I got an actual FOREST MORPH Pandinus imperator!!!

[Diao]

So I've been doing some research into what determines these 'giant' specimens to appear randomly out of the populations, and after speaking to a few people I would consider experts on Pandinus imperator, I believe the extreme size actually comes down to two different factors, and savannah vs forest locations isn't necessarily what makes the difference.

The main influence on whether an individual is going to reach a giant size or be just an average 4-5" emp is the genetics of a given population. You will find in both savannah and forest locations of Africa that there are certain populations of emps that reach a larger overall size compared to perhaps another region even close by. This could be the result of food availability in certain areas or even other location factors that have favored larger individuals to survive and populate a certain area over smaller individuals. Pretty obvious, and I'm sure this isn't something new to any of us lurking here on this forum. However, what I have started learning that IS new, is that in some populations certain individuals will continue molting even after maturity. I was always under the impression that once a Pandinus was mature, that it was done molting, same as the majority of scorpions. I've since spoken with a few people that were importing Pandinus even back in the 80s and quickly learned that within the imports that out of no where there would be what seemed to be random individuals of an import that would go through ecdysis, even after mature. Not only that, but that these individuals would sometimes even continue molting until their death, with anecdotes of individuals closing in on 30 years of age at 10th instar. Although I never made it a primary focus, I have always had Pandinus imperator in my collection through the years, and have yet to experience one go through this additional ecdysis, although now I might be aware of a few things that help spur it on. Those things are fairly obvious, which is heat, humidity, and food availability. This is most likely why we have come up with the "forest form" label over the years, as it is most likely that individuals residing in the forest locations are provided more consistently high temperatures and humidity, as well as a much high abundance of food.

There are a few indicators I believe your larger individual displays which would make me believe it has gone on to perform at least one additional ecdysis beyond that of your other mature female you showed next to it in one of the photos. If you could possibly get measurements of the larger individual, this could help with narrowing the cause of its size down further. Much appreciated of any additional information you might be able to provide!

 

[Moakmeister]

So I've been doing some research into what determines these 'giant' specimens to appear randomly out of the populations, and after speaking to a few people I would consider experts on Pandinus imperator, I believe the extreme size actually comes down to two different factors, and savannah vs forest locations isn't necessarily what makes the difference.

The main influence on whether an individual is going to reach a giant size or be just an average 4-5" emp is the genetics of a given population. You will find in both savannah and forest locations of Africa that there are certain populations of emps that reach a larger overall size compared to perhaps another region even close by. This could be the result of food availability in certain areas or even other location factors that have favored larger individuals to survive and populate a certain area over smaller individuals. Pretty obvious, and I'm sure this isn't something new to any of us lurking here on this forum. However, what I have started learning that IS new, is that in some populations certain individuals will continue molting even after maturity. I was always under the impression that once a Pandinus was mature, that it was done molting, same as the majority of scorpions. I've since spoken with a few people that were importing Pandinus even back in the 80s and quickly learned that within the imports that out of no where there would be what seemed to be random individuals of an import that would go through ecdysis, even after mature. Not only that, but that these individuals would sometimes even continue molting until their death, with anecdotes of individuals closing in on 30 years of age at 10th instar. Although I never made it a primary focus, I have always had Pandinus imperator in my collection through the years, and have yet to experience one go through this additional ecdysis, although now I might be aware of a few things that help spur it on. Those things are fairly obvious, which is heat, humidity, and food availability. This is most likely why we have come up with the "forest form" label over the years, as it is most likely that individuals residing in the forest locations are provided more consistently high temperatures and humidity, as well as a much high abundance of food.

There are a few indicators I believe your larger individual displays which would make me believe it has gone on to perform at least one additional ecdysis beyond that of your other mature female you showed next to it in one of the photos. If you could possibly get measurements of the larger individual, this could help with narrowing the cause of its size down further. Much appreciated of any additional information you might be able to provide!

Whoa. That’s groundbreaking information if true. Can anyone on these forums find evidence of Pandinus being able to molt after hitting maturity? I would absolutely love to hear it.

 

[Moakmeister]

So I've been doing some research into what determines these 'giant' specimens to appear randomly out of the populations, and after speaking to a few people I would consider experts on Pandinus imperator, I believe the extreme size actually comes down to two different factors, and savannah vs forest locations isn't necessarily what makes the difference.

The main influence on whether an individual is going to reach a giant size or be just an average 4-5" emp is the genetics of a given population. You will find in both savannah and forest locations of Africa that there are certain populations of emps that reach a larger overall size compared to perhaps another region even close by. This could be the result of food availability in certain areas or even other location factors that have favored larger individuals to survive and populate a certain area over smaller individuals. Pretty obvious, and I'm sure this isn't something new to any of us lurking here on this forum. However, what I have started learning that IS new, is that in some populations certain individuals will continue molting even after maturity. I was always under the impression that once a Pandinus was mature, that it was done molting, same as the majority of scorpions. I've since spoken with a few people that were importing Pandinus even back in the 80s and quickly learned that within the imports that out of no where there would be what seemed to be random individuals of an import that would go through ecdysis, even after mature. Not only that, but that these individuals would sometimes even continue molting until their death, with anecdotes of individuals closing in on 30 years of age at 10th instar. Although I never made it a primary focus, I have always had Pandinus imperator in my collection through the years, and have yet to experience one go through this additional ecdysis, although now I might be aware of a few things that help spur it on. Those things are fairly obvious, which is heat, humidity, and food availability. This is most likely why we have come up with the "forest form" label over the years, as it is most likely that individuals residing in the forest locations are provided more consistently high temperatures and humidity, as well as a much high abundance of food.

There are a few indicators I believe your larger individual displays which would make me believe it has gone on to perform at least one additional ecdysis beyond that of your other mature female you showed next to it in one of the photos. If you could possibly get measurements of the larger individual, this could help with narrowing the cause of its size down further. Much appreciated of any additional information you might be able to provide!

I would very much like to measure her, but she never fully straightens her tail. My attempts have been fruitless.

 

[Moakmeister]

If you could possibly get measurements of the larger individual, this could help with narrowing the cause of its size down further. Much appreciated of any additional information you might be able to provide!

Aha! She just stretched out her tail fully, totally straight, and I grabbed my ruler. From front edge of carapace to the end of her tail, not including the telson, 6 inches on the dot. I then measured the telson’s length separately and it seems to be half an inch long, so we’ll call it 6.5 inches? I also tried measuring her arm length, although she won’t stretch it out straight either. It’s about 2.25 inches long from shoulder to claw tip while bent in a gentle arc, so if she fully straightened it, it’d probably be 2.5 to 2.75 inches.

I realize that brings the total to as much as 9.25 inches, which literally breaks the record for the largest scorpion ever recorded. There’s no way that’s true. We’ll call it a conservative 8.5-8.75. This was just the best I could get with my ruler on the outside of the enclosure and an uncooperative scorpion who won’t hold still. We won’t ever truly know until she passes away and I can stretch her out on the table and measure everything for real. But she’s clearly incredibly large.

 

[Veno Manus]

My female was also an absolute unit.
This is a female btw. Theres a bit of sexual dimorphism in Pandinus. Males are typically smaller.

 

[Veno Manus]

Could this be due to the actual diet in the region of whats available? Most fed available food in most cases is crickets and roaches for most and id assume that the nutrition isnt at most adequate for the growth strength levels to provide the proper nutrients in order for the rapid growth. Could it be an insect thats high in a certain level of nutrient? I didnt really consider the fact of different regions where they could be found as being different availability of food sources since they shouldn't be to far off but I guess that makes a lot of sense. This is interesting stuff. Ill have to mention this to a couple mates of mine.

So I've been doing some research into what determines these 'giant' specimens to appear randomly out of the populations, and after speaking to a few people I would consider experts on Pandinus imperator, I believe the extreme size actually comes down to two different factors, and savannah vs forest locations isn't necessarily what makes the difference.

The main influence on whether an individual is going to reach a giant size or be just an average 4-5" emp is the genetics of a given population. You will find in both savannah and forest locations of Africa that there are certain populations of emps that reach a larger overall size compared to perhaps another region even close by. This could be the result of food availability in certain areas or even other location factors that have favored larger individuals to survive and populate a certain area over smaller individuals. Pretty obvious, and I'm sure this isn't something new to any of us lurking here on this forum. However, what I have started learning that IS new, is that in some populations certain individuals will continue molting even after maturity. I was always under the impression that once a Pandinus was mature, that it was done molting, same as the majority of scorpions. I've since spoken with a few people that were importing Pandinus even back in the 80s and quickly learned that within the imports that out of no where there would be what seemed to be random individuals of an import that would go through ecdysis, even after mature. Not only that, but that these individuals would sometimes even continue molting until their death, with anecdotes of individuals closing in on 30 years of age at 10th instar. Although I never made it a primary focus, I have always had Pandinus imperator in my collection through the years, and have yet to experience one go through this additional ecdysis, although now I might be aware of a few things that help spur it on. Those things are fairly obvious, which is heat, humidity, and food availability. This is most likely why we have come up with the "forest form" label over the years, as it is most likely that individuals residing in the forest locations are provided more consistently high temperatures and humidity, as well as a much high abundance of food.

There are a few indicators I believe your larger individual displays which would make me believe it has gone on to perform at least one additional ecdysis beyond that of your other mature female you showed next to it in one of the photos. If you could possibly get measurements of the larger individual, this could help with narrowing the cause of its size down further. Much appreciated of any additional information you might be able to provide!

 

[Diao]

Could this be due to the actual diet in the region of whats available? Most fed available food in most cases is crickets and roaches for most and id assume that the nutrition isnt at most adequate for the growth strength levels to provide the proper nutrients in order for the rapid growth. Could it be an insect thats high in a certain level of nutrient? I didnt really consider the fact of different regions where they could be found as being different availability of food sources since they shouldn't be to far off but I guess that makes a lot of sense. This is interesting stuff. Ill have to mention this to a couple mates of mine.

I have looked into this as well, and it seems that most information out there state that their favorite food in the wild is millipedes. I looked into what people in the herp hobby call the calcium to phosphorus ratio, where they want their feeders to provide a close to a 1:1 ratio of calcium and phosphorus as possible. Most feeders are drastically lower in calcium than phosphorus, which is why you see calcium powder for "dusting" crickets, roaches, etc, too get that ratio closer to 1:1. When researching this, I found that millipedes are naturally EXTREMELY close to this 1:1 ratio, far far closer than what crickets and roaches provide naturally. This might be a contributor, but as I understand it, scorpions don't really digest calcium like reptiles, so is not really a concern. There still might be something else that they are contributing to their nutrition, however. I'm also wondering if when they matte could also be a factor, especially with males. If they get to reproduce as soon as they hit maturity, then their body could shut down growth and devote all resources towards reproduction, similar to other species of scorpion that stop growth after they have successfully reproduced. Males of Scorpionidae are known to engage in their arm span battles, where the individual with the widest arm span overpowers the smaller one, and is thus granted rule over the area and access to it's females. So my thinking is that if provided enough food and kept nice and warm, but denied the ability to matte after maturing, this could help spur on that additional ecdysis. From what I've heard from someone who has had this happen it can be years after maturing that this molt occurs, and the growth from these latter molts is much greater than from their previous molts prior to maturity.

A lot to go through, but I'm still doing more research. One big indicator of the extra ecdysis in emps is that the granulation on the manus of the chela will begin to smooth out with each additional molt. One of the largest individuals I've seen was a display model and the chela were not even really granulated, it looked closer to tiny "ripples", like a slightly disturbed water surface.

Also, lastly, these additional molts aren't unique to Pandinus imperator, it apparently happens in other Pandininae and Heterometrinae, like G.swammerdami and H.spinifer.

 

[Wolfram1]

Very interesting, this reminds me of how certain species that undergo matriphagy may liquify their innards except certain vital organs like heart and the ovaries in order to be able to produce a second clutch if the first one fails to develop/is taken. In their case death is certain however, whether they produce a second cluch or not.

All for that eventual reproduction.

are you certain that it is tied to temperatures? i would expect forests to be less extreme/more even than open, exposed landscapes.

Considering the exosceleton is worn down over time it does not surprise me that some Arachnids may have the ability to molt a few additional times if they have not been able to reproduce yet. Tarantulas have a much thinner exosceleton and new worlds even tie a defense mechanism to it that can be used up and needs replacement.

This could be a reason why postultimate molts have become the norm rather than the exception. Another even rarer, but similarly widespread ability amongst arachnids is parthenogenesis. Has this been documented with emperor scorpions as well?

 

[Moakmeister]

This is all blowing my mind. But if it’s true, why doesn’t it happen with every non-breeding scorpion in captivity?

 

[Veno Manus]

My guess is that the more limitations and the environment change is to drastic for its metabolism. All the benefits happing at the same time in the wild giving those critical bits where in captivity it has to be replicated. Theres a fine sciene to it im sure.

QUOTE="Moakmeister, post: 3453416, member: 116670"]
This is all blowing my mind. But if it’s true, why doesn’t it happen with every non-breeding scorpion in captivity?
[/QUOTE]

 

[adam james]

I realize that brings the total to as much as 9.25 inches, which literally breaks the record for the largest scorpion ever recorded.

I believe the measurement for a scorpion is tip of telson to chelicerae, or full length stretched out without including the pedipalps. So 6.5 would be the length. Still a pretty good size though

 

[Moakmeister]

I believe the measurement for a scorpion is tip of telson to chelicerae, or full length stretched out without including the pedipalps. So 6.5 would be the length. Still a pretty good size though

Are you saying the longest ever scorpion was 9 inches from chelicerae to telson? That’s ludicrous, there’s no way!

 

[Diao]

Are you saying the longest ever scorpion was 9 inches from chelicerae to telson? That’s ludicrous, there’s no way!

I posted some pictures in a previous thread of a few 8" specimens, but there are anecdotal reports of field collected emps that were over 9" (using the proper method of measurement, of course). I've seen a G. swammerdami that was around 21cm, possibly a bit longer. It was a male randomly caught and then released and it clearly wasn't wanting to pose for photos. So it wouldn't surprise me if its possible they attain 9" in the wild. As far as captive bred specimens there are some photos that have been floating around for a while of a captive bred emp that between 20-21cm, and after it died the owner had it stuff and posed in a glass box. They also stated that it went through several molts after maturity and that they had owned several emps that had made it to 10th instar. So again, it probably relies on a certain few key components of emulating their environment perfectly, and then also just having individuals with the genetics to continue pushing on after maturing.

Also, as far as length goes, I'll have to dig it up, but I've got a photo of a deceased male H. troglodytes that is over 11", which is considerably impressive even with its absurdly long tail.

 

[Moakmeister]

I posted some pictures in a previous thread of a few 8" specimens, but there are anecdotal reports of field collected emps that were over 9" (using the proper method of measurement, of course). I've seen a G. swammerdami that was around 21cm, possibly a bit longer. It was a male randomly caught and then released and it clearly wasn't wanting to pose for photos. So it wouldn't surprise me if its possible they attain 9" in the wild. As far as captive bred specimens there are some photos that have been floating around for a while of a captive bred emp that between 20-21cm, and after it died the owner had it stuff and posed in a glass box. They also stated that it went through several molts after maturity and that they had owned several emps that had made it to 10th instar. So again, it probably relies on a certain few key components of emulating their environment perfectly, and then also just having individuals with the genetics to continue pushing on after maturing.

Also, as far as length goes, I'll have to dig it up, but I've got a photo of a deceased male H. troglodytes that is over 11", which is considerably impressive even with its absurdly long tail.

Someone’s gonna need to verify this. If it’s true, I feel like I shouldn’t pair my female with any males because if she doesn’t put that energy toward reproduction, she’ll keep molting again. I don’t want to cut off her potential.

 

[Moakmeister]

I emailed Dr. Jerome Rovner, an arachnologist. This was his reply:

 

[Moakmeister]

Wow holy shit. He confirmed it. Scorpions can get up to nine inches long from face to tail.

It looks as though my imperator really is small fry compared to the real biggest scorpions in the world. That’s absolutely shocking.

 

[Diao]

He was pretty specific to put bold out that he hasn't seen any published scientific reports on mature scorpions continuing to molt. I can also add that for several decades I thought the same thing, until going down a bit of a rabbit hole recently and found and spoke with several unrelated sources all saying the same thing, that some scorpions, seen more commonly in certain buthids than members of Scorpionidae, will continue to molt after sexual maturity. This is more than likely due to environmental conditions and the individual's genetics, but it is not common so it makes it difficult to really perform studies or gather decent data with its low and random rate of occurance.