# Beginner's guide to sexing tarantulas



## garlicpickle (Jan 16, 2009)

We get a lot of questions here along the lines of “Is my spider male or female?”. There are guides on other forums, the main one which comes to mind being Craig McInnes’ “Sexing a tarantula”. I thought I’d do one just for our members here. I've tried not to make it too technical. If you want to know the functions of the various structures, I suggest you read Craig's article here


It is sometimes possible to sex a tarantula by looking at its underneath in a good light and possibly some added magnification. If you wish to try this method, please refer to Rick West’s guide here

The main and most reliable method of sexing is to examine the spider’s moulted skin, and it is this method I’m going to describe. If the skin is less than about 6cm leg span you will probably need a magnifying glass or even a USB microscope unless your eyesight is very good. For now I’m going to assume that your spider is bigger than this and therefore large enough to be sexed with the naked eye.

The sex organs of male and female tarantulas differ, and luckily they shed some of these organs along with their skins, which makes our job easier. So first of all you want a shed skin. If the skin is dried up and crispy you will need to rehydrate it so that it doesn’t crumble and break up. The easiest way to do this is probably to give it a good spray with water. Then leave it a few minutes.

Put the dampened skin on a flat surface in good lighting with the inside uppermost. Examine the abdomen section. Is it crunched up or folded over? If so you need to open it up so you can see the inside of it. Depending on the size of the skin you can use a couple of needles, a cocktail stick, a pair of tweezers etc. You can cut off and discard the legs and carapace parts if they are in the way. The only part you need is the abdomen skin containing the 4 white patches (the spider’s book lungs) Now look closely at the area between the front pair of book lungs. 

Female tarantulas

There are 3 structures you need to look for to determine if your spider is female. The first is the spermathecae. These vary between species and can be a useful guide to ID’ing species. In some spiders the spermathecae are a separate pair and in others it is fused into one structure. 


The second is the uterus externus. This is a clear flap just in front of the spermathecae.

The third is the bursa copulatrix. This is the recessed space under the other two structures.

There are a couple of species of tarantula which don’t have spermathecae (E. olivacea being one) but if female it will still have the uterus externus and the bursa copulatrix present. 



An example of paired spermathecae (P. cambridgei) unfortunately there is a bit of book lung obscuring the bursa copulatrix in this picture.










Fused spermathecae (P. rufilata)











Male tarantulas

Male tarantulas do not have any of the above structures. Instead they have a small opening called a gonopore. They also have accessory organs, which in some species are quite prominent. It’s possible to be confused and accidentally ID a male as a female by mistaking large accessory organs for spermathecae. But the lack of uterus externus and bursa copulatrix will determine the sex as male.

Thanks to Roch7121 for the picture of the male B. albiceps moult.













I hope this has been helpful to some.


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## selina20 (May 28, 2008)

Good thread hun very informative.


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## Dr3d (Jul 31, 2010)

great Thread Lisa more sticky material :no1:


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## mcluskyisms (Jan 24, 2010)

Stickies ahoy!!!

Well written and presented


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## Stelios (Aug 28, 2009)

Nice on Lisa, it will get stickied but I bet it wont stop the questions but at least we can just link them to this now.:no1:


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## Paul c 1 (Sep 30, 2009)

Good thread...
-P


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## GRB (Jan 24, 2008)

Stickied in FAQ

-G


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## Tarantulaguy01 (Mar 31, 2012)

This thread has been so eye opening though i've been keeping for just to years not long i know i can now sex my t's. 1 question i do have though is it possible to sex from the outside on i live t as i've heard the book lungs on a female are further apart than a male ?.


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## selina20 (May 28, 2008)

Tarantulaguy01 said:


> This thread has been so eye opening though i've been keeping for just to years not long i know i can now sex my t's. 1 question i do have though is it possible to sex from the outside on i live t as i've heard the book lungs on a female are further apart than a male ?.


You can but its not always accurate whereas sexing by a moult is 100% accurate


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## Tarantulaguy01 (Mar 31, 2012)

selina20 said:


> You can but its not always accurate whereas sexing by a moult is 100% accurate


thankyou i'm of to sex my g rosea as he/she moulted 2 days ago


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## selina20 (May 28, 2008)

Tarantulaguy01 said:


> thankyou i'm of to sex my g rosea as he/she moulted 2 days ago


If the moult is hard try soaking it with some water that will soften it up and make it less brittle


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## Tarantulaguy01 (Mar 31, 2012)

selina20 said:


> If the moult is hard try soaking it with some water that will soften it up and make it less brittle


all done and i have a female thanks to this thread i can now sex my tarantula's . On doing enclosure maintenance i found my p ornata has just gone into moult ! Are pokie's the same for sexing?


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## selina20 (May 28, 2008)

Tarantulaguy01 said:


> all done and i have a female thanks to this thread i can now sex my tarantula's . On doing enclosure maintenance i found my p ornata has just gone into moult ! Are pokie's the same for sexing?


Yup but their lady bits will look different


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## AilsaM (May 18, 2011)

Great thread and now in my favs so I can find it.


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## Tarantulaguy01 (Mar 31, 2012)

selina20 said:


> Yup but their lady bits will look different


oh god just when i've learned how to sex t's you tell me there bits differ from others lol


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## selina20 (May 28, 2008)

Tarantulaguy01 said:


> oh god just when i've learned how to sex t's you tell me there bits differ from others lol


Some look like ears and others look like domes lmao.


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## Tarantulaguy01 (Mar 31, 2012)

Does anyone have pic's of a male / female pokie moult please


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## selina20 (May 28, 2008)

Tarantulaguy01 said:


> Does anyone have pic's of a male / female pokie moult please


None of mine are old enough sadly


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## garlicpickle (Jan 16, 2009)

Tarantulaguy01 said:


> Does anyone have pic's of a male / female pokie moult please


This is a female P. rufilata - males won't have anything there. Be aware that pokies can be late bloomers, they can be quite a size before their bits are developed enough to see properly.


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## Tarantulaguy01 (Mar 31, 2012)

garlicpickle said:


> This is a female P. rufilata - males won't have anything there. Be aware that pokies can be late bloomers, they can be quite a size before their bits are developed enough to see properly.
> 
> image


many thanks for everyone's help


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## Craig Mackay (Feb 2, 2009)

Have a look here and you should find what you'll be looking out for: Spermathecae Gallery


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## Tarantulaguy01 (Mar 31, 2012)

Craig Mackay said:


> Have a look here and you should find what you'll be looking out for: Spermathecae Gallery


i've bookmarked this into my laptop very useful information thanks for the link


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## spidersnake (Dec 1, 2009)

Thank you, I've wanted to know how to sex my own T's for a while now. But I must be thick. I still dont know exactly what I'm looking for or at lol - they just look so similar to me that I'm sure I'll make a total balls up if I try it myself.
Is there a 'Tarantula Sexing Guide for Dummies' available anywhere? :lol2:


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## Bab1084 (Dec 9, 2011)

Great thread!  

What would ppl say is a good size for a T to be before you can sex them accurately?


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## garlicpickle (Jan 16, 2009)

It depends on the species. It's worth having a look from 2-2.5" legspan as you may be able to see something with the naked eye. But some species mature later so may appear male at a casual glance when they are still juveniles.


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## Bab1084 (Dec 9, 2011)

Thank you, I think I will be waiting a while before I can attempt sexing mine then haha there only about 1-2cm & 2-3cm still


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## 8and6 (Jan 19, 2010)

added to FAQ sticky


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## Sylvi (Dec 30, 2008)

Nice male molt here for info.


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## AilsaM (May 18, 2011)

Sylvi said:


> Nice male molt here for info.
> 
> 
> 
> image


Great pic Sylvi to add to a really helpful thread.


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## Mrchancellor87 (Jan 10, 2012)

My T. cupreus' female bits. Lil bunny ears


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## AilsaM (May 18, 2011)

My G pulchra, lil bunny ears female bits :2thumb:


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## pcharlton (Mar 23, 2012)

Saved thank you:2thumb:


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## selina20 (May 28, 2008)

Sylvi said:


> Nice male molt here for info.
> 
> 
> 
> image


Whos that lol. Thought you had weeded out all the boys?


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## Sylvi (Dec 30, 2008)

selina20 said:


> Whos that lol. Thought you had weeded out all the boys?


He isn't mine, a friend wanted it sexed. I do have a few boys left though. The one in the photo is a salmon pink.


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## selina20 (May 28, 2008)

Sylvi said:


> He isn't mine, a friend wanted it sexed. I do have a few boys left though. The one in the photo is a salmon pink.


Did think it looked a bit hairy for you


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## Sylvi (Dec 30, 2008)

I do have something hairy....... I have a blondie......with bunny ears


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## selina20 (May 28, 2008)

Shush dont say that iv already confirmed that she is mine if you ever sell her which is incredibly unlikely lol


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## DrummyGooders (Aug 18, 2013)

Hey guys. 

Can anyone help me sex a specimen from these pics please? It's from a 7cm Lasiodora Parahybana. Many thanks.


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