Checking the Exuvium to determine sex of tarantulas.

[Matthew Baines]

I am just querying about the best way too determine the sex of my tarantulas by there exuvium and the best size too do so , i also just bought a 30x magnification lens will that be of any help? Any guidance in checking the exuvium will be much appreciated

[matthew spooner]

you can check the sex of your T using a microscope with their skin from the 4th moult onwards. i am not 100% at sexing so someone else would be better to give you advice on how to do it

[Zoltan Mihaly Lestyan]

Hi,
The area you will be curious about is between the anterior (top) booklungs, the area where the epigastric furrow is. You will need to straighten that part of the exuviae out to get a good look. If it's to dry to manipulate, put it in a plastic box - or something similar - with wet paper towels in the bottom for a few hours, that should help regain some flexibility. Also, needles work well for manipulating the skin. If there are spermathecae in the area I mentioned above, you have a female - these vary in shape and type (it can be fused or not, I'm not sure about the correct terms). For info on how the spermathecae of some species look like, I suggest checking Mikhail F. Bagaturov's website >>click me<< - pretty good pictures at the bottom. Males do not possess spermathecae and the area is flat and straight compared to the "flap" look of the female spermathecae. Good luck!
Hope this helps,

[Peter Roach]

These photos may help you as well.

http://www.arachnophiles.co.uk/forum/showthread.php?t=2069

[Mark Pennell]

Here is an old page from my seriousbite website, its over 10 years old now but still has good info on it.

http://www.seriousbite.com/sexing_your_tarantula.htm

Cheers
Mark

[Alexander Abrams]

Interseting site, Mark. I'll have a go and see if I can work out the sex of my couple, but if I'm unable (more than likely), is there anyone out there I can send the molt to?

Thanks
Alex.

[Johanna Turner]

Sexing

I have been shown what to look for and I'm almost sure what I have checked so far is correct, but I just wanted clarification.

With a male T exuviate, the epigastric furrow is completely flat and smooth. The female on the other hand, has a 'flap' that protrudes on the inside of the exuviate. This 'flap', on certain species, has the spermethicae visible on the one side. Is this right?

I just sexed a sub-adult T apophysis and this showed just a large semi-circular flap, with no apparent spermthecae structure. I was under the impression, if this was a male, there would be nothing prominent on the inside of the exuviate at all??

[Zoltan Mihaly Lestyan]

Hello,
It's probably a female. Some species possess spermathecae with a shape that is simply a "flap" with no divided structures. Here is a picture that shows the exuviae of a female T. apophysis: http://www.arachnoboards.com/ab/gall...p?imageid=8361 - it's not very good, but you can see the spermathecae.

Hope this helps,

[Johanna Turner]

Thanks!

Cheers Zoltan, that's a help. It must be a female then. It just seems too obvious I guess, I was questioning myself