Yes, this is another 'Sex my fish' thread. I picked up two adult blue gene dempseys last night - one is a definite male and one I'm 50/50 on. Have a look see and see if anyone can tell any better than I can. The size says male, but the cheek spangling says maybe female.
Definately male. Blue gene means it carries the Blue gene but doesn't exhibit the trait, thus sexing should be the same as a normal JD. Female JDs typically have blue ONLY on the gill cover and a relatively plain rest of the body. Males have color covering the body and can have a little or a lot of color on the gill cover. It all depends on the individual fish. Here is a pic of my male and female so you have a reference, if it helps.