A question for someone more experienced than myself.

[MassExodus]

How can a tarantula that is only an inch and a half be sexed as female? I've seen the sexing size get smaller and smaller for dealers. I can sex one around three inches because its starting to mature, and I do use a decent usb microscope. What do you look for at 1.5"? Is it reliable? I've had three sexed females turn out male, all of them sexed at at least 2.5" by people who are thought of as reliable in the hobby. I'm in no way bashing them, lets get that clear. Nor will I name any names. One was my albopilosum(honduran), that was a sexed female freebie ..supposed to be anyway. But thats a freebie right? The other was my gbb, and now I'm suspecting I need to check my P metallica when she molts. Two are from the same transaction, with a guy I've bought alot of spiders from.
Sorry for the rambling, but can they be sexed reliably that small? How?

 

[Paul Bowen]

I've thought the same thing...maybe T sex fairies help?

 

[CrypticSpider]

Perhaps our talented and shy @plessey may have some advice.

 

[Nicolas C]

Well, I am certainly not more experienced than you, Mass, but I've been trying to molt sex tarantulas with a binocular microscope for many years now. In my experience, it has been easier to molt sex some spp. when young (after 4-5 molts), but for other spp. I had to wait longer. For instance, I wasn't able to see the spermatheca of my G pulchra until "she" (I first thought it was a male!) was 3 cm BL, and for my Phormictopus sp green even bigger (4 cm BL): before that size, there was nothing to be seen (at least for me and my binocular!). Then I guess it all depends of the spp., the quality of the remaining molt (because T like to chew after molt the very part which is the most moist, i.e. the abdomen), the magnifying glass and the eyes of the owner!

A reputed swiss dealer sold me a young C cyaneopubescens certified female... who was in fact a male! But most of the time, IMOHE, I've thought that my Ts were male (because I didn't see anything) and they turned out to be female.

Of course there are other ways to sex (epiandrous fusillae, extern uterus, etc.) but I don't know how to use them in a skillful way.

Interesting link: http://www.birdspiders.com/faq_sex.php

 

[MassExodus]

Well, I am certainly not more experienced than you, Mass, but I've been trying to molt sex tarantulas with a binocular microscope for many years now. In my experience, it has been easier to molt sex some spp. when young (after 4-5 molts), but for other spp. I had to wait longer. For instance, I wasn't able to see the spermatheca of my G pulchra until "she" (I first thought it was a male!) was 3 cm BL, and for my Phormictopus sp green even bigger (4 cm BL): before that size, there was nothing to be seen (at least for me and my binocular!). Then I guess it all depends of the spp., the quality of the remaining molt (because T like to chew after molt the very part which is the most moist, i.e. the abdomen), the magnifying glass and the eyes of the owner!

A reputed swiss dealer sold me a young C cyaneopubescens certified female... who was in fact a male! But most of the time, IMOHE, I've thought that my Ts were male (because I didn't see anything) and they turned out to be female.

Of course there are other ways to sex (epiandrous fusillae, extern uterus, etc.) but I don't know how to use them in a skillful way.

Interesting link: http://www.birdspiders.com/faq_sex.php

Nicolas you'd laugh if you knew how many times I've read and reread and studied the pics on that link when I first started collecting. It should be required reading imo.

 

[Nicolas C]

Nicolas you'd laugh if you knew how many times I've read and reread and studied the pics on that link when I first started collecting. It should be required reading imo.

Me too!!! But unfortunately, in a way or another, I wasn't able to acquire the skills to perform it!!! LOL!

 

[plessey]

The thing that I have banged on about for over a decade now when it comes to sexing tarantulas is that there are 3 structures (spermathecae, uterus externus & bursa copulatrix) you need to look for not just one. Most hobbyists are guilty of just looking for spermathecae alone and because of this a lot of them fall into the trap of mistaking male accessory organs for spermathecae. When it comes to sexing really small moults it is even more important that you have a good grasp of what these structures look like. At 1.5" you can pretty much rule out the bursa copulatrix on most species as it wont be developed enough to see so that leaves the spermathecae and uterus externus. You will also need around 60 - 80X magnification microscope with underlighting. If you are seeing two little bumps is there a small clear flap of skin over the top of them or a little button hole like structure? If its a flap that covers both the bumps then it is female. If it's a little button hole like structure (or in the case of some species a small rectangular flap that doesn't cover the bumps) then it is male.
As I said most hobbyists just look for spermathecae so they see two little bumps and automatically think it is female. Of course it's not just hobbyists that make this mistake, look at the absolute clanger made in this paper - http://dugesiana.cucba.udg.mx/dugesiana_agost2013/63-66.pdf

 

[MassExodus]

Jesus. Thanks @plessey that's fantastic..I don't have underlighting on my scope but I can figure something out. I have a feeling that no matter how informative this post is, what it comes down to is this: "When it comes to sexing really small moults it is even more important that you have a good grasp of what these structures look like." It comes down to hands on experience, which makes sense to me. I'll be referring to this, appreciate it

 

[plessey]

Hands on experience and keep referring to this - http://www.tarantulaforum.com/threads/how-to-sex-your-tarantula.281/

 

[CrypticSpider]

@plessey - thank you so much for your answers.