# When does a female tarantula become an adult female?



## antcherry88 (Mar 28, 2011)

As above.

Obviously I'm new to tarantulas and can't seem to find the answer. When does a female stop being a juvi and start being an adult?


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## kris74 (May 10, 2011)

antcherry88 said:


> As above.
> 
> Obviously I'm new to tarantulas and can't seem to find the answer. When does a female stop being a juvi and start being an adult?


What do you mean? Like age or something? It depends entirely on the species I would imagine. Some females can breed from quite a smaller size that they would be when fully mature, like as big as they're going to get. M.balfouri are a good example of that. Not sure I understand your question properly though so my answer may be crap!


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## ojo (Jun 8, 2011)

When you look inside the moult and the spermathcae is fully formed


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## Craig Mackay (Feb 2, 2009)

It depends what you define as adult; fully grown or sexually mature?

Females are capable of breeding before they reach their maximum size when their spermathecae become sclerotised (hardened). You can check this when you look inside a moult however, it's worth considering that the state of the spermathecae is only an indication of what it was before the spider moulted. Some people have noticed their spiders going from sclerotised spermathecae to unsclerotised one moult after the other. Perhaps natures way of ensuring a female gets a rest from the energy expended in mating, creating an egg sac and looking after it?


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## gambitgareth (Sep 18, 2011)

craig mackay: "bish bash bosh"


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## antcherry88 (Mar 28, 2011)

Craig Mackay said:


> It depends what you define as adult; fully grown or sexually mature?
> 
> Females are capable of breeding before they reach their maximum size when their spermathecae become sclerotised (hardened). You can check see this when you look inside a moult however, it's worth considering that the state of the spermathecae is only an indication of what it was before the spider moulted. Some people have noticed their spiders going from sclerotised spermathecae to unsclerotised one moult after the other. Perhaps natures way of ensuring a female gets a rest from the energy expended in mating, creating an egg sac and looking after it?


Well thats what I'm asking what is an adult tarantula defined as? For example in the classifieds you see juvenile females and adult females for sale. What's the boundary between a juvi and an adult? 

Does adult simply refer to a specimen of adult size (obviously species dependant) or is there a more scientific definition.

How would a seller prove they had an adult female and what would a buyer ask for as evidence? Or does it simply not matter as there's not much difference in price?


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## gambitgareth (Sep 18, 2011)

yes I'm afraid so - I understand what you mean, in a legal sense a claim that a specimen is a mature female would be difficult to prove as a misrepresentation unless you had the specimens previous moult, as at that stage it would have fully developed spermathecae - generally - as pointed out.

If your worried about not getting a fair deal for a purchase - always try to ask for an example photo so you can see for yourself - ideally next to something that you can gauge the size with - especially as its not such an exact science.. such as 'juvenile' can represent anything from a sling to an adult depending on seller. 

on price I think there isnt' much difference in the benefit of a sub adult to adult. if your going to breed, a fresh matured fem could be smaller and therefore less likely to munch the male... but then there are exceptions to the rule.. price however can be v expensive for adult over juvenile, it often depends on how fast a species grows - b.smithi an example that comes to mind - or simply from sellers demands being different. - 
is there a particular offer your not sure of?


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## EffyDaydream (Jan 29, 2012)

antcherry88 said:


> Well thats what I'm asking what is an adult tarantula defined as? For example in the classifieds you see juvenile females and adult females for sale. What's the boundary between a juvi and an adult?
> 
> Does adult simply refer to a specimen of adult size (obviously species dependant) or is there a more scientific definition.
> 
> How would a seller prove they had an adult female and what would a buyer ask for as evidence? Or does it simply not matter as there's not much difference in price?


As far as buying and selling, a lot of places just do it on size rather than maturity and in there cases it's generally their decision what they class it as. As a slightly different example on Virginia Cheeseman's website a sling is up to 1.5cm, a juvi up to 5 and an adult bigger (or something like that), but TSS have slings up to about an inch. And of course, some people will advertise it as a mature specimen so as to get more money. :\


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## gambitgareth (Sep 18, 2011)

i was stung by that my recent purchase fr VC was a medium p formosa, arrived as a 1"-1.5" sling.. not to give bad feedback - I know the difference when a sling comes and it has been looked after (the t was in excellent condition) just that a medium t for me would be up to sub adult, since the next size up would be large - which for me should be the maximum or adult... so definately sale price is determined by vendor requirement not size.


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## antcherry88 (Mar 28, 2011)

Thanks for your replies. Much better understanding now! 

There's no particular deal I'm looking at it just crossed my mind. In shops etc I can generally spot a mature male by the tibial spurs and/or bulbs on the pedipalps, as well as the 'leggy' look of the spider. I only ever look at common terrestrial species so it's a good guess.

This got me thinking as to how you determine an adult female. I assumed it would involve inspection of the moult to determine whether it was female in the first place but was unsure as to what constitutes an 'adult'. 

Now I realise its to do with the sclerotised spermathecae. Or if buying/selling it can just mean a female of adult size. 

Cheers :2thumb:


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