# Diplocentridae question



## John Bokma (Oct 17, 2005)

I think I found yesterday my first Diplocentridae sp. (Or maybe I already have a juvenile one, but I am not 100% sure, will post pictures later, when I can take them).

wat does "subaculear spine on the telson" mean (http://www.ub.ntnu.no/scorpion-files/scorpionidae.php)?

Also diplo means 2 IIRC, and centridae something in the middle? What?


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## Richard_uk (Oct 17, 2005)

A subaculear spine is a small spike above the main point of the sting.


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## redhourglass (Oct 17, 2005)

Hi John,

Sorry about not getting back at you with regarding the Veajovis.

I as well look _forward_ to your pictures and website update.  If you have juveniles then for sure species determination can't be provided even if I had them under the scope.  Adult males are prefered and females second to compare with the literature...ranting now so please foregive me LOL.  

Post those Diplos ASAP  

Best Wishes.

Sinc. Chad  



			
				John Bokma said:
			
		

> I think I found yesterday my first Diplocentridae sp. (Or maybe I already have a juvenile one, but I am not 100% sure, will post pictures later, when I can take them).


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## Prymal (Oct 17, 2005)

John-

The members of the scorpionid genus Diplocentrus possess a sub-aculear tubercle (spine) on the ventral surface of the vesicle of the telson. When the telson is viewed laterally, the SAT looks like a miniature aculeus (stinger) in *some* species hence, 2 (double) sharp points (SAT + aculeus) = Diplocentrus or, more simply put = "double pointed".
If you have sub-adult specimens of Diplocentrus spp. identification to species may be quite difficult unless the sub-adults were found with adult specimens or is/are a member of a species with a limited geographic distribution range/habitat preference.
I wish you all the best of luck on an ID!

Luc


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## Prymal (Oct 17, 2005)

John-

And do post pics of your Diplocentrus species!

Luc


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## John Bokma (Oct 17, 2005)

Note that I might be very wrong with my guess, so don't sting me too hard 

I was thinking diplocentrus because the right (looking from the tail to the head) claw looks a lot like the right claw in this picture: http://www.ub.ntnu.no/scorpion-files/diplocentrus_sp.jpg (i.e. larger, and a kind of flat part).


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## John Bokma (Oct 17, 2005)

Barkscorpions said:
			
		

> John-
> 
> The members of the scorpionid genus Diplocentrus possess a sub-aculear tubercle (spine) on the ventral surface of the vesicle of the telson. When the telson is viewed laterally, the SAT looks like a miniature aculeus (stinger) in *some* species hence, 2 (double) sharp points (SAT + aculeus) = Diplocentrus or, more simply put = "double pointed".


Isn't that the same with centruroides, or do I not understand this correctly:







I see "two" stingers, and as far as I know this is a juvenile (4th instar or so) C. gracilis.


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## John Bokma (Oct 17, 2005)

redhourglass said:
			
		

> Hi John,
> 
> Sorry about not getting back at you with regarding the Veajovis.


No worries. I counted 16 pectines on both sides, and I am afraid that that amount doesn't make it easier (I looked up some pectine counts, and 16, from what I remember, is quite common).



			
				redhourglass said:
			
		

> I as well look _forward_ to your pictures and website update.  If you have juveniles then for sure species determination can't be provided even if I had them under the scope.  Adult males are prefered and females second to compare with the literature...ranting now so please foregive me LOL.
> 
> Post those Diplos ASAP
> 
> ...


Posted, and I hope I am right. I mean, I seem to find only vaejovids recently (and plenty of those), and I am really hoping that this is something different.


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## Prymal (Oct 17, 2005)

John-

Several scorpion genera possess SAT's. As for the meaning of Centruroides - I think (not 100% on this) it means something like - sharp, center spine?

Luc


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## Prymal (Oct 17, 2005)

John-

Without going into lengthy detail - examine the ventral surface of the chelae. Are these surfaces flat or arched?

Luc


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## Prymal (Oct 17, 2005)

John-

Next, use a magnifying loupe and find the main (primary) row of denticles on the surface of the moveable finger. Follow the main row of denticles to the base. Examine this area carefully for a cluster of small tubercles ("bumps"! LOL).

Luc


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## John Bokma (Oct 18, 2005)

Barkscorpions said:
			
		

> John-
> 
> Several scorpion genera possess SAT's. As for the meaning of Centruroides - I think (not 100% on this) it means something like - sharp, center spine?
> 
> Luc


Thanks! That clears some things up  :}  Is there somewhere online a kind of checklist to do a kind of raw classification? (I have been called a vaejovis a centruroides before  :wall: ). I wouldn't be amazed if I am wrong again this time, and it's "just" a vaejovid.







I see only one stinger, no SAT.






I also notice that its tail has quite large ridges

Oh, and habitat: Mexico, Veracruz, close to the border with Puebla: 





No, that's not a joke, I found it 2-3m from this snake. The ground is quite wet (locally), and covered with volcanic rock etc.

A general overview of the surroundings:


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## Prymal (Oct 18, 2005)

John-

Reviewing the new photos above, the first that that tends to jump out is the surface texture of the carapace. Typically, the carapace of Diplocentrus species is smooth; weakly granulated in specific regions and only weakly punctate.
Next, the extent of the distinct and well-formed carinae of the metasomal segments. Both characters are absent in the members of genus Diplocentrus. Even the posture in the photo is uncharacteristic of Diplocentrus spp. Diplocentrus species tend to keep the pedipalps widely spaced or extended slightly forward and outward from the body; rarely, drawn rearward against the body as the scorpion in your photo. Also, the position of the metasoma is uncharacteristic of Diplocentrus spp. that tend to keep the metasoma extended or extended with only metasomal segment V and the telson elevated. To be honest, if it were not for the chelae, I'd say it's a buthid or vaejovid.
Tentatively, the specimen in the photo above is not a diplocentrus spp. However, I'm no expert and I could be wrong?

Luc


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## John Bokma (Oct 18, 2005)

Barkscorpions said:
			
		

> John-
> 
> Without going into lengthy detail - examine the ventral surface of the chelae. Are these surfaces flat or arched?
> 
> Luc


Scan of the underside (1282x861)

I counted 19 pectines (top), and 18 (bottom). I would say that the ventral surface is arched, but I have no idea how flat v.s. arched looks.


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## Prymal (Oct 18, 2005)

John-

I'm going with that scorpion being a buthid - probably a Centruroides spp? Maybe Eric (Ythier) or one of the other buthiphiles can assist in a possible ID?

Luc


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## John Bokma (Oct 18, 2005)

Barkscorpions said:
			
		

> John-
> 
> Reviewing the new photos above, the first that that tends to jump out is the surface texture of the carapace. Typically, the carapace of Diplocentrus species is smooth; weakly granulated in specific regions and only weakly punctate.
> Next, the extent of the distinct and well-formed carinae of the metasomal segments. Both characters are absent in the members of genus Diplocentrus. Even the posture in the photo is uncharacteristic of Diplocentrus spp. Diplocentrus species tend to keep the pedipalps widely spaced or extended slightly forward and outward from the body; rarely, drawn rearward against the body as the scorpion in your photo. Also, the position of the metasoma is uncharacteristic of Diplocentrus spp. that tend to keep the metasoma extended or extended with only metasomal segment V and the telson elevated. To be honest, if it were not for the chelae, I'd say it's a buthid or vaejovid.
> ...


Many thanks Luc, I learned a lot today, and also that I have to learn a lot and lot more. (It took me quite some time to translate your message to scorpion parts  ). The size of the chelae was what me made think of diplocentrus, since I remembered vaguely that they are large. Also, some time ago someone wondered why I hadn't been able to find a diplocentrus yet.


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## Prymal (Oct 18, 2005)

John-

I've been looking at the telson closely - I see no sub-aculear tubercle.

Luc


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## Prymal (Oct 18, 2005)

John-

Now, take into account that I'm no expert and I could very well be wrong. And as for more to learn - join the club! And remember, even the "experts" don't agree on scorpion systematics and placements 

Luc


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## John Bokma (Oct 18, 2005)

Barkscorpions said:
			
		

> John-
> 
> I've been looking at the telson closely - I see no sub-aculear tubercle.
> 
> Luc


Yes, I think I already mentioned that  Maybe you overlooked it, because our posts are a bit intertwined.


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## Prymal (Oct 18, 2005)

John-

I don't know what you have there but it's not a member of genus Diplocentrus. If it were not for the sub-pentagonal sternum, I'd say a buthid. However, my taxonomic knowledge is limited to just a few groups and I do know that some buthids possess subpentagonal sternums.

Whatever it is, it's a nice looking scorp. The posture of the scorpion in the photographs reminds me of various buthids and vaejovids. It is very unusual to see a diplocentrid assume a posture in which, the chelae are drawn rearward and held laterally against the body. It is also rare for them to position the metasoma as your scorpion in the photo. During movement and generally, when at rest, diplocentrids extend the metasoma or partially extend it outward onto the substrate. 
As for the habitat photos and locality (Veracruz) - diplocentrids are found in many habitats and environments, and down your way, there should be more than a few species. Don't feel amiss that you haven't located specimens as almost all diplocentrids are obligate burrowers, with burrows typically excavated in relationship to surface and sub-surface structures. They also tend to be highly reclusive and secretive. Your best bet would probably be to find areas with a preponderance of rocks and blacklight during the night. However, based on reports in the literature, even during the night, diplocentrids are rarely as active and abundant on the surface as are other scorpion species. Good luck!

Luc


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## Michael (Oct 18, 2005)

hi John,
I can't help you with the ID for this specimen, but i can say that it isn't a Buthid  

regards
Michael


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## Aviculariinae (Oct 18, 2005)

Hi Michael


			
				Michael said:
			
		

> hi John,
> I can't help you with the ID for this specimen, but i can say that it isn't a Buthid
> 
> regards
> Michael


Just curious to why you said it wasn,t a buthid?


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## Nazgul (Oct 18, 2005)

Hi,

it´s not a Buthid cause the sternum in Buthidae is more triangular shaped. The sternum of the specimen above is clearly pentagonal which rules out Buthidae. It´s neither Diplocentridae cause it doesn´t have a subaculear tubercle. By the way, the family Diplocentridae has been moved to Scorpionidae recently, it forms the subfamily Diplocentrinae.

I´d say it´s a Vaejovid but I can´t really backup this opinion. It just looks like one to me because of the metasoma and the shape of the telson. Also Vaejovids are having a really high diversity in Mexico. It could as well be another family, Chactidae for example (although I´m not very experienced in determining members of other families than Buthidae, Vaejovidae and Euscorpiidae). You should check out this paper:

SOLEGLAD M.E. & V. FET (2003): High-level systematics and phylogeny of the extant scorpions (Scorpiones: Orthosterni) – Euscorpius 11: 1-175

which you can download here

Regards
Alex


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## Prymal (Oct 18, 2005)

Nazgul,

Thanks for stepping in. Unfortunately, my primary interest (taxonomic-wise) is the diplocentrids. I only mentioned buthids because I know that some (according to reports) possess a sub-pentagonal sternum. A vaejovid is a possibility due to the fact that there's so many species and Mexico has such a high abundance of diverse species (probably many as yet undescribed or unknown). As for the members of other families, like yourself, I am not familiar.

Luc


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## Kugellager (Oct 18, 2005)

It's not a buthid.  It's some type Vaejovid.  I am leaning toward Paruroctonus but there are one or two other genera that look similar to Paruroctonus. Note many of the distinct Paruroctonus characteristics it has in common with this image of Paruroctonus bantai...I'm not suggesting it is P.bantai but am just using it as an example of the P genus for comparison.

http://www.ub.ntnu.no/scorpion-files/p_bantai.jpg

John
];')


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## redhourglass (Oct 18, 2005)

Hi.

With the photos provided it is clearly a Vaejovis.  The following article should help with this thread.

Systematic studies of the _nitidulus_ group of the genus _Vaejovis_, with descriptions of seven new species. (Scorpiones, Vaejovidae).  Journal of Arachnology, 19:  4-28.

This paper [ CLICK ] should help you out John B.

If you find Megacormus their pectinal teeth counts are low.

Cheers.

Sinc. Chad


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## Prymal (Oct 19, 2005)

Chad-

Thanks for the ID!
Very beautiful and wicked-looking vaejovid.

Luc


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## redhourglass (Oct 19, 2005)

Hi Luc,

I did suggest to a species but had it edited out yesterday for we know an species determination can't be made from photos. :wall: 

When I saw the scan John provided the chela gave me the impression of the nitidulus group but one has to view the trichobothria placement on the pedipalp chela to exclude it from the other groups of Vaejovis.

A very good thread to say the least !

Cheers.

Sinc. Chad  



			
				Barkscorpions said:
			
		

> Chad-
> Thanks for the ID!
> Very beautiful and wicked-looking vaejovid.
> Luc


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