Damsel killing chromis

RynoBrooks · Jan 28, 2016

I have cycled my tank and had 2 yellow tail damsels in the tank for about a week, a few days into having both damsels in there one died, he had marks on his side. I added 4 green chromis and one by one they are dying, the damsel has been picking at them, the remaining chromis has marks on his side. Is this common? Im thinking about getting rid of the damsel because I don't want to start spending money on expensive fish and have him kill them.

The only fish in the tank right now 1 yellow tail damsel 1 green chromis

or am I wrong with whats going on here? Here is a picture of one of the dead chromis

Duke4Life · Jan 28, 2016

What size tank? And yes damsels can be aggressive once established.

RynoBrooks · Jan 28, 2016

its a 150 gallon DT

Duke4Life · Jan 28, 2016

RynoBrooks said:
its a 150 gallon DT

Now that's odd, I have a yellowtail in a 125g and it's the model citizen (added last). Remove to your sump.

Duke4Life · Jan 28, 2016

What else do you plan on stocking?

RynoBrooks · Jan 28, 2016

I planned on mainly having a reef tank, corals and a few fish, clowns, tangs, just the basic reef tank.

RynoBrooks · Jan 28, 2016

you can kind of see the marks on the remaining chromis

Duke4Life · Jan 28, 2016

RynoBrooks said:
I planned on mainly having a reef tank, corals and a few fish, clowns, tangs, just the basic reef tank.

I'd remove the damsel to your sump until you're stocked more. That way you give whatever else you add the chance to stake out territory and settle in.

RynoBrooks · Jan 28, 2016

heres a better picture

Duke4Life · Jan 28, 2016

RynoBrooks said:
you can kind of see the marks on the remaining chromis

Mine looks just like that and is my shyest fish, in with a few wrasses 4, 2 firefish, filefish, and chainlink eel.

RynoBrooks · Jan 28, 2016

these marks were not on him last night. i think I'm just going to remove the damsel honestly. I'm sick of his crap

Duke4Life · Jan 28, 2016

They definitely look picked on.

RynoBrooks · Jan 28, 2016

I just wanted to rule out I was doing something wrong with my water. If I can catch this guy he's going into the sump and no more damsels for me.

Duke4Life · Jan 28, 2016

Fish can be odd at times. Get a rough list going and get the least aggressive 1st, then work up the ladder to most aggressive on list. Always quarintine, go check the disease forum out and you'll understand why.

Caylua · Jan 29, 2016

I have had the same problem with chromis and other fish. Those markings on the side I believe are some sort of bacterial/fungal infection. If they were being bullied you would see nipped fins. I have used Melafix in the past. Some make it, most do not once they have that reddish line/blotch down the side. It is very fast killing, usually overnight to 2 days. It is usually only that mark also, no other signs of attack or disease, color is even good. I had a yellowtail damsel that got it and was cured with melafix/rid fungus. He went on to live 7 years.

Even friendly fish will start picking on one if they know it is sick. While your fish count is low for that tank size or just getting going, you might want to add some nitrifying bacteria and then little fish food each day (more then what the 1-2 fish eat) so it breaks down for the bacteria. You need more poopers to keep the bacteria/cycle in check.

There are stronger medications out there that might help if you do not have or plan to have inverts/shrimp/corals. Or use them now before you have inverts. Just read up and make sure they will not leech and stay in the rock/sand. Someone else might have better suggestions, but I do not think it is an aggression problem. It looks like you have plenty of rockwork so the yellowtail will claim an area and the chromis can go elsewhere in a tank that size. My damsels will always chase other fish away from their home, some come back like its a game.

The green chromis coming in to the retail chain fishstores and even larger online sales have not been doing well sadly.

RynoBrooks · Jan 29, 2016

Caylua said:
I have had the same problem with chromis and other fish. Those markings on the side I believe are some sort of bacterial/fungal infection. If they were being bullied you would see nipped fins. I have used Melafix in the past. Some make it, most do not once they have that reddish line/blotch down the side. It is very fast killing, usually overnight to 2 days. It is usually only that mark also, no other signs of attack or disease, color is even good. I had a yellowtail damsel that got it and was cured with melafix/rid fungus. He went on to live 7 years.

Even friendly fish will start picking on one if they know it is sick. While your fish count is low for that tank size or just getting going, you might want to add some nitrifying bacteria and then little fish food each day (more then what the 1-2 fish eat) so it breaks down for the bacteria. You need more poopers to keep the bacteria/cycle in check.

There are stronger medications out there that might help if you do not have or plan to have inverts/shrimp/corals. Or use them now before you have inverts. Just read up and make sure they will not leech and stay in the rock/sand. Someone else might have better suggestions, but I do not think it is an aggression problem. It looks like you have plenty of rockwork so the yellowtail will claim an area and the chromis can go elsewhere in a tank that size. My damsels will always chase other fish away from their home, some come back like its a game.

The green chromis coming in to the retail chain fishstores and even larger online sales have not been doing well sadly.

dang should I pull the final one in there then? I'm going to go show the picture to the store I bought them from and see how they react and what they say

Caylua · Jan 29, 2016

I would ask them. I am not sure what their policy is though, but if you just got it, it was probably already sick. You can try to treat him, but with those markings I would prepare for the worst. Try your best to treat the damsel even if he is not showing signs of it yet. You said another damsel died looking the same?

Yellowtails like all damsels can be aggressive but I have found they are usually pretty mellow compared to other damsels. You don't have to ban damels from your tank totally with it being so large. Once you have other larger fish in the tank things even out.

Try melafix and kordon rid fungus. They are natural and will in no way harm your reef or reef inverts if directions are followed. If you can set up another smaller treatment tank you could try some of the antibiotics or copper meds that are not reef safe for the chromis. I hate giving the harsh stuff to fish as a preventative, but if it is already visable they need help.

All my new fish get Melafix and it has cut down on loss and sickness tremendously.

I hope yours get better. It can be a rough hobby at times, but once you get your tank set it is great.

RynoBrooks · Jan 29, 2016

I added turbo start or something like that about a week ago the damsel that is in there looks good. Not acting weird at all and I don't see any markings on him

RynoBrooks · Jan 29, 2016

I took the chromis out for fear of it infecting my tank anymore

BrotherSheepDog · Jan 30, 2016

I'm not sure if this is what wrong with your fish but I believe i's a type of VIBRIO disease that is very common with blue/green Chromis. I have had experienced this blue green chromis from time to time and the looked identical to what your picture shows. It appears to be open wound type gash on the fish. I have been successful treating my chromis with Chloroquine Phosphate in Qt.

Some simple internet searches will show others have been successful treating vibrio with chloroquine phosphate as well.

Some might ask why even bother treating a $3 fish. All lives matter that's why! =D good luck