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Just how venomous are Sicarius?

Venom

Arachnoprince
Old Timer
Joined
Jul 21, 2002
Messages
1,709
The worst part about neurotoxin is that it is fast...very fast. But stoppable. Cytotoxin is slower, but much less can be done about it.

The S.hahnii / S.terrosus thing....is more or less academic IMO. We do know that Sicarius hahnii is likely the most toxic of its genus, but we don't know by how much. I am not aware of any testing having been done on S.terrosus, and certainly not much in the way of bite / venom figures are known for S. terrosus. We don't know whether it is 50% less venomous than S.hahnii, or only 5% less venomous. The difference might be significant, or slight. In either case, any Sicarius is going to be at least as toxic as the higher-end Loxosceles. I don't see S.terrosus being less potent than L. laeta, and L. laeta has fatalities.

In defining shades of toxicity among the Sicariids, we are splitting hairs. It's like comparing an Exocet missle with a Sidewinder missle. BOOOM or Booom-- you still have a problem. Regardless of how S. terrosus stacks up against S. hahnii, it is still very toxic, and the potential for a very strong envenomation is very real, especially considering how little we know about these things, and how the various species compare. I'm sticking with my original info, that these CAN cause strong systemic effects.
 

cogmonkey17

Arachnopeon
Joined
Jul 7, 2008
Messages
26
obvious observation

these Sicarius spp. and Loxosceles spp. sound like twins, I've been trying control the recluse population in our house (secluding them as pets, with possible matings for fun), I wouldn't feel to swell if a fellow family member (including animals) were injured because of my hobbies, i believe capturing and enclosing the little guys would pose much less danger than having a potentially pain-full experience wait in your clothes(they are also killing off most of the wolf spider population). Anyway, all the Loxosceles spp. that i see are ALWAYS on the ground, i have yet to see a specimen roaming on an elevated area (no matter what degree). I haven't seen a Sicarius spp., but im sure they share the same behavior. Since they are small spiders, that are not dependent are webbing, or size, to trap prey, it's imperative for them to have a potent venom, i guess since Sicarius is a desert dweller with very little opportunity, they need the extra spice for what prey they do come by...... One guy ruins it for everyone else, it's not just pet owners though, back when scientist used African Clawed Frogs for pregnancy test (40s?), when they didn't need the frogs anymore they just tossed em out back in the woods, now they are illegal to keep in some states and killing off native frogs. Unfortunately the government has to be strict, they are just doing their job though, and their is enough information out here for them to make a fair decision, educating anyone you come across can only make this info more readily available (how can they deny you if you have a Tarantula Shirt on), we responsible hobbyist as just as much at fault as the others.
 

cjm1991

Arachnoprince
Old Timer
Joined
Apr 25, 2008
Messages
1,210
on a serious note tho all it will take is one person to die from a bite and that could easily have a huge impact on our hobby.i
Thats very true.

I was interested in a A.Robusta until I realised how big of deal they can become. So I limit myself with my Deathstalkers( only becuase they cannot climb glass). A spider like that, especially if its able to climb slick surfaces is not the best spider to keep.. think of the consiquences you know? For the sake of the hobby if not for yourself.
 

proper_tea

Arachnobaron
Old Timer
Joined
Oct 11, 2007
Messages
551
Does anyone have any knowledge of research being currently done to establish more reliable toxicity information on these spiders. They are something I am considering keeping a few years down the road, when/if there is more information available, but personally I don't feel like I have the experience/guts for them right now. I generally don't have any interest in keeping hot species, but these are behaviorly so very charming that I want one. If terrosus is like getting tagged by a recluse... that's a risk I can handle... if it's "there's no anti-venom and yet gonna die..." I might just have to keep watching youtube videos of other people's spiders for a while.
 

coffin pest

Arachnopeon
Joined
Jun 17, 2008
Messages
28
I have heard accounts of victims of the Sicarius hahni requiring immediate amputation to save the life of the victim, but the toxicological research is scarce and hazy. What is known is that Siciarius sp. venom contains higher quantities of the amino acid sphingomyelinase D (juxtaposed with Loxosceles laeta that is), which is the agent attributed to dermonecrosis in mammals.
I don't really believe that the effects of a brown relcluse come close to those of Sicarius sp. (be it hahni or terrosus-the two most common); in terms of venom toxicity and reactivity with cells (cytotoxicity) Sicarius is a heavyweight, of that you can be sure. Let the buyer beware.
 

proper_tea

Arachnobaron
Old Timer
Joined
Oct 11, 2007
Messages
551
I don't really believe that the effects of a brown relcluse come close to those of Sicarius sp. (be it hahni or terrosus-the two most common); in terms of venom toxicity and reactivity with cells (cytotoxicity) Sicarius is a heavyweight, of that you can be sure. Let the buyer beware.
Yeah... sounds like it will be a number of years before I consider getting one of these...

bummer, really, cause they're adorable...
 

Venom

Arachnoprince
Old Timer
Joined
Jul 21, 2002
Messages
1,709
I have heard accounts of victims of the Sicarius hahni requiring immediate amputation to save the life of the victim, but the toxicological research is scarce and hazy. What is known is that Siciarius sp. venom contains higher quantities of the amino acid sphingomyelinase D (juxtaposed with Loxosceles laeta that is), which is the agent attributed to dermonecrosis in mammals.
I don't really believe that the effects of a brown relcluse come close to those of Sicarius sp. (be it hahni or terrosus-the two most common); in terms of venom toxicity and reactivity with cells (cytotoxicity) Sicarius is a heavyweight, of that you can be sure. Let the buyer beware.
Well said! :clap:
 

buthus

Arachnoprince
Old Timer
Joined
Jun 8, 2006
Messages
1,381
I have heard accounts of victims of the Sicarius hahni requiring immediate amputation to save the life of the victim, ...
You live up in the Bay Area? ...where ya hear these accounts?

Ok.. all of the crap ive read has been just that...crap.
Supposably 2 victims recorded ...both died. Thats the story that keeps going round and round. Does anyone have any official and/or media documentation that proves this?

I will venture to say.. there is a GOOD chance that NO human being has ever been bitten by a Sicarius. Science CAN be boring 'cause life can be mundane.
 

coffin pest

Arachnopeon
Joined
Jun 17, 2008
Messages
28
That's rather slippery of you, buthus. Perhaps I was too colloquial with one of my written sentences. Let me rephrase myself; "I have happened upon written rumors concerning this spider, consisting of envenomations that have taken place in a third-world country". I cannot ascertain the credibility behind these "stories". But the toxicology behind sphingomyelinase D is not crap, I assure you.
 

coffin pest

Arachnopeon
Joined
Jun 17, 2008
Messages
28
This data is extrapolated from "The phylogenetic distribution of shingomyelinase D activity in venome of Haplogyne spiders", credit to Greta Binford and Michael Wells, Department of Biochemistry and Molecular Biophysics, Univ. of Arizona>
As we all know, the bites from spiders in the genus Loxesceles cause severe necrotic lesions and varied systemic effects in humans throughought the world. Now, this information presupposes that one takes into account the importance of Sicarius sp. be a relative of Loxesceles sp. Loxesceles being distributed throughout the Americas Mediiterranean Europe and Africa as well, Siciarus delimited to regions of central America and North Africa primarily. This information is propadeutic and appurtenant to certain individuals who may become confused to the location of these spiders in relation to myself in the Bay Area :D.
There is sound clinical and experimental research regarding the dermenecrotic effects evinced in human flesh resulting from bites of the six eyed crab spider in the genus Sicarius (Newlands, 1982, Van Aswegan et al, 1997). This is empirical fact supporting the notion that the venoms from both Siciarus and Locesceles contain respective quantities of molecules of sphingomyelinase D (SMD), pertinent because SMD is quite possibly the only molecule, at least under the concernment of spiders, that produces necrotic effects in subjects of the mammalian type.
Loxesceles aside, spiders of Sicarius hahnii exhibited 193.2 micrograms of the molecule SMD within venom sample and Sicarius Testaceus exhibited 331.4 micrograms of SMD. Comparatively, loxesceles reclusa exhibited 30.0 micrograms of SMD. All venoms were milked from adult females.
Thus, we infer from this that Sicarius venom has the potential of containing several times the amount of SMD as that of most loxesceles sp.
I'm not familiar with the two deaths aforementioned in this thread, but I am aware of the causal properties of Siciarus sp. venom, and its propensity towards massive cellular destruction upon mammalian tissues. In fact, some African researchers have described Sicarius sp. as the most dangerous spider in the known world, however the behavioral characteristics and environment conditions of their habitations makes human contact with these animals rare (Newlands and Atkinson, 1990).
Goodnight.
-Patrick
 
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Venom

Arachnoprince
Old Timer
Joined
Jul 21, 2002
Messages
1,709
Then again, Buthus, if you don't believe the toxicology data, you could always do like Cacoseraph, our human venom lab! ;)

I say that in jest, I really really don't want to see you or anyone else bitten by one of these. Their venom is no joke.
 

buthus

Arachnoprince
Old Timer
Joined
Jun 8, 2006
Messages
1,381
That's rather slippery of you, buthus. Perhaps I was too colloquial with one of my written sentences. Let me rephrase myself; "I have happened upon written rumors concerning this spider, consisting of envenomations that have taken place in a third-world country". I cannot ascertain the credibility behind these "stories". But the toxicology behind sphingomyelinase D is not crap, I assure you.
If I was being slippery, you'd be still slippin'! :D No... just calling u out and you recovered instantly. (please always take me with a good dose of humor)
We just need to stop the spread of false or unsubstantiated info. You do a search on "Sicarius" and guess where you end up?.. on a thread like this one at Arachnoboards ...learnin' all that we know about em.
The venom... not denying that they have a nasty venom. I DO have my doubts regarding bites/deaths and the amount of monster-like danger assigned to these species.

Ok.. now from what I have gathered (yes, Im terrible with sources) recluse species have been slowly but surely downgraded when it comes to their medical significance AND it looks like MOST wounds diagnosed as recluse bites where/are probably something else.
Hobo spiders are still holding on to there monster status, but there has been no proof that they deserve such a status and again, I have run into lit that states that fact. 1000s of years in Europe living with man and they never gained such a rep. A few years in the US and all of a sudden, they are dangerous. :?

So.. Sicarius ...its bite dosage is 4 times (or whatever) worse than "not so bad".

Im not trying to downgrade the danger, but I am trying balance reality with the myth. Those of us into venomous creatures tend to want these things extra scary ...its more exciting that way, but its not so great for the sake of general knowledge.
 

Venom

Arachnoprince
Old Timer
Joined
Jul 21, 2002
Messages
1,709
I understand your point, buthus. A lot of what we hear is hard to track back to the original source, if there indeed is one. I first read, however, of the toxicity of this species, and of the human deaths, on the website of a natural history museum based in Zambia, Africa, so I'm pretty sure they knew their stuff. Other sources I've checked include a survey of hazardous invertebrate species conducted by the US military. The testing done on the venom of Sicarius sp. seems to indicate they have approx 10x the concentration of SMD ( sphingomyelinase-D) in their venom, when compared to Loxosceles reclusa. The test was done on equal quantities ( volume to volume ) of venom, which thus does not test for the larger quantity of venom that a 2 - 3 inch Sicarius could yield, when compared with a 1 - 2 inch Loxosceles sp. Both volume and toxicity are thus superior to Loxosceles sp.

I believe the toxicity of T.agrestis is pretty well established also, but I will check up on that, and do some more research.
 

coffin pest

Arachnopeon
Joined
Jun 17, 2008
Messages
28
Not a problem, buthus. Your suspicion brings upon relevant conversation. I didn't mean to be excessively serious.
Now, one has every right to question the nature (i.e. element of danger) of Sicarius sp. simply because so little is known. That is fair. However, let's consider this from a different angle.
The infamous spiders Phoneutria nigriventer and Atrax robustus have developed their ill repute due to numerous encounters with human beings. That's not to say that their agressiveness and prowess were not at play there, but a multitude of cases and mishaps involving people certainly do not imbue their "public relations" with any positivity. Quite the contrary. For that is what makes them "infamous".
Sicarius sp., on the other hand, is, to an extent, an unknown; a wild-card. Rarely seen, the spiders' bite has become perhaps over inflated. Perhaps. I don't know, but toxicology conclusions speak for themselves I think. Although records of human envenomation are inadequate.
Our ignorance concerning this spider makes it that much more pertinent and significant.
-Patrick
 

Raikiri

Arachnosquire
Old Timer
Joined
May 10, 2006
Messages
95
Hi,

I'm reading this thread from the beginning, and to be honest I don't understand why do you fear of Sicarius spp. I have terrosus for ages, also from different bloodlines, I've breed this species, raised from 1. instar to adulthood and I haven't ever notice any attack, even a little bit higher defense aginst me. Their venom is very dangerous, that's right, but they are so gentle. My females didn't try to bite the male, when I moved them with a tweezer they just ran away. Very easy to control, and no attacks. Loxosceles spp. do attack, bite my tweezers and the male, but IMO Sicarius spp. are not so dangerous !IF! you know how to control it. It's like a granny with a shotgun.. The weapon is dangerous, but the user is not at all.
 

coffin pest

Arachnopeon
Joined
Jun 17, 2008
Messages
28
I, too, keep terrosus and it is of very calm temperament. So, you're right about that. I wouldn't handle it though {D .
 

Raikiri

Arachnosquire
Old Timer
Joined
May 10, 2006
Messages
95
Yeah, of course they are not toys to handle them. Anyway I don't handle spiders what are big enough to bite me. They can sense the skin on my hand, recognise the tissue, they now I'm a living creature not a piece of wood, so any movement what can the spider senses as an attack may cause a bite.
 

tarantulasperu

Arachnopeon
Joined
Jul 22, 2008
Messages
46
ive been bitten by a Sicarius terrosus

these spiders are very common in peru and until now i didnt know they were poisonous i just guessed they were harmless:wall: . In peru i would go to the deserts and collect these spiders by hand. they are extremely docile and will not bite even if grabbed and held in you hand. they are so common here that i would feed them to my scorpions so one day i grabbed one and fed it to mi scorpion by hand and the Sicarius terrosus bit me i did not get worried and just let the scorpion feed. well nothing happend and a year later i read this and said thank god iy was a dry bit cuz i could have been in some real trouble i could have died:eek:
 

Randolph XX()

Arachnoprince
Old Timer
Joined
Aug 10, 2004
Messages
1,458
I first learned about this spiders from Todd Gearhart (tarantulaspiders.com), and on his site he mentioned they are highly venomous, among THE most venomous spiders in the world. They can also live as long 15 years, making among the most long-lived true spiders.
i wonder how much can you quote Mr.Gearhart's info these days after the famous 44" Galapagos pede
 

lhystrix

Arachnobaron
Old Timer
Joined
Sep 22, 2007
Messages
355
i wonder how much can you quote Mr.Gearhart's info these days after the famous 44" Galapagos pede
Don't forget the Phidippus audax x regius hybrid. What a joke. The spider was nothing more than one of the countless variations of female P. regius. And a crappy specimen at that.
 
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