Southwestern US Species Differences?

[gzophia]

Hello everyone,

I have been interested in the smaller scorpions of the southwestern United States for a few months now. I have done research on the ecology/care of various different genera/species but have not made a purchase yet.
Soon, I will have the chance to obtain some scorpions, and I am currently trying to decide between Paravaejovis spinigerus, Paravaejovis confusus, and Paruroctonus silvestrii.

I was wondering about the differences between these species, such as their stings, temperaments, size, lifespans, and such so I could make my decision-- I only want one at the moment.
It seems like in general, they all do well in mostly dry conditions, have mild venom (around a bee sting), and reach 2-3 inches. They are all somewhat feisty and are fine with digging scrapes as opposed to burrowing. However, I was not able to find much else regarding specifics.

From what I have read, I believe that P. spinigerus and P. confusus are quite similar, but how would they compare to P. silvestrii? And what about any slight care differences? Which one would be the "easiest?"

It would be incredibly helpful if I had the chance to see these scorpions in the wild, but alas, the only species I can observe in my area are Uroctonus mordax and Serradigitus gertschi...

Thanks.

 

[MorbidTecolote]

OH BOY! US NATIVE TALK!
As for size comparisons I actually took pictures of all my adults next to a ruler to give a good gage on what an adult scorpion from each of these species looks like.

Paravaejovis spinigerus - Paruroctonus silvestrii - Uroctonus mordax - Smeringurus mesaensis

Anuroctonus phaiodactylus - Centruroides vittatus - Centruroides sculpturatus - Superstitionia donensis

These are older pics because I don't have these two individuals anymore, but this is Paravaejovis puritanus and Paravaejovis confusus.

Generally you got it right! Most of these guys are scrapers (except the Centruroides) and most have mild venom (except Centruroides sculpturatus). Anuroctonus and Smeringurus definitely burrow more in the wild but mine have been fine with making scrapes, they both seem to do both depending on their environment. As far as personality, Anuroctonus have been some of the most defensive and fiesty scorpions I've ever dealt with, they're quick to threat pose and quick to throw hands when you're doing tank maintenance.

They're active, fun, and very pretty.
Second feistiest would be Paravaejovis spinigerus or Smeringurus mesaensis. PS are more defensive and more ready to threat pose, SM are kind of interesting to deal with to be honest. They're very bolty, fast, and one of the only scorpions I've had that has actually tried to envenomate the forceps. Anuroctonus and Paravaejovis threat pose, and maybe will pinch or hit with their tails, but I've never seen either seriously go for a sting.

Care wise they're all pretty straight forward. Uroctonus mordax is more temperate and needs more humidity, I keep them on soil and keep that soil slightly moist at all times. Smeringurus mesaensis are dune desert arid species, I keep them on sand and don't give them water at all. Everything else is that weird SoCal/Arizona arid, it's desert but I don't think they're as moisture adverse as people think. In the wild Centruroides sculpturatus seek moist microclimates, and Anuroctonus burrows are moister lower in the ground than the surface humidity is. Really I think the thing with all of them is that moist substrate is a big no-no, because sitting on moist substrate is a recipe for mycosis. But all of them have appreciated a corner I mist every few days, or I'll occasionally put down a shallow water dish for the night so they can drink out of it.
View attachment tumblr_s7j5s8bZKf1y37m0w_720.mp4

















Here's a video of my Anuroctonus drinking out of a water dish I gave her. For all of the ones besides Uroctonus mordax and Smeringurus Mesansis I use a combination of soil and sand, I vibe out the ratio based on where the scorpion is from. For example Paruroctonus silvestrii gets more soil than Anuroctonus phaiodactylus because PS live further up into California and AP live in the Mojave desert and SoCal. Obviously also both Centruroides are arboreal and need vertical hides instead of scrapes or burrowing space. I've had a lot of success with pieces of terracotta pot as a hide, but I also use cork bark, depending on where the scorpion is from. And I keep all of them around 80F, but that's more because they're in a space where I maintain temperature for all of my scorpions together. Definitely Uroctonus mordax and Paruroctonus silvestrii can go cooler than that, but I wouldn't keep any scorpion below 75F.

For me personally, it's hard to pick a favorite or recommend any one specifically because they're all extremely cool and I could say any one of these was my favorite species. If you exclude the medically significant Centruroides sculpturatus any of these other ones would be an excellent beginner scorpion. The only precautions I would give is for size, Superstitionia is definitely one of the smallest scorpions available in the US and Paravaejovis confusus and Serradigitus gertschi are both on the smaller side.

Hope this helps!

 

[gzophia]

Oh WOW, thank you so much!
Yes, I'm a big fan of US-native species, and I don't know why.

I kind of forgot about this thread as I was worried that I had asked a question that was too specific to be answered. I'm so thankful that you were so kind as to provide this extremely detailed reply; not only does it answer my questions and alleviate my concerns, but it also provides information on a multitude of other species I am interested in keeping. Incredibly helpful!

Generally you got it right! Most of these guys are scrapers (except the Centruroides) and most have mild venom (except Centruroides sculpturatus). Anuroctonus and Smeringurus definitely burrow more in the wild but mine have been fine with making scrapes, they both seem to do both depending on their environment. As far as personality, Anuroctonus have been some of the most defensive and fiesty scorpions I've ever dealt with, they're quick to threat pose and quick to throw hands when you're doing tank maintenance.

Got it; that's fantastic since I prefer scorpions that scrape rather than burrow. I mainly keep vinegaroons, so it's nice to have a non-fossorial arachnid, haha! Anuroctonus sp. really are pretty, and those photos are so funny and adorable-- the gun picture and the one with the claws wide open are so dang cute!

Second feistiest would be Paravaejovis spinigerus or Smeringurus mesaensis. PS are more defensive and more ready to threat pose, SM are kind of interesting to deal with to be honest. They're very bolty, fast, and one of the only scorpions I've had that has actually tried to envenomate the forceps.

Interesting; I really like Smeringurus mesaensis (it is the most beautiful US scorpion in my opinion) but I think I'll gain more experience with Paravaejovis sp. and Paruroctonus silvestrii before I get one.

Care wise they're all pretty straight forward. Uroctonus mordax is more temperate and needs more humidity, I keep them on soil and keep that soil slightly moist at all times. Smeringurus mesaensis are dune desert arid species, I keep them on sand and don't give them water at all. Everything else is that weird SoCal/Arizona arid, it's desert but I don't think they're as moisture adverse as people think. In the wild Centruroides sculpturatus seek moist microclimates, and Anuroctonus burrows are moister lower in the ground than the surface humidity is. Really I think the thing with all of them is that moist substrate is a big no-no, because sitting on moist substrate is a recipe for mycosis. But all of them have appreciated a corner I mist every few days, or I'll occasionally put down a shallow water dish for the night so they can drink out of it.

Great! At the time of my writing my initial post, I didn't keep any US scorpions. However, I now have 26 Uroctonus mordax. They're really easy to keep, and I am trying to breed them to establish CB individuals. 26 is a bit too many though; I plan to release 8 of the juveniles back exactly where I found them. And I did hear about keeping S. mesaensis on plain sand, but I also heard sources stating that it must be able to burrow as an obligate fossorial or something like that. It's good to hear that they're fine with just sand for scraping!
Indeed; that weird arid climate is what threw me off. I've never been to SoCal or AZ before, so I have no idea what it's like. I did consider those methods of providing moisture, so I am glad that they work well in practice! Yep, definitely no moist substrate-- scorpion mycosis is a big fear of mine.

Here's a video of my Anuroctonus drinking out of a water dish I gave her. For all of the ones besides Uroctonus mordax and Smeringurus Mesansis I use a combination of soil and sand, I vibe out the ratio based on where the scorpion is from. For example Paruroctonus silvestrii gets more soil than Anuroctonus phaiodactylus because PS live further up into California and AP live in the Mojave desert and SoCal.

Lovely video; those are some prominent chelicerae! As for the substrate combination, I use the same mixture, but I never considered adjusting the ratio accordingly. I'll make sure to do that!

For me personally, it's hard to pick a favorite or recommend any one specifically because they're all extremely cool and I could say any one of these was my favorite species. If you exclude the medically significant Centruroides sculpturatus any of these other ones would be an excellent beginner scorpion. The only precautions I would give is for size, Superstitionia is definitely one of the smallest scorpions available in the US and Paravaejovis confusus and Serradigitus gertschi are both on the smaller side.

Yeah, I find it difficult too. I'm heavily biased towards U. mordax as it was the first scorpion species I ever saw in the wild, as well as the first species I ever kept. But the others are amazing too! Especially Superstitionia donensis-- its small size is actually one of the most appealing things to me. It's just that the prices for individuals are crazy!

I'll be getting a Paravaejovis confusus and a Paruroctonus silvestrii in a week and a half (circumstances changed and I can now get two) and I am extremely excited! I'm feeling quite confident thanks to this new information.

Say, do you breed any of these species? You have so many different US-native scorpions; I haven't seen many people who have a native assortment this varied!

Again, thanks so much!

 

[MorbidTecolote]

Oh WOW, thank you so much!
Yes, I'm a big fan of US-native species, and I don't know why.

I kind of forgot about this thread as I was worried that I had asked a question that was too specific to be answered. I'm so thankful that you were so kind as to provide this extremely detailed reply; not only does it answer my questions and alleviate my concerns, but it also provides information on a multitude of other species I am interested in keeping. Incredibly helpful!

Got it; that's fantastic since I prefer scorpions that scrape rather than burrow. I mainly keep vinegaroons, so it's nice to have a non-fossorial arachnid, haha! Anuroctonus sp. really are pretty, and those photos are so funny and adorable-- the gun picture and the one with the claws wide open are so dang cute!

Interesting; I really like Smeringurus mesaensis (it is the most beautiful US scorpion in my opinion) but I think I'll gain more experience with Paravaejovis sp. and Paruroctonus silvestrii before I get one.

Great! At the time of my writing my initial post, I didn't keep any US scorpions. However, I now have 26 Uroctonus mordax. They're really easy to keep, and I am trying to breed them to establish CB individuals. 26 is a bit too many though; I plan to release 8 of the juveniles back exactly where I found them. And I did hear about keeping S. mesaensis on plain sand, but I also heard sources stating that it must be able to burrow as an obligate fossorial or something like that. It's good to hear that they're fine with just sand for scraping!
Indeed; that weird arid climate is what threw me off. I've never been to SoCal or AZ before, so I have no idea what it's like. I did consider those methods of providing moisture, so I am glad that they work well in practice! Yep, definitely no moist substrate-- scorpion mycosis is a big fear of mine.

Lovely video; those are some prominent chelicerae! As for the substrate combination, I use the same mixture, but I never considered adjusting the ratio accordingly. I'll make sure to do that!

Yeah, I find it difficult too. I'm heavily biased towards U. mordax as it was the first scorpion species I ever saw in the wild, as well as the first species I ever kept. But the others are amazing too! Especially Superstitionia donensis-- its small size is actually one of the most appealing things to me. It's just that the prices for individuals are crazy!

I'll be getting a Paravaejovis confusus and a Paruroctonus silvestrii in a week and a half (circumstances changed and I can now get two) and I am extremely excited! I'm feeling quite confident thanks to this new information.

Say, do you breed any of these species? You have so many different US-native scorpions; I haven't seen many people who have a native assortment this varied!

Again, thanks so much!

 

[MorbidTecolote]

Definitely trying to! I was in the hobby in 2019 and ended up with 5 broods from wild caught adult females, two Serradigitus gertschi, one Paravaejovis puritanus, and two Paravaejovis spinigerus. I had to leave the hobby because of work tho and sold off my whole collection, so starting over now I really want to focus on captive breeding US natives because I like them so much and it does suck that most of them are wild caught. Right now there are some I have that I'm just hoping are gravid already because they're wild caught females, I don't have males right now for my Paravaejovis spinigerus, Paruroctonus silvestrii, Centruroides sculpturatus, or Centruroides silvestrii. I have been really trying to get my Uroctonus mordax to mate, I have one male and 3 females and all three of them rejected him so far. Again, I think there's a good chance adult wild caught females are already gravid. And jeez, I have a Smeringurus pair but I haven't gotten a successful mating. He judders at her and she isn't outright aggressive to him, they clasp pedipalps but then nothing really happens after that. From what I've read about them in the wild (since there's actually a lot of information about their wild habits) they're extremely seasonal, so either they won't really mate until May or they need some temperature drop or rainy period to be convinced to mate, and if it's the second thing I'm boned because I wouldn't really know how to recreate that in captivity and I would have to wait until next year to get through another wintering period.

As far as them burrowing, there's one paper about them making burrows in dunes that states that they spend 95-97% of their lives in a burrow, but this study was done in an open sand dune desert and they're definitely not exclusively found on bare open sand. I've seen people here say they've found them in scrapes in areas where theres some rocks or vegetation that allows them to do that, which is why I think their burrowing habits change depending on what's available in their environment. That study also demonstrated that they make burrows by digging at an angle into the side of a sand dune, and having dry sand stay stable enough to do that is really hard to recreate in captivity, so I'd say you'd either have to add clay to it so it would support a burrow better or if you wanted to just use sand then provide a hide for them to scrape into. This is kind of a my personal opinion on keeping them though.

 

[Kada]

OH BOY! US NATIVE TALK!
As for size comparisons I actually took pictures of all my adults next to a ruler to give a good gage on what an adult scorpion from each of these species looks like.

Paravaejovis spinigerus - Paruroctonus silvestrii - Uroctonus mordax - Smeringurus mesaensis

Anuroctonus phaiodactylus - Centruroides vittatus - Centruroides sculpturatus - Superstitionia donensis

These are older pics because I don't have these two individuals anymore, but this is Paravaejovis puritanus and Paravaejovis confusus.

Generally you got it right! Most of these guys are scrapers (except the Centruroides) and most have mild venom (except Centruroides sculpturatus). Anuroctonus and Smeringurus definitely burrow more in the wild but mine have been fine with making scrapes, they both seem to do both depending on their environment. As far as personality, Anuroctonus have been some of the most defensive and fiesty scorpions I've ever dealt with, they're quick to threat pose and quick to throw hands when you're doing tank maintenance.

They're active, fun, and very pretty.
Second feistiest would be Paravaejovis spinigerus or Smeringurus mesaensis. PS are more defensive and more ready to threat pose, SM are kind of interesting to deal with to be honest. They're very bolty, fast, and one of the only scorpions I've had that has actually tried to envenomate the forceps. Anuroctonus and Paravaejovis threat pose, and maybe will pinch or hit with their tails, but I've never seen either seriously go for a sting.

Care wise they're all pretty straight forward. Uroctonus mordax is more temperate and needs more humidity, I keep them on soil and keep that soil slightly moist at all times. Smeringurus mesaensis are dune desert arid species, I keep them on sand and don't give them water at all. Everything else is that weird SoCal/Arizona arid, it's desert but I don't think they're as moisture adverse as people think. In the wild Centruroides sculpturatus seek moist microclimates, and Anuroctonus burrows are moister lower in the ground than the surface humidity is. Really I think the thing with all of them is that moist substrate is a big no-no, because sitting on moist substrate is a recipe for mycosis. But all of them have appreciated a corner I mist every few days, or I'll occasionally put down a shallow water dish for the night so they can drink out of it.
View attachment 471128

















Here's a video of my Anuroctonus drinking out of a water dish I gave her. For all of the ones besides Uroctonus mordax and Smeringurus Mesansis I use a combination of soil and sand, I vibe out the ratio based on where the scorpion is from. For example Paruroctonus silvestrii gets more soil than Anuroctonus phaiodactylus because PS live further up into California and AP live in the Mojave desert and SoCal. Obviously also both Centruroides are arboreal and need vertical hides instead of scrapes or burrowing space. I've had a lot of success with pieces of terracotta pot as a hide, but I also use cork bark, depending on where the scorpion is from. And I keep all of them around 80F, but that's more because they're in a space where I maintain temperature for all of my scorpions together. Definitely Uroctonus mordax and Paruroctonus silvestrii can go cooler than that, but I wouldn't keep any scorpion below 75F.

For me personally, it's hard to pick a favorite or recommend any one specifically because they're all extremely cool and I could say any one of these was my favorite species. If you exclude the medically significant Centruroides sculpturatus any of these other ones would be an excellent beginner scorpion. The only precautions I would give is for size, Superstitionia is definitely one of the smallest scorpions available in the US and Paravaejovis confusus and Serradigitus gertschi are both on the smaller side.

Hope this helps!

Wow. That's some cool stuff! As someone that is in Adja, actually we REALLY like US exotic species. The foreigness of shapes and habits make them very interesting for us. Probably one of those things, we like what we can't have. Haha. I love the southern US/Mexican/central American scorpions so much. Really cool animals.


Pardon my ignorance, but can I ask what you guys mean be "scrapers". I am thinking like scraping a bowl from its food contents. But not sure how this relates to scorpions haha. Apologies for the dumb question.

 

[MorbidTecolote]

Wow. That's some cool stuff! As someone that is in Adja, actually we REALLY like US exotic species. The foreigness of shapes and habits make them very interesting for us. Probably one of those things, we like what we can't have. Haha. I love the southern US/Mexican/central American scorpions so much. Really cool animals.


Pardon my ignorance, but can I ask what you guys mean be "scrapers". I am thinking like scraping a bowl from its food contents. But not sure how this relates to scorpions haha. Apologies for the dumb question.

Scraping is when a scorpion makes a shallow bowl under a hide, in the wild it's usually a rock or something that can be dug under. It's not really a burrow because it doesn't go into the ground.

 

[gzophia]

Definitely trying to! I was in the hobby in 2019 and ended up with 5 broods from wild caught adult females, two Serradigitus gertschi, one Paravaejovis puritanus, and two Paravaejovis spinigerus. I had to leave the hobby because of work tho and sold off my whole collection, so starting over now I really want to focus on captive breeding US natives because I like them so much and it does suck that most of them are wild caught. Right now there are some I have that I'm just hoping are gravid already because they're wild caught females, I don't have males right now for my Paravaejovis spinigerus, Paruroctonus silvestrii, Centruroides sculpturatus, or Centruroides silvestrii. I have been really trying to get my Uroctonus mordax to mate, I have one male and 3 females and all three of them rejected him so far. Again, I think there's a good chance adult wild caught females are already gravid. And jeez, I have a Smeringurus pair but I haven't gotten a successful mating. He judders at her and she isn't outright aggressive to him, they clasp pedipalps but then nothing really happens after that. From what I've read about them in the wild (since there's actually a lot of information about their wild habits) they're extremely seasonal, so either they won't really mate until May or they need some temperature drop or rainy period to be convinced to mate, and if it's the second thing I'm boned because I wouldn't really know how to recreate that in captivity and I would have to wait until next year to get through another wintering period.

Nice! That's really cool; I always loved Serradigitus gertschi and am still looking for them. And yeah, sometimes life gets in the way; glad to hear you're back though!
I have two gravid U. mordax and am trying to get the other non-gravid females to breed in captivity. I've had some near successes, so I think I'll be able to do it soon! It can be tricky though.
Smeringurus mesaensis seems to have a reputation for being hard to breed; some can be crazy aggressive and others can be picky about conditions... best of luck though!

As far as them burrowing, there's one paper about them making burrows in dunes that states that they spend 95-97% of their lives in a burrow, but this study was done in an open sand dune desert and they're definitely not exclusively found on bare open sand. I've seen people here say they've found them in scrapes in areas where theres some rocks or vegetation that allows them to do that, which is why I think their burrowing habits change depending on what's available in their environment. That study also demonstrated that they make burrows by digging at an angle into the side of a sand dune, and having dry sand stay stable enough to do that is really hard to recreate in captivity, so I'd say you'd either have to add clay to it so it would support a burrow better or if you wanted to just use sand then provide a hide for them to scrape into. This is kind of a my personal opinion on keeping them though.

Interesting; that all makes sense. If I do keep them, I'll be sure to recreate a habitat that encourages scraping.

Pardon my ignorance, but can I ask what you guys mean be "scrapers". I am thinking like scraping a bowl from its food contents. But not sure how this relates to scorpions haha. Apologies for the dumb question.

It's alright; "scraping" is a weird term that doesn't really have much background anywhere else on the web haha. Yes, just as @MorbidTecolote said, "scraping" is when a scorpion "scrapes" out dirt underneath an object to form a hide.

I'm so glad to see that this thread now has lots of useful info!

 

[HOITrance]

OH BOY! US NATIVE TALK!


For me personally, it's hard to pick a favorite or recommend any one specifically because they're all extremely cool and I could say any one of these was my favorite species. If you exclude the medically significant Centruroides sculpturatus any of these other ones would be an excellent beginner scorpion. The only precautions I would give is for size, Superstitionia is definitely one of the smallest scorpions available in the US and Paravaejovis confusus and Serradigitus gertschi are both on the smaller side.

Hope this helps!

This is one of the most informative posts i have read on this forum, and now has me interested in native US species! I had no idea we had so many cool ones! Anuroctonus and Uroctonus mordax have definitely shot up my list!

 

[gzophia]

This is one of the most informative posts i have read on this forum, and now has me interested in native US species! I had no idea we had so many cool ones! Anuroctonus and Uroctonus mordax have definitely shot up my list!

Definitely; U. mordax is one of the hardiest and most interesting species to keep; I'm trying to CB them so people stop relying on WC specimens. Amazing animals!