# A new table of Scorpion LD50 numbers



## fusion121 (Jul 20, 2005)

Hi
I notice that sources of LD50 info are often asked for on this forum so I thought I'd post this here, I hope you enjoy  :

http://scorpions.dimensional-rift.co.uk/LD50table.htm

It’s a list of LD50 values that as far as I can tell covers nearly all LD50 values recorded for scorpions in the literature, as well as the amount of venom injected by the scorpion per sting. There are already some great lists out there but this includes the last 10+ years of venom research and so quite a few new species. 

I've been compiling it for a while, mostly while reading up on recent scorpion venom research, its designed for the hobbyist primarily so leaves out  allot of other data on the experimental method, but I think it should give people a good idea of the danger that certain species present.  

If you've got any other venom data to add to it, give me an PM (any on the Vaejovidae would be great as I could find diddly squat  )


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## TheNothing (Jul 20, 2005)

Thanks Oliver!
an excellent resource


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## carpe scorpio (Jul 20, 2005)

Nice work, Oliver, :clap:  I just printed it out. Thank you very much.


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## demolitionlover (Jul 21, 2005)

Yeah this is pretty cool. I have been looking for something like this for awhile now. Thanks : )


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## latastei (Jul 21, 2005)

Thanks for the table realy good


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## Kugellager (Jul 21, 2005)

Added the link to the FAQ Sticky: http://www.arachnoboards.com/ab/showthread.php?t=24231

John
];')


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## fusion121 (Jul 22, 2005)

Thanks, I hope people find it useful, I'll try to update it as I get more data.


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## G. Carnell (Jul 23, 2005)

Hi
glad to see the T.cambrigdei is 12 and not 0.12  

this IS T.paraensis yes?


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## fusion121 (Jul 23, 2005)

Good point, I need to update that


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## EmperorJay (Jul 23, 2005)

How do you read the LD50 chart?  I don't know what all the numbers mean.


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## fusion121 (Jul 23, 2005)

Its the minimum dose of the venom ( in mass of venom/ mass of body mass) required to kill 50% of the test animals. Basically you get a group of mice, say ten (though more if you want statistical significance), and inject them with different amounts of the venom. The dose of venom which kills 50% of the mice is then scaled up (from the mouse’s body mass) to get the LD50 in mg/kg. This test cannot be done in a lot of countries now as you need to kill a lot of mice to get a meaningful value. 

The lower the number, the lower the minimum lethal dose and so the more dangerous the venom (assuming the same correlations hold for humans as for mice)

Other possible methods exist for determining the toxicity of scorpion venom such as the “Contraction-Paralysis Unit” (CPU) done with blowfly larvae. However these methods are not very common, and given a different indication of the toxicity then the LD50 value with mice.


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## Ythier (Jul 24, 2005)

fusion121 said:
			
		

> Good point, I need to update that


Hi,
You don't need, Lourenço just said me that he will probably change the name soon (T.nigrisomething or something like that, I don't remember).

Thanks for this very useful work :clap: 
Btw, did you use the more recent works to do the table ? Because I saw that some data don't correspond to the table of http://web.singnet.com.sg/~chuaeecc/venom/rpotent.htm  :?  (for example O.doriae : your is 5,6 (Latifi et al, 79), the other is 0,19 (Hassan, 1984)).
Cheers,
Eric


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## fusion121 (Jul 24, 2005)

Hi
I tried to use the most recent work where available, or if I thought one paper was particularly good and I liked its methods then I would use that value. Basically it my opinion of what is the most accurate value (which may not be a very good opinion  ) 

In the case of O.doriae, both Hassan's and Latifi et al. were very good works (though I haven't seen all of Hassan's). I chose Latifi et al because I saw his data on his sample sizes all of which were very large so I trusted the value. (he milked 16,672mg of O.doriae venom  ). Often Its very difficult to tell which value should be trusted, for example Hassan and Latifi gave very different values for H. lepturus, 5.81 and 113 mg/kg respectively (both were I think i.v. injections), which I think reflects that LD50 values are not really a great measurement of toxicity.

My table is not meant to be comparison between literature values (often the literature values are massively different, which for the hobbyist isn’t that useful).


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## Nazgul (Jul 24, 2005)

Hi Oliver,

it would be nice if you´d mention in the table if the venom had been injected s.c. or i.v. (if being mentioned in the citation).

Regards
Alex


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## fusion121 (Jul 24, 2005)

Hi Alex
Most of them are s.c. results (80-90%) since I thought that this was the most relevant value for people who keep scorpions. The list is designed for hobbyist and I thought including the method of injection complicated the issue, when all I wanted to do was make a list of the general danger of various scorpion species.

I think I may make another more technical list including injection method as well as the known proteins that make up the various venoms, since its a topic I find quite interesting.


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## Tityus (Jul 24, 2005)

Nice work, Oliver, :worship:  I just printed it out now  :clap:


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## Ythier (Jul 24, 2005)

fusion121 said:
			
		

> In the case of O.doriae, both Hassan's and Latifi et al. were very good works (though I haven't seen all of Hassan's). I chose Latifi et al because I saw his data on his sample sizes all of which were very large so I trusted the value. (he milked 16,672mg of O.doriae venom  ). Often Its very difficult to tell which value should be trusted, for example Hassan and Latifi gave very different values for H. lepturus, 5.81 and 113 mg/kg respectively (both were I think i.v. injections), which I think reflects that LD50 values are not really a great measurement of toxicity.
> 
> My table is not meant to be comparison between literature values (often the literature values are massively different, which for the hobbyist isn’t that useful).


Ok thanks a lot for your reply Oliver.
Good job :clap: 
Cheers,
Eric


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## Ythier (Jul 26, 2005)

Hey Oliver,
C.sculpturatus = anc. name of C.exilicauda, no ?
Cheers,
Eric


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## fusion121 (Jul 26, 2005)

Hi Eric 
I'm not sure, but you are probably right.   I'm going to update the list tonight.


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## Nazgul (Jul 26, 2005)

Hi,

yes, sculpturatus is a synonym for C. exilicauda.

Regards
Alex


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## fusion121 (Nov 1, 2005)

I thought I'd let interested people know that I've updated the list, with corrections, some new data, all the available LD50 data for the species and I've also included the method of administration, hope its helpful  

http://scorpions.dimensional-rift.co.uk/LD50table.htm


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## TheNothing (Nov 1, 2005)

great work once again, oliver!


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## Kugellager (Nov 1, 2005)

And I see your link has not changed either...Excellent!

By the way...In case everyone does not know the link is in the FAQ section. 

John
];')


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## ocdave67 (Nov 1, 2005)

If I am reading this chart correctly that makes Buthus mardochei the most venomus scorpion in the world?


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## TheNothing (Nov 1, 2005)

wow
thats what it says
but
can never trust LD50 ratings...


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## misfitsfiend (Nov 1, 2005)

ocdave67 said:
			
		

> If I am reading this chart correctly that makes Buthus mardochei the most venomus scorpion in the world?


  injection method has to do with some of it. Notice it's 0.0015 when injected iv, but 0.15 when injected Sc. Also You should know that these numbers can varry from location to location and even in individuals. Also I do believe many of these toxins were tested on mice, and considering that we are not exacly a close cousin to rodents that could effect the numbers. This really doesnt say much about how harmfull a scorpion is to a human but It can give you a good idea of what scorps you should REALLY avoid getting stung by. as far as I know The Death stalker (L.q.) still posseses the most potentially lethal venom to humans.

 The only thing I think is a little off about this table is the fact that volume can not be measured in grams. Other than that, I love it and have prited out 3 copies.


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## skinheaddave (Nov 2, 2005)

Oliver,

What were the methodologies used in determining the volume of venom delivered?  This seems to me a far more tricky test to do than LD50, as well as one even more subject to error.  An interesting area to look into to be sure.

Cheers,
Dave


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## Michael (Nov 2, 2005)

I keep several Buthus mardochei's...  


Hilarious work Oliver!!!


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## 1/2 (Nov 2, 2005)

Ofcorse there is one problem for me... I am not quite sure on how to read these LD50 numbers.... Is the most dangerous the one with the lowest nr. or the one with the highest nr? (Verry new to this)

Feel a bit silly not knowing this, please enligten me.


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## skinheaddave (Nov 2, 2005)

1/2 said:
			
		

> Ofcorse there is one problem for me... I am not quite sure on how to read these LD50 numbers....


Post #11 in this thread covers it nicely.

Cheers,
Dave


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## 1/2 (Nov 2, 2005)

Thanks, makes a bit more sence now.

Just to be positive that I got this right:

The values are mg of venom per kg of what ever it stings for it to be lethal?


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## fusion121 (Nov 2, 2005)

ocdave67 said:
			
		

> If I am reading this chart correctly that makes Buthus mardochei the most venomus scorpion in the world?


 :8o  good point, thats a multiplication mistake on my part it is actually 1.50mg/kg

There are surprising values in the table, but they are the ones reported in the literature. As people have said it basically comes down to the fact that LD50 values are very variable depending on how the measurements are done. I would only ever take them as a general guideline.


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## fusion121 (Nov 2, 2005)

skinheaddave said:
			
		

> Oliver,
> 
> What were the methodologies used in determining the volume of venom delivered?  This seems to me a far more tricky test to do than LD50, as well as one even more subject to error.  An interesting area to look into to be sure.
> 
> ...


Hi
Generally the venom yield is not reported (as you can see from the lack of values for most species) which is a shame as it’s nearly as important as the LD50 value. Multiplying venom yield by the LD50 can give you a good idea of the relative toxicity of species. 

Normally the venom is obtained by either milking (giving a more natural value) or electrostimualtion, both methods seem to be used with equal regularity generally as per the Polis method in “Biology of Scorpions”. Venom yields are generally reported in mg or micrograms, occasionally in microlitres as with the P.transvaalicus I used.  As you say its going to be very variable (perhaps why its rarely reported in toxological reports), though papers that quote it do generally report it as an average of several milkings so it should be reasonably representative. 

Personally for species with an unknown venom yield I would generally assume venom yields of about 0.6-0.7mg that seems to be about average for average sized scorpions.


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## errit (Nov 2, 2005)

usually the iv method has lower ld50 values than sc method, in this list it mostly seems to be the other way around.


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## Jmadson13 (Nov 2, 2005)

awesome, thanks for posting


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## skinheaddave (Nov 3, 2005)

fusion121 said:
			
		

> though papers that quote it do generally report it as an average of several milkings so it should be reasonably representative.


It would be interesting to try to evaluate the situational factors which affect venom delivery and subsequently attempt to devise a milking method which is considered reliable for this type of question.  

Cheers,
Dave


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## fusion121 (Nov 3, 2005)

I think irritating the scorpion then making it sting your container is going to be the most useful method for determining the natural amount of venom injection (for a defensive injection at least), though I guess you'd need a substantial sample size with many individuals to get a meaningful result. I think normally milking is just done by holding the metasoma and collecting the venom that way, which probably won’t give you a very natural result. It would certianly be interesting to investigate.


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