Here is an interesting read on non-exuvium sexing.

www.birdspiders.com/faq_sex.php

I think the point is that it is possible to sex ventrally, but there are hard and fast rules. It has more to do with the type of setae and not the furrow that we usually look for.

One interesting bit is where the author states that at VERY young age, the exuvium of the male has a more apparent furrow or pocket(not used for sperm) than the females spermethecae punch that will develop later.

Even upto the day that I sold my fairly large P ornata male, I thought ventrally it looked like a female, but the exuvium doesn't lie.

In the end, I think if any breeders are "sexing" slings (only possible from 2nd instar exuvium onwards), they are still taking a gamble.
Most breeders start selling slings at 2nd instar when they are eating. Some species only start eating at 3rd instar, at which point they are only sellable. So not always possible to sex them before they are marketable.

but selling 5 and 6th instar slings without them having been sexed is also possible. My one avicularia and P cambridgei has destroyed their molts all the time. I was only able to sex them both (as females) by waiting for them to finish and immediately removing the shed, while it is still soft.

Thanks SynergyZA very interesting read!!

Maybe it is possible maybe that guy has so much time to waste he can do it!!
If the dude chooses to hold back all the females and only sell the males then so be it.
But it will cost him more money in the long run to do so.

For an example If "MR Bs breeder" has a egg case held of 1000 slings and out of those 1000 slings 400 are males, so he sales them off at R100 each.
So know he’s got 600 slings that are females that he has to look after until they reach 8cm, just so he can sell them for a bit more money as females!
The amount of work and money he will have to put into looking after them will cost him at the end of the day.
So I don't think a breeder will be so silly maybe will only keep 10 or so.

Why do you think some people will buy 4 to 10 slings just to insure they get a chance to have a female!
I’m sure there will be some massive riots if some one buys 10 slings and all 10 end up male!



I'm sure if you have a powerful microscope and steady hand and time to waste I'm sure you can see your tarantulas pretty small cause logic is they are born with their sex organs, just under developed though.
But I can tell you the big breeders don't do such a thing because I have had females and males in my collection bought from a couple of breeders!

I agree cascade.

The reason you sell you slings at such a young age is so that you don't have to struggle with feeding them all.

I know someone that had a 1300 strong egg sac of Salmon Pinks, she got 50/50 split, meaning 650 slings. I do not want to feed 650 slings even once a week with pin-heads until they are all sold. Rather let the go as quickly as possible for as little as possible.
Imagine the size of your colony of crickets or roaches if you had to feed 650 babies roaches to the slings.

I think a higher possibility could be that someone who bought (or imported before it became virtually impossible) only, say, a hundred slings of something more pricey or rare, finds it well worth the effort to sex them before selling off the males first.

It needs a lot of skill and experience to sex small slings but amost anyone can learn to do so quickly from a legspan of 4 cm up.

I'm very careful when buying unsexed slings and juvies from 4 cm. Either I sex them myself or I know I can trust the seller implicitly. The only other options would be a very tempting deal or that I don't really care which way the sex will go.

A while back when I was looking for a P metallica, I was told that the people the export them (not to SA since it is illegal) sometimes sell males off as premium priced females. No matter what efforts you put in, photo of the spider, exuvium, etc. no matter what size, you don't know what they stick into the container when they ship them. Might not be the same specimen.

Especially with those rarer and more expensive species, it is easy to find a juvie, odds are, it will be male. And yes, at some point someone might require a male, which is exactly why I bought the one I did, but if you want a guaranteed female, don't buy over the post or unless you really know the person and can trust them.

So would you say the 4x P.regalis 4cm i got from a well known breeder are probably all males?