Baboon spiders

[Matt W]

I'm a new spider keeper, recently picked up a couple of new world starters (C. versicolor and B. hamorii), then a few more, including one old world species: a solo juvenile M. balfouri. There are, interestingly, no actual M. balfouri bite reports here, nor on reddit and folks's typical response to the question of how venomous they are is to say "Well they're baboon spiders, so assume they have strong venom." That's probably good advice, but got me wondering what exactly is a baboon spider?

There are three broad subfamilies commonly called baboon spiders. One is Harpacterina or Southern Baboon Spiders, which includes genera like Pterinochilus and Ceratogyrus. A second is Stromatopelminae, or Western Baboon Spiders which includes the Stromatopelma genera. And finally there is subfamily Eumenophorinae or the Eumenophorine Baboon Spiders, which includes genera Monocentropus, Hysterocrates, and Pelinobius. A problem here is that these subfamilies are, apparently, not all particularly closely related. Here's a recent phylogeny from this paper:



You can see that Harpactirinae and Stromatopelminae are sister clades and are both known to have potent venom, as is their cousin clade Poecilotheriinae. Eumeniphoridae, though, is not very closely related to those and though I know there are some reports of reactions to, say, H. gigas bites (e.g. https://arachnoboards.com/threads/hysterocrates-gigas-bite.173001/) the reactions seem mild compared to the reports of bites from pokeys and OBTs.

Anyway, I don't plan to get bitten, but my point is that although M. balfouri is called a baboon spider, it isn't particularly closely related to other baboon spiders like P. murinus and you can't necessarily infer the toxicity of their venom by analogy.

 

[l4nsky]

"Baboon tarantulas" is just a colloquial term for a species native to Africa, in the same way that "Birdeaters" is a colloquial term for larger species native to South America and "Earth Tigers" is a colloquial term for species native to SE Asia.

You're diving just a little bit too far lol. These are all just informal naming conventions, no latin required .

 

[Matt W]

Interestingly, that paper is the first place I've seen that supports the idea that new and old world tarantulas diverged from ancestral groups after the breakup of Gondwana in the Triassic. I've seen earlier papers with more muddled phylogenies that suggested multiple colonization events, but this one definitely shows the bottom group of new world sub-families distinct from the top group of old world sub-families. So tarantulas are like primates with distinct old and new world populations.

"Baboon tarantulas" is just a colloquial term for a species native to Africa

Ah, I hadn't realized that, thanks! That does, however, make assigning traits by analogy even more fraught.

 

[viper69]

Rick West has a great paper on phylogeny

Nice to see someone delve into the science instead of spouting “can I train my T to eat plants”- yes this was a true question because the op was a vegetarian

 

[gabrieldezzi]

Rick West has a great paper on phylogeny

Nice to see someone delve into the science instead of spouting “can I train my T to eat plants”- yes this was a true question because the op was a vegetarian

Reminds me of when someone online was a vegan and kept trying to feed their dog plants

 

[Tentacle Toast]

This is an exceptional first thread by a new member.

 

[Matt W]

Aw thanks! If anyone is interested (and maybe this has been posted before), but there's a really good preprint article available on the incidence of arachnid bites:

Love Bites – Do Venomous Arachnids Make Safe Pets? - [v3]

I found this chart super interesting:


So, like most bites are from handling, maintenance and rehousing and almost all are on the hand. Wear protective gloves and don't handle if you'd like to avoid bites. Also interesting is that bite frequency has decreased in the last decade for unknown reasons. Also this chart:



Vertical axis is percent of bite reports that involve these genera and the horizontal axis is popularity based on number of mentions in articles about husbandry. You expect more popular spiders to have more bite reports. But you can see that pokeys and OBTs are especially bitey. and Brachypelmas are especially docile. Surprising maybe that Grammostolas are bitey too. Maybe it's because G. rosea and G. pulchripes seem like spiders you can handle?

 

[The Spider House]

Reminds me of when someone online was a vegan and kept trying to feed their dog plants

I was walking my dog today. A woman stopped me and said I know you from the vegetarian club.
I had never seen herbivore.

 

[Tarantuland]

Balfouris are possibly the most docile old world species, but a bite would hurt I'm sure. I love that Love bites preprint article you posted. While it hasn't been published yet, It's very helpful information. People report P muticus king baboon spider bites being brutal, so maybe balfouri would be similar. From what I've seen and heard, S cal bites seem more likely and much worse and Poectilotheria sp

 

[Olan]

Its a good point, Eumenophorinae not being related to other African groups does raise the question of whether their bites are similarly nasty.

Balfouris are possibly the most docile old world species, but a bite would hurt I'm sure. I love that Love bites preprint article you posted. While it hasn't been published yet, It's very helpful information. People report P muticus king baboon spider bites being brutal, so maybe balfouri would be similar. From what I've seen and heard, S cal bites seem more likely and much worse and Poectilotheria sp

Yeah, I remember someone on here reporting nasty effects of P. muticus bite. So likely the whole group is reasonably bad.
I keep a lot of Eumenophorinae. But unfortunately for science, I have never been bitten.

 

[ComputerDellLI]

Its a good point, Eumenophorinae not being related to other African groups does raise the question of whether their bites are similarly nasty.
Yeah, I remember someone on here reporting nasty effects of P. muticus bite. So likely the whole group is reasonably bad.
I keep a lot of Eumenophorinae. But unfortunately for science, I have never been bitten.

The venom is also reported to be hallucinogenic.

 

[jbooth]

I think pretty much anything causing a 103+ fever is hallucinogenic, at least I was hallucinating when I was that sick, or is it a tryptamine? Heteroscodra maculata is another one, not a baboon, but sure does mimic one well The stout-legged pink-toe

 

[Ultum4Spiderz]

I think pretty much anything causing a 103+ fever is hallucinogenic, at least I was hallucinating when I was that sick, or is it a tryptamine? Heteroscodra maculata is another one, not a baboon, but sure does mimic one well The stout-legged pink-toe

I thought Heteroscodra maculata Is considered the ornamental baboon. I’ve never been bitten by an old world and only have one currently a s cal.

 

[jbooth]

I thought Heteroscodra maculata Is considered the ornamental baboon.

It is, they put it in the Aviculariinae subfamily though.

 

[Olan]

But the recent paper puts them near Harpactirinae:

I'm a new spider keeper, recently picked up a couple of new world starters (C. versicolor and B. hamorii), then a few more, including one old world species: a solo juvenile M. balfouri. There are, interestingly, no actual M. balfouri bite reports here, nor on reddit and folks's typical response to the question of how venomous they are is to say "Well they're baboon spiders, so assume they have strong venom." That's probably good advice, but got me wondering what exactly is a baboon spider?

There are three broad subfamilies commonly called baboon spiders. One is Harpacterina or Southern Baboon Spiders, which includes genera like Pterinochilus and Ceratogyrus. A second is Stromatopelminae, or Western Baboon Spiders which includes the Stromatopelma genera. And finally there is subfamily Eumenophorinae or the Eumenophorine Baboon Spiders, which includes genera Monocentropus, Hysterocrates, and Pelinobius. A problem here is that these subfamilies are, apparently, not all particularly closely related. Here's a recent phylogeny from this paper:

View attachment 460854

You can see that Harpactirinae and Stromatopelminae are sister clades and are both known to have potent venom, as is their cousin clade Poecilotheriinae. Eumeniphoridae, though, is not very closely related to those and though I know there are some reports of reactions to, say, H. gigas bites (e.g. https://arachnoboards.com/threads/hysterocrates-gigas-bite.173001/) the reactions seem mild compared to the reports of bites from pokeys and OBTs.

Anyway, I don't plan to get bitten, but my point is that although M. balfouri is called a baboon spider, it isn't particularly closely related to other baboon spiders like P. murinus and you can't necessarily infer the toxicity of their venom by analogy.

 

[l4nsky]

Ah, I hadn't realized that, thanks! That does, however, make assigning traits by analogy even more fraught.

Yes and no. IMO, the association of all baboons being in possession of a potent venom has more to do with them being considered Old World tarantulas as opposed to having the common name of 'xyz baboon'.

IMHO, I think a better general indicator of venom potency would likely be the presence of urticating hairs or not. If you think about it, New Worlds are generally regarded as having weaker venom and those with such a reputation all have urticating hairs as a primary line of defense. Those that break this NW mold and lack urticating hairs, like Psalmopoeus spp and Tapinauchenius spp, are all considered to have more potent venom then their other NW counterparts, which I believe is because the venom is now the primary line of defense.

In the end though, venom potency is really only one part of the equation when you're talking about the damage these animals can do. I mean, Theraphosa spp may have a potentially weaker venom than say a Poecilotheria spp, but it has A LOT more of it by comparison and the physical damage from those fangs could include severed muscle, tendons, and secondary infections. It's all relative I guess lol.

 

[Ultum4Spiderz]

It is, they put it in the Aviculariinae subfamily though.

I had no clue I guess I’m out of date this species was switched genus. But it’s still known a baboon spider and old world even if it’s no longer classified as such . thanks for the information.

I'm a new spider keeper, recently picked up a couple of new world starters (C. versicolor and B. hamorii), then a few more, including one old world species: a solo juvenile M. balfouri. There are, interestingly, no actual M. balfouri bite reports here, nor on reddit and folks's typical response to the question of how venomous they are is to say "Well they're baboon spiders, so assume they have strong venom." That's probably good advice, but got me wondering what exactly is a baboon spider?

There are three broad subfamilies commonly called baboon spiders. One is Harpacterina or Southern Baboon Spiders, which includes genera like Pterinochilus and Ceratogyrus. A second is Stromatopelminae, or Western Baboon Spiders which includes the Stromatopelma genera. And finally there is subfamily Eumenophorinae or the Eumenophorine Baboon Spiders, which includes genera Monocentropus, Hysterocrates, and Pelinobius. A problem here is that these subfamilies are, apparently, not all particularly closely related. Here's a recent phylogeny from this paper:

View attachment 460854

You can see that Harpactirinae and Stromatopelminae are sister clades and are both known to have potent venom, as is their cousin clade Poecilotheriinae. Eumeniphoridae, though, is not very closely related to those and though I know there are some reports of reactions to, say, H. gigas bites (e.g. https://arachnoboards.com/threads/hysterocrates-gigas-bite.173001/) the reactions seem mild compared to the reports of bites from pokeys and OBTs.

Anyway, I don't plan to get bitten, but my point is that although M. balfouri is called a baboon spider, it isn't particularly closely related to other baboon spiders like P. murinus and you can't necessarily infer the toxicity of their venom by analogy.

best guide I’ve seen so far on
baboon spiders.

 

[slocoj91]

Yes and no. IMO, the association of all baboons being in possession of a potent venom has more to do with them being considered Old World tarantulas as opposed to having the common name of 'xyz baboon'.

IMHO, I think a better general indicator of venom potency would likely be the presence of urticating hairs or not. If you think about it, New Worlds are generally regarded as having weaker venom and those with such a reputation all have urticating hairs as a primary line of defense. Those that break this NW mold and lack urticating hairs, like Psalmopoeus spp and Tapinauchenius spp, are all considered to have more potent venom then their other NW counterparts, which I believe is because the venom is now the primary line of defense.

In the end though, venom potency is really only one part of the equation when you're talking about the damage these animals can do. I mean, Theraphosa spp may have a potentially weaker venom than say a Poecilotheria spp, but it has A LOT more of it by comparison and the physical damage from those fangs could include severed muscle, tendons, and secondary infections. It's all relative I guess lol.

This. Venom potency, quantities available, willingness to use it, plus mechanics of the bite/size of fangs (and potentially intended purpose of the bite), and any alternative defense mechanisms available will play a part.

The thread here has made me wonder, though, whether there are factors related to captivity that influence some of those items above.

To clarify, one might assume that the lack of typical threats present in the wild may result in an 'abundance' of venom - lots available or able to be produced if any is used, little need to use it. Now I need to check if venom is produced until capacity is reached, or if its a selective or semi selective process - ie can the store be empty but no venom produced simply because instinct says there'll be no need for it, or is it produced when there's enough or an abundance of certain nutrients? Will it be produced even if this means a lack of those nutrients elsewhere? With these questions in mind, I could it be reasonably assumed that due to the abundance of food in captivity, meaning good access to nutrition, then venom production would be more likely? Or does that abundance of food combined with absence of predators mean that venom is less likely to be needed, so in the event stores were used maybe it wouldn't be replenished at the same rate as for Ts in the wild...in this case slower?
Does having a keeper selecting appropriately sized prey - meaning there's little need for any overt subduing of food - mean venom is used less?

If anyone has resources on anything like that I'd be interested to see. I do have a WSC sub, though I sometimes don't get on with its search. And apologies if I've got any details of what I say above incorrect - I haven't dedicated much time to reading about venom delivery and such, as I don't intend to need the information! I like to learn just because, I just haven't had much time to dedicate recently due to useless gvment agencies

 

[AphonopelmaTX]

In the end though, venom potency is really only one part of the equation when you're talking about the damage these animals can do. I mean, Theraphosa spp may have a potentially weaker venom than say a Poecilotheria spp, but it has A LOT more of it by comparison and the physical damage from those fangs could include severed muscle, tendons, and secondary infections. It's all relative I guess lol.

What has led to you to believe a Theraphosa species produces a higher volume of venom than a Poecilotheria species?

 

[l4nsky]

What has led to you to believe a Theraphosa species produces a higher volume of venom than a Poecilotheria species?

Uggh, this is going to quickly devolve isn't it? I'm going to say inference based upon adult size (and confirm I was talking about adults and not similarily sized juveniles because I wasn't clear), then you're going to ask me to quote a paper, then I'm going to say I don't know of one, and then I'm going to ask you to quote a paper saying that they don't and then you're not going to be able to provide one because Theraphosids in general are extremely understudied and then we're going to agree to disagree as there isn't anything proving either of us correct, then I'm going to modify my statement to read "it can be reasonably inferred that...." in light of this, then we'll be done......

Yeah, I'm just going to skip to the end here.....