A taxonomic exercise

[skinheaddave]

The last remaining C.gracilis I got from Mat (chau0046) just moulted the other day so I thought I'd take the oportunity to put a tiny bit more experience in positive identification under my belt. I went through the key to Centruroides I have (Stahnke 1977) and took pictures for every detail except overall colouration. Sure enough, it looks like I have a gracilis (well duh!). Since the pictures are quite neat, I thought I'd share them with everyone.

The first step was to determine the number of denticle rows. This is a picture of the chela with the denticles in focus.

Cheers,
Dave

 

[skinheaddave]

Next was to take a closeup of the chela apex to see the configuration of the apical rows. Here the narrow depth of field at 200x magnification became a limiting factor. I probably could have played around for a better shot, but this one served its purpose.

Cheers,
Dave

 

[skinheaddave]

The next step that I took a shot of was the subaculear tooth.

Cheers,
Dave

 

[skinheaddave]

Next up was the granulation on the metasomal keels.

 

[skinheaddave]

And last of all, pectine tooth counts. First the right ....

 

[skinheaddave]

... and then the left.

 

[skinheaddave]

Diagnosis was C.gracilis, but then I saw the mother and I could have made that diagnosis from across the room in poor light. As I said, this was just practice for me.

Cheers,
Dave

 

[Immortal_sin]

holy shamoly!
that is awesome Dave! Love the pics, and it seems pretty clear cut with those keys, doesn't it?!
Gotta have that magnification though...which I don't have

 

[skinheaddave]

Holley,

If you've got the cash, you should get yourself a QX3. It could be very useful for you, but it would also be a great deal of fun for Shelby. It comes with software that lets you take movies, time-lapse movies, make presentations, augment your pics (paint program) etc. etc. It is designed for kids, so it is all very user-friendly. Unfortunately, it sucks up resources, so people with pathetic computers like mine are better using a standard TWAIN imager for taking snapshots. If your computer is fast, though (mine is a 233 and it barely copes) then it could be a blast.

Cheers,
Dave

 

[Immortal_sin]

good idea...maybe for Christmas!
Can you PM or email me details on where/how to get one?
I think it's a great idea!

 

[chau0046]

Great stuff Dave!

It`s nice to see more focused threads with people shareing keys like this. These keys you have...are they on the internet?

Mat

 

[skinheaddave]

They're not on the internet. The complete reference is:

Stahnke, H.L., Calos, M. 1977. A key to the species of the genus Centruroides Marx (Scorpionida: Buthidae). Ent News, 88:111-120.

PM me if you need help tracking it down.

Cheers,
Dave

 

[Henry Kane]

Nice work Dave. Sounds like a lot of fun breaking it all down to the fine details like that. Thanks for showing each anatomical feature used to help in the id too. That's good stuff to know.

Atrax

 

[scorpio]

Hey!! Im not the only person who thought the QX3 was cool!

I got one like 4 years ago. Very neat microscope. Then I wasnt too interested in scorps, but I might have some pics somewhere. I reccomend everybody getting one. Mine doesnt work so well anymore because if you have XP, you need new software that is kinda messed up. Mine takes bad pixeled imaged now

But very nice tool. Looks like a kids toy, but if you can get it nice and focused, it takes pics that are better than a lot of the old digital cameras. It takes some work on 200x considering there is no fine adjustment button.

 

[skinheaddave]

scorpio,

First of all, forget about their software. When you install the software, it instals twain drivers, so just load up Windows Imaging, select the microscope as your source and then aquire images through it. That doesn't allow you access to some of the neater features, but you can take lots of pics quickly and without any hastle. I understand you can take videos using some webcam software, but I have never tried this myself.

Also, be sure to use supplemental illumination at 200x (it helps at 60x as well). I have a small halogen desk lamp that helps to bring out some of the detail. It can also be moved around to illuminate from different horizontal and vertical angles.

Cheers,
Dave

 

[scorpio]

Really? Excellent. Im gonna try that today.

 

[redhourglass]

Hi Dave,

Good job !

Nice to see you taking full advantage of the QX3 options.

A good product but I expect nothing else from Intel.

Keep up the great work,

Sinc. Chad
http://www.geocities.com/redhourglass/scorpions.html

 

[skinheaddave]

Oddly enough it just moulted again. That's less than a month.

Cheers,
Dave

 

[chau0046]

Nice!

Did you raise the temp? I`m pretty sure i have a m/f pair out of the two i have left!! I dont want them to breed but he`ll probably knock up the other adult female i have. Might beable to continue making a brood after all. If all goes well next year i should have my 20 gal tall filled!! First things first ...though. I plan on introducing two 6th instars to one 7th instar and hope all will be well in a five gal for now.

Laters,
Mat

 

[skinheaddave]

Mat,

Yes, but not intentionally. I moved the rack it is on to a different part of the warm area and it may have raised the temps a few degrees.

Cheers,
Dave