Although I was quite sure the Emperor scorpion I had bought today in a pet shop in Xalapa was a female, I wanted to be 100% sure. So I looked up on the Internet, using the almighty Google, how to sex a Pandinus imperator scorpion.
The easiest way to sex an Emperor scorpion is to look underneath it, at the genital operculum (genital opening), which is located next to the feather like structures, see the photo above. If this part of their body is oval shaped, it's a male. If it's heart shaped, or as I like to call it, looks like the head of a fly, it's a female.
From the above photo, which I took by placing the scorpion carefully on a diner plate made out of glass, and placing the camera under the dish, it's clear that the Emperor scorpion I bought today is a female. See Handling an Emperor scorpion for more photos of this specimen, imported from Ghana ( Africa) and how to handle it, in case you want to determine the sex of a Pandinus imperator yourself.