With the fins erect above, its still hard to tell... because if those dark areas start to connect as they age, and grow, they would be female, but if the dark areas separate more as they grow, they end up male, and still appear to me be quite young to me, and sometimes you just need to wait to know.
I also don't see a difference in head shaped profile, it has not yet developed.
Note how high an adult male profile is compared to a female.
Yours all seem to still have the youthful torpedo shape.
duanes just an update. I believe I have a pair forming. Advice on when to remove the rest of the Cuban grow outs? Should I leave them in the tank til the pair become aggressive? They currently all get along. With the occasional picking. Thanks again for all your help!