I have a breeding pair of El Dorados in a 20g vert, with 2 froglets in the tank and, I think, a few soon to morph out. There is another froglet that was removed from the tank a month or so ago, to make more room.
Anyway, I'd never seen any aggression in the tank until today. I saw the, very egg laden, female chasing one of the froglets around the tank. Over branches, under leaves. She was clearly after this one froglet. The other froglet was left alone.
I'm guessing that the one she was chasing is female and the one she ignores is male. Dunno. They are around 4 months old, and, still tiny.
Hmm, now that I think about it, the other day, when the male was calling, I thought I saw this froglet paying attention and maybe moving in closer to him.
So, I made a new froglet tank
Just my observations
eta: I have not witnessed aggression from the male.