C. gracilis pics

[Kugellager]

You have to remember though; scorpions have the ability to regulate the amount an type of venom they inject...each scorpion my respond differently to subduing its prey or defending themselves against a perceived threat. That is why basing how a scorpion will affect you from a sting received by someone else is not necessarily a good method.

I suspect that the people who may have been sent to the hospital for the C.gracilis Florida species were either small/children at the time or possibly suffered an allergic reaction...which would be quite rare.

The only accounts I have heard in the FL species is similar to those Gary mentioned.

John
];')

 

[Eurypterid]

You have to remember though; scorpions have the ability to regulate the amount an type of venom they inject...each scorpion my respond differently to subduing its prey or defending themselves against a perceived threat. That is why basing how a scorpion will affect you from a sting received by someone else is not necessarily a good method.

That's true, but if we're simply talking about potential, not the actual effects of any one particular sting on one given person or prey item, what I've observed indicates that at least some Florida scorpions may have the ability to deliver a very nasty sting. As far as amount, I would assume that those leaving the sting in longer, or stinging multiple times, are probably the ones injecting the greatest quantity. Though that may not be the case, it seems a reasonable hypothesis. So the difference probably lies in quality, not quantity, of venom.

By the way, these scorps were collected in Pompano Beach. It's possible that some of the ones in that area are more potent than what is typical for Florida (probably from drinking that city's water;P ). As you noted earlier John, these also seem to be different in coloration than the more commonly seen C. gracilis.

Gary

 

[Reitz]

It's an interesting thought, though you would need to study the animals intensely to find out what's really going on. CNN came out with an article a little while ago about the two types of venom John mentioned. It's possible that the first kind (the "pain" venom) would be easier to produce as that is probably what the P. trans sprays (the study was done on P. trans). Both types of venom are lethal to insects, though perhaps to a different extent. It's possible that some of the scorpions are using the more powerful venom right off the bat, while the others are conserving that venom and just using the "weaker" kind.

On a similar note, my female P. trans (at least that what I think it is, I'm waiting on a positive ID over at my thread ) will actually inject her sting into a cricket and twist it from side to side. It looks REALLY painful. The male, on the otherhand, hits them once and they're out for the count. What's really strange is that the crickets that the female stings are dead on the first hit as well, but she insists on twisting all the venom she can into them. What a sweetheart.

Chris

 

[CID143ti]

Here's my two cents about the different coloration of C. gracilis.

We all have heard that C. gracilis from Florida is not as hot as C. gracilis from Central America. I've kept several colonies of C. gracilis. I have two varieties of C. gracilis; one, is from Florida and the other, is from Honduras. Anyway, The variety from Florida have always been much darker in coloration...the deep red to black legs and grape or black bodies. The Honduran variety have always been much lighter in coloration...the pale yellow legs and burgundy body. I know that their are several color morphs of these guys but, I've noticed these coloration patterns seem to correlate with the collection location.

Anyway, I've read (or at least think I have) that C. gracilis was imported from Central America quite a long time ago while shipping goods (several hundred years ago...maybe longer). Over time, the venom potency may have reduced. Now, is it possible that the people that have suffered severe stings may have been stung from scorpions that may have been imported more recently?

Thanks,

W. Smith

 

[Reitz]

It's possible, though inspection standards are much higher today than they were way-back-when. I guess it's feasible that the 6 or 7 that get though every year (that's just a random guess, of course) could be the culprits, but the odds seem slim at best.

Chris

 

[Kugellager]

IMO they could have just as likely have been present in FL for thousands of years due to rafting on debris from Central america or Cuba...they are bark scorpions and would already live in/on debris thats floats. The Caribbean has a very active climate and the prevailing weather patterns run west to east. Hurricanes commonly skirt Central America and the Yucatan. Seems only natural that some species from those regions would be found in Florida.

John
];')

 

[Eurypterid]

It is possible that there have been new introductions. Florida is notorious for them. The lizard fauna here changes almost yearly due to them, and the vast majority of introductions are incidental, due to hitch-hikers on imported plants, or natural migrations. And the area of Pompano where I collected these has a lot of small businesses, at least some of which I'm sure receive frequent shipments from overseas. All of Florida's non-native pest insects got here that way. Despite an over-reaction from the Ag department, and urban legend, not a single pest arthropod species has ever been introduced in Florida because of an intentional import.

Another possibility is that some of the early invaders have always been as potent as their Latin American relatives. It's unlikely that lower toxicity "evolved" in the Florida population, in the sense that it is somehow a new state for this species, different from C. gracilis in other areas. That would require a new novel mutation (or even more than one) that would then have to spread through the entire population, displacing the more venomous genetic type.

It's much more likely that the original invasion was made up mostly or entirely of individuals that were already genetically some of the ones with weaker venom. Just by chance, they were the ones brought over. This is called "founder effect", a special case of an evolutionary force called genetic drift. If the original invaders were very few, there is a good chance that they weren't "typical" representatives of the species. This would be a form of evolution, in that the new population would be different genetically from the source population, but it wouldn't require a new form of the gene(s) to arise, or for those new forms to push out the old.

If the original invaders did just happen to be a few individuals with weaker venom, from a source population that included a range of toxicities, then either a small minority of them may have had stronger venom, or some of them with weaker venom might have been carrying a few copies of the genes for stronger venom. In either case, we might expect either small populations of Florida scorpions today to still have the stronger venom, or for a rare individual to inherit the right combination of gene forms so that every once in awhile a scorp with stronger venom is born here. Of course, Chris is right: it would take a bit of study to know which, if any, of these is the case.

As far as a scorpion's ability to make different kinds of venom, everthing I've seen so far was research done on P. transvaalicus. I think it would be risky to assume that the same is true in other scorps. After all, that species also has the ability to spray its venom. It might be that the "pain" venom is a co-adaptation along with spraying, since a strictly neurotoxic spray wouldn't be very useful as a defense. Scorps that do not spray may not have the same ability. Has anyone seen research on this ability (variety of venoms) in non-spraying species?

Gary

 

[Kugellager]

There is another recent study(last 6-9) months that came out where almost every scorpion they tested had two types of venom and the ability to control which was used. I have no recollection on the name or who did it but it is a recent study..

I remember one of the theories to come out of it was that they have two types of venom for two different uses...one for killing prey and another for causing pain for defense.

I may have even posted a link somewhere here but I'll be damned if I remember where.

John
];')

 

[Eurypterid]

If you remember it, could you post it again? In the mean time I'll do a search and see if I can turn it up.

Gary

 

[Tim R.]

This might help, It was on Cnn's website a while back.

Link

 

[Kugellager]

That would be the study I was referring to...now we should be able to find that paper somewhere.

John
];')

 

[Eurypterid]

I have this article. This is the work done on P. transvaalicus. What he means when he says "...every scorpion we tested..." is every individual P. transvaalicus they tested, not every species of scorpion.

Here's that reference:

One scorpion, two venoms: Prevenom of Parabuthus transvaalicus acts as an alternative type of venom with distinct mechanism of action._Inceoglu, Bora, et. al.; Proceedings of the National Academy of Sciences of the United States of America 100, no. 3 (February 4, 2003): 922-927

So, it looks like no one has checked other species for this ability yet.

Gary

 

[Eurypterid]

Sorry. I just pulled this article out again, and they do mention that they have seen "similar behavior" in other species, though they only list 2 (Androctonus australis and Uroctonus mordax), and they don't give any details.

I think it's interesting to note, however, that they make no mention of the scorpion's ability to control which form is used when, except to suppose that it might be so. In fact, it appears that, as the other person mentioned in the CNN article noted, this might simply be a carrier fluid. As the authors themselves say, "...we observed that the first droplet of venom that is secreted has different physical properties than the rest of the venom." That sounds a lot more like incidental leakage of the thinner carrier fluid of a complex secretion than it does a specific unique form of venom. In that case there is no regulation of it by the scorpion, it simply happens to leak out a little at first because it's less viscous.

Also, all the supposition they make about the reasons and uses for "prevenom" vs. "venom" are just that. They present no evidence (and apparently made no observations) supporting any of it. They simply throw out a bunch of unsupported hypothetical justifications for why such a "prevenom" would exist in order to prop up their claim that it does.

To be honest, I never read the full article closely before. Now that I have, I'm completely unconvinced that two unique forms of venom even exist. Looks to me like an extremely weak attempt to pad one's list of publications. Very poor science.

Gary