Chromis killing!!!

[sanchoy]

I started off with 6 green chromis. They schooled very nicely at first, however after 6 months I noticed that I only have 3 left. When I observe them they tend to get more aggressive towards eachother as they mature and time goes by. What gives?

Do they eliminate each other.. and forget about the school party?

 

[nauticac4]

Ive had 9 going on 3 years now. Some rule to having a school of chromis.

1. Feed them feed them feed them. Hungry fish will compete with each other more than fish that have full stomachs and whose needs are met. I throw a few Hikari S pellets in any time I am by the tank on top of the frozen I feed in the evenings.

2. Have an odd number. Dunno why this works but I have never had luck with even numbers or small numbers. I recommend 7 minimum.

3. Make sure there are plenty of places for them to dart in and out of (i.e. holes in the aquascape/corals)

4. Good flow and constant parameters will also help with stress which can lead to demise

5. QT learned this lesson the hard way more then once. Make sure they are healthy so that you know once you have a school they aren't being killed off by disease.


What other fish are in the tank>

 

[IFbettas]

I started off with 6 green chromis. They schooled very nicely at first, however after 6 months I noticed that I only have 3 left. When I observe them they tend to get more aggressive towards eachother as they mature and time goes by. What gives?

Do they eliminate each other.. and forget about the school party?

Unfortunately, this is pretty typical of chromis when they are kept together in aquariums. You will most likely end up with one individual or a pair.

 

[jmaneyapanda]

2. Have an odd number. Dunno why this works but I have never had luck with even numbers or small numbers. I recommend 7 minimum.
>

Not picking on you, nauticac4, but if ANYONE can try to explain this to me. I cannot fathom, for the life of me, why anyone would think this is important.

 

[xxtriggermanxx]

Not picking on you, nauticac4, but if ANYONE can try to explain this to me. I cannot fathom, for the life of me, why anyone would think this is important.

That comment makes me laugh , if that was the case only one should die for that magical odd number effect to take place.

I feed fairly heavy ,have boat loads of hiding spaces , bought seven, and now am down to four . it has taken some time, 16 months . the original 7 lasted about a year. but slowly have dwindeled down to the current 4. all about the same size. tank is a 265 so i think they had plenty of room.

 

[mark97r6]

Hi,
Is this the case for all chromis species, are the other varieties just as prone?

Mark

 

[Russter]

I have found that with green chromis, no matter how many you got, they would always pick on the smallest/weakest until it would die, then they would start picking on the next smallest, ect...until there was only one or two left.

 

[MaJaCa]

Yeah, I picked up 6 from the lfs 2 weeks ago, and within the first few days I was down to 3.

Currently, still at 3 haha

 

[Wolverine]

I started off with 6 green chromis. They schooled very nicely at first, however after 6 months I noticed that I only have 3 left. When I observe them they tend to get more aggressive towards eachother as they mature and time goes by. What gives?

Do they eliminate each other.. and forget about the school party?

What you're seeing is very typical for chromis. Some people are able to keep them in groups, and I've heard all sorts of anecdotal "methods" that fail as often as they work (the "odd number rule" being one of them).

 

[crabbejoe]

I think you just need to get a lot of them to spread out the aggression amongst themselves. I mean, look at the size of the schools they have in the wild! The more the better.

 

[Fieroguy19]

Well I started out with just one and wanted to add three more to my 40gal breeder. i thought the one large one might kill the newer smaller ones, but it was not able to. When I went to the LFS to pick out the three smaller fish, they happened to have a bunch of of fish all in the same tank. Yellow tail damsels, blue devils, chromis, etc. were all in the same ~10 gals and chasing each other constantly. I figured if the chromis can survive in the environment with all fins in tact then they might have a chance against the big guy that was already in my tank. Well I think that did the trick because the new fish got chased quite a bit, but the new fish were used to it and never really got harmed. They still chase each other occasionally but I have never seen any fin damage on any of them.

 

[luckyk0505]

I had 10 in my tank and I end up with 3

 

[palmer373]

Ive had up to 5 in my 75 and i always end up with just 1, the same 1 for a fact. Im just gonna buy 2 more soon and hopefully leave it at 3.

 

[jt_milstead]

They are still a Damsel.Eventually the will get mean.

 

[Terra Ferma]

Most likely your chromis have been collected with cyanide, or other dubious means, and have then been shipped to your country (USA) in a bag that is unfathomably small to the average person. Keep in mind these fish cost 10 - 20 cents from the exporter. As a result, they are not in good health when you get them and as a result die off over time. They are also vulnerable to vibrio in their compromised state. If you want chromis that "live" a good choice are the larger, allegedly net caught ones from French Polynesia.

 

[IPowderBlueTang]

Chromis killing!!!

Most likely your chromis have been collected with cyanide, or other dubious means, and have then been shipped to your country (USA) in a bag that is unfathomably small to the average person. Keep in mind these fish cost 10 - 20 cents from the exporter. As a result, they are not in good health when you get them and as a result die off over time. They are also vulnerable to vibrio in their compromised state. If you want chromis that "live" a good choice are the larger, allegedly net caught ones from French Polynesia.

Good point.

 

[Roadkillstewie]

I figure their just... nuts and not popular in their own 'lil world'.

Started with 5, almost a year later.. down to 1, and like other said it..it seems the horde would gang up on the smallest...til there was 1 left.

That remainig Chromis, will chase my Occ male... then the female occ chases the Chromis, heck at least once a day even the bangai get's irked and will chase the Chromis.

 

[jmaneyapanda]

After reading this thread, and the countless other similar ones displaying how chromis WILL kill each other when attempted to be kept in groups artficially, it kills me how often people continue to try to do so, and will recommend to other to try.

 

[Wolverine]

I think you just need to get a lot of them to spread out the aggression amongst themselves. I mean, look at the size of the schools they have in the wild! The more the better.

That's somewhat true, but it's tough to get enough for that to make a difference unless you have a really big tank. The problem is that there's a hierarchical beating. In some fish, the single most dominant one will attack all the smaller fish, so in those cases, this approach works. With chromis, it's not uncommon for several of them to beat on the smallest one, so the deaths just work their way up the chain.

Most likely your chromis have been collected with cyanide, or other dubious means, and have then been shipped to your country (USA) in a bag that is unfathomably small to the average person.

I don't disagree with the rest of what you said, but I do disagree that this is "most likely" the problem. More likely the issue is that the chromis are killing each other. This is especially true given that it's unlikely his fish came through the US.

 

[spsfreak]

Also, lets not foget if you have a couple of star serpents in the tank..... if not fed well WILL eat your Chromis. In my last tank I had too many serpents - I have litereally seen the same green serpent eat three different chromis. On two occasions I know the Chromis' were still alive and healthy when taken down and eatin. Those green serpents with spines are monster eaters. Aside from that... I concur with the 'pecking order' theory... it deffinately happens.