fish fight

I have an awesome fish tank with African Cichlid fish in it set up in my living room.  I spend a lot of time arranging the tank with coral so that there are lots of hiding spots for the fish (about 15 of them). Cichlids are known to be aggressive, but mine usually aren't.  There is one that swims around to the other fish and shakes his tail in there face, then darts off.  I researched this and found that it some sort of mating thing.  Can't you just see running up to some guy, shaking your butt at him and running off?  Well, I guess it is working out well for her because we have had a few baby fish appear in the tank, and I assume that they are getting there from all that tail-shaking. The other night, I was watching the fish, and getting ready to feed them, when all of a sudden two of the fish were locked jaw to jaw and splashing all around- a fish fight!  How do you break up a fish fight?!  I jumped up and banged on the glass, and they let each other go and swam away.  They seem to have left each other alone since then.  I wonder if all the other fish were yelling, "fight!" (in fish talk) and swimming in a circle around them like they do in middle school.  I didn't notice.