Tarantula Reports from Originating Countries?

[bryverine]

I've been thinking about it lately and the whole "nobody has died from a tarantula" is curious to me and seems misleading or maybe not the whole truth.

In the US, black widow bites aren't common, but haver been reported as biting people over 2500 annually.
Source:
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3200105/

Are there available country reports on Poecilotheria, Heteroscodra, or any OW from their native country?

I know most tarantulas probably avoid populated locations, but I'm sure it's not just physically mature tarantula enthusiasts that have been bitten.

There have to be reports or at least some documentation on age ranges being bitten by potent OW tarantulas, don't there?

I know there's probably no active research being done, but passive documentation seems like something that might happen and may even be necessary in the countries of origin.

 

[BorisTheSpider]

It's a question of the potency of the venom being injected . I just don't think tarantulas pack that much of a punch .

 

[shaneshac]

I lived for two weeks with an indigenous colony in Peru. There was one o more Avicularia aurantiaca nests inside their thatched roof shacks

I asked and not one had been bitten according to their elders

 

[bryverine]

It's a question of the potency of the venom being injected . I just don't think tarantulas pack that much of a punch .

I know very little about toxins and their effects other than reading that so-and-so toxin blocks potassium gates and so-and-so inhibits voltage gates; but if tarantulas can 'easily' kill mice, where is the mass limit of a tarantula's lethality? Obviously this hasn't been studied, but even a doctor documenting symptoms in case they see it again seems like it has to have happened somewhere.

I'm sure the actual ratio of the population density of these tarantulas to human population density plays a large factor in this documentation, but you'd think it wouldn't be impossible that someone happens across a pissed off (frightened) OW tarantula.

 

[Toxoderidae]

I could test! I'm a teen with some OW, I'll document the venoms effect on me. If I die, my spiders go to 14pokies, viper, and poec54

 

[bryverine]

I could test! I'm a teen with some OW, I'll document the venoms effect on me. If I die, my spiders go to 14pokies, viper, and poec54

OK, now we got a study going!

Anyone else care to join in? I would, but I'm ... much too large for such an experiment...

 

[Andrea82]

I think the people living in the areas where these T's live have adapted themselves to the fact that there could be a pissed off poecie or obt in a tree or a hole in the ground. The regions where these T's live have more dangerous insects and animals, so I imagine they are brought up with what too look out for.
Or, in the case of T's being food, how to catch them without being bitten.

 

[louise f]

No thanks. I think i am wayyyyy too busy that day

 

[Poec54]

Many OW's are native to Third World countries, where there aren't nearly enough doctors and hospitals. Reporting who's been bitten by spiders and what the outcome was is of just about no interest or importance to them. They have much bigger issues deaths caused by disease, famine, drought, floods, inadequate medicine and health care, sanitation, etc; they don't care about getting info to curious hobbyists in industrialized nations wanting know about their native animals. They don't have systems in place to track the hundreds or thousands in their country that die annually from snake bite; you're not going to get much, if anything, from them about invertebrates. They're not going to be nearly as excited about a few villagers dying from tarantula bites as we are; they have many more dying from so many other causes.

 

[borotasinisa]

But what about Australia, India, or some African regions which aren't that miserable as people think for example South African Republic, Algeria..?

 

[AntikInsomniak]

Most taranulas, and mygalomorphs for that matter, tend to rely on size for subduing prey. Spiders such as jumping spiders and some wolf spiders have potent venom that shuts down the nervous system of their prey.

Yet, it's worth noting that most prey comes in the form of insects.
Back to tarantulas: They do have a moderate toxin, but these toxins (which vary between genera) tend to be focused on shutting down the nervous system of insects. In the first source listed, there is a table referencing potency across multiple cell lines. From this, we can gather 2 ideas:
1. That larger spiders will more likely rely on sheer size, than venom potency given that they have very low IC50 or just no effect.
2. Venom is more suited towards common prey type, shown by .

Most tarantula venoms (i don't know all but I have studied my good share of venoms, specifically Sicariidae, Latrodectus, and Theraphosidae) are neurotoxins, implying that they affect the nervous system mainly through the inhibition of ion channels. Not all animals share the same channels, though. What might inhibit the channels of one cell, will not have a strong effect on another. In fact, that is the basis on some medicine. The venom might still have an effect, but it should be of moderate concern.

To the point:
The main reason no one has probably actually died from the bite, is because the venom doesn't seem to be potent enough to cause death. Any deaths associated from tarantulas are most likely secondary infections from the mechanical bite, which don't count as death by tarantula. I guess the only area where it could be life-threatening is allergic reactions to the venom, but I don't know how that is classified in CoD reports, so I will refrain from commenting.

Overall, Tarantula venom is too weak to really cause damage to the point of death. There might be some bias in reporting bites/deaths in third world countries, but I feel it's safe to assume that the numbers are so low (if any at all) that they are probably associated to another cause of death that supersedes the tarantula bite itself...

I'm only listing a couple sources, unless I get hounded for more.
(http://download.bioon.com.cn/view/u...9_3145e92db4cabb6a79c0JS1puEZ1Wedi.attach.pdf)

(https://opus.lib.uts.edu.au/handle/10453/23403) <-- Long, but a great read!

 

[Poec54]

The main reason no one has probably actually died from the bite, is because the venom doesn't seem to be potent enough to cause death.

We don't know that: 1) no one's died from a tarantula bite, and 2) that the venom isn't potent enough to.

1) It's highly unlikely that we'd know if people had died from tarantula bites. Not like it's going to make headlines in those countries. We know about the occasionally fatal bites of Black Widows and American vipers and rattlesnakes, because of our medical reporting and news coverage, even though some of those species rarely cause deaths. They're still considered 'deadly'. In a third world country, a few locals dying from spider bites isn't going to make it in their Top 10 list of health concerns. Don't assume the lack of information means it doesn't occasionally happen. A child playing outside and dying from the bite of a venomous animal in the US will make the television news. In a third world country, the next village over may not know.

2) Reading bite reports, there have been some serious reactions to OW bites (trips to an emergency room in the middle of the night, etc). A bite that hits a vein, or to a child or elderly person could be very serious. As would a bite in the head or neck, which is certainly possible with arboreal species. Stromatopelma bites have been associated with heart arrhythmia, which is very serious. The venoms of only a small percentage of tarantula species have been studied. Since arboreals are subduing prey that can quickly escape by jumping, falling, or flying, it makes sense that they would have stronger and faster-acting venoms. They're much less likely to be able to track down wounded prey than a terrestrial tarantula.

Mammalian predators take a toll on tarantulas (baboons, mongeese, honey badgers, etc) and some of their venoms may have evolved not only to subdue prey, but also be a potent defense against mammals.

 

[bryverine]

A bite that hits a vein, or to a child or elderly person could be very serious. As would a bite in the head or neck, which is certainly possible with arboreal species. Stromatopelma bites have been associated with heart arrhythmia, which is very serious. The venoms of only a small percentage of tarantula species have been studied. Since arboreals are subduing prey that can quickly escape by jumping, falling, or flying, it makes sense that they would have stronger and faster-acting venoms. They're much less likely to be able to track down wounded prey than a terrestrial tarantula..

This exactly - are children, women, or elderly more likely to receive fatal bites?

I found a nice article "Tarantulas:eight-legged pharmacists and combinatorial chemists" that describes the time to death in mice injected with 0.1uL of venom by several species from Africa, Asia, and America. It's not surprising that the OW are all well under 20 minutes; several (Heteroscodra, Poecilotheria, Pternochilus, Stromatopelma, etc) are well under 10. I'd post the figure, but I don't believe this counts as a classroom under fair use

@AntikInsomniak you seem to be on a much higher understanding than I about these things. Besides our sheer size difference, would you say there is something about our biology that would make us less succeptable to fatal tarantula injections regardless of size?

If a smaller/weaker specimen of the human race was bit, besides the increase in pain which would obviously increase stress levels in the bite victim, do they have a greater chance for the toxin to kill them rather than the symptoms?

 

[AntikInsomniak]

We don't know that: 1) no one's died from a tarantula bite, and 2) that the venom isn't potent enough to.

1) It's highly unlikely that we'd know if people had died from tarantula bites. Not like it's going to make headlines in those countries. We know about the occasionally fatal bites of Black Widows and American vipers and rattlesnakes, because of our medical reporting and news coverage, even though some of those species rarely cause deaths. They're still considered 'deadly'. In a third world country, a few locals dying from spider bites isn't going to make it in their Top 10 list of health concerns. Don't assume the lack of information means it doesn't occasionally happen. A child playing outside and dying from the bite of a venomous animal in the US will make the television news. In a third world country, the next village over may not know.

2) Reading bite reports, there have been some serious reactions to OW bites (trips to an emergency room in the middle of the night, etc). A bite that hits a vein, or to a child or elderly person could be very serious. As would a bite in the head or neck, which is certainly possible with arboreal species. Stromatopelma bites have been associated with heart arrhythmia, which is very serious. The venoms of only a small percentage of tarantula species have been studied. Since arboreals are subduing prey that can quickly escape by jumping, falling, or flying, it makes sense that they would have stronger and faster-acting venoms. They're much less likely to be able to track down wounded prey than a terrestrial tarantula.

Mammalian predators take a toll on tarantulas (baboons, mongeese, honey badgers, etc) and some of their venoms may have evolved not only to subdue prey, but also be a potent defense against mammals.

I was talking in terms of Venom potency of a bite, which is my area of study and focus. As far as mechanical injury (in the case of hitting an artery, as a vein wouldn't be as life-threatening), it's obvious this could be fatal IF severe. Likelihood is small and again, not related to the venom. What you've stated is the mechanical injury. Example: Steve Irwin didn't die from stingray venom, he died from being speared through the heart. I also stated that there are probably deaths, however few, that are probably due to another issue not pertaining to the bite (in terms of venom). I don't assume that a lack of reports indicates its lack of presence, by the way. A main issue with science is failure to report incidents or findings. That's a whole other topic though, and not suited for this forum.

You're right in saying that we have not fully studied all venoms. However, from those that have been studied, there are clearly trends. Let's focus on Theraphosidae. The Theraphotoxin, which is the characteristic toxin in these venoms, all follow a similar primary structure. They may not be exact copies, but functional groups of amino acids are similar across the board. Linked is a paper reflecting these (the paper includes mainly NW species, given that it focuses on a NW discovery). They mainly function through inhibitory cysteine knots. Arboreals do as well. In fact, most prey for an arboreal are insects, and occasional small amphibians as opposed to terrestrials/fossorials, which have the added chance of mice and small reptiles/amphibians. Another note on arboreals, would be less human interaction (excluding the hobby scene) leading to a smaller chance of ever being bit by one, so I feel as if this might be a moot point when talking about third world countries. Let's carry on, though.

Mammalian predators do prey on tarantulas, and spiders have a decent IC50 on rat neuroblastoma cells. Rats being a predacious mammal to tarantulas. It's in the paper that I cited first. Channels also vary within mammals, however. The second paper listed below references AUS tarantula bites on both humans and dogs. All reported bites by the tarantula resulted in death. None of the human bites resulted in serious complications other than persistent pain ranging from severe to weak. Since humans do not prey on tarantulas, at least not commonplace, there is/was no need to build a toxin against us through evolution. So, most venoms from Theraphosidae have little to no effect on us.

So, to reiterate my point, the chances of dying from a tarantula bite in terms of envenomation is slim to none. In fact, I'd go to say that there are still few deaths resulting from the mechanical aspects. I can't find the paper on my laptop, but I had one that referenced one death from a secondary pathogenic infection of a bite site, but it was not a result of the bite itself but rather a secondary infection/complication.

1.http://www.ncbi.nlm.nih.gov/pubmed/23651762
2. http://www.sciencedirect.com/science/article/pii/S0041010102003951

I can provide more papers if needed.

 

[AntikInsomniak]

This exactly - are children, women, or elderly more likely to receive fatal bites?

I found a nice article "Tarantulas:eight-legged pharmacists and combinatorial chemists" that describes the time to death in mice injected with 0.1uL of venom by several species from Africa, Asia, and America. It's not surprising that the OW are all well under 20 minutes; several (Heteroscodra, Poecilotheria, Pternochilus, Stromatopelma, etc) are well under 10. I'd post the figure, but I don't believe this counts as a classroom under fair use

@AntikInsomniak you seem to be on a much higher understanding than I about these things. Besides our sheer size difference, would you say there is something about our biology that would make us less succeptable to fatal tarantula injections regardless of size?

If a smaller/weaker specimen of the human race was bit, besides the increase in pain which would obviously increase stress levels in the bite victim, do they have a greater chance for the toxin to kill them rather than the symptoms?

Our body size has a little to play, given that the venom has to affect more tissue. Also, our cell biology differs from other animals. Mammals are more or less the same, but channels are tricky. We are not really a threat to tarantulas, evolutionary-speaking, so venom tends to not be a big issue from them. Also, venom is metabolically EXPENSIVE to make for the tarantula. It is less likely to use it on something it won't be eating. In most cases, a bite is all that is needed to ward off most prey.

 

[bryverine]

Our body size has a little to play, given that the venom has to affect more tissue. Also, our cell biology differs from other animals. Mammals are more or less the same, but channels are tricky. We are not really a threat to tarantulas, evolutionary-speaking, so venom tends to not be a big issue from them. Also, venom is metabolically EXPENSIVE to make for the tarantula. It is less likely to use it on something it won't be eating. In most cases, a bite is all that is needed to ward off most prey.

Your statement indicates to me that even a child, given the proper treatment for mechanical damage, would most likely survive a OW bite (though would be traumatized no doubt). Very interesting! I'll go ahead and keep my locks on the enclosures and room door anyways.

I had made the assumption that an adult male (~180lbs) compared to a child (~30lbs) would see the venom linearly as 6x more powerful. So this would be incorrect?

My approach to tarantulas: First start by taking your spherical tarantula then put it in a vacuum...

 

[jrh3]

veey interesting debate, now i wanna so some research on venom.

 

[AntikInsomniak]

Your statement indicates to me that even a child, given the proper treatment for mechanical damage, would most likely survive a OW bite (though would be traumatized no doubt). Very interesting! I'll go ahead and keep my locks on the enclosures and room door anyways.

I had made the assumption that an adult male (~180lbs) compared to a child (~30lbs) would see the venom linearly as 6x more powerful. So this would be incorrect?

My approach to tarantulas: First start by taking your spherical tarantula then put it in a vacuum...

Well, yes and no. IC50 does work in a linear fashion, similar to how you described. The issue is that the toxins in the venom do not specifically affect humans. Our biology differs from other animals, so the effects are quite mild. Add in that tarantulas just have intrinsically weaker venoms, they are just not meant to kill us or greatly harm us. Insects and mice? absolutely. But not so much humans.

 

[Toxoderidae]

What would happen if I got my two formerly communal regalis, and let them attack? I'm fairly small <90 pounds with a leanew build and a weak immune system. I feel like it would do much more damage than with a bite to per say, the average T keeper <180 - 230 pounds.

 

[Chris LXXIX]

Interesting question but i wouldn't rely on that too much. There's people who lived their entire life in India and never saw a genus Poecilotheria Theraphosidae.

Same for some African nations. On the other hand (among other things and interest i have, i'm an ancient masks collector, like old good Bob Ibold in the US) and there's that tribe, now "disappeared", that used genus Hysterocrates sac for making the "eyes" of their tribal masks, so technically ah ah they knewed those but IMO not the way we want.
Tough i love always to hear weird stories about T's from Natives. The more BS and drama they add, the better