blue-green chromis psychology

[CiXeL]

ok i have 8 blue-green chromis now. 1 died i assume was eaten by the others during the period of time our power was out from hurricane wilma. i kept the whole system alive with a car battery, bilge pump and battery operated air bubbler

now its been a number of days that we've had power back and the lights come back on/theyve been fed on time
the problem now though is that following the death of #9 the group has now fractured into 2 groups

4 hang out in the corner bullied by the other 4 on the other half ot the tank which school.

anyone know if theyll reintegrate over time? the bullied 4 seem to be eating but they dont seem very afraid of my hand

should i add some more to stir up the mix and confuse them into rejoining the school?

not sure what to do here. i know bullied fish usually wind up dying but i dont know what i need to do to force them to rejoin the school.

 

[LA-Lawman]

try moving some rocks around. mix up the " boundries"..... comfuse all of them.....

hth

 

[Anonymous]

I would try what the LA Lawman says about moving the rocks.

However, sometimes this is just the case with Chromis's.

 

[Anonymous]

Usually it's said that groups of chromis will pick on the weakest one until it jumps or gets killed. This supposedly happens until only one is left, though I could see this wouldn't be a problem with a really big tank. I've seen this happen with my group, down from 10 to 6 over a year.

If there's a significant size difference, I'm not sure there's much you can do. I have a feeling this isn't about territory (which would be addressed by moving the rocks), but more about the pecking order.

I would be interested to know how many people have had long term success with a group of chromis in a smallish tank without any casualties. Mine's a tall 90g and I don't think big enough for a group of these fish.

 

[Anonymous]

I went from 5 to 2 in my 125 gallon.

 

[LA-Lawman]

I have 12 in a 180g. i started with 17 about 6 months ago... i guess we will see...

 

[Anonymous]

I wonder whether the recommendations about stocking for these fish shouldn't be altered to take this into account. Sure, if you don't mind the attrition, they're a lovely addition to a tank, but otherwise they're maybe better suited to a big, big shoal in a big, big tank, where the aggression can be dispersed by the sheer number of fish, and the victim has plenty of space to flee.

 

[LA-Lawman]

i was thinking the same thing. but what gets me is they are all hunky dory in the 40gallon rack mounted tank at the LFS. my LFS doesn't sell fish unitl the have been QT'd for 3 weeks.... so it seems if you give them a little space they "freak out"...

wonder if it is the whole "built in" instinct thing comming around again?