discus behavior
 

I have three discus, orange in color. One is clearly the aggresive or
dominent, one is bigger than the other two and when he raises his fins, its
quite impressive, the other two hide all day, dont come out at all, even
during feeding. They must be eating something but I never see them eat. Of
these 2, I believe one is male and one female.
Do discus behave in this way normally?

I also have a rather dominent black angel, king of the tank so to speak.

thanks
John