Do green chromis kill eachother in schools?

[criticle]

I turned on my lights this moring to find, one of my three green chromis on the sand dead. I saw an injury in front of his dorsal fin and theres nothing else in the aqaurium to hurt it. Is it common for chromis to attack eachother in schools?

[Obi-dad]

This happened to me when I had 3 in a 29g tank. They picked on the smallest one, it died. Then the bigger one left picked on the smaller one until it died. This happened over a period of months though. If yours are new then the death might be due to other causes.

[criticle]

No, Ive had the the three for two and a half weeks now and I suspect that both bigger chromis attacked it.

[AndyB4784]

three chromis is not a school. i'd say that the MINIMUM number for a school would be 6 however i'd go with about 10 for a nice school. take the remaining chromis out and return it or add 4+ more.

[Hop]

Occasionally they do. I had a group of nine and one, by one, three were singled out and killed. The remaining six are fine.

There was a thread not too long ago about this and some people had zero problems and others had the same experience as I did:)

[HBtank]

I think most descriptions of Chromis are wrong, they seem to overlook they aggression they can and will show towards their own species at times.

Almost every description says they are a "peacefull schooling fish".

My blue chomis is anything but that. Not only will it go on a rampage towards other chromis, but it is pretty aggressive all around.

I think that as juveniles and packed together they might be, but full grown and in a medium sized aquarium, not at all for me.

[notyet]

what else is in the tank with them?

schooling is a defensive response to potential threats. if there are bigger/aggresive fish in the tank the chromis will rely on the school for a sense of security. if there are no potential threats, the "school" may turn on each other...

at least that is my understanding...

[jeffhaag]

I've had 8 grene chromis in my tank for over 2 years. I have always had huge problems with acclimating chromis and have probably seen a 30% loss rate in my two tanks within the first 2 weeks. They will develop pink fleshy spots on them and die almost within a day of getting the spots. Once they make it through the first 2 weeks though, I have never lost one that didn't jump from the tank. I think it has to do with poor capturing techniques and shipping techniques. Afterall, how much care do you think they take of a $5 fish. I do not have these problems with any other fish I have aquired and tank parameters are perfect on both of my tanks.

[davocean]

I've had the same 6 chromis for over 4 years now w/ no problems.
Model citizens, and help bring out shy fish.
Mine have even adapted to enter both my nems.

[tkeracer619]

None of my blue/green chromis in a year have been lost due to agression. One died in qt and one jumped. Now im down to 7.

they have never attacked each other that I can tell.

They did school a lot more before I removed a grumpy 3 stripe damsel. Now they hang out in my corals and school during feeding.

[Snakebyt]

i had 7 and they slowly one by one disappeared till there were none

[ReeferAl]

There's no question they can be aggressive and territorial to each other. I've noticed that the fighting is considerably lessened when I feed more in volume and frequency.

Allen

[evilsike]

I have 6 blue/green chromis in 3 years now and yea, they are model citizen in my tank. my mandarin was really shy and like one posted above, it brings out the shy fish. I do see they chase each other once in a while but not bad. they stop chasing after a foot.