Just how venomous are Sicarius?

[Tarantula_man94]

i think they use nerotoxins of some kind

 

[tarantulasperu]

their venom is quite a powerful necrotic type ive had one catch a small lizard and kill it instantly. i checked were the spider pt him and that part was completly liquified

 

[EMW Black Mamba]

If you get bitten you have a problem, but you gotta make sure they can't escape. They can't climb like tarantula's.
I read a lot about dangerous this and dangerous that. The one I have lives in a terrarium in my bedroom. I only open the box for feeding and cleaning up. A sand terrarium is easy to clean with a tea strainer.
The spider isn't dangerous. The careless owner is dangerous.

 

[Venom1080]

The spider isn't dangerous. The careless owner is dangerous.

wheres the logic in that? the owner is only a danger to himself. not our problem.

 

[Crone Returns]

wheres the logic in that? the owner is only a danger to himself. not our problem.

This is a very intetesting thread. Thanks for opening it up, Venom.

 

[Venom1080]

This is a very intetesting thread. Thanks for opening it up, Venom.

hey blame EMW Black Mamba or whatever.

 

[Crone Returns]

hey blame EMW Black Mamba or whatever.

Naw...I leave Black Mambas alone.

 

[DrPonts]

They are far, FAR beyond the widow / recluse spiders in toxicity, and probably more toxic than the funnelwebs ( Atrax and Hadronyche ) as well. These are absolutely at the top of arachnid toxins, and they can very easily kill a human, none of this "dangerous for children/ elderly" stuff.

As for the specifics, the genus Sicarius is in Sicariidae along with the recluse spiders, their close relatives. They therefore share the same toxic compound: Sphingomyelinase D, an enzyme which acts to dissolve tissues. In otherwords, it is a cytotoxic venom: it acts by "popping" all kinds of cells, bursting them like balloons. However, in the Sicarius venom, this toxin is far more concentrated than in recluse venom, which, coupled with the Sicarius' large size ( 3+ inches ), means this species injects both more venom, and a much more toxic venom than our native L. reclusa. This has a number of wide-ranging effects. First of all, like the recluse spiders, it causes a spreading wound of tissue death: a necrotic sore. Unlike the typical recluse bite, this very easily can become enormous, and cause the loss of a limb (a documented occurrence). Massive local tissue loss is expected to be typical, rather than the exception.

Secondly, the venom of Sicarius, like that of Loxosceles, bears the possibility of leaching out into the bloodstream, where it attacks red blood cells. ( only, again, on a more massive level than L.reclusa ). This first causes a loss of red blood cells to carry oxygen, but no problem, these can be replaced by the spleen and bone marrow. The problem comes in with what happens to the dead blood cells: they become so numerous, as more blood cells are "popped," then replaced, and the replacements "popped," that the bloodstream ends up carrying more skins of blood cells than the kidneys can filter or the liver can absorb. This sheer overload of dead cell membranes in the blood shuts down the kidneys.

However, the death of blood cells is not the only cardiovascular problem to occur. The arteries and veins are also composed of soft cells, and so are vulnerable to the venom, which attacks them also, wearing away the integrity of your blood vessels ( it's an equal-opportunity destroyer, rupturing every cell-based tissue it contacts ). This results in hemorrhages throughout the body, as blood vessels become weakened from the action of the venom, and begin rupturing here and there ( aneurysms ).

Clotting is also messed up, as the venom causes the blood, thickened with its own dead cells, to clot. This produces millions of tiny blood clots everywhere in the circulatory system, which lodge in vessels ( especially the narrow capillaries ), and cause occlusions, which cut off blood supply in random regions of the body, which results in more areas of necrotic tissue developing. This action of the venom can result in strokes, heart attacks, and other occlusion conditons, in addition to the aneurysm epidemic as weakened blood vessels lose integrity.


But wait, there's more. The venom also causes swelling of the liver, and heart damage, and leaves you open to massive infection of your gaping bite-area wound.

So there you have it: your kidneys shut down, the heart and liver are being damaged, heart attacks, strokes and aneurysms are going off all over. You have no blood flow to speak of, and tissue is dying right left and center, even far away from the bite site. You have the equivalent of accellerated leprosy, combined with Ebola. There is no antivenom. Have a nice day.




Yes, extremely new. They have not been in the US hobby until last fall I believe. Even so, they are very scarce, and only a handful are available at a time.



Probably. Most true spiders can, and with the nearness of relation of Sicariidae to Sparassidae, I would expect the glass climbing ability to be present in Sicarius as well.



Hmm, haven't heard anything about this. I really doubt it though.



They are EXTREMELY quick, agile, and maneuverable. Just check out the videos on Youtube. Lightning quick, and strong feeding response.



That would be an appropriate caution. You don't want this escaping, or anyone tampering with it. As always, though, count the cost. These things are risky, and the cost for a mistake is your life. This isn't a widow, where an "oops" is pretty much survival guaranteed, unless you're a kid, elderly or ill. These have a VERY high chance of fatality, and even if you survive, you have the (VERY STRONG ) possibility of heart, liver, kidney, muscle, and brain damage. Don't think I am exaggerating, these are at least as toxic as Atrax robustus, and far worse than Phoneutria in overall effect. You won't walk away unscathed. Or, I'll put it this way. I know of two documented bite cases from a Sicarius sp. One was fatal, and the other man lost his arm. That's 50% established fatality, and 100% morbidity so far in documented cases. Not statistics to be fooling with or taking lightly.

So please, consider whether you are ready for this kind of animal. They really ought to be an experts-only species.

Very great description of this venom's effect! One further thing to consider is that with all those dead blood cells clotting up everywhere, causing ischemia/infarction, they are probably going to use up a TON of the body's clotting factors, which will then result in the paradoxical simultaneous diffuse clotting and inability to stop bleeding (DIC, disseminated intravascular coagulation), which will certainly exacerbate the aforementioned hemorrhages. Very, very difficult to survive something that gets that bad.

 

[Andrea82]

The stories about them not being able to climb are not really true either. Where the edges of the enclosures are sealed together with that glue (I don't know the word in english, we just call it kit), it provides enough if a rough surface for it to climb on.

They look adorable when digging, but with that kind of venom and abilities...no thank you.

 

[RTTB]

They are far, FAR beyond the widow / recluse spiders in toxicity, and probably more toxic than the funnelwebs ( Atrax and Hadronyche ) as well. These are absolutely at the top of arachnid toxins, and they can very easily kill a human, none of this "dangerous for children/ elderly" stuff.

As for the specifics, the genus Sicarius is in Sicariidae along with the recluse spiders, their close relatives. They therefore share the same toxic compound: Sphingomyelinase D, an enzyme which acts to dissolve tissues. In otherwords, it is a cytotoxic venom: it acts by "popping" all kinds of cells, bursting them like balloons. However, in the Sicarius venom, this toxin is far more concentrated than in recluse venom, which, coupled with the Sicarius' large size ( 3+ inches ), means this species injects both more venom, and a much more toxic venom than our native L. reclusa. This has a number of wide-ranging effects. First of all, like the recluse spiders, it causes a spreading wound of tissue death: a necrotic sore. Unlike the typical recluse bite, this very easily can become enormous, and cause the loss of a limb (a documented occurrence). Massive local tissue loss is expected to be typical, rather than the exception.

Secondly, the venom of Sicarius, like that of Loxosceles, bears the possibility of leaching out into the bloodstream, where it attacks red blood cells. ( only, again, on a more massive level than L.reclusa ). This first causes a loss of red blood cells to carry oxygen, but no problem, these can be replaced by the spleen and bone marrow. The problem comes in with what happens to the dead blood cells: they become so numerous, as more blood cells are "popped," then replaced, and the replacements "popped," that the bloodstream ends up carrying more skins of blood cells than the kidneys can filter or the liver can absorb. This sheer overload of dead cell membranes in the blood shuts down the kidneys.

However, the death of blood cells is not the only cardiovascular problem to occur. The arteries and veins are also composed of soft cells, and so are vulnerable to the venom, which attacks them also, wearing away the integrity of your blood vessels ( it's an equal-opportunity destroyer, rupturing every cell-based tissue it contacts ). This results in hemorrhages throughout the body, as blood vessels become weakened from the action of the venom, and begin rupturing here and there ( aneurysms ).

Clotting is also messed up, as the venom causes the blood, thickened with its own dead cells, to clot. This produces millions of tiny blood clots everywhere in the circulatory system, which lodge in vessels ( especially the narrow capillaries ), and cause occlusions, which cut off blood supply in random regions of the body, which results in more areas of necrotic tissue developing. This action of the venom can result in strokes, heart attacks, and other occlusion conditons, in addition to the aneurysm epidemic as weakened blood vessels lose integrity.


But wait, there's more. The venom also causes swelling of the liver, and heart damage, and leaves you open to massive infection of your gaping bite-area wound.

So there you have it: your kidneys shut down, the heart and liver are being damaged, heart attacks, strokes and aneurysms are going off all over. You have no blood flow to speak of, and tissue is dying right left and center, even far away from the bite site. You have the equivalent of accellerated leprosy, combined with Ebola. There is no antivenom. Have a nice day.




Yes, extremely new. They have not been in the US hobby until last fall I believe. Even so, they are very scarce, and only a handful are available at a time.



Probably. Most true spiders can, and with the nearness of relation of Sicariidae to Sparassidae, I would expect the glass climbing ability to be present in Sicarius as well.



Hmm, haven't heard anything about this. I really doubt it though.



They are EXTREMELY quick, agile, and maneuverable. Just check out the videos on Youtube. Lightning quick, and strong feeding response.



That would be an appropriate caution. You don't want this escaping, or anyone tampering with it. As always, though, count the cost. These things are risky, and the cost for a mistake is your life. This isn't a widow, where an "oops" is pretty much survival guaranteed, unless you're a kid, elderly or ill. These have a VERY high chance of fatality, and even if you survive, you have the (VERY STRONG ) possibility of heart, liver, kidney, muscle, and brain damage. Don't think I am exaggerating, these are at least as toxic as Atrax robustus, and far worse than Phoneutria in overall effect. You won't walk away unscathed. Or, I'll put it this way. I know of two documented bite cases from a Sicarius sp. One was fatal, and the other man lost his arm. That's 50% established fatality, and 100% morbidity so far in documented cases. Not statistics to be fooling with or taking lightly.

So please, consider whether you are ready for this kind of animal. They really ought to be an experts-only species.

 

[RTTB]

I find it amazing that such a small creature has such a potent venom. I am curious as to where/what type of environment they live in. Maintaining them in captivity seems like to equivalent of keeping a Black Mamba. High risk potential.

 

[basin79]

I find it amazing that such a small creature has such a potent venom. I am curious as to where/what type of environment they live in. Maintaining them in captivity seems like to equivalent of keeping a Black Mamba. High risk potential.

They're desert dwellers. So when food happens to come by they have to make sure it doesn't escape. They're unbelievably simple to keep and pose absolutely no threat if you use tongs. They're not aggressive and can't climb smooth surfaces.

 

[Tuffz]

What really scares me is how cheap they seem to be (might be wrong but i just searched over some exchange boards). I just saw some slings of Sicarius terrosus for 18€a piece... They could easily get in the wrong hands for that price

 

[RTTB]

Just watched a couple videos on them. Fascinating. I totally understand the interest in them.

 

[schmiggle]

They're desert dwellers. So when food happens to come by they have to make sure it doesn't escape. They're unbelievably simple to keep and pose absolutely no threat if you use tongs. They're not aggressive and can't climb smooth surfaces.

While this is true, I have seen people who have had issues with sicarius climbing the rubber seal on a terrarium, which I think had collected sand. So perhaps "absolutely no threat as long as you use tongs and make sure that your terrarium is actually composed only of smooth surfaces."

 

[Chris LXXIX]

What really scares me is how cheap they seem to be (might be wrong but i just searched over some exchange boards). I just saw some slings of Sicarius terrosus for 18€a piece... They could easily get in the wrong hands for that price

Ah ah, said a similar thing once and I've ended lambasted, eh eh :-/

Anyway, man, especially in UK and Poland, there was that (genus) Sicarius rapture, lol. While I found them interesting for less than 5 minutes, I also think they are boring as hell, plus, I like a somewhat attitude. I would take a M.calpeiana anytime, on that sense.

 

[Nephila Edulis]

So sicarius are basically the inland taipan of spiders? Actually, that fits quite well. Both live in the desert, aren't too aggressive, are rarely seen, are very fast and aren't seen on the surface too much

 

[Nephila Edulis]

So... the inland taipan of spiders in other words?

 

[Rick McJimsey]

Hi,

If you're interested in learning more about the venom of Sicarius and Hexophthalma, check out these two articles. There is much more to it than what is in this thread.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3749972/

https://academic.oup.com/zoolinnean...rs-Araneae-Haplogynae?redirectedFrom=fulltext

 

[edesign]

Excellent, thank you Rick!

So, if I'm following what I've read correctly (still working through the second link but I'm an engineer, not a biology related field, so I don't understand it in detail but try to follow the main gist), italics for fun and to help point out spiders involved, the Brazilian Sicarius ornatus venom has active effects that match those of Brazilian Loxosceles spp. which confirms it has toxicity in humans and what some of those effects would be.

From the second link:
"However, despite the presence of SMase D like proteins in venoms of several New World Sicarius species, they had reduced or no detectable SMase D activity."

So it points out that there is a difference between presence and activity in that it can be present but not active noting that the African species (Hexophthalma genus, more on that below) venoms' showed high activity levels in previously published papers by the same author(s). I'm curious how it could be present but not active. Anyone know? In layman's terms if possible lol.

Noting that discrepancy about presence not necessarily indicating activity they tested the venom effects against venoms with known effects and compared.

I also noticed that the authors mention an "intraspecific variation" in that the female's venom was stronger than the males in S. ornatus both in observed effects and some kind of testing method.

My takeaway from this, and why you mentioned there is much more to it than what's in this thread, if I haven't completely misunderstood what I've read...

The first link outlines some taxonomy changes that were published in March of this year. It notes Sicarius from the Americas and Africa have an "interesting" taxonomic structure (they used much fancier words, I looked them up, sorta understood, I think lol) which led the authors to resurrect the genus Hexophthalma for the old African Sicarius. Because of their taxonomic structure and the venom potency variation observed between male and female S. ornatus there could be reason to believe that there is variation in the strength of venom between the African and American genera (the venom paper was written about four years before the taxonomy restructure but did specifically mention it in regards to New World species).

Any reason it couldn't have carried over to the Hexophthalma species beyond a single ancestor that didn't have that trait (could be formed through mutation later on though)? If I understood the basics of the genus structure type correctly from the diagrams on Wikipedia about (reciprocal) monophyletic groups.

Or am I so far lost that SAR has been called off? lol