Chromis stopped schooling?

[FiveGallonSea]

..... or shoaling. Whatever you want to call it.

I have a group of 5 reef Chromis who were always together and active. Mainly during the white light phase of the day, but it was a routine. About a month or so ago they all found their own respective crevices in the rock work and I will MAYBE see them all out during feeding time. One has even disappeared a couple days ago. Wondering what the change is in the behavior. I had a very aggressive duo- my Flame Angel and my Yellow Tang. My Flame passed and I swapped out my adult Hippo and Yellow Tang for babies and added a young Blonde Naso. The tank now is much more peaceful than it has ever been, but they are hiding all day.

Any thoughts? Experiences?

 

[Kmsutows]

They are likely maturing and establishing dominance and will start dying one by one.

 

[noahreefer]

They are likely maturing and establishing dominance and will start dying one by one.

That just recently started happening with mine.

 

[DangerDave]

I wouldn’t worry about it. You have to remember that they are still shoaling. Tanks are a small. Once they’re comfortable they will spread a bit. I have 11 in a 160 with a bunch of anthias and a few other fish. If they feel uncertain from say a loud noise they start grouping tightly. Same happens when I come up to the tank quickly. Chromis (and anthias) do better in larger groups I’ve noticed. It keeps the social aggression down.

Dave