Spermathecae Resource Thread

Snipes

Arachnoprince
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metzgerzoo said:
Well, this is all peachy, however, all of you are forgetting one little MAJOR thing, not all tarantulas are female AND it's just as important for those new to the hobby to also be able to know and detect the epiandrous fusillae as well.
Well, think of it this way. How can you tell what sex a baby human is? If there were a thread on that, there would be pics on males because they are the most obvious. So a lack of the ahem, distinctive factor would suggest a female. It is exactly the opposite here, with females having the "thingy" and males not. So what you need to look for is the absense of any of the different female flaps.
edit: Oh, i forgot to mention, DO NOT post pics of naked babies here :), or anywhere for that matter. Twas just an example that everyone would be able to understand.
 

metzgerzoo

Arachnoangel
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Snipes said:
Well, think of it this way. How can you tell what sex a baby human is? If there were a thread on that, there would be pics on males because they are the most obvious. So a lack of the ahem, distinctive factor would suggest a female. It is exactly the opposite here, with females having the "thingy" and males not. So what you need to look for is the absense of any of the different female flaps.
edit: Oh, i forgot to mention, DO NOT post pics of naked babies here :), or anywhere for that matter. Twas just an example that everyone would be able to understand.
You are absolutely correct, in part. To use your example with human babies (no pix posted:D ) the male organs may be obvious, however, that is not always the case, as there are many times (with humans) that upon birth, it is not so easy to determine gender if the external orgains are not either fully developed or descended. It is just as easy or difficult to identify a human female as it is a male by the same method.
Since this thread is, by it's title, for "dummies" then, don't you think, for the sake of having a well rounded knowledge and understanding, that a novice should be aquainted with both aspects of sexing tarantulas, thus, covering the whole spectrum?
Going by the presence or absence of spermacathacae can and has been proven to be misleading in its own right, especially with smaller spiderlings and with those not familiar with sexing and who do not know the differences in appearence from species to species. Unlike humans, who's genitals all look the same (generally speaking), a female tarantula's spermacathcae can look very different from one species to the next, whereas the epiandrous fusillae of the males look basically the same from species to species.
In addition, the spermacathacae can be very difficult to see in a small spiderling due to development level or lack thereof, whereas the fusillae of a male is more clearly visible at a much earlier instar.
Just because there doesn't appear to be a "pouch" or "flap" does not always mean it's a male and just because there does appear to be such does not always mean it's a female, especially when the person doing the sexing isn't 100% certain what they are even looking at or for.
So, my point is, if we're going to teach how to prooperly sex tarantulas, we need to be showing how to and what to look for with regard to male tarantulas as well as female.
 

smof

Arachnodemon
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Some ventral shots. All confirmed by moults.

4" G. aureostriata - Male:


Same spider as above, male chaco:


3" B. smithi - Male:


Same spider as above, male smithi.


I think the different-textured patch of hair that is a sign of maleness is pretty clear in all these shots. Somebody correct me if I think I'm seeing something that I'm not ;)
Note that the 2 photos of the Chaco were taken of an exuvium which has dried out, which I think contributes to the clarity. It was nowhere near that clear when he was still wearing it. The smithi shots are from a live spider tho.
 

smof

Arachnodemon
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B. emilia female

No B. emilias in this thread yet! So here's one. Mine just moulted yesterday and is female.

Ventral shot from when she was a 2" legspan. (sorry it's not very clear but as there are none up so far thought it was worth posting anyway)


Exuvium shot:
 

phil

Arachnoknight
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here's a couple of Brachypelma spermathecae taken ventrally



 

David_F

Arachnoprince
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Poecilotheria regalis spermathecae (cut away from exuvia)


 

bananaman

Arachnobaron
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Knock yourself out :p here's a couple of recent molts...

Brachypelma auratum FEMALE





Brachypelma auratum MALE (not mature yet)




 

Snipes

Arachnoprince
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thank ye kindly loaf
Here is one that finally molted last night...

Female Avicularia versicolor
Molt:




Ventral:



Note: Avic molts are usually really twisted up and this one was no exeption. Pluse it was a day old and hard. Here is the trick, take a small cup of water mixed with dish soap, and dunk the exuvia. Avic molts usually are in a way that the legs are all pointed up and so the body is at the bottom, so just dunk the bottom. Then it is all too easy to open the molt up.
 

NixHexDude

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Is there anyway we can get a few pics of the procedure you guys use to stretch out the opisthosoma of the exuviums? This is the part I have problems with.
 

David_F

Arachnoprince
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Is there anyway we can get a few pics of the procedure you guys use to stretch out the opisthosoma of the exuviums? This is the part I have problems with.
I don't have any pics and there's really not enough involved in opening an exuvium for sexing to justify taking them. Sorry. :D Moisten the exuvium with water, a mix of water + dish soap, window cleaner, or whatever you want to use and use a couple straight pins, needles, fine-tipped tweezers, or whatever to open the abdomen of the exuvium. Pretty simple. Just give the water time to soften it up and work slowly and carefully.
 

Windchaser

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Male P. metallica

Here are several shots from an immature male P. metallica









 

becca81

Arachnoemperor
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Homoeomma sp. "Blue" spermathecae


Brachypelma vagans male
 

billopelma

Arachnolord
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An example of what you're up against finding spermathecae on juvie T's...

~3" P. pulcher spermathecae




And another shot of same for some perspective




Bill
 

billopelma

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N. chromatus, the owner of this exuvium just molted into a mature male... The denser patch of epiandrous fusillae (sp?) is very evident even from this side.




Ventral patch on a freshly molted 1.0.0 G. pulchra, ~4" dls, about the most obvious one I've seen.




0.1.0 P. metallica spermathecae and ventral, ~3" dls. Spermathecae looks obvious here but was very tricky to locate and photograph.







1.0.0 E. cyanognathus ventral




Bill
 

ballpython2

Arachnoprince
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These arent really clear but his is a ventrical shot of my Curly Hair Tarantula (Brachypelma albopilosum)..Can this guy / gal be sex correctly?..I was thinking male.....(one of the dummies :? )



 
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