African cichlid Aggression problems

Question
Hello, I have recently set up a 55 gallon african cichlid fish tank. I have 13 cichlids (Juvys) in it right now.
1 Yellow lab
1 Blue zebra
1 albino cichlid with red fins on top and 3 egg spots
1 male kenyi
1 male johanni
1 Auratus
1 male Electric blue Ahli
1 Peacock cichlid (it is white with black spots and sort of orange) do you know what it is?
1 red empress
1 livingstonii
2 frontosa
1 borleyi hap ( I dont think it is a borleyi because it has sulfer yellow on his head and blue everywhere else with 1 black line)



OKAY, so the Johanni is chasing everybody and just being mean everyday! Should i remove him from my tank ? my tank seems like its so agressive because my ahli chases the (borleyi)   and the tank realy is never calm


Water is perfect
25% water change every week- to two weeks
75 gallon filter
lots of rock 50 plus pounds

PS my auratus is so wierd cause somedays he/she is yellow and black and somedays brown and dull

what should i do to help the agression problems?

I KNOW MY TANK IS SLEGHTLY OVERSTOCKED!
PLZ NO COMMENTS ABOUT OVERTOCKING  

Answer
Hi there,
Johani african cichlids in general are a very territorial and aggressive species. Males in particular are very bossy and may continually dominate and attempt to kill other males or perhaps even other species.

Ahlis and Auratus are both quite aggressive species with Auratus being one of the most aggressive mbunas. Obviously their behavior and such creates a situation where it can be hard to mix them with other species.

You tank may simply not have enough territorial boundaries and hiding retreats for the other fish if they are getting continually bullied.

And if the aggression continues you may be better off giving away the most aggressive cichlids.

Its difficult to know the peacock cichlid species you have because there are so many hybrids of almost every african cichlid species. It definitely sounds like a hybrid though. Try checking out this photo

    (Aulonocara sp. x Pseudotropheus estherae OB)

http://www.aquahobby.com/gallery/img/OB_Peacock_1.jpg


I hope this helps!
Karen~