Sexing orinos

[Spakase]

Any tips on sexing Orinos? Recently came across some, and I wanted to get a male/female pair.

 

[High City Rida]

What size are they? And congrat's on the find.

 

[Morledzep]

when they are about a foot long.. lol..

i personally would just buy a bunch.. and when they get big enough to tell the difference i would put em in a bigger tank...

 

[Spakase]

Mine's more than a foot long, and it's really beautiful. The lfs that sold me the orino says it's a female, and his logic is that females are bigger than males.
Would there be any marking differences between males and females? Or venting would be the only way to tell? I've vented the PB and suspect it's a male, contrary to what the lfs told me.
I've spotted another Orino (not so beautiful as the one I have) in another lfs and now trying to sex them, hoping to get a pair in the end.

 

[Spakase]

when they are about a foot long.. lol..

i personally would just buy a bunch.. and when they get big enough to tell the difference i would put em in a bigger tank...

So how to tell?

I did before (ie kept a group) but can't find small ones in the market and be assured the are orinos, as they could end up to be hybrids with monos or one of the others. I used to have a good source, but the lfs has closed!