Quick question about B. vagans sexing

[saturnthegrey]

I have a 1.5" red rump and I know it'll be a while til it's old enough to sex but i'm just curious. About what size do they have to be in order to be properly sexed?

Once again, I know it will be a long while until this one will be big enough.

 

[lalberts9310]

They can be vent sexed around the 1.5" - 2" mark. But vent sexing is not as reliable and accurate. The best way to confirm the sex of a T is by looking at the exuvium to see if spermathecae and uterus externus are visible. Small molts will have to be sexed via microscope or magnifying glass as locating spermathecae/uterus externus in small molts can be difficult and sometimes impossible with the naked eye.

 

[saturnthegrey]

Greeeaaat... I have neither a microscope nor a magnify

 

[Poec54]

You don't have to 'wait a while.' I can vent sex most of mine at 2" without magnification (deli cup and a flashlight). If you post pics, you're not going to get responses if they're out of focus and full of glare.

 

[Poec54]

You don't have to 'wait a while.' I can vent sex most of mine at 2" without magnification (deli cup and a flashlight). If you post pics, you're not going to get responses if they're out of focus and full of glare.

I learned to sex by looking at a bunch of vent sexing pics on tarantula sites. Keep doing it until you get a feel for it.

 

[saturnthegrey]

I'll get up on my research for sexing then.

 

[bryverine]

I'll get up on my research for sexing then.

You can also buy a small cheap microscope on amazon. I just sexed (I'm pretty sure) my 1.5-1.75" GBB at approximately 60x.

Bottom lighting helped.

I'm not sure if it would work for you, but for $20 you can buy a "decent" USB microscope on amazon or eBay.

I've also been curious but haven't really found if slings of all sizes have spermatheca (even if they're super tiny) or of they developed these organs after they get to a particular instar/size.

 

[saturnthegrey]

Maybe ill try taking some pictures with my fiancés canon and uploading them, my phone camera is garbage

 

[bryverine]

Good luck! BTW, the molt was actually 1.5" (I measured it).

 

[peterUK]

Brachypelma, like most terrestrial tarantulas can be easily be sexed using a microscope at around 1.25 - 1.5 inch legspan.
If you intend staying in the hobby and intend to breed at a later date then I would recommend that you acquire a good microscope so that future spiders can be sexed at a young age.

This is the spermatheca of a Brachypelma boehmei (1.5 inch LS)
photo taken with my cell phone down the eyepiece of the microscope

 

[TomKemp]

A good eye loupe works great under good lighting. You can grab one online for anywhere between 10-20 bucks.

 

[saturnthegrey]

I read somewhere you can even take the lens from an old cd player and it works great as a magnifier