Do urticating hairs have venom?

[fullmetalcommunist]

I always assumed that they did, and all of the sources I've read say that they do, but someone tried to argue with me about it on facebook, so I'm wondering if I'm wrong or if the other person is. They say urticating hairs are irritating just because of the shape of the hairs and that they don't release venom onto the hairs, but that seems wrong to me. This convo also made me more interested in learning, if they do have venom on their hairs, is it the same venom as their bite or a different one, and how is it delivered to the hairs? I would imagine it is a different venom since T venom is (to my understanding) mostly designed to dissolve food while the hairs are used solely as a defensive mechanism. Anyone have sources to learn more about this?

 

[AphonopelmaTX]

The answer is no, urticatious setae does not contain venom or any chemical component to cause irritation. This shouldn't even be a poll since it isn't a matter of opinion. For more information, see the following research paper which is freely available to download and read.

Cooke, J. A., Roth, V. D., & Miller, F. H. (1972). The urticating hairs of theraphosid spiders. American Museum novitates; no. 2498.
http://digitallibrary.amnh.org/handle/2246/2705

 

[antinous]

What sources were you looking at? Urticating hair does not have venom

 

[cold blood]

They say urticating hairs are irritating just because of the shape of the hairs and that they don't release venom

They are correct....hairs have no venom...if they did, they would need a venom gland at the base of the hairs, venom glands supply the fangs and only the fangs.

 

[8LeggedLair]

I always assumed that they did, and all of the sources I've read say that they do, but someone tried to argue with me about it on facebook, so I'm wondering if I'm wrong or if the other person is. They say urticating hairs are irritating just because of the shape of the hairs and that they don't release venom onto the hairs, but that seems wrong to me. This convo also made me more interested in learning, if they do have venom on their hairs, is it the same venom as their bite or a different one, and how is it delivered to the hairs? I would imagine it is a different venom since T venom is (to my understanding) mostly designed to dissolve food while the hairs are used solely as a defensive mechanism. Anyone have sources to learn more about this?

Definitely not man, Venom are in glands behind the basal chelicerae. When the spider fangs pierce the prey the spider releases its venom through the venom duct from the chelicerae into the fangs out into its prey...the dude you were arguing with probably just wants to piss you off lol
They can’t spray it on their abdomen... even if they could how? They cannot rotate their head...

 

[chanda]

While the urticating hairs of tarantulas are not venomous, the reactions to them are not based purely on the mechanical action of the various types of urticating hairs (the little barbs and prickles). There is also a biological component - but it is an allergic reaction to the hairs themselves, rather than a toxin that is present on the hairs. People who are more susceptible to that allergen will experience more severe reactions than those who are less susceptible. Also, some people may experience little or no reaction to an initial exposure to urticating hairs, but may experience increasingly severe reactions to urticating hairs over extended periods of time and repeated exposures, as they become more sensitized to the allergen.

Here's a study that looked at allergic reactions to urticating hairs: https://www.jacionline.org/article/S0091-6749(95)70087-0/fulltext

 

[fullmetalcommunist]

There is also a biological component - but it is an allergic reaction to the hairs themselves, rather than a toxin that is present on the hairs. People who are more susceptible to that allergen will experience more severe reactions than those who are less susceptible.

Ah, I think this is where my misunderstanding came from. I saw a study that referenced "chemical irritation" in setae (still trying to find it), and someone said,
"The latest studies suggest urticating hairs from tarantulas present not just a mechanical but a chemical influence on the skin and mucous membranes."

http://arachnoboards.com/threads/urticating-hair.186598/

Can't find the studies they're referring to. Additionally, there are some websites (not reliable sources, I know, but I made an assumption) out there that refer to urticating hairs as mildly venomous. I also know that some other animals and plants have urticating hairs (not tarantulas) that do secrete toxins. Thanks for the info, guys!

So, next question, and this is like rookie level so bear with me. What distinguishes venom from other chemical irritants that aren't venom? I know the obvious mantra that poisonous means you eat it it hurts you and venomous means it bites/stings you it hurts you. What is it called when there are chemicals designed to cause an allergic reaction, and what makes that distinct from venom? I guess what I'm asking is what defines venom as venom? Cuz now that I'm thinking of it, plants that have that mechanism in them aren't invenomating you per say but they are stinging you a toxin. What's the difference?

 

[boina]

What is it called when there are chemicals designed to cause an allergic reaction

These aren't 'chemicals' designed to induce an allergic reaction. They are normal proteins that are included in the structure ot the hairs and people may or may not react allergic to them. They are designed to cause mechanical irritation.

Venom: Substance (usually a cocktail of various toxins) designed to cause direct damage to cells
Allergen: Generally harmless substance the mammalian immune system may overreact to

 

[8LeggedLair]

Definitely not man, Venom are in glands behind the basal chelicerae. When the spider fangs pierce the prey the spider releases its venom through the venom duct from the chelicerae into the fangs out into its prey...the dude you were arguing with probably just wants to piss you off lol

Ah, I think this is where my misunderstanding came from. I saw a study that referenced "chemical irritation" in setae (still trying to find it), and someone said,
"The latest studies suggest urticating hairs from tarantulas present not just a mechanical but a chemical influence on the skin and mucous membranes."

http://arachnoboards.com/threads/urticating-hair.186598/

Can't find the studies they're referring to. Additionally, there are some websites (not reliable sources, I know, but I made an assumption) out there that refer to urticating hairs as mildly venomous. I also know that some other animals and plants have urticating hairs (not tarantulas) that do secrete toxins. Thanks for the info, guys!

So, next question, and this is like rookie level so bear with me. What distinguishes venom from other chemical irritants that aren't venom? I know the obvious mantra that poisonous means you eat it it hurts you and venomous means it bites/stings you it hurts you. What is it called when there are chemicals designed to cause an allergic reaction, and what makes that distinct from venom? I guess what I'm asking is what defines venom as venom? Cuz now that I'm thinking of it, plants that have that mechanism in them aren't invenomating you per say but they are stinging you a toxin. What's the difference?

yea venomous: bite or sting
Poisonous: ingested or secreted to be ingested etc like some frogs, they secrete toxins through their skin.
Chemical: isn’t like that of venom or poison however you will be poisoned if ingested said chemical you wouldn’t be cheminoused.

 

[chanda]

So, next question, and this is like rookie level so bear with me. What distinguishes venom from other chemical irritants that aren't venom? I know the obvious mantra that poisonous means you eat it it hurts you and venomous means it bites/stings you it hurts you. What is it called when there are chemicals designed to cause an allergic reaction, and what makes that distinct from venom? I guess what I'm asking is what defines venom as venom? Cuz now that I'm thinking of it, plants that have that mechanism in them aren't invenomating you per say but they are stinging you a toxin. What's the difference?

A toxin is, by its own nature, harmful - and it is universally harmful, to everyone. Rattlesnake venom, for example, contains hemotoxins that destroy red blood cells and neurotoxins that disrupt or damage the nervous system. They will have these effects in any person who is bitten and envenomated.

Allergens, on the other hand, are harmless by themselves. Peanuts, for example, are a tasty treat for most people with no harmful effects - but if you are allergic to peanuts, then your own immune system will overreact to the proteins in the peanuts and attack your body, causing such diverse reactions as hives, swelling, itching, or difficulty breathing or swallowing. Also, while an initial exposure might result in just a mild reaction, prolonged or repeated exposure can lead to your immune system becoming hypersensitized to the allergen, causing increasingly severe reactions with each subsequent exposure.

When you mention stinging plants, I assume you are talking about things like poison oak or poison ivy or stinging nettles? Despite containing the word "poison" in their names, poison oak and poison ivy also initiate an allergic reaction when the urashiol on them comes into contact with the proteins in the skin. However, a lot more people will suffer an allergic reaction to urashiol than to peanuts. Stinging nettles on the other hand, have hollow hairs that inject biochemical irritants into the skin, and it is the direct action of these irritants - rather than an immune response to them - that causes the burning sensation.

 

[Tenebrarius]

no venom, but the ephobopus has urticating setae on its pedipalps, The structure of the hair can change too based on species, the allergic reaction is probably similar to like dog hair, imagine if dog hair had venom

 

[fullmetalcommunist]

[QUOTE="chanda, post: 2855344, member: 54156"Stinging nettles on the other hand, have hollow hairs that inject biochemical irritants into the skin, and it is the direct action of these irritants - rather than an immune response to them - that causes the burning sensation.[/QUOTE]

So the irritants in nettles are toxic because they're inherently designed to destroy cells, (what do you call this in plants? Not 'venomous' lol but its like the plant equivalent) While the irritants in poison ivy are just irritants because they're designed to illicit an immune response? And in Ts, the venom is toxic because it's designed to destroy cells but the hairs are not toxic because they're designed to illicit an immune response to make cells irritate themselves rather than destroying cells themselves. And when someone has an allergic response to venom, the venom is simultaneously destroying cells AND the person's immune system is attacking itself in response? Makes more sense now

So some people have less of a response to hairs because their body doesn't react to those proteins by "attacking itself." How come some people are more or less sensitive to venom? Is that purely based on whether they have an allergic reaction or not?

 

[SpiderDan1981]

Follow-up question: who has taken a hair to the eyes?
What was your body's reaction? How long did the irritation and redness last? How severe? I went to the eye dr. 3 weeks ago, where they removed a hair from my eye (definitely a T hair), but the redness has not only not gone away, it's gotten worse since, despite being treated with steroidal eye drops. They've diagnosed it as episcleritis and put me on another course of different, stronger steroidal drops. Did you get your eye treated professionally or just wait for the symptoms to subside? If treatment was involved, was it the same as what I've described?

 

[8 legged]

I recently rubbed my eyes after putting the skin of a young Theraphosa under the microphone. My wife was able to remove 3 tiny hairs near the lacrimal gland with the tweezers. I lost some tears and had to blink for a few hours ... That was all that happened. As I wrote back then: more luck than brains!
If hair is actually in the eye, rinse immediately and it would be very stupid not to see an ophthalmologist! The hairs do not fall off by themselves and it is to be expected that they wander behind the eyeball, where they can cause irreversible sheep!