Green Chromis

Randy Holmes-Farley

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Don’t know the exact reasons why, but the three green chromis I got from Dr Reef have been happy and seemingly peaceful additions from last April.

There are several hypothesis why some folks have issues, including aggression, disease (uronema), and high metabolism.
 
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Alfredomeinhardt

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I bought 4 green Chromis about 4 weeks ago, and three of them are doing just great. But one, about 1 week after i bought it, started to swim vertically, and it has been just in a corner of the tank at the surface, swimming like that ever since. I thought it was going to die, so I took it and put it in an acclimation box so I could check it and retrieve it if it died. But it hasn't died, it is just there vertically.

Any thoughts??

1.jpg 2.jpg

It does have some damage to the upper lobe of the caudal fin caused by tankmate aggression. The swimming posture may or may not be related to that though.

Is the fish still isolated?
Is it still eating?
Is not eating. And I took him out of isolation today.
 

Jay Hemdal

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Is not eating. And I took him out of isolation today.

That was my worry - if it might be getting beat up because something else was affecting it (and one sign of that would be not eating). Aren’t you worried that it will just continue to be attacked by the other fish if it isn’t in isolation?
 

dedragon

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I thought chromis were peaceful shoal fish?
yea but i dont think 4 qualifies as a shoal. they need more to be able to spread out aggression and not have just one poor guy getting all of it
 

Rob A

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yea but i dont think 4 qualifies as a shoal. they need more to be able to spread out aggression and not have just one poor guy getting all of it
I put 10 in my 300gal lagoon about 3 months ago I have 4 left as of yesterday they shoaled until they started killing each other😛
 
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areefer01

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I put 10 in my 300gal lagoon about 3 months ago I have 4 left as of yesterday the shoaled until they started killing each other😛

Could always feed more, smaller portions, and provide a couple of large Acropora colonies to make them feel more at home. /shrug
 

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Don’t know the exact reasons why, but the three green chromis I got from Dr Reef have been happy and seemingly peaceful additions from last April.

There are several hypothesis why some folks have issues, including aggression, disease (uronema), and high metabolism.


Uronema seems to be common with these species.

Anywho.....How many did you get?
 

Sharkbait19

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Any suggestions on what to do?
Short of rehoming, all you can really do is hope they stop. Getting more can work, or just create more dead fish - tank size and disease introduction (these guys love to get uronema) would also be a concern.
Larger fish can potentially intimidate the chromis into wanting to school, but you’re limited by tank size there too.
Rearranging the tank can help with some species, but chromis aggression isn’t really territorial.
 

Randy Holmes-Farley

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Uronema seems to be common with these species.

Anywho.....How many did you get?

I aimed for 5, 4 arrived and one was doa, but those three are doing great.
 

BZOFIQ

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I aimed for 5, 4 arrived and one was doa, but those three are doing great.

I see, wondering if they stay together in such small group or will they pick each other out one by one.

They are on my list too although i'm thinking 12-15 for my 270
 

Randy Holmes-Farley

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I see, wondering if they stay together in such small group or will they pick each other out one by one.

They are on my list too although i'm thinking 12-15 for my 270

No problem aggression in my tank. :)
 
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Alfredomeinhardt

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I will keep an eye on him. I haven’t seen any aggression so far towards him but I am not there all the time so who knows.

I will maybe take him out of the tank and put him in another tank by himself to see how it goes.
 

SirSaltyNutz

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My guess is the other 3 were ganging up on it and when he is gone the other 2 will gang up on one and when there only 2 left one day there will be only one left it's the chromis way.🤣
This is the way with Green Chromis...
 

SirSaltyNutz

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My guess is the other 3 were ganging up on it and when he is gone the other 2 will gang up on one and when there only 2 left one day there will be only one left it's the chromis way.🤣
I thought chromis were peaceful shoal fish?
To my understanding this is very bad information that needs to be removed from our hobby, if fact really no fish we can keep in our saltwater tanks will shoal. With Green Chromis, it is like the movie Highlander...their can be only one (unless you have a large tank with lots of broken sightlines became if they see each other, fight is on!)
 

Randy Holmes-Farley

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To my understanding this is very bad information that needs to be removed from our hobby, if fact really no fish we can keep in our saltwater tanks will shoal. With Green Chromis, it is like the movie Highlander...their can be only one (unless you have a large tank with lots of broken sightlines became if they see each other, fight is on!)

I think that is an excessively strong statement since quite a number of reef2reef members have kept groups for lengthy periods.
 

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I have/had 6 (started with 6) in my 150 gallon 6 foot long mixed reef going on 15 months now -- so I am one of those that have been able to keep them and not lose any - heck I even had them survive through an ICH bout in the main DT and they were in a 55 gallon tank (Copper treated) while the DT went fallow for 85 days (used the avast plank to keep up feeding)


I think the key for me is other "bigger fish" multiple small feeding times throughout the day (using avast plank) and lots of rock work and strong flow --- they still all stick together and swim the entire tank and set up in front of the Powerheads sometimes but can go and hide in different areas of the tank/rock if needed
 

SirSaltyNutz

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To my understanding this is very bad information that needs to be removed from our hobby, if fact really no fish we can keep in our saltwater tanks will shoal. With Green Chromis, it is like the movie Highlander...their can be only one (unless you have a large tank with lots of broken sightlines became if they see each other, fight is on!)

I think that is an excessively strong statement since quite a number of reef2reef members have kept groups for lengthy periods.
For a period, then they start disappearing;)
 

cdemoss01

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To my understanding this is very bad information that needs to be removed from our hobby, if fact really no fish we can keep in our saltwater tanks will shoal. With Green Chromis, it is like the movie Highlander...their can be only one (unless you have a large tank with lots of broken sightlines became if they see each other, fight is on!)

I think that is an excessively strong statement since quite a number of reef2reef members have kept groups for lengthy periods.
I agree
 

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