders! All the articles on this site will provide you with the most accurate and up-to-date information written by me and a group of writers, that is well-researched and fact-checked before it’s published.

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The Brazilian Wandering Spider

A box of bananas were delivered to a pub in Bridgwater, England in 2005. Unbeknownst to the person opening the bananas, an aggressive spider was hiding in the bananas and bit him. Later on it would be identified as the venomous and speedy species Phoneutria fera (Brazilian Huntsmen) from South America.

Our topic today is about the Phoneutria species of spiders. There are 8 species, with only a few being the ones that are primarily interesting for envenomation. They all are recognizable by their defensive posture. They have a leg span of about 6 inches and have light stripes under their legs that are revealed while in the posture. When threatened, they assume a characteristic defensive position by raising their four front legs, displaying their fangs, bristling their leg spines, and moving position to continually face their threat. At this point it would be worth mentioning they can jump over a foot in distance.

Phoneutria fera/Phoneutria nigriventer are the most venemous. P. fera is only in the Amazon while P. nigriventer is in Brazil, northern Argentina, and Uruguay. They are generally only found in the Amazon. Phoneutria nigriventer is also known as a Brazilian armed spider (arantia armadeira in Portuguese).

In their native Amazon, they wander the jungle floor at night and hide inside termite mounds/fallen logs/banana plants. In populated ares they also like to hide in houses/cars and can even be inside boots.

Life Lesson : Always shake your clothes and boots out before putting them on in a tropical country. Keeping your luggage closed is also ideal unless you want a hitchhiker.

Their location spans forests from Costa Rica and Panama down to the Amazon. In South America, this includes Colombia, Venezuela, Guianas, Ecuador, Peru, Bolivia, Brazil, and Paraguay. The importance here is that their location also can include other countries as they sometimes get transported with bananas – 7 of 135 spiders found in north American banana shipments were Phoneutria in 2014.

Toxin : PhTx3 (broad spectrum calcium channel blocker that inhibits glutamate release, calcium uptake, and glutamate uptake in neural synapses). They are aggressive but the good news is that most of their bites do not contain significant amounts of venom. Only 1% of bites result in severe envenomation. Significant envenomation produces severe pain locally followed by both sympathetic and parasympathetic stimulation. This results in a combination of tachycardia/hypertension with nausea, vomiting, diaphoresis, salivation. The most interesting neurotoxic effects are from spinal cord impairment which result in priapism and CNS effects - vertigo, visual changes. Some of the proposed mechanisms for priapism include two chemicals (PhTx 2-5 & PhTx 2-6) which lead to nitric oxide release. Paralysis and pulmonary edema leading to respiratory arrest can occur as well. Children and the elderly are at highest risk for serious envenomation. Most healthy adults recover in 1 to 2 days. Death, shock and ARDS are rare.

Treatment: Local anesthetic infiltration at the bite site can control pain. A polyvalent antivenom (Instituto Butantan, São Paulo, Brazil) is available for cases of severe envenomation from P. nigriventer. If you are far from Brazil, this might be coordinated with your local poison center. Benzodiazpines can help with the excessive tachycardia/hypertension with the goal being symptomatic control with due caution since both sympathetic and parasympathetics are activated. Definite airway should be obtained if significant paralysis. The goal for priapism is detumescence with retention of potency. Aspiration with or without 9% NaCl solution irrigation of the corpora cavernosa may be effective. The current understanding is that priapism is NO mediated so I doubt an α 1 -adrenergic agonist (100–500 μg/mL phenylephrine solution) instilled into the corpora cavernosa would work. The dosage for states of α 1 -adrenergic antagonism are 0.5 to 1 mL every 3 to 5 minutes up to 1 hour. Oral terbutaline (5–10 mg) is effective for PGE 1 -induced prolonged erections but recent studies show the NO effects of the toxin are from a different pathway. If persistent priapism, an operative venous shunt placement may be required. Some studies are being performed with 7-nitroindazole which blocks nNOS (neuronal nitric oxide synthase) to reverse the effects but this is not FDA approved or widely available.

https://www.researchgate.net/publication/302556178_Phoneutria_nigriventer_Venom_and_Toxins_A_Review

Bucaretchi F, Mello SM, Vieira RJ, Mamoni RL, Blotta MH, Antunes E, et al. Systemic envenomation caused by the wandering spider Phoneutria nigriventer with quantification of circulating venom. Clin Toxicol (Phila) 2008;46(9):885–9. doi: 10.1080/15563650802258524. https://www.tandfonline.com/doi/full/10.1080/15563650802258524?scroll=top&needAccess=true

Bucaretchi F, Deus Reinaldo CR, Hyslop S, et al. : A clinico-epidemiological study of bites by spiders of the genus Phoneutria . Rev Inst Med Trop Sao Paulo . 2000; 42: 17. [PubMed: 10742722]

Vetter RS, Crawford RL, Buckle DJ (2014). "Spiders (Araneae) Found in Bananas and Other International Cargo Submitted to North American Arachnologists for Identification". Journal of Medical Entomology . 51 : 1136–1143. doi : 10.1603/me14037

https://www.livescience.com/41591-brazilian-wandering-spiders.html

"Pub chef bitten by deadly spider" . BBC News. 2005-04-27

Brazilian Wandering Spider Facts: What Happens If It Bites You?

Brazilian wandering spiders belong to the genus Phoneutria and are represented by eight spider species that are native to Central America and South America. This spider group is also collectively known as armed spiders and banana spiders. In Brazil, they are locally known as "aranha armadeira" which means armed spider. With these, some people often wonder if a person can survive after being by a member or species of this group.

What is a Brazilian Wandering Spider?

The genus Phoneutria , which the Brazilian wandering spider and related spider species belong to, was first described in 1833 when two species was included on it. The following century saw various scientists to move the Phoneutria species between genera Phoneutria and Ctenus . In 1936, Mello-Leitao restored Phoneutria and currently contains eight species, as reported by the University of Florida.

Banana spiders, a name given to the arachnid group due to their frequent presence on banana leaves, are large and robust arachnids in the family Ctenidae . They resemble the morphological appearance of wolf spiders. In addition, their body length can grow ranging from 17 and 48 millimeters and their leg span can reach 180 millimeters. Their distinct color ranges from light brown, brown, or grey. Furthermore, the natural habitats of armed spiders are forests.

Also Read: Deadly Erection-Giving Spider Crawls Out of Banana In Bristol

What Happens If It Bites You?

The natural prey of Brazilian wandering spiders includes small animals like crickets, mantids, and katydids, and larger ones like bats, frogs, and lizards. However, they can still bite humans and other animals not native in their habitats. In the past, scientists have identified that the bite of banana spiders living in Central and South American rain forests can lead to shortness of breath and excessive salivation.

According to wildlife experts, a Brazilian wandering spider bite can also lead to other serious symptoms, including increased blood pressure, above-normal pulse, and unusual respiratory rate, as well as extreme pain, hours-long penile erection, and death, in some cases. These spiders inject neurotoxin venom to its bitten victim and can be deadly to humans, particularly for children. However, it is not the world's deadliest spider.

Venomous Spider

In a study published in the journal Frontiers in February 2023, researchers stated that the Brazilian wandering spider is amongst the world's most dangerous venomous spiders in the world. In Brazil, there have been an estimated 4,000 envenomation accidents of Phoneutria nigriventer spider species each year in Brazil. Additional symptoms were also observed, including blurred vision, priapism, and vomiting.

The armed spider only follows the world's most venomous spider, which according to the Guinness World Records , is the Sydney funnel-web spider ( Atrax robustus ).

Like the Brazilian wandering spider, the venom of A. robustus can be neutralized by anti-venoms but some cases still lead to deaths when these arachnids bite a human, who did not receive any medical attention. Experts also weigh that the mortality of venom depends on the amount that enters a human body.

Related Article: Arachnophobia Nightmare: Giant Spider Found Inside Banana Box at Grocery Store in Germany

Tags Brazilian wandering spider , banana spider , Spider , spider bite , animals , Wild Animals

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AnimalBehaviorCorner

Brazilian Wandering Spider

Brazilian Wandering Spider , scientifically known as Phoneutria, emerges as a captivating enigma in the realm of arachnids.

Renowned for its formidable reputation as one of the world’s most venomous spiders , Phoneutria embodies a plethora of intriguing traits that have captured the curiosity of enthusiasts and researchers alike.

From its distinctive appearance and neurotoxic venom to its nomadic hunting strategies and unique mating behaviors , this remarkable spider species holds a wealth of fascinating secrets waiting to be unraveled.

Join us as we embark on a journey to explore the captivating world of the Brazilian Wandering Spider, shedding light on its captivating characteristics and dispelling myths that have shrouded its true nature.

1. Taxonomy and Distribution of the Brazilian Wandering Spider

A. scientific classification of phoneutria.

The Brazilian Wandering Spider, scientifically referred to as Phoneutria, occupies a distinct place within the arachnid taxonomy.

Belonging to the family Ctenidae, this spider genus is further categorized into several species, each boasting unique traits and behaviors .

Phoneutria’s taxonomic position not only distinguishes it from its arachnid counterparts but also underscores its intriguing evolutionary journey.

B. Native Habitat in South and Central America

Endemic to the lush landscapes of South and Central America, the Brazilian Wandering Spider finds its natural haven within these diverse regions.

From the rainforests of the Amazon to the tropical stretches of the Caribbean, Phoneutria has adapted to a range of environments over the course of its evolution.

The spider’s ancestral ties to these regions are tightly woven into their behaviors , anatomy, and survival strategies.

C. Preference for Tropical Rainforests and Urban Areas

Within its native territories, the Brazilian Wandering Spider exhibits remarkable versatility in its chosen habitats.

While it thrives amidst the vibrant biodiversity of tropical rainforests, it has also displayed a propensity for urban locales.

Phoneutria’s adaptability has led it to establish a presence in urban areas, where it often finds shelter in crevices, gardens, and even human dwellings.

This adaptability to both wild and urban spaces further showcases the spider’s resilience and capacity to thrive in varying conditions.

2. Physical Characteristics of the Brazilian Wandering Spider

A. size, coloration, and distinctive markings.

The Brazilian Wandering Spider , a creature of remarkable visual intrigue, boasts an array of captivating physical attributes.

Ranging in size from a few centimeters to several inches, Phoneutria showcases a size diversity that reflects the breadth of its genus.

Its coloration varies across species, encompassing shades of brown, black, and gray, often accompanied by intricate patterns and markings that adorn its exoskeleton.

These unique markings serve not only as a visual spectacle but also as essential components of its survival toolkit.

B. Camouflage and Defense Mechanisms

The Brazilian Wandering Spider’s appearance is a masterpiece of evolution, meticulously crafted to ensure both survival and predation .

Its coloration and markings are tailor-made for blending seamlessly into its surroundings, granting it a potent advantage in ambushing prey and evading predators . Moreover, these markings also play a role in its defense mechanisms.

When threatened, Phoneutria adopts a defensive posture, raising its front legs and revealing its striking markings, a visual warning to potential threats. This dual-purpose camouflage and defense strategy exemplify nature’s ingenuity at its finest.

C. Sexual Dimorphism: Unveiling Gender Differences

A fascinating facet of the Brazilian Wandering Spider lies in the realm of sexual dimorphism , where gender-based variations manifest in pronounced ways.

Females tend to be larger and more robust than their male counterparts, showcasing a size disparity that has evolved in tandem with their roles in reproduction and hunting .

Beyond size, other characteristics, such as leg structure and coloration, also exhibit subtle differences between male and female Phoneutria specimens.

This divergence in physical traits adds depth to our understanding of the species’ intricate biology and behavior .

In exploring the physical characteristics of the Brazilian Wandering Spider , we uncover a canvas painted with size diversity, intricate coloration, and unique markings.

These features, finely tuned by evolution, contribute to its prowess in camouflage and defense, while the fascinating interplay of sexual dimorphism further enriches our perception of this captivating arachnid species .

3. Venomous Nature of the Brazilian Wandering Spider

A. potent neurotoxic venom: a silent lethal weapon.

The Brazilian Wandering Spider, known scientifically as Phoneutria, harbors a venomous arsenal that stands as a testament to nature’s intricate design.

This spider’s venom contains a potent concoction of neurotoxic compounds, tailored by evolution to incapacitate its prey swiftly and efficiently.

The neurotoxins interfere with nerve cell communication, leading to paralysis and ensuring that Phoneutria’s quarry is rendered immobile and defenseless, setting the stage for a successful meal.

B. Effects on Prey and Human Hazard

When a victim succumbs to the Brazilian Wandering Spider’s venom , the effects are a symphony of paralysis and predation .

The venom’s impact on the prey’s nervous system results in swift immobilization, offering the spider a decisive advantage in subduing its catch.

While this venomous efficiency is well-adapted for predation, it also underscores the potential danger to humans.

A bite from Phoneutria can lead to a series of neurotoxic reactions, with varying degrees of severity depending on factors such as the individual’s age and overall health.

While human envenomations are relatively rare, they can result in a range of symptoms, from localized pain and swelling to more severe neurological effects.

C. Recorded Cases of Envenomations: Unraveling the Symptoms

Throughout history, documented cases of Phoneutria envenomations have offered insights into the spider’s potential threat to humans .

Symptoms typically include intense pain at the bite site, accompanied by swelling and redness . In some instances, victims have reported systemic reactions, such as muscle cramps, elevated heart rate, and even breathing difficulties.

Swift medical attention and the administration of antivenom have proven effective in mitigating the severity of these symptoms.

These cases serve as a reminder of the delicate balance between the Brazilian Wandering Spider’s potent venom and the potential risks it poses to those who unwittingly encounter it.

4. Hunting and Diet of the Brazilian Wandering Spider

A. hunting techniques and wandering behavior.

The Brazilian Wandering Spider, scientifically known as Phoneutria, unveils a mesmerizing repertoire of hunting techniques that set it apart as a master predator .

Displaying an agile and nomadic behavior , Phoneutria does not confine itself to the confines of a web. Instead, it actively prowls its surroundings, tirelessly searching for potential prey.

This dynamic wandering behavior ensures that its chances of encountering a variety of food sources are maximized, showcasing a strategic approach to sustenance.

B. Active Hunting Triumphs Over Web-Building

Unlike its web-weaving counterparts, the Brazilian Wandering Spider relies on a more hands-on approach to securing its next meal.

While weaving webs might seem an efficient method, Phoneutria’s active hunting strategy offers a distinct advantage in versatility.

By forgoing the constraints of a stationary web, it can tailor its approach to suit different environments and prey types, adapting its tactics on the fly.

This adaptability demonstrates the spider’s remarkable ability to adjust its methods for optimal results.

C. Diverse Prey Spectrum: Insects to Small Vertebrates

Phoneutria’s diet is a testament to its prowess as an opportunistic predator . Its menu spans a diverse range of creatures, from insects like crickets and cockroaches to small vertebrates such as lizards and frogs , and even small rodents.

This wide-ranging palate highlights its ecological significance in controlling various populations within its habitat.

By consuming creatures both large and small, Phoneutria ensures a balanced ecosystem, playing a crucial role in maintaining biodiversity and ecological equilibrium.

5. Mating and Reproduction of the Brazilian Wandering Spider

A. courtship rituals and behaviors: a complex affair.

The Brazilian Wandering Spider, scientifically referred to as Phoneutria, reveals a captivating array of courtship rituals and behaviors that form the cornerstone of its reproductive cycle.

Courtship among these arachnids is a complex affair, involving intricate dances and displays that serve as both communication and assessment.

Male Phoneutria employs a combination of visual cues, vibrations, and tactile interactions to court potential mates.

This elaborate courtship process highlights the significance of precise communication in the delicate dance of reproduction .

B. Cannibalistic Tendencies: A Post-Mating Phenomenon

An aspect that sets Phoneutria’s mating process apart is the notorious cannibalistic tendency exhibited by females after mating.

Following successful mating, females may exhibit an inclination to consume their partners. This seemingly counterintuitive behavior has evolutionary underpinnings.

It is believed that this cannibalistic act not only provides the female with a much-needed nutritional boost but also eliminates potential competitors and safeguards the male’s investment in the next generation.

This intriguing behavior sheds light on the complexities of reproductive strategies within the species.

C. The Unique Mating Plug Phenomenon: A Puzzling Enigma

A distinctive feature in Phoneutria’s reproductive saga is the enigmatic mating plug phenomenon. After mating, male Phoneutria deposit a specialized substance that forms a plug within the female’s reproductive tract.

This plug is believed to serve multiple purposes. It may prevent other males from mating with the female, thus ensuring the successful transmission of the mating male’s genetic material.

Additionally, it might aid in sealing off the female’s reproductive tract, potentially protecting her from external pathogens.

This phenomenon underscores the intricate interplay of biological strategies that contribute to the species’ reproductive success.

6. Human Interaction and Urban Legends of the Brazilian Wandering Spider

A. occasional presence in urban areas: nature in our midst.

The Brazilian Wandering Spider, scientifically known as Phoneutria, has carved a niche for itself not only in the wild but also in the fabric of urban environments.

While its primary habitats are the lush landscapes of South and Central America, Phoneutria occasionally ventures into human -inhabited spaces. Its adaptability allows it to find shelter in gardens, crevices, and even within homes.

This coexistence with humans adds an intriguing dimension to our encounters with this enigmatic arachnid .

B. Debunking Misconceptions: Separating Fact from Fiction

The presence of the Brazilian Wandering Spider has sparked a plethora of misconceptions and exaggerated tales, contributing to the creation of urban legends.

Stories of spiders leaping from banana bunches or hiding under toilet seats have become part of modern folklore, often fueled by sensationalism.

It’s crucial to sift through these tales and recognize that while Phoneutria’s venom is potent, the likelihood of encountering a dangerous encounter is relatively low.

Separating fact from fiction empowers individuals to approach these creatures with accurate knowledge.

C. Importance of Proper Education: Identifying Friend from Foe

Education plays a pivotal role in fostering a harmonious coexistence between humans and the Brazilian Wandering Spider .

Learning to identify and understand the behaviors of Phoneutria species enhances safety for both humans and the spiders themselves.

Instead of succumbing to unwarranted fear, individuals can take steps to reduce the chances of accidental encounters and, if necessary, engage in responsible removal methods.

By arming themselves with knowledge, individuals can navigate encounters with urban-dwelling Phoneutria specimens with confidence and respect.

7. Brazilian Wandering Spider Conservation and Misunderstanding

A. significance of phoneutria in ecosystem dynamics.

The Brazilian Wandering Spider , scientifically termed Phoneutria, assumes a pivotal role within its ecosystem, contributing to a delicate balance of populations and interactions.

As a top-tier predator , it plays a crucial part in controlling insect and small vertebrate populations, preventing unchecked growth that could disrupt the ecosystem’s equilibrium.

By maintaining these population dynamics, Phoneutria ensures the health and stability of its habitat, highlighting its significance beyond its ominous reputation.

B. Impact of Fear and Misunderstanding: Hindrances to Conservation

Despite its ecological contributions, the Brazilian Wandering Spider often falls victim to fear-driven misconceptions that negatively impact conservation efforts.

Misunderstandings surrounding its behavior and potential danger can lead to unwarranted extermination campaigns and habitat destruction.

Fear-driven reactions not only disrupt the natural balance but also hinder opportunities to study and appreciate the species for its ecological significance.

Addressing these misconceptions is crucial to ensuring the spider’s survival and maintaining the health of its ecosystems.

C. Efforts to Dispel Myths and Promote Coexistence

Efforts to conserve the Brazilian Wandering Spider are interwoven with endeavors to educate and dispel myths.

By providing accurate information and dispelling exaggerated tales, conservationists aim to reshape public perception.

Collaborative initiatives emphasize coexistence, highlighting the importance of responsible behavior when encountering Phoneutria.

Educating communities about the spider’s role, behavior, and conservation status fosters an environment where fear gives way to appreciation, and where balanced cohabitation becomes a reality.

8. Research and Medical Significance of the Brazilian Wandering Spider

A. ongoing scientific research on phoneutria venom.

The Brazilian Wandering Spider , Phoneutria, has garnered significant attention from the scientific community due to the unique properties of its venom.

Ongoing research delves into the intricate composition of the venom, aiming to unlock its mysteries and potential applications in various fields.

The diverse array of compounds within the venom, particularly its neurotoxic components, has attracted interest for their potential medical and therapeutic implications.

B. Antivenom Development and Therapeutic Prospects

One of the most promising areas of research surrounding Phoneutria lies in the development of antivenoms and therapeutic agents.

The venom’s potent neurotoxic effects on the nervous system have spurred efforts to create targeted treatments for conditions such as chronic pain and neurological disorders .

Additionally, the potential for antivenoms holds promise in mitigating the effects of envenomations, offering a lifeline for individuals who encounter these spiders .

This focus on harnessing the venom’s properties for positive medical outcomes highlights the transformative potential within this enigmatic arachnid .

C. Balanced Perspectives: Navigating Ethical and Scientific Endeavors

While research on the Brazilian Wandering Spider’s venom offers tremendous potential, it necessitates a balanced perspective.

As researchers probe the venom’s properties, ethical considerations arise, including the well-being of the spiders and their ecosystems.

A holistic approach acknowledges the value of understanding Phoneutria’s natural behaviors and conserving its habitats.

This balanced perspective extends to utilizing the venom’s potential responsibly, ensuring that breakthroughs are achieved while respecting the complex interplay of science and nature.

9. Frequently Asked Questions about the Brazilian Wandering Spider

What is the brazilian wandering spider.

The Brazilian Wandering Spider , scientifically known as Phoneutria, is a venomous arachnid found in South and Central America. It’s notorious for its potent venom and is considered one of the most venomous spiders in the world.

Is the Brazilian Wandering Spider dangerous to humans?

Yes, the Brazilian Wandering Spider’s venom contains potent neurotoxins that can cause a range of symptoms in humans , from localized pain and swelling to more severe reactions. While bites are relatively rare, it’s advisable to exercise caution when encountering these spiders.

What is the spider’s habitat?

The Brazilian Wandering Spider is native to tropical rainforests of South and Central America. However, it’s adaptable and can also be found in urban areas, such as gardens and houses.

How does the Brazilian Wandering Spider hunt?

Unlike many spiders that build webs, Phoneutria is an active hunter. It roams its environment in search of prey, relying on its keen senses to detect vibrations and movements.

Are Brazilian Wandering Spiders aggressive toward humans?

Brazilian Wandering Spiders are not naturally aggressive towards humans and will typically only bite in self-defense. However, caution is advised, especially in areas where these spiders are known to inhabit.

Can the Brazilian Wandering Spider’s venom be used for medical purposes?

Yes, research is ongoing into the potential medical applications of Phoneutria’s venom. Its neurotoxic properties have sparked interest in pain management and neurological treatments.

Is the spider’s reputation for crawling into banana shipments true?

While there have been stories of Brazilian Wandering Spiders being found in shipments of bananas, these occurrences are extremely rare. Spiders are unlikely to survive the conditions of shipping and storage.

How can I stay safe around Brazilian Wandering Spiders?

To stay safe, it’s important to be cautious when encountering spiders in their natural habitat. Avoid provoking or handling them, especially if you’re unsure of their identity. If you suspect you’ve been bitten, seek medical attention promptly.

Are there any efforts to conserve the Brazilian Wandering Spider?

Conservation efforts for the Brazilian Wandering Spider are intertwined with public education and dispelling myths. Recognizing its role in ecosystems and promoting coexistence are essential steps in preserving this unique species.

What can I do if I find a Brazilian Wandering Spider in my home?

If you encounter a Brazilian Wandering Spider in your home, it’s advisable to contact local pest control professionals who can safely remove the spider without causing harm.

In the intricate tapestry of nature, the Brazilian Wandering Spider , Phoneutria, emerges as a creature of both fascination and caution.

Its venomous nature and captivating behaviors have earned it a place among the most enigmatic arachnids .

As we continue to explore its world, debunk myths, and understand its vital role in ecosystems, we find a delicate balance between awe and respect.

Armed with knowledge, we navigate the realm of Phoneutria, appreciating its complexity while fostering coexistence, a testament to the intricate dance between humans and the natural world.

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How to Identify a Brazilian Wandering Spider

Last Updated: February 12, 2021 Approved

This article was co-authored by wikiHow Staff . Our trained team of editors and researchers validate articles for accuracy and comprehensiveness. wikiHow's Content Management Team carefully monitors the work from our editorial staff to ensure that each article is backed by trusted research and meets our high quality standards. There are 8 references cited in this article, which can be found at the bottom of the page. wikiHow marks an article as reader-approved once it receives enough positive feedback. In this case, 93% of readers who voted found the article helpful, earning it our reader-approved status. This article has been viewed 133,493 times.

The Brazilian wandering spider is a large, hairy spider that lives in South and Central America. It’s considered the most venomous spider in the world. Since these spiders sometimes wander right into towns, cities, and shipments of fruit, it’s important to be able to recognize this spider and know its habitat. If you happen to be bitten, you should get immediate medical attention. Don’t panic, however! These bites can almost always be treated.

Recognizing a Brazilian Wandering Spider

Step 1 Watch out for 6-inch (15 cm) long spiders with leg span.

Some spiders may be more yellowish than brown. Others may appear to have black legs, or black bands on brown legs. [3] X Research source

Step 3 Be prepared for a fast-moving spider.

Do not try to trap this spider. Call animal control professionals if you think you have one in your home or outdoor buildings, and leave those buildings while you wait for help.

Being Aware of Their Habitats

Step 1 Be on guard in Central and South America.

Small, unlit closets or nooks in homes
Outdoor sheds and garages
Unused clothes, shoes, or gloves
Boxes of food in pantries
Boxes in attics or garages

Step 3 Take care when opening fruit shipments.

Avoiding a Bite

Step 1 Wear protective gear in dark spaces or when moving firewood.

If a spider falls out, don’t panic. Back away slowly and leave the area.

Step 3 Inspect dark spots like closets before entering them.

You can also spray bug and spider repellant around doors and windows to ward off creepy crawlies.

Step 5 Don’t store firewood against your house.

Treating a Bite

Step 1 Contact emergency medical personnel right away.

In men, these bites can also cause a long and painful erection.

Step 3 Clean the wound with soap and water.

Community Q&A

Keep in mind that these spiders prefer to wander along the ground. Always wear sturdy shoes if you are in an area where these spiders are known to live. Thanks Helpful 1 Not Helpful 0
These spiders are highly dangerous and should not be approached or provoked unless you are an expert such as an entomologist. They are recognized as one of the most dangerous spiders in the world and are the most venomous so they should always be treated with care and respect. Thanks Helpful 1 Not Helpful 0
Children are more susceptible than adults to the venom of a Brazilian wandering spider, and you should ensure that any child who’s bitten gets medical attention as quickly as possible. Thanks Helpful 5 Not Helpful 0

↑ https://www.livescience.com/41591-brazilian-wandering-spiders.html
↑ http://www.wandering-spiders.net/phoneutria/gallery/
↑ https://animalcorner.co.uk/animals/brazilian-wandering-spider/
↑ http://bioweb.uwlax.edu/bio203/s2013/johnson_jor4/habitat.htm
↑ http://www.mayoclinic.org/diseases-conditions/spider-bites/manage/ptc-20204189
↑ https://www.livescience.com/37974-he-surprising-cause-of-most-spider-bites.html
↑ http://www.mayoclinic.org/first-aid/first-aid-spider-bites/basics/art-20056618
↑ http://www.webmd.com/first-aid/snakebite-treatment

About this article

To identify a Brazilian wandering spider, look for a spider with a long leg span of about 6 inches and a brown, hairy body. Also, carefully examine the spider from afar to see if it has large red fangs, which are common in Brazilian wandering spiders. Keep in mind that Brazilian wandering spiders only live in South and Central America. If you encounter one, move away slowly since Brazilian wandering spiders are aggressive and very poisonous. To learn how to avoid getting bitten by a Brazilian wandering spider, scroll down! Did this summary help you? Yes No

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A spider in motion: facets of sensory guidance

Friedrich g. barth.

Department of Neurosciences and Developmental Biology, Faculty of Life Sciences, University of Vienna, Althanstr.14, 1090 Vienna, Austria

Spiders show a broad range of motions in addition to walking and running with their eight coordinated legs taking them towards their resources and away from danger. The usefulness of all these motions depends on the ability to control and adjust them to changing environmental conditions. A remarkable wealth of sensory receptors guarantees the necessary guidance. Many facets of such guidance have emerged from neuroethological research on the wandering spider Cupiennius salei and its allies, although sensori-motor control was not the main focus of this work. The present review may serve as a springboard for future studies aiming towards a more complete understanding of the spider’s control of its different types of motion. Among the topics shortly addressed are the involvement of lyriform slit sensilla in path integration, muscle reflexes in the walking legs, the monitoring of joint movement, the neuromuscular control of body raising, the generation of vibratory courtship signals, the sensory guidance of the jump to flying prey and the triggering of spiderling dispersal behavior. Finally, the interaction of sensors on different legs in oriented turning behavior and that of the sensory systems for substrate vibration and medium flow are addressed.

Introduction

Neuroethology aims at an understanding of the neural and sensory mechanisms underlying behavior, which most obviously manifests itself as motion. Motion, in turn, is primarily thought of as locomotion taking the animal from one place to another, as rhythmic motion like walking, running and flying. However, the motion also implies a large range of other ethologically relevant movements associated with prey capture, courtship, idiothetic orientation, and dispersal behavior, to name just a few examples.

A lot still has to be learned regarding the sensory feedback control of motive behavior in spiders and the relevant proximal sensory cues, which allow the necessary ad hoc adaptations to the environment. So far, the study of spider motion has focused on questions of physics and engineering, such as how muscles, the hydraulic leg extension system and the exoskeletons generate and support the forces enabling locomotion. Much less attention has been given to its sensory control. This is also seen when looking at the list of contents of the present Special Issue, which, therefore, provides a welcome platform to draw attention to this deficit.

Several lines of our neuroethological research on the Central American wandering spider Cupiennius salei and its close relatives, although often with a different focus, have revealed a number of interesting aspects of the sensory guidance of a variety of motions. The present review reports some of these findings. It is not a novelty paper but shortly summarizes what might serve as a springboard for future research. The field is still wide open and there are numerous problems deserving renewed interest by neuroethology and sensory biology, not to mention the open questions regarding kinematics (analysis of movement) and dynamics (analysis of forces and torques).

Cupiennius —a model spider

Cupiennius salei and its closest relatives, C. coccineus and C. getazi , are a group of similarly large and robust neotropical spiders with leg spans of 10 cm and more. Considering their prominent role in the research described below, their outstanding importance gained in many other fields of research (Barth 2002a , b , 2008 ; McGregor et al. 2008 ), and their usefulness for future research these spiders shall shortly be introduced here (Fig. 1 a–c).

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The three large Cupiennius species which turned out be perfect “model spiders “. a Cupiennius salei , b C. getazi , c C. coccineus (fotos FG Barth; with permission of SpringerNature; modified from a Barth 2015a; c Barth 2002b.)

The family assignment of the genus Cupiennius has been with the Ctenidae (Lachmuth et al. 1984 ; Barth 2002a , b ; Barth and Cordes 2008 ) since Simon ( 1891 ) first placed them there almost 130 years ago. Recently, however, based mainly on molecular phylogeny, the genus was moved into the “fishing spiders “, Trechaleidae (Piacentini and Ramirez 2019), a sister group of the wolf spiders (Lycosidae).

In the context of the present Special Issue of JCP-A and future research on sensory-motor integration a few practical aspects may be more relevant to communicate than knowledge of the taxonomic assignment. The three large species of Cupiennius ( C. salei, C. getazi, C. coccineus ) can easily be bred in large numbers, thus being readily available for a large range of laboratory work. They are wandering spiders, not using a web for prey capture, which makes their handling and study much easier than that of delicate spiders living in fragile webs. The three big Cupiennius species are robust spiders well-tolerating handling and many experimental procedures. All of these qualities have contributed to make Cupiennius a model spider much appreciated in many laboratories worldwide for a broad spectrum of research. Existing studies include research in general biology, sensory physiology, neuroanatomy, biomechanics, exoskeletal structure and functional material properties, venom and hemolymph biochemistry, circulatory system, muscular metabolism, ecology, evolutionary developmental biology, taxonomy, friction control, and more (reviews: Barth 2002a , b , 2008 ; McGregor et al. 2008 ; some examples: Melchers 1963 ; Seitz 1966 ; Linzen et al. 1985 ; Paul et al. 1994 ; Fabian-Fine et al. 2000 , 2002 , 2017; Schwager et al. 2007 ; Politi et al. 2012 ; Kuhn-Nentwig and Nentwig 2013 ; Wolff and Gorb 2013 ). There is of course highly relevant research on other spider species as well, but there is certainly not a single one species having been studied in similar depth and breadth as C. salei (and to a lesser degree its two allies).

Mechanoreceptors—types of sensors

Spiders are well equipped with high-quality sensors located on and in their exoskeleton, that is at the interface to the environment. In Cupiennius and most likely in the majority of other spiders as well the sensory cells in the body´s periphery by far outnumber the neurons in the central nervous system. This underlines both the importance and refinement of the sensory periphery. As has been amply shown substantial pre-processing of information by the sensory receptors is a common phenomenon. It saves the central nervous system a lot of processing and integration of the sensory input (Barth 2019 ). Interestingly, the particular relevance of the sensory periphery in spiders such as Cupiennius is also underlined by the fact that the number of neurons estimated for the brains of locust and honeybee are larger by a factor of almost 4 and 10, respectively (spider: Babu and Barth 1989 ; Barth 2016 ;locust: Burrows 1996 ; bee: Witthöft 1967 ).

Although in some groups of spiders, an outstanding example being the jumping spiders, vision is a dominant sense, overall the mechanical senses are especially well developed and of corresponding behavioral significance. They respond to different types of force, like that of airflow, touch, substrate vibration and proprioreceptive input resulting from the spiders´ own locomotion (Seyfarth 1985 ; Barth 2002a ). Some mechanosensors like the trichobothria, which respond to the slightest whiff of air (Barth 2014 ), and the slit sensilla, which respond to minute strains in the cuticular exoskeleton (Barth 2012b ; Blickhan et al. 2021 ), show absolute sensitivities at the limit of the physically possible. The reader interested in details is referred to the literature, which summarizes our present knowledge of spider mechanoreceptors and highlights their technical perfection (Barth 2004 , 2014 ; Humphrey and Barth 2008 ; Fratzl and Barth 2009 ; Barth 2012a , b ). Spiders, like other arthropods, not only have mechano-sensitive cuticular exteroreceptors (hair-like sensilla or setae) but also proprioreceptors (slit sensilla, kind of embedded biological strain gages in the exoskeleton; hair-like sensilla; internal joint receptors) usually found in increased density near the joints. However, spiders do not have the equivalent of insect chordotonal organs, nor of vertebrate muscle spindles and Golgi tendon organs. In the following, some examples of the involvement of mechanosensitive spider sensilla in various motion behaviors will be given.

Walking on solid substrate—a wealth of proprioreceptors

Spiders spread their body weight across eight legs which need to be coordinated. As has been known for a while, like many arachnids they exhibit the “alternating tetrapods” walking pattern, moving the legs in groups of four with those diagonally opposed roughly in synchrony. The most common step sequence of Cupiennius salei is 4–3-1–2, the numbers indicating legs 1 to 4 moving in a forward wave. Whereas leg pairs 1 and 2 pull, leg pairs 3 and 4 push (Seyfarth and Bohnenberger 1980 ; Seyfarth 1985 ; Brüssel 1987 ; Barth 2002b ). However, the exact time at which a particular leg is moved can vary considerably, depending on walking speed, adjustment to the profile of the substrate and on the rather common loss of one or even two legs (Wilson 1967 ; Seyfarth and Bohnenberger 1980 ; Seyfarth 1985 ). Obviously then, sensory information and reflex control is an important aspect of spider locomotion, allowing for the continual adjustment to changing mechanical conditions, which does not result from a rigid program in the central nervous system.

The question then is which sensors play a role here, enabling the spider to adjust to a broad spectrum of conditions. There are many proprioreceptors (Seyfarth 1985 ; Barth 2002b ) providing the spider with a detailed picture of its movements. Their feedback information to the central nervous system most likely massively contributes to the fine adjustments of movement. Such adjustment is for instance seen during prey capture, walking over rough terrain, walking on inclined and vertical surfaces or upside down, or during the spinning of an egg sac or a web. The versatility of motion also reflects the fact that spiders have at least 30 muscles per walking leg (Ruhland and Rathmeyer 1978), whereas insects and crustaceans have only about 10 and 16, respectively. It also reminds us, that spider muscles are innervated by multiterminal and many more motoneurons than the muscles of insects (Seyfarth 1985 ). In addition, spiders apply a sophisticated hydraulic system for the extension of important leg joints (femur/patella and tibia/metatarsus joints lack extensor muscles; see Blickhan and Barth 1985 ; Liu et al. 2019 ).

The sensor types, which supply the leg joints, are ( i ) the slit sense organs, among them, in particular, the compound or lyriform organs (Barth and Libera 1970 ; Barth 2012a , b ; Schaber et al. 2012 ), ( ii ) large numbers of proprioreceptive hair-like sensilla (innervated setae) (Barth 2015 , 2016 ; Schaber and Barth 2015 ) and ( iii ) a few stout cuticular bristles bridging the joints. In addition, there are ( iv ) internal receptors located close to joints. They form clusters of 3–13 multiterminal receptor cells with their dendrites ending below the joint membrane and monitoring joint position and movement (Foelix and Choms 1979 ; Seyfarth 1985 ; Seyfarth 1985 ). So far there is no compelling evidence for the existence of muscle receptor organs in spiders, although their occurrence still seems to be a possibility as indicated by the existence of small muscles with unusually (compared to normal leg musculature) small fiber diameters of 18–30 µm (Parry 1960 ; Ruhland and Rathmeyer 1978; Seyfarth 1985 ; Seyfarth et al. 1985 ). Scolopale organs such as chordotonal organs, widespread in insects and crustaceans, do not occur in spiders and other arachnids. However, as is well known from insects, there are distinctly grouped ( v ) hair plates on the coxae stimulated by the rolling over of the pleural membrane during lateral leg movements (Seyfarth et al. 1990 ). There are two such hair plates on the chelicerae of Cupiennius salei as well (Barth 2016 ). For anatomical details of the leg nerves and the muscles of Cupiennius salei walking legs and representative for spiders in general see Seyfarth ( 1985 ).

Seyfarth and Pflüger ( 1984 ) extensively studied the dorsal hinge joint between tibia and metatarsus of the walking leg of Cupiennius salei to describe its proprioreceptor outfit in detail. Two paired muscles provide the bending of this joint. Hemolymph pressure is used for its hydraulic extension as is also the case at the femur/patella joint, the other “knee “ of the spider leg (predominantly showing flexion and extension movements), and in the metatarsus/tarsus joint. There are four lyriform slit sense organs at the distal end of the tibia. The three lateral ones (HS8 and HS9 on the posterior aspect of the tibia and VS4 on its anterior aspect) are located in an area of the exoskeleton where they are compressed and thus stimulated when the joint is bent by the flexor muscles against a mechanical resistance as to be expected during locomotion (Bohnenberger 1981 ). Thanks to the PhD work by Reinhard Blickhan (Blickhan and Barth 1985 ; see also Blickhan et al., this issue), which enabled us to measure exoskeletal strains at the relevant locations of the lyriform organs (and other slit sensilla) in freely walking spiders, we know that the lateral organs are indeed stimulated during joint flexion, mainly during the support phase of the step. The ventral organ (VS5) is only stimulated by strains due to increased hemolymph pressure during joint extension. This implies that the presence of the four lyriform organs allows for the distinction of the phases of the stepping cycle and between strains due to muscular force and hemolymph pressure, respectively. Considering the uniqueness of the interaction between muscular contraction and hydraulic mechanisms in spiders this is a finding of particular relevance.

Surprisingly, normal locomotion and leg coordination of Cupiennius salei is not or only little affected by the ablation of lyriform organs on femur and tibia, nor even by cutting the major sensory nerves in tibia and femur. The basic rhythmic forward–backward motion was maintained after the operation and the untreated legs remained unaffected by it. It is difficult to demonstrate a deficit even after such drastic operations (Seyfarth and Barth 1972 ; Seyfarth and Bohnenberger 1980 ; Seyfarth 1985 ). One either deals with a remarkable plasticity of a central nervous program or/and a remarkable redundancy of the sensory periphery. Clearly, such general statements ask for more research. Deficits, however, can well be shown regarding proprioreceptive muscle reflexes in the walking legs (Seyfarth 1978a , b ; 1985 ) and, more surprisingly, in regard to kinaesthetic orientation (path integration) ( Cupiennius salei : Seyfarth and Barth 1972 ; Seyfarth and Bohnenberger 1980 ; Pardosa amentata : Görner and Zeppenfeld 1980 ). This is discussed in the following.

Idiothetic (kinesthetic) orientation—lyriform slit sense organs involved in path integration

Imagine an experiment bringing together a hungry spider and a stationary buzzing fly. Alerted by its trichobothria, which respond to the slightest movement of air (like that produced by the fly), the spider will run towards its prey and catch it. When separated from the fly (which can be done by delivering an electric shock through the fly) and having been gently driven away Cupiennius salei shows a remarkable behavior. After a few minutes´ rest and the complete removal or relocation of the fly the spider turns around and walks back to the site of prey capture (Fig. 2 a). It does this in complete darkness and with its eyes covered, without the use of a dragline, chemical or tactile and gravitational cues and from a distance of at least 70 cm (Seyfarth and Barth 1972 ). The “homing” spider orients itself on its way back to where the fly was using stored information on its previous movement sequences, without relying on external references. This is why such behavior is referred to as idiothetic orientation (Mittelstaedt and Mittelstaedt 1973 ; Mittelstaedt 1985 ). Carefully executed ablation experiments proved the involvement of identified proprioreceptors for the first time in an arthropod: The spider’s orientation is strongly impaired after the inactivation of lyriform organs on tibia and/or femur (Seyfarth and Barth 1972 ; Seyfarth et al. 1982 ). (Fig. 2 b).

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An early experiment on kinesthetic (idiothetic) orientation of C.salei . Example of a return path of C. salei from “start “ to the site of prey capture after the relocation of the fly. a Intact animal , successful return; b animal with all tibial lyriform organs destroyed, unsuccessful return. At point 1–12 the spider paused and/or turned. (modified: a , b. From Seyfarth and Barth 1972 ; with permission of SpringerNature)

To reliably judge the orientedness of the spider’s motion and to quantify it three criteria were selected: ( i ) the frequency of arrival at the correct place, ( ii ) the starting angle of the return path and ( iii ) the route taken. Organ inactivation affects all three parameters. The femoral lyriform organs have an even more pronounced effect than the tibial organs. The relevance of both is underlined by the control animals with holes in the nearby cuticle but intact lyriform organs. They show the same perfection as intact animals. According to experiments where the spiders were driven away from the site of prey capture through a semicircular corridor the way back to the goal is very close to the ideal straight route, saving about half of the distance through the corridor. This kind of detour compensation has been described for many animals, among them other spiders (Görner and Claas 1985 ; Mittelstaedt 1985 ). According to present understanding, the navigation of Cupiennius underlying its return to the site of prey capture is “route/path integration “, as in case of the homing behavior of other arthropods like desert ants, the champions of this art (Wehner 1992 , 2020 ). Information about the angle and distance of the outward journey may come from different sources in the natural situation, such as visual ones like the sky compass or landmarks—or as directly shown in Cupiennius —be truly “kin-esthetic” information, that is information on actual movement sequences. More details are found in the original literature and a review chapter in Barth ( 2002b ). It would certainly be worthwhile to extend these experiments to learn more about the underlying neuronal and sensory mechanisms. Attention should also be given to the integrative activity of the spider central nervous system (Görner and Claas 1985 ; Mittelstaedt 1985 ; Hartmann and Wehner 1995 ; Wittmann and Schwegler 1995 ). It has not been studied in any detail for almost half a century since the first experimental proof of the involvement of identified kinesthetic sensory organs in idiothetic orientation.

Muscle reflexes in the walking legs—movement versus force receptors

The involvement of lyriform organs in the triggering of leg reflexes, assumed to be relevant for adaptive walking and leg coordination, is a rather old story, too (Seyfarth 1978a , b ;1985; Seyfarth and Pflüger 1984 ; Barth 2002b ) and unfortunately nothing really new has been added, except a few findings related to the spinnerets (see below).

In short, there are two kinds of proprioreceptive muscle reflexes: the well-known resistance reflex, which resists the imposed force, and the synergistic reflex, which is an avoidance and protective reflex withdrawing the body or its affected part from the stimulating force. By simultaneously recording the activities of both the sensilla and the leg muscles in Cupiennius salei and Aphonopelma sp. it was shown that resistance reflexes are elicited by the stimulation (imposed joint movement) of internal proprioreceptors, whereas synergic reflexes needed the stimulation of lyriform organs. Muscles were activated in the stimulated leg only by both types of reflexes (Seyfarth 1978a , b ).

The resistance reflex did not disappear after the removal or inactivation of the external proprioreceptors, both hair-like sensilla and lyriform organs, at the affected joint (on leg segments patella, tibia, tarsus) but disappeared after sectioning the sensory leg nerve containing the axons of the internal sensory cells below the joint membrane. Resistance reflexes are well known to be involved in the fine control of locomotion (negative feedback control of limb position) in many arthropods as discussed by Seyfarth ( 1985 ) and Barth ( 2002b ).

Synergic reflexes were found to activate extrinsic muscles, not however the intrinsic muscles of the stimulated joint. To give an example: Patellar muscles are activated to move the tibia away from an external force moving the metatarsus sideways against the fixed tibia. The cuticular strain due to the imposed movement and effectively stimulating lyriform organs is reduced by the reflex. Thereby the imposed movement is reinforced and the leg pulled away, which most likely has a protective function. The reflex fails after the destruction of specified lyriform organs at the tibia/metatarsus joint.

Cupiennius salei is literally covered by thousands of mechanosensitive hair-like sensilla (setae) (Barth 2016 ). Touching (deflecting) such sensilla usually leads to a withdrawal of the stimulated leg, as can be seen easily in many other spiders as well. Whereas upon tactile stimulation only the stimulated leg is visibly affected (no response of muscles in another ipsi- or contralateral leg) (Seyfarth and Pflüger 1984 ) body raising behavior is different. It was analyzed in detail and is shortly reviewed below in a separate section.

As pointed out and reviewed by Seyfarth ( 1978b ) there seems to be a general tendency across the arthropods that “force receptors “ such as insect campaniform sensilla and spider slit sense organs elicit stimulus-synergic responses, whereas “movement receptors “ such as hair-like sensilla, muscle stretch receptors and chordotonal organs are dominating the resistance reflexes.

Cupiennius is equipped with some particularly long tactile hair-sensilla on many parts of its body. These are the outposts of its tactile sense. Their stimulation by deflection of the hairshaft elicits a variety of stereotyped movements, all needed for the spider’s natural daily life behavior and easily observed (Seyfarth and Pflüger 1984 ; Friedrich 1998 , 2001 ; Barth 2016 ). Examples are: the raising of the opisthosoma by stimulation of such long tactile “hairs” ventrally on the opisthosoma; lowering of the body by stimulation of them just behind the eyes; withdrawal of the spinnerets and more. An interesting feature of these reflex behaviors is their stepwise nature due to an additive effect of repeated stimulation. Ventrally on metatarsus and tarsus the same type of tactile sensilla is found. Most likely they monitor the leg’s contact with the substrate and serve step control and fine adjustment during locomotion. Among all the tactile hairs tested, these are the ones most easily deflected indicating a corresponding mechanical sensitivity (Barth 2016 ). Neuroethological research on their involvement in locomotion control would certainly be rewarding.

Joint movement—monitored by sensory “hairs” (setae)

Although of obvious relevance in the context of locomotion, an example of the working and proprioreceptive adaptations of sensory setae at the joints of the spider leg has been studied in some detail only recently (Schaber and Barth 2015 ). Ventrally on the joint between tibia and metatarsus there are hairs (some 20 on the tibia and c. 75 on the metatarsus) opposing and deflecting each other when the joint flexes. At the end of the swing phase, when the tarsus touches the substrate, the joint angle measures a maximum of c. 178°. The smallest angle (at the end of the power stroke) is only c. 124°. The mean amount of joint flexion, therefore, is about 60° during unrestrained slow forward walking. At walking speeds between 1 and 20 cm/s the stepping frequency is 0.3–3 Hz. Among the many setae found proximally and distally at the joint and deflected by joint flexion during locomotion ventral hair sensilla, which deflect each other reversibly by up to 30°, were studied in regard to their functional morphology, mechanical directionality and physiological responses to natural stimulation. Their adaptedness to proprioreceptive function clearly emerged (Fig. 3 a–c).

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Proprioreceptive hair sensilla of C. salei at the tibia-metatarsus joint. a Movement of the joint (note joint angle β) during slow locomotion at a speed of 2 cm/s; frame-to-frame video analysis. Red line indicates the mean angle at which the hair sensilla start to deflect each other. b Position of the proprioreceptive hair sensilla ventro-laterally on tibia and metatarsus (see red circles). c SEM picture showing the microtrichs on the hair shaft of the tibial (top) and metatarsal sensilla (below) at a joint angle β of 135° (with permission of SpringerNature;

modified from Schaber and Barth 2015 )

(i) The shaft of the setae (hairs) is covered by thousands of microtrichs arranged in rows parallel to the shaft axis and in high density (15 per µm hair length in the tip region). These microtrichs (protuberances) are up to 5 µm long and c. 1 µm in diameter, with a small “hook” at their tip. While deflecting each other the opposing hairs on tibia and metatarsus are reversibly interlocked by their elaborate microtrichs, which enhance the friction between them. (ii) The structure of the hair sockets selectively facilitates large deflection in the behaviorally relevant direction. Torque measurements reveal a pronounced mechanical directionality, the setae being much more easily deflected in the direction of natural proprioreceptive stimulation than in all other directions. Torque values reached with deflections below 50° measure up to about 1 nN m in the “natural” direction, whereas in the opposite direction values of 8 nN m and more were measured, even at much smaller deflection angles. The corresponding torsional restoring constants S for both directions differ by one to two powers of ten (tibia setae: 5.92 × 10 –10 and 3.69 × 10 –8 Nm/rad; metatarsus setae: 8.03 × 10 –10 and 1.51 × 10 –8 Nm/rad). (iii) When applying roughly natural stimulation of the joint using sinusoidal half-wave deflections (resulting in a hair-shaft deflection angle of 30°) the sensory neurons supplying the setae show rapidly adapting bursts of action potentials only during the deflection phase away from their resting position. There is no response to the static deflection. These joint “hair” sensilla are typical movement receptors monitoring joint flexion at every step. Particularly at low stepping rates, the velocity of joint flexion is well reflected by the action potential rate. Thus these “joint hairs” very likely serve the local feedback fine control of the joint movement.

Body raising—distributed neuromuscular control

The most intensively studied case of motion control by the sense of touch in Cupiennius salei (and in four other species of Cupiennius , in the jumping spider Phidippus regius and the theraphosid spider Brachypelma sp . ) is the raising of its body when it meets an obstacle protruding from the ground and passes over it (Fig. 4 ), which is a common event (review: Seyfarth 2002 ). Although stereotyped and easy to elicit this behavior is not a “simple “ reflex as shown by a neuroethological analysis of the underlying flow of information, both in the sensory periphery and the central nervous system (Eckweiler and Seyfarth 1988 ; Milde and Seyfarth 1988 ; Seyfarth 2002 ). As opposed to local reflexes, which allow for rapid motor responses, the body raising behavior requires processing in the central nervous system and results from a distributed neuromotor control.

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Body raising upon tactile stimulation by an obstacle. a The spider approaches (arrow) the obstacle (above green symbol) from the left side. b It raises its body upon tactile stimulation of mechanosensitive hair sensilla located ventrally on its legs and prosoma. (With permission from Aarhus University Press;

modified from Seyfarth 2002 )

The sequence of events is as follows. (i) Stimulation of tactile hair sensilla ventrally on the proximal leg segments and/or sternum activates the levator coxae muscle of the stimulated leg. (ii) As a consequence, the coxa is pulled against the prosoma and the stimulated leg is extended hydraulically. (iii) The activity of the coxal levator muscle stimulates internal proprioreceptors at the tergo-coxal joint, which in turn triggers the simultaneous extension of the seven remaining legs. (iv) According to neuroanatomical studies (Babu and Barth 1984 , 1989 ; Anton and Barth 1993 ; Ullrich 2000 ; Seyfarth 2002 ) and intracellular recordings from neurons in the subesophageal ganglionic mass the primary afferent fibers end ventrally in the suboesophageal ganglion and largely remain in the ipsilateral leg neuromer. The somata of the motorneurons activating the coxal muscles, however, are located about 200 µm away in the dorsal motor area. They are believed to be connected to the afferent endings monosynaptically, an important argument being a delay of only c. 30 ms of the local response following the tactile stimulation. There are both mono- and plurisegmental spiking interneurons extending into several leg neuromers and eliciting leg extension. Presumably they distribute the activity of the internal joint receptors to all legs. Most interestingly, there are also non-spiking pre-motor interneurons with longer-lasting graded potentials reflecting the graded character of the body raising behavior.

Active courtship vibrations—signaling with two out of 36 muscles

Substrate vibrations are an important source of information for spiders. They lead the hungry spider to its prey and to its sexual partner and also warn of predators. When Cupiennius is courting on a plant like a banana “tree “ the male and the female use self-generated vibrations to communicate over distances of up to several meters to decide on the right partner and to find each other. The neuroethology of this courtship and vibratory communication has been analyzed in depth and reviewed (Barth 1997 , 2002b ). This includes the metatarsal lyriform organ, which is the highly sophisticated main vibration receptor showing manifold adaptations to the natural behavior of Cupiennius (Barth 2004 , 2009, 2012).

A few aspects of the motor side shall be summarized here to explain how the spider moves to generate its vibratory courtship signals. In Cupiennius these signals are highly structured and critical for species identification. They come in syllables similar to cricket song and are produced by an up and down movement of the opisthosoma without touching the substrate (Fig. 5 a–c). The opisthosomal vibrations are introduced into the substrate (the plant) through the legs. The carrier frequency in the male signal is 80–100 Hz and the female’s innate releasing mechanism is tuned to a specific combination of syllable duration and the duration of the pause between the syllables (Schüch and Barth 1990 ; Baurecht and Barth 1992 ). Regarding the opisthosomal motion there are several questions. What does the exact movement look like? Which muscles are involved? Is the main frequency of the male signal of 80–100 Hz a direct result of muscle contractions at this frequency or are passive mechanisms like resonance involved? The answers are as follows (Dierkes and Barth 1995).

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Vibratory courtship signals. a , b Movements (arrows) of the opisthosoma ( C. getazi ) of a courting male. Note that the opisthosoma does not touch the substrate. c Vibrations introduced by the spider into the substrate (leaf of a bromeliad). (with permission of SpringerNature ( a , b ) and Birkhäuser ( c ); a , b. Dierkes and Barth 1995; c Barth 1997 )

Using high-speed video analysis and laser Doppler vibrometry the freely courting males were shown to move their opisthosoma about an axis located in the petiolus and almost perfectly up and down with only little lateral movement. Taking the spinnerets as a reference the amplitude is c. 2° (or c. 0.4 mm) at the beginning of a series of syllables. It increases to c. 30° (c. 6 mm) in the three to four final syllables of the series, without the opisthosoma ever touching the substrate. According to spectral analysis the movement contains a low-frequency component of 10–20 Hz and a superimposed component of c. 80 Hz. The latter component occurs during the upswing of the opisthosoma and is closely correlated with the appearance of the corresponding substrate vibrations. There are no resonances in a typical dwelling plant in the relevant frequency range. Transfer functions of various body parts of the spider, beginning with the leg tarsi (which pick up the substrate vibrations), show resonances between 0 and about 250 Hz (Dierkes and Barth 1995). Such measurements are hard to do with the spider under sufficiently natural conditions and assuming a controlled body posture. The significance of these body resonances should, therefore, not be overestimated yet.

Electrophysiological recordings of the muscle activity in courting males clarified the origin of the high-frequency component of the male courtship vibration. There are as many as 36 muscles in the petiolus region potentially involved in the opisthosomal courtship movements (Dierkes and Barth 1995). According to the specifics of its attachment, only muscle 81 looks like a levator muscle. Muscle 85 (a large paired muscle) is the depressor. It was found to be active during courtship only, but not during locomotion. According to the electrophysiological recording from muscle 85 and the simultaneous monitoring of both the opisthosoma movement and the substrate vibrations the 80 Hz component of the courtship vibrations is not due to plant resonances but actively produced by the spider. A downward movement of the opisthosoma is initiated by a first action potential of the depressor muscle 85. Its subsequent discharges go along with a tetanic muscle contraction which keeps the opisthosoma in its ventral position. While the levator muscle (most likely Nr.81) moves the opisthosoma upward again depressor muscle 85 contracts three to five times: It thereby moves the opisthosoma slightly downward three to five times at high velocity. This is how the main frequency component of 80–90 Hz of the courtship signal is generated. The high contraction frequency of muscle 85 is in the range of the resonances of the spider body. The vibratory signal may thus be amplified on its way through the body into the plant (see above), but we are still largely ignorant regarding the effect of leg positions, muscle tensions, and hemolymph pressure on details of vibration transmission through the spider body.

How about the sensory side of this motion? The male starts generating vibratory courtship signals when it comes across a female dragline. It probes the dragline with its pedipalpal chemoreceptors and perceives the female sexual pheromone (S-dimethyl ester of citric acid) attached to it (Gingl 1998 ; Schulz et al. 2000 ; Tichy et al. 2001 ; Barth 2002b ). Whether the prominent slit sensilla found on the petiolus or/and the small slit sensilla found ventrally on the opisthosoma (Libera and Barth 1970; Barth 1985b) play a role in the fine tuning of the opisthosoma’s motion is still an open question.

Jump into the air—airflow guides to flying prey

Cupiennius salei and its two big relatives ( C. getazi, C. coccineus ) are “sit and wait- hunters”. Being alerted by vibrations of the substrate (a plant) they commonly wait motionlessly until the prey (such as a cockroach or an earwig) producing them comes within the reach of a jump. The spiders change from being motionless to moving like a flash within milliseconds (Melchers 1967 ). Maybe the most spectacular kind of prey capture motion of Cupiennius is when it catches flying prey from the air (Fig. 6 a, b).

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Catching flying prey. a A tethered humming fly approaches (arrow) a juvenile C. salei sitting on a bromeliad leaf with its front (green asterix) oriented away from the fly (above). The spider turns towards the approaching fly when it is still a few centimeters away (middle). It finally jumps into the air to catch the fly when its position is above the closest tarsus (below). b Airflow measured above the spider tarsus and showing the abrupt change in flow turbulence which triggers the spider’s timely jump. (with permission of SpringerNature;

modified from a Barth 2014 ; b Klopsch et al. 2013 )

One of the several questions associated with this motion behavior is: Which cues and information uses the spider when jumping into the air, well oriented and at just the right moment in time to catch a freely flying fly passing by at a speed of 1 m/s and more? The most relevant and fully sufficient cue comes from the airflow generated by the flying prey. The natural stimulus is multimodal but by careful experimentation the necessity of visual input, substrate vibration and airborne acoustic stimulation could be safely excluded and the dominance and effect of airflow alone confirmed. Being deprived of its airflow sensors, Cupiennius never jumps into the air to catch prey, but it readily does it with its eyes covered. The functional morphology, physiology and biomechanics of the airflow sensors, the trichobothria, have been intensively studied (reviews: Humphrey and Barth 2008 ; Barth 2014 ). Trichobothria are the functional equivalent of the analog insect “filiform hairs “. They are extremely sensitive. As seen by the action potentials generated by their sensory cells, they are deflected and stimulated by frictional forces (at a threshold deflection of the hairshaft by 0.01° and forces in the order of 0.4 to 4 × 10 –6 N) resulting from the slightest movement of air (velocities as slow as 0.15 mm/s). The elastic restoring force at the articulation of the hair shaft is extremely small as is the corresponding spring stiffness (in the order of 10 –12 Nm/rad).

Cupiennius has some 100 trichobothria dorsally on the tibia, metatarsus and tarsus of each leg. Including the pedipalps this comes to a total of close to 1000 trichobothria, which is the largest number so far known of any spider. In general, wandering spiders have more trichobothria than web spiders for which the airflow-sense seems to be much less important behaviorally. We have never succeeded in eliciting a similar jump in any web spider by an airflow stimulus (Barth 2014 , p. 173).

Technology like high-speed video analysis and digital particle image velocimetry (DPIV) had to be used to find out what the relevant stimulus parameters of the airflow are, which make the spider jump (Klopsch et al. 2012 , 2013 ; review Barth 2014 ). An attractive prey like a freely flying fly (Calliphora erythrocephala) generates both a circulating airflow in front of itself and a wake pointing obliquely downward behind itself. An approaching fly first exposes the spider to its “front flow “. The velocity of this flow increases nearly exponentially with time and decreasing distance and shows very little fluctuation. Its maximum velocity at the site of the nearest tarsal trichobothria is c. 0.16 m/s. The spider reacts to this flow when the fly is still about 4 cm away by turning around towards the flow (Fig. 6 a). It always turns into the direction given by the leg stimulated first but never jumps in this situation. The actual jump is triggered by an abrupt change in flow characteristics which occurs when the fly is above the tarsus (Fig. 6 b). Trichobothria are now stimulated by the fly’s wake. Different from the “front flow “ this flow is highly fluctuating and has an increased vertical velocity component. Its power spectrum indicates a shift of the main frequency component towards higher values (from c. 8–c. 18 Hz) and now contains frequencies up to 250 Hz and more, which are not usually contained in the natural background flow. The trichobothria form a strictly phasic sensory system. They respond to stimulus dynamics as opposed to static stimulation as was also found in corresponding central nervous neurons. Thus the trichobothria are sensors perfectly adapted to being activated by prey-generated highly fluctuating airflow.

As one would expect, the high-frequency components in the fly wake quickly disappear with distance. At a fly distance of ca. 25 cm the airflow is very similar to background flow and the spiders don’t jump anymore, which of course makes sense.

Considering the main focus of this Special Issue of JCP-A it may be worth noting that Cupiennius adjusts its leg and body position while already in the air, another remarkable motion phenomenon deserving further study.

Dispersal by wind—initiated by trichobothria

Two types of motion still shall be mentioned. One is a “pre-ballooning “ kind of dispersal behavior, the other is rowing on the water surface. Both activities are not a daily practice of Cupiennius but still they are important in the relevant ecological contexts (see also Bonte 2013 ).

Unlike many insects, spiders do not normally fly. The notable exception is “ballooning” which may take spiderlings passively away to great heights and sometimes distances of hundreds of kilometers. As far as we know Cupiennius (the three large species studied) is not even “ballooning”. However, it can be readily watched to show a behavior roughly similar to what in many of its passively flying relatives is referred to as pre-ballooning (Decae 1987 ).

About 9 days after leaving the egg sac the spiderlings of the large species of Cupiennius are still small, with a body length of about 2 mm and an average mass of about 1.26 mg (Fig. 7 a–c) (Barth et al. 1991 ). By then the yolk they have been provided with is almost used up. They need food from outside now and have to deal with severe competition for resources among hundreds (up to more than 1000) of fellow spiderlings crawling around in a small tangle of threads spun by their mother around the eggsac they have left. Overpopulation has to be avoided and there is even the risk of cannibalism. What to do? The answer is the so-called “drop and swing behavior”.

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Drop and swing dispersal behavior. a Upon exposure to adequate airflow (arrows) spiderlings drop from their dwelling plant and swing on a lengthening thread in the wind (1,2,3). When touching a nearby substrate they attach to it. Inset: C. getazi spiderling, 9 days after leaving the egg sac. b Trichobothria of a spiderling ( C.salei ) at the age of 9 days after leaving the egg sac. c Spiderlings in a tangle of silken threads spun by the female at the time of the spiderlings leaving the egg sac. Scale bars in a and b 1 mm (with permission of SpringerNature;

modified from a Barth et al. 1991 ; b Barth 2002b ; c foto FG Barth)

Instead of assuming the tiptoe position in an elevated location as it is seen in truly ballooning spiders before take-off Cupiennius drops from its dwelling plant hanging on its dragline and swings in the wind with the dragline lengthening progressively. When it touches solid substrate it frequently repeats this process. The distances covered are usually small, with the spiderling landing on another leaf of the same or on a nearby plant. Therefore, the drop and swing behavior of Cupiennius provides a small scale dispersal only, an ecological consequence being that the spiderlings and thus the population is kept in a safe and reasonably stable habitat (Barth et al. 1991 ; Barth 2002b ).

But what triggers the actual dropping motion of the spiderlings? The answer to this question is once more closely related to the trichobothria. Cupiennius spiderlings at the young age considered here have only six to seven trichobothria on each leg (as opposed to almost 100 in the adult stage) (Fig. 7 b). Nevertheless, due to the fragility of the spiderlings it is hardly possible to remove all trichobothria without uncontrolled damage to the animals. However, there is good indirect evidence of the role played by the trichobothria in the drop and swing behavior. It comes from the physical conditions in the environment, which make the behavior possible and elicit it. The spiderlings were exposed to controlled airflows in a wind tunnel (Barth et al. 1991 ). At an age of about 9 days up to 70% of the spiderlings started to run around and to show drop and swing behavior when exposed to wind. The percentage much depended on wind speed and on the degree of turbulence of the airflow, which the spiderlings obviously are able to sense. The effective wind speed may be as low as 0.2 m/s, but at 1.5 m/s and more the spiders do not drop from the plant anymore. On the contrary, those having dropped already return to their starting point. Apart from a certain range of wind speed the other critical parameter is the degree of turbulence. The larger it is the higher is the number of responses. Thus at a mean velocity of 0.7 m/s of a quasi laminar airflow (5% turbulence only) there were only about half as many reactions than at 35% turbulence. At the same time, the most effective average response frequency shifted from 0.7 to 0.9 m/s wind speed. The wind speeds found to be effective for Cupiennius getazi are similar to those given for truly ballooning spiders (Richter 1970 , 1971 ; Vugts and van Wingerden 1976 ; Bell et al. 2005 ).

Being a phasic system of receptors, only responding to stimulus dynamics, the trichobothria are particularly well suited to respond to turbulent airflow and to tell the spider when the conditions are right for dispersal. Their role in finding out about the right wind conditions is also suggested by the behavior of truly ballooning spiders which may even raise their front legs to probe the airflow conditions actively before assuming the typical tiptoe position and finally releasing their silken ballooning fibers (Cho et al. 2018 ).

A turn towards the stimulus—sensors on eight legs

Having identified a vibratory stimulus as being generated by close-by prey Cupiennius has to turn rapidly and precisely towards it for a successful catch. As is easily observed the spider ‘s vibratory “view” is a horizontally all-around view, making use of the radial arrangement of its eight legs, which it keeps in a stereotyped position when ready for prey capture. But how does the spider decide on the correct turning angle towards the source of vibration? In numerous experiments, different combinations of the legs were exposed to electronically controlled prey-like substrate vibrations and their effect on the turning angle studied (Hergenröder and Barth 1983b ; Barth 2002a , b ) (Fig. 8 a). The turn towards the stimulus source is slightly more precise when it comes from in front than from behind (smaller error angle when stimulating forelegs than with stimulation of the other legs). And surprisingly, the spider turns faster for stimuli from behind than from in front, which makes sense biologically: It is crucial to reach the prey as quickly as possible. The main conclusion from many of these experiments is that the spider turns correctly on the basis of the stimulated leg combinations alone, even when they are stimulated simultaneously by identical stimuli (including no difference in magnitude). This led to the elaboration of a diagram describing the interaction of the sensory input from the legs in the central nervous system. The connectivity diagram does indeed allow the correct quantitative prediction of the turning angles of the freely behaving spider. Its important features are (i) an error angle smaller for stimulation of the forelegs than of the hindlegs, (ii) an additive ipsilateral inhibition (unidirectionally directed from front to back) between the legs of one bodyside, and (iii) a connection of the legs on opposite sides by a multiplicative contralateral inhibition (Hergenröder and Barth 1983b ; Barth 2002b ). A qualitatively determined model of central connectivity in another arachnid, the scorpion Paruroctonu s mesaensis, postulates ipsi- and contralateral inhibition as well, but according to present knowledge the differential weighting of the input from different legs as well as the unidirectionality of the inhibition are special for Cupiennius (Brownell and Farley 1979 ; Brownell and van Hemmen 2001 ).

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Turning towards or away from a stimulus source. a Turning movement (arrow) of C. salei towards a vibratory stimulus applied to the tarsus of its right hindleg. Quantification of the spider’s motion by measuring the parameters indicated. α stimulus angle, B site of stimulation, β turning angle, γ error angle, A center of prosoma. b Behavioral thresholds of C. salei for its approach (prey capture) and withdrawal (escape) reaction to stimulation with substrate vibrations. The approach reaction has a considerably lower threshold than the escape reaction and is lower for band-limited noise stimulation (bars) than for sinusoidal stimulation (circles). (With permission of SpringerNature; from Hergenröder and Barth 1983a , b )

While in the laboratory the spider turns correctly on the basis of the sensory connectivity of its legs alone, differences in magnitude and time of arrival of the stimuli reaching its different legs are part of natural stimulation, when the spider is sitting on a plant with all eight legs exposed to substrate vibrations. Again, experiments with electronically controlled vibrations allowed for a quantification of the effect of differences in time of arrival (Δt) and stimulus amplitude (Δd). Cupiennius consistently turns towards the leg stimulated first or more strongly as if it had been the only leg stimulated. Values of 4 ms for Δt and 10 dB for Δd had a strong effect. There are interneurons in the subesophageal ganglia which nicely reflect the whole spider’s behavioral responses (Speck-Hergenröder and Barth 1987 ). Because of the dispersive propagation of vibrations in a plant Δt depends on frequency. The values for exposure to female or male courtship vibrations (main frequency components 30 and 80 Hz, respectively) are still in the behaviorally effective range. For prey vibrations which contain higher frequencies the values are below 1 ms and do not elicit responses in the behavioral experiment. The scorpion Paruroctonus mesaensis still does react at values down to 0.3 ms (Brownell and Farley 1979 ). As to the Δd values: Considering the attenuation (damping) of signals propagating on typical Cupiennius plants the values found to be effective in the laboratory experiments are to be expected in the natural situation as well. However, due to the heterogeneity of vibration propagation in the plants the spider has to deal with a frequency-dependent spatial pattern of stimulus intensities and we do not know how the spider handles this seemingly big problem (Wirth 1984 ). More research is encouraged!

Escape or attack—the interaction of two sensory systems

In Cupiennius prey capture behavior is easily released by substrate vibrations alone. Signals carried by airflow as well as vision are not needed. However, prey capture can also be elicited by adequate airflow signals such as those generated by a flying insect (Klopsch et al. 2012 , 2013 ). The interaction of the two sensory systems involved, the slit sensilla and the trichobothria, is complex even though one sensory channel alone is fully sufficient to trigger/control a specific behavior. How, in the given case, does stimulation from above (airflow) interact with stimulation from below (substrate vibration)? The answers turned out to be quite intriguing (Hergenröder and Barth 1983a ).

Actually, substrate vibrations elicit two opposing behaviors, depending on their magnitude and frequency. Whereas upon weak stimulation the spider shows approach/attack behavior, it withdraws/escapes following strong stimulation. The respective threshold curves (necessary displacement versus stimulus frequency) show this clearly (Fig. 8 b). Surprisingly, after the removal of the trichobothria thresholds for the turning-away response (escape) rose by ca. 10 dB. Obviously, trichobothria are co-stimulated when only vibrating the substrate. Although the thresholds for the turning-towards response (attack) did not change, the response probability did. Removal of the trichobothria goes along with a decrease of the number (frequency) of negative responses, which explains itself by the corresponding shift of the behavioral threshold curve. The close relationship in particular between the negative (escape) response and the trichobothria is further underlined by the increased response time after inactivation of the trichobothria. The interaction between the two sensory systems is both behaviorally significant and complex. A simplified diagram of the interactions mainly describing current behavioral knowledge may serve as a start for future research (Hergenröder and Barth 1983a ).

Rowing on the water surface—water depth, surface tension, viscosity

Fishing spiders (Pisauridae) such as the North American Dolomedes triton and the European D. fimbriatus are comfortable on the water surface, where they hunt for prey, escape from predators and search for mates (Shultz 1987 ; Bleckmann 1994 ; Bleckmann et al. 1994 ). As has been well studied and reviewed they propel themselves forward on the water surface using two different gaits, rowing and a spectacular galloping. The biomechanics of horizontal thrust generation for these types of locomotion has been analyzed by Suter and Wildman ( 1999 ) and Suter et al. ( 1997 , 2003 ). Horizontal thrust is mainly due to the drag resistance generated when a leg and its associated water dimple at its tip are moved over the water surface during the stance phase of the stepping cycle. Both surface tension and bow waves were found to be less important in providing the resistance to the moving legs, which is needed for locomotion on the water surface (Suter et al. 1997 ).

Cupiennius , recently put into the family of Trechaleidae, is not commonly seen on the waters of ponds or rivers. It is predominantly terrestrial, but nevertheless capable to move forward on the water surface like many of its fellow trechaleids, which—tale-tellingly—are also called fisher spiders. In addition to rowing, Cupiennius is occasionally seen to jump forward on the water surface. Its ability to stay and move on the water surface is believed to be advantageous during the rainy season in its neo-tropical habitats. When on the water surface and changing its normal locomotory gait to rowing, Cupiennius lies flat on the water with its legs extended and the surface tension bearing its weight. Its hind legs are not used for rowing and both legs of pairs 1,2, and 3 are moved simultaneously each and the pairs in succession 1–2–3 (Barnes and Barth 1991 ).

The question of particular interest in the present context is: Which features of the substrate and correlated sensory stimuli induce the change of gait? The answer potentially also provides a hint as to the sensory receptors involved. To find out about the switch inducing the behavioral change, the European Dolomedes fimbriatus (Pisauridae), a semiaquatic spider routinely moving on both solid substrate and the water surface, was compared to Cupiennius salei , a terrestrial wandering spider typically found on solid substrate rather than on the water. The parameters experimentally modified were water depth, kinematic viscosity of the fluid (sugar solutions) and surface tension (olive oil, water, mercury). The outcome of these experiments was as follows (Barnes and Barth 1991 ). (i) Water depth : The switch of gait can be induced not only on water but also on mercury. In addition, both species can walk in shallow water. This implies that water as such is not a condition for changing the gait. Overall, the change can be more easily elicited in Dolomedes than in Cupiennius , which reflects the difference in lifestyle. In Cupiennius, in particular, the water depth at which rowing can be elicited correlates negatively with the spider’s leg length (age) but not with its mass. Whereas Cupiennius waded at water depths as large as 10 mm and seemed to avoid rowing as long as possible (until losing contact with a firm substrate), Dolomedes started to row at depths below 1 mm already. (ii) Viscosity : The resistance during the power stroke, when the leg is retracted, depends on the kinematic viscosity of the liquid, and indeed seems to be measured by the spiders. Using sucrose solutions of different concentrations, the percentage of walking as opposed to rowing varied accordingly. It much increased at 216 cS and beyond, both in Dolomedes and young Cupiennius of the same size. Dolomedes started to row at lower values of viscosity and adult Cupiennius showed a much higher percentage of rowing and a lower percentage of walking at 216 cS than its young conspecifics. (iii) Surface tension : Olive oil with its very low surface tension (32 mN/m) does not sufficiently support the spiders. They simply sink into it. On the water (73 mN/m) they row, whereas on mercury with its high surface tension (435 mN/m) but lower viscosity than water Cupiennius mostly walks and Dolomedes mostly rows, but also jumps and walks. For Cupiennius a high surface tension affects the gait in the same way as does the contact with the substrate, that is it inhibits rowing.

Although the data at hand are providing first insights only it is tempting to conclude that slit sensilla measuring cuticular strains (Barth 2012a, b; Schaber et al. 2012 ) are substantially involved in inducing the change of gait. Direct evidence and the identification of the receptor location still have to be provided. Slit sensilla may also contribute information about the contact of the leg with a solid substrate. Such contacts imply a reaction force and thus strains in the exoskeleton. However, there are also highly sensitive tactile hair sensilla on the ventral surface of the tarsi, which might well do the job, alone or in addition to the slit sensilla (Barth 2014 ). More research on the neuroethology of the change of gait is both needed and promising.

As amply demonstrated by several contributions to the present Special Issue on arachnid locomotion and kinematics a number of rather technical and physical aspects have already received considerable attention. Examples are leg coordination in rhythmic walking and running, the hydraulics of leg extension at the leg’s two dorsal hinge joints (where extensor muscles cannot be implemented), ground reaction forces, strains in the exoskeleton, models of 8-legged locomotion, energy efficiency, micromechanics of adhesion, and more recently also biomimetics of spider locomotion and its application to robotics (Wang et al. 2011 ;Spagna and Alleyne, this issue). The interest in the sensory control of spider motions has been much more limited. This may surprise since the usefulness of all these motions critically depends on the spider’s ability to control them.

The few examples given in the present review point to the richness of non-locomotor movements and stress their relevance for the spider’s everyday life and survival. They also underline the richness and subtlety of the spider’s relation to its environment and the fundamental role of its sensory systems in controlling and adapting its different types of motion. Movements not mentioned here include those seen during copulation, the anchoring of the dragline (see Wolff 2021 ), the handling of prey, the spinning of the elaborate egg sac (Melchers 1963 ) and of the tangle of threads for the spiderlings when leaving it, movements in the narrow retreat on their dwelling plant, and more. Obviously, Cupiennius and other spiders are well equipped with sensors, in particular mechanoreceptors responding to different kinds of force (exerted by air flow, strain, touch, substrate vibrations, joint movements), and enabling them to manage all of these motions in an adaptive way.

To understand the behavioral significance of the spider’s myriads of sensory receptors and their synergistic and integrative interaction is both a rewarding and a challenging task. Evidently, its sensors provide the spider with a very detailed “picture” of its motions, highly resolved both in time and space. Among the challenges research faces are (i) the sheer number of the receptors, redundancies, and receptor functions in only hard to detect subtleties of behavior. An example illustrating this is the puzzling persistence of leg coordination and of the basic rhythmic motion after substantial deafferentiation by cutting leg nerves (Seyfarth and Barth 1972 ; Seyfarth and Bohnenberger 1980 ; Seyfarth 1985 ). Another challenge resides in the (ii) general problem with ablation experiments. Not seeing a deficit or any behavioral change just tells us that the receptors under study are not a necessary condition under the given circumstances for the behavioral performance studied. One simply might not have chosen the right behavior to detect the deficit. The ablation of lyriform organs and the following absence of an obvious effect on normal walking but the pronounced effect on kinesthetic orientation (as described above) is a telling example. A further challenge are (iii) dependencies on the circadian rhythm (Seyfarth 1978a , b ; Schmitt et al. 1990 ), as shown by the decreased willingness of night-active Cupiennius to exhibit courtship behavior or even “simple” local reflexes during daytime as compared to dusk and night time (Seyfarth 1978a , b ; Barth 1997 ). Clearly, an adequate combination of reductionist laboratory work and general biology is strongly needed, including careful observations in the field. In spiders, a particular additional complication is a pronounced (iv) efferent control of the sensory periphery, which is well established anatomically. All the receptors addressed in the present review show profuse efferent innervation with numerous synapses on the somata and their dendrites and axons (Foelix and Choms 1979 ; Fabian-Fine et al. 2000 , 2002 ) indicating neuronal integration in the sensory periphery. Octopamine and GABA B were shown to enhance and to inhibit, respectively. There is evidence for other transmitters as well, acting locally as opposed by circulating as a neurohormone (Panek et al. 2003 ; Barth 2004 ; Widmer et al. 2005 ; Tarr et al. 2018 ). Unfortunately, the functional role of the efferent signal modulation in actual spider behavior still is essentially unknown. Finally, (v) multimodality has to be kept in mind. For good reasons there is a strong tendency of experimental research to consider a system in a reduced but manageable way. As a consequence, the most prominent behaviors and the most clearly involved sensory systems receive most of our attention, although several sensory systems may be involved, even though in a subtle way. Fragmenting the organism in a reductionist way to understand basic sensory and neuroethological mechanisms has been a very successful approach as is shown by a multitude of examples from all sorts of sensory modalities. However, one has to be aware, that at least in many if not all natural behaviors the spider will make use of a combination of all sensory data available.

Clearly then, the examples of sensory guidance given in the present review are just a modest beginning. There is still a long way to finally understand the interaction of all the components making up the entire sensori-motor system, which underlies a particular spider motion and makes its adjustment to changing conditions possible. We are still far from a full appreciation of the complex motor programs and of the integration and processing of sensory information in the central nervous system, needed in addition to the remarkably competent pre-processing in the sensory periphery (Barth 2019 ).

However, despite all this the beginnings have told us a lot already and are promising. They may well serve as a springboard for further research, keeping the organismic “whole-system” picture of natural behavior in mind.

Acknowledgments

I am grateful to the many students and associates who made our research work both possible and enjoyable and contributed to make Cupiennius a model in spider sensory biology. The German and the Austrian Science foundations generously supported us over many years. A DARPA grant was instrumental in expanding our collaborations with engineers and physicists.

Open access funding provided by University of Vienna.

Compliance with ethical standards

The author declares no conflict of interest.

Publisher's Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

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Scientists taught a spider how to jump so they can one day do the same for robots

Kim the spider has a thing or two to teach us.

By Neel Patel | Published May 9, 2018 3:00 AM EDT

Environment

We know spiders best as quiet, eight-legged monsters who lurk around and trap their prey with webs and venom. But 13 percent of the more than 450,000 arachnid species can aggressively stalk prey and lunge at them with a jump attack, like an eight-legged tiger, or a horrible version of Aragog’s children on steroids.

Terrifying as it is, the way these spiders jump is worth studying. They can leap six times the distance of their body length from a standing start (humans can only manage a paltry 1.5 times their own length), and carry five times their weight into the air. Translating these physiological wonders into engineering strategies could revolutionize the type of robots we build and deploy—though hopefully not ones that lunge at human prey.

A team of researchers from the University of Manchester in the UK ran a study that trained a regal jumping spider ( Phidippus regius ) named Kim to jump across various distances of a platformed obstacle course, all while ultra-high-speed videos took footage of the leaps. The new findings, published in Scientific Reports on Tuesday , provide a more detailed look at the jumping mechanism by which this species and others make extraordinarily long and precise leaps.

“Our key finding for this species is that short range jumps tend to use low angled trajectories that minimize flight time,” says Russell Garwood, a paleontologist at the University of Manchester and a coauthor of the new paper. These types of jumps, traversing about 30 millimeters, were faster and prioritized speed and accuracy over other requirements.

Meanwhile, longer jumps (up to 60 millimeters in distance) used steeper takeoff angles to optimize flight time and allow the spider to travel a greater distance, but also minimized the amount of energy exerted. “Hence it seems the dynamics of the animals’ jumps differ depending on the nature of the jump,” says Garwood.

Jumping spiders possess an incredibly sharp sense of vision compared to other arachnids and arthropods, with four large eyes in front and four more smaller ones on the top of the head. This vision likely allows the spider to size up the distance and determine the proper timing and angle needed for the big (or small) leap. But that doesn’t mean these spiders can see very far. Kim’s upper limit of 60 millimeter jumps was self-imposed—she refused to attempt distances longer than that—likely not because she couldn’t make the distance (she often overshot the long jumps anyway), but because her eyesight failed her.

The researchers bought several regal jumping spiders from the local pet story in hopes of training them, but only the 150-milligram, 15-millimeter-long little bugger named Kim was willing to acquiesce to these demands. “I think, if I am honest, we largely overcame this through luck,” says Garwood. “We had to work really hard to even capture the jumps we did manage to capture on camera.”

The researchers noticed the regal jumping spider seems to use acute muscle contraction in order to pull off the leap, as opposed to using stored energy in a catapult-like mechanism, as many other arthropod species do.

“The key thing we had hoped to identify with this study,” says Garwood, “was whether this species used hydraulics in addition to muscles to power its jumps.” Spiders use haemolymph pressure (haemolymph is basically the arachnid version of blood) to extend their legs, and it was initially believed that hydraulic force worked in conjunction with the sheer power of the leg muscles to allow Phidippus regius execute ascending leaps, not just lateral or descending ones.

“Unfortunately we weren’t able to clarify this for sure,” says Garwood. Based on the jump observations and leg physiology data collected through 3D CT scans, the researchers found the jumps ought to be possible based solely on the power provided by leg muscle mass. Hydraulic force created by the haeolymph might give a boost to the spider as it jumps, but it’s not an essential feature . “We hope that future studies may shed light on this a little further.”

If the jumping physics could be replicated in a flying or jumping robot, it could help solve a lot of biomechanical constraints keeping most robots on the ground—namely, the balancing act between keeping a robot light and giving it enough power to leap large distances into the air—and maybe lead to a new era of microrobots. In factthe research team used the 3D CT scans of Kimto build a scale model of the spider’s legs and body structure complete with a jumping mechanism. Unfortunately, it bombed during the actual jump test. Turns out we’re still pretty bad at developing electronics that operate smoothly at this scale, and we’ll need more data that illustrates how spiders and other small creatures control how much force they exert when they jump and move around.

If the world ever becomes inundated by an army of small, jumping arachnoid robots, you’ll know this is one of the key research projects that begat that doom and gloom.

Note: a previous version of this article incorrectly stated that the spider weighs 150 grams. It actually weighs 150 milligrams. We regret the error and apologize for the nightmares.

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Amazon Travel Guide

Spiders Of The Amazon

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The Amazon rainforest is known for being home to an incredible range of animals and wildlife. Jaguars , manatees , sloths , toucans, butterflies , medicinal plants … and spiders . There are about 3,600 species of spiders inhabiting the Amazon basin, many of which cannot be found anywhere else in the world.

Big, small, deadly, harmless, living out of sight or in plain view, the world of spiders in the Amazon is endlessly fascinating. From the classic Amazonian Tarantula to the Goliath Bird-Eating Spider , here are some of the most interesting spiders of the Amazon – and everything you need to know about them.

Tarantula In The Pacaya Samiria Reserve, Peru

The Tarantula

Tarantulas have inhabited the Earth since the time of dinosaurs, and continue to reside in several parts of the world, often living up to 30 years of age.

Tarantulas are the largest spiders in the world, and the Amazonian variety is the largest of them all. Anyone visiting the Amazon rainforest can be sure to spot them. In fact, it’d be hard not to – some adults can measure up to 13 inches across! Don’t worry though, because despite being the largest spiders of the Amazon, their bites are not venomous. A bite from a tarantula will usually feel similar to a bee or wasp sting and has no lasting effects. The hairs covering their body, however, can be extremely irritating to human flesh, so maybe avoid getting too close!

These giants live in burrows in the ground or high in treetop nests, but can often be spotted on the sides of trees during the day or night. You’ll recognize their massive brown bodies, covered in black and brown barbed hairs.

Jumping Spiders

Another fascinating species of spiders in the Amazon, these much smaller creatures can also be quite alarming at first glimpse. They live in the rainforest canopy and are known for leaping from tree to tree, using a safety line of excreted silk. They’re some of the friendliest spiders of the Amazon, as they’re quite curious. Anything new requires investigation, and that often includes unsuspecting travelers! Luckily, they’re also harmless to humans, so never fear if one jumps onto your snacks to inspect. Over 500 known species of jumping spiders exist in the Amazon, so your chances of spotting one are good.

Brazilian Wandering Spider

The Brazilian Wandering Spider

Unlike the tarantulas and jumping spiders of the Amazon, the Brazilian Wandering Spider is one you might want to be a little more concerned about. Eight species of spiders fall under this category, all highly aggressive and venomous. They are part of the genus Phoneutria, coming from the Greek word for “murderess”, which is perhaps a more appropriate name for the dangerous arachnids. They are thought to be the most venomous spiders in the Amazon, and on Earth, and an untreated bite can kill a human in as little as 25 minutes.

There are eight different species of Brazilian wandering spiders, the largest being about 5 inches across. While it may seem big for a spider, it’s just small enough for them to sneak into exported fruits. Another nickname for these creatures is “banana spiders” since they have been known to hide in bunches of bananas, remaining undiscovered until reaching lands as far away as the USA or UK. These are the spiders you’ll hope not to see on an tour of the Brazilian Amazon.

The Goliath Bird-Eating Spider

Although they more regularly eat insects, rodents, snakes, and bats, the Goliath bird-eating spider got its name when an early Amazon explorer witnessed one eating a hummingbird.

If you can believe it, that’s not even the most shocking part of their diet: the female Goliath is known for sometimes eating their mates after copulation. On the bright side, males usually don’t live much longer anyways, often dying once they reach maturity, which is only one-fifth of the lifespan of females (females usually live up to 25 years). The goliath bird-eater is a member of the tarantula family and holds the crown of the largest spider on the planet by body mass (weighing up to 6.2 oz (175 g), falling a close second place in terms of leg span to the Giant Huntsman Spider of Laos that can grow up to 12 inches in diameter (30cm).

As terrifying as the Goliaths sound, their bites are similar to those of tarantulas in how they affect humans. Their fangs (sometimes up to 1.5 inches long) can easily puncture human skin, yet the venom is harmless to humans. Deep burrowers, a run-in with a Goliath bird-eating spider is not as common as with other spiders of the Amazon.

Giant Fishing Spider

As if spiders weren’t creepy enough, one particular genus of arachnid in the Amazon has developed the ability to hunt fish. These spiders can be found waiting by the side of rivers, pools, and streams to pounce on unsuspecting fish or tadpoles. They have even been known to coat themselves in an air bubble and swim underwater to ambush fish .

Decoy Spider

It’s already one of the most stunning phenomena in nature how spiders spin their incredibly precise and detailed webs. This little spider takes it to the next level, however. The tiny decoy spider creates a huge spider-shaped sculpture in its web using bits of old leaf and plant matter, dead insect husks, and even its own shed skin! It then creates a pocket in the middle of the huge effigy that it sits in to await its unwary prey. This clever arachnid is a fairly recent discovery, and scientists are still unsure as to why it exhibits this incredible behavior.

Luckily for spider enthusiasts, these are just six of the most interesting spiders of the Amazon- but there are over 3,000 more for you to discover! It’s the magic of the Amazon that you can see such arachnids, bigger than your hand, able to jump from tree to tree, even able to catch and eat birds. Travel with a knowledgeable tour guide and you can be sure to spot the best of the spiders of the Amazon – and know which ones to avoid! Contact us for more information about taking an Amazon River Cruise and seeing them in person for yourself.

While Rainforest Cruises aim to provide accurate and up-to-date information, we make no representations as to the accuracy or completeness of any information herein or found by following any link on this site. Rainforest Cruises cannot and will not accept responsibility for any omissions or inaccuracies, or for any consequences arising therefrom, including any losses, injuries, or damages resulting from the display or use of this information.

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Brazilian Wandering Spider
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Wandering Spider(Ctenidae)Facts, Identifications & Pictures
9 Facts About Jumping Spiders That Will Amaze You
Wandering Jumping Spider, Cairns, Queensland, Australia Photograph by

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JUMPING SPIDERS in Dark Den after a long time!

COMMENTS

Brazilian Wandering Spider facts
Do wandering spiders jump? Wandering Spiders are excellent at jumping. They can jump several feet when surprised, and may occasionally use this as a tactic to evade predators. Jumping at you isn't part of how bites happen though. When faced with humans, Wandering Spiders usually stand their ground and use their threat display of raised legs ...
Brazilian wandering spiders: Bites & other facts
Jump to: Classification/taxonomy Size & characteristics Behavior ... These arachnids "are called wandering spiders because they do not build webs but wander on the forest floor at night, actively ...
Wandering spider
Wandering spiders (Ctenidae) are a family of spiders that includes the Brazilian wandering spiders.These spiders have a distinctive longitudinal groove on the top-rear of their oval carapace similar to those of the Amaurobiidae. They are highly defensive and venomous nocturnal hunters. Wandering spiders are known to hunt large prey, for example hylid species Dendropsophus branneri.
Wandering spider
wandering spider, (family Ctenidae), any member of the family Ctenidae (order Araneida), a small group of large spiders of mainly tropical and subtropical regions, commonly found on foliage and on the ground. Their first two legs are armed with strong bristles on the lower side. Cupiennius salei, found in rainforests in Central and South America, has a characteristic banding pattern on its ...
Brazilian Wandering Spider
The Brazilian wandering spider can grow to have a leg span of up to 4 - 5 inches. They are large hairy spindly-looking spiders who have eight eyes, two of which are large. Brazilian wandering spiders are fast-moving spiders, their legs are strong and spiny and they have distinctive red jaws which they display when angered.
Brazilian Wandering Spider Facts
The venom glands of the Brazilian Wandering Spider are over a centimetre long, and this is all housed inside the bright red chelicerae (mouth parts) which they are quick to display whenever they get upset. 1. 4. They're aggressive. These spiders can grow quite large and have long, brightly-coloured legs.
Wandering Spider Facts: Understanding This Species
Brazilian Wandering Spiders are extremely fast, extremely venomous, and extremely aggressive. These large and dangerous true spiders are ranked among the most venomous spiders known to man. In fact, the Brazilian Wandering Spider is the most venomous spider in the New World! ... Many hunting spiders can jump quite well. It looks very much like ...
Phoneutria
Phoneutria is a genus of spiders in the family Ctenidae.They are mainly found in northern South America, with one species in Central America. Members of the genus are commonly referred to as Brazilian wandering spiders. Other English names include armed spiders (armadeiras in Brazilian Portuguese) and banana spiders (a name shared with several others).
Brazilian Wandering Spider (Phoneutria): Bite, Attacks ...
Brazilian wandering spiders are the most poisonous spiders on the planet. They belong to the genus Phoneutria, which consists of a number of spider species. A couple of these species, including Phoneutria nigriventer, P. keyserlingi and P. fera are referred to as Brazilian wandering spiders.
Phoneutria nigriventer
Phoneutria nigriventer is a species of medically significant spider in the family Ctenidae, found in the Southern Cone of South America (Brazil, Uruguay, Paraguay, and Argentina). Along with other members of the genus, they are often referred to as Brazilian wandering spiders.. Its bite can cause severe symptoms, including increased pulse, blood pressure, and respiratory rate; extraordinary ...
Brazilian Wandering Spiders (Phoneutria): Facts ,Identifications & Pictures
Size: They are large in size, with their body being 17- 48mm (.67 - 1.89 inches) long and they also have a leg span of 130 - 150 mm (5.1-5.9 inches). Color: The color may vary from one species to the other, though most of them have a brown hairy body, with black spots on their stomach. Some have bright, red hairs on their mouthparts or ...
Brazilian Wandering Spider: Care, Food, Habitat & Preventions
The Brazilian wandering spider, scientifically known as Phoneutria, Maximilian Perty kickstarted the Phoneutria genus in 1833. The name comes from the Greek word φονεύτρια, which means "murderess" and falls under the Animalia kingdom, Arthropoda phylum, and Arachnida class. Within Arachnida, it is classified in the order Araneae ...
The Brazilian Wandering Spider
Brazilian Armed Spider (Phoneutria) A box of bananas were delivered to a pub in Bridgwater, England in 2005. Unbeknownst to the person opening the bananas, an aggressive spider was hiding in the bananas and bit him. Later on it would be identified as the venomous and speedy species Phoneutria fera (Brazilian Huntsmen) from South America.
Brazilian Wandering Spider Facts: What Happens If It Bites You?
In a study published in the journal Frontiers in February 2023, researchers stated that the Brazilian wandering spider is amongst the world's most dangerous venomous spiders in the world.
Brazilian Wandering Spider
The Brazilian Wandering Spider, known scientifically as Phoneutria, harbors a venomous arsenal that stands as a testament to nature's intricate design. This spider's venom contains a potent concoction of neurotoxic compounds, tailored by evolution to incapacitate its prey swiftly and efficiently. The neurotoxins interfere with nerve cell ...
4 Ways to Identify a Brazilian Wandering Spider
Recognizing a Brazilian Wandering Spider. 1. Watch out for 6-inch (15 cm) long spiders with leg span. Adult Brazilian wandering spiders have a body that's about 2 inches (5 cm) large. Their leg span, which may be easier to recognize, is about 6 inches (15 cm) in length.
A spider in motion: facets of sensory guidance
In general, wandering spiders have more trichobothria than web spiders for which the airflow-sense seems to be much less important behaviorally. We have never succeeded in eliciting a similar jump in any web spider by an airflow stimulus (Barth 2014 , p. 173).
Scientists taught a spider how to jump so they can one day do the same
We know spiders best as quiet, eight-legged monsters who lurk around and trap their prey with webs and venom. But 13 percent of the more than 450,000 arachnid species can aggressively stalk prey ...
Spiders Of The Amazon
The Brazilian Wandering Spider. Unlike the tarantulas and jumping spiders of the Amazon, the Brazilian Wandering Spider is one you might want to be a little more concerned about. Eight species of spiders fall under this category, all highly aggressive and venomous. They are part of the genus Phoneutria, coming from the Greek word for ...
7 Spider Species That Can Jump (and How to Get Rid of Them)
The wolf spider, jumping spider, yellow sac spider, and tarantula are the most commonly found spiders that jump in the United States. Around the world, there are plenty of other spiders that jump. Camel Spider (Solfugid.) The huntsman and camel spider are two well-known spiders that have been known to jump on prey.
TARANTULA VS JUMPING SPIDER
In today's video we talk about 10 care differences between keeping tarantula species and jumping spider species!Micro Wilderness: https://www.microwilderness...
Rabid Wolf Spiders: What They Are and Prevention Methods
Some species are commonly heard of, including the jumping spider, tarantula, and orb weaver. Others are less common and not frequently heard of, such as the ghost spider. ... "wandering spider ...

Brazilian Wandering Spider facts

Quick Facts

Other Common Names

Brazilian Wandering Spider Venom

What’s the Benefit of Having Such Strong Venom?

Brazilian Wandering Spider Deaths

Brazilian Wandering Spider Size

Brazilian Wandering Spider Location and Habitat

Brazilian Wandering Spider Speed

What Does the Brazilian Wandering Spider Eat?

Final Thoughts…

FAQ related to the Brazilian Wandering Spider

Do wandering spiders jump?

Is Brazilian wandering spider friendly?

Are Brazilian wandering spiders in Australia?

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Brazilian wandering spiders: Bites & other facts

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Brazilian Wandering Spider

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Brazilian Wandering Spider Diet

Brazilian Wandering Spider Reproduction

Brazilian Wandering Spider Venom

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Brazilian Wandering Spider Facts

Brazilian Wandering Spider Facts Overview

Interesting Brazilian Wandering Spider Facts

2. Banana Spiders

3. They have the largest venom glands of any spider

4. They’re aggressive

5. They give some men erections

6. And some people die

7. But they’re rarely fatal

8. They do invade the UK sometimes

Brazilian Wandering Spider Fact-File Summary

Understanding the Wandering Spider: Quick Essential Facts

Scientific Classification and Naming

Identification and Appearance

Habitat and Distribution

Geographical Coverage

Types of Wandering Spiders

Brazilian wandering spiders

Phoneutria nigriventer

Ctenus captiosus

Behavior and Diet

Prey and Predators

Nocturnal Activities

Venom and Its Effects

Symptoms and Severity

Medical Treatment and Antivenom

Reproduction and Mating

Egg Sacs and Offspring

Danger and Defense Mechanisms

Comparison with Other Dangerous Spiders

Comparison to Brown Recluse

Comparison to Wolf Spider

Comparison to Sydney Funnel-Web Spider

Interesting Facts and Guinness World Records

Prevention and Safety Measures

Reader Emails

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Brazilian Wandering (Phoneutria)

Scientific Classification

List of Spiders Belonging to This Genus

Spiderlings

Are Brazilian Wandering Spiders Venomous?

Can Brazilian Wandering Spiders Bite?

How Fast Can a Brazilian Wandering Spider Kill One?

Ecological Importance and Behavior of the Brazilian Wandering Spider

Quick Facts