One of my female blue genes will occasionally chase the male electric blue away but she never bites. They're both about the same size but the female does seem a bit fatter than him. They definitely haven't paired but I've also never seen the electric blue at a corner or the top of the tank. He(?) still swims freely around. I have no idea if the female is rejecting him or if he might even be a she. Are the chances of an EBJD being female likely?
But regardless, do you remember the size of the two?