How to sex German Blue Rams?

[maxwellag]

I would like to get a pair of GBRs for my twenty long. I want to make sure I get a male and female. How can I tell them apart at the store?

 

[jpchin]

German Blue Ram

here's a nice article on the gbr. it's the one i read before i got my rams.

 

[maxwellag]

Thanks.