German and black ram

[Fishnob23]

I just picked up a german blue and black ram. I had the blue for about 2 weeks was very peaceful got the black one today since I put it in the blue been chasing the black ones around non stop. anyway to tell if make or females and how to stop the aggression?

 

[MacZ]

The normal one is a male. The black ones generally lack most signs, and this one has roughed up fins, so I can't tell. You can only make this stop by separating them.