what is killing my peacocks

You're mixing two different groups of african cichlids (mbuna & peacocks). While from the same lake (Lake Malawi) they occupy different environments within the lake.

Mbuna (which includes ur yellow labs, mbamba, kenyi, etc) r much more aggressive & territorial than peacocks (which can be aggressive among each other but can not really compete with the likes of mbuna).

You also added the less aggressive type last (mbuna typically do not kindly accept newcomers unless they happen to be as or more aggressive than they are). By placing the lesser aggressive fish in a tank already containing territorial established mbuna is the major problem.

Secondly, by adding only two peacocks it makes it easier for them to be singled out. The peacocks would have fared better if the tank were larger & a half dozen were added (first).

Basically, peacocks do not belong (or thrive for long) in a mbuna dominated tank.

Solution: establish a peacock species tank (which would be awesome) or just get more mbuna.

what

Look to the kenyi as the the aggressors. Peacocks really should not be with the more aggressive mbuna because u get this situation. If u want to keep peacocks get rid of the kenyi & a few others so all u have r labs, rusties & peacocks.

As for the johanni, it was killed because it was new or the kenyi saw it as a threat to it is status. When I add fish, I add them in groups so that no one fish can be targeted. Electric Blue johanni might be M. cyaneorhabdos & they r the least aggressive of the Melanochromis species. They might also be okay with peacocks. Also cichlids r not pairing fish, they r harem breeders. Males will harass a female to death. Find a good cichid forum & learn about ur stocking options

i think the peacocks are too gentle to be with the other africans
my husband used to raise them
i do not recognize the names of the fishes you listed but i know you have to be very careful with these type

cichlids their very aggressive they like to eat other fish not flakes

I am not real familiar with Africans, but I know they r very territorial. I had some awhile back, & the guy told me that u want to add them at the same time. And u want to get ones all around the same size. That way they can stake claim to their territories. Now u add a new one to a tank that is already got their own myspace, & havoc erupts. That is happened to me before, I'd added 3 fish at different times, only 1 made it & that is because I relocated him to another tank.
I just started going to these forums, seem pretty good & informative. Have lots more info about Africans there, I like them they're beautiful fish, but I just never got around to being serious with them.
http://aquariacentral.com/

http://aquariumboard.com/forums/home.php

Here is a link to specifics on the Cichlid species - hopefully it helps.

http://aquariacentral.com/species/cichlids.shtml

Good luck!

Whoah, are not Cichlids supposed to be kept in a species only tank? They will attack fish much larger then themselves if they felt like it. Especially Africans. Further their salinity, water temps, and Ph levels are uniquely high. I am not that into fish anymore, but that is what caught my eye here.

cychlids are aggressive fish that eat your other fish

YOU MIXED SALT WATER AND FRESH WATER FISH