Newbie Q's - At what size can you tell sex by exuvium? And what do you do with your male T's?

ryancreek

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Nov 27, 2010
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I recently tentatively sexed my 2" (front to back leg, and maybe a bit longer) Brazilian White Knee (A. genic) as male. Looked for spermathecae in the exuvium between the first set of booklungs and found nothing at all - indicating a male. I am wondering though, if T's maybe don't develop their parts until they are a bit older, or if spermatecae would already be present in a T of this size if it were female? :?

Supposing this is a male A. genic, and I DO NOT at this time plan to breed T's.... What should I do with this male T when it gets close to becoming a MM? Sell it and let someone else use it for breeding? Is that sort of the standard in this hobby?
 
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Hobo

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You can see spermathecae at a really small size if you have a good scope... otherwise it's very, ver difficult to see with even a magnifying glass. I was able to see spermathecae clearly without any kind of magnification at around 3 - 3.5" for my sexed female juvies (B. smithi, P. lugardi, P. irminia).

With the P. irminia, I raised her from a sling and I wasn't able to see ANYTHING until she was about 3"; the spermathecae suddenly stuck out like a sore thumb.

Typically, you would send him out to a fellow hobbiest when your male matures, and in exchange, you get half of the offspring should the female produce a viable sack from the pairing. Of course, you can always sell him, or make other trades. It's up to you really.
 

AmbushArachnids

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The spermatheca may not be visible at 2". Try looking with a microscope or a magnifying glass.
 

flamesbane

Arachnobaron
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Depending on the species you can sex them at 1-1.5" with a microscope no problem.
 

ryancreek

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Nov 27, 2010
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The spermatheca may not be visible at 2". Try looking with a microscope or a magnifying glass.
Hmmm... well thanks for your replies both of you.

Looked again with a dissecting probe (don't ask why I have that but no magnification), and there does appear to be a VERY miniscule flap in the right spot, but it does not look like the spermatheca for this species AT ALL. It seems that unless I can pick up something to magnify it with, I may just have to wait and get a better idea with the next molt when it's closer to 3 inches, but for now I am leaning male.
 
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AmbushArachnids

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Hmmm... well thanks for your replies both of you.

Looked again with a dissecting probe (don't ask why I have that but no magnification), and there does appear to be a VERY miniscule flap in the right spot, but it does not look like the spermatheca for this species AT ALL. It seems that unless I can pick up something to magnify it with, I may just have to wait and get a better idea with the next molt when it's closer to 3 inches, but for now I am leaning male.
Ive had a few Ts i thought were male and ended up female when i didnt have a microscope. But when in doubt I always lean male. {D
 
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