Yellow Tang not eating

[Brew12]

My tang used to eat great and was the tank bully. Ever since I introduced a convict and kole tang he isn't eating nearly as much and is starting to get very thin.

I've had him around 10 months and looked to be fully grown when I got him. No signs of any sickness on him or any other fish. Would it be normal for a fish to stop eating because of a change in the social structure? No one is showing any aggression to him so I don't believe that is the cause.

I may pull him and put him in a QT to see if I can get him eating again. Good idea or not? Any other thoughts?

 

[nautical_nathaniel]

I've had fish get freaked out about a new addition before and not eat as much as they used to. It can definitely be frustrating for sure!

Some of the things I have done in the past that have worked for me is to feed fish in different parts of the tank at the same time, this can help curb some aggression or territory issues. I've also made sure to feed less per feeding but feed multiple times a day. This helps new and adjusting fish get used to feedings but also helps your original fish get used to the new guys eating with them. If there's something that you feed that your fish absolutely goes crazy over, I would feed more of that but still offer a variety of foods for them. Also, with herbivores, I like to keep some nori in the tank most of the time, like put a good piece in when you leave for work and take whatever is left out of the tank when you come home and replace it.

If none of that worked, I would do like you're thinking and set up a QT/rehab tank for the fish in question and get them back into prime condition. Wouldn't necessarily medicate anything, just feed it some good food and give it a low-stress environment.

 

[ngoodermuth]

If he was full grown when you got him...is it possible he is aging? Kole tangs can be a little obnoxious, but convicts are probably one of the most peaceful tangs out there. And either way you'd notice if they were bullying him...

How thin is thin? Is it possible it's unrelated to the new tangs...maybe internal parasites or something along those lines?

 

[Brew12]

If he was full grown when you got him...is it possible he is aging? Kole tangs can be a little obnoxious, but convicts are probably one of the most peaceful tangs out there. And either way you'd notice if they were bullying him...

How thin is thin? Is it possible it's unrelated to the new tangs...maybe internal parasites or something along those lines?

Aging is a possibility. He is much thinner now than he was 6 months ago. Thin enough to make me worried and he used to go nuts when I put the LRS in the tank, now he pretty much ignores it.

I've never seen the white stringy poo to indicate parasites from him or any other fish in my DT. I've always gotten them cleared up in a QT prior to adding them.

 

[Brew12]

I do most of what you suggest already but am only able to feed 2 times a day. I may have to get him into a QT for more observation where I can more closely monitor exactly what it is he is or is not eating.

I've had fish get freaked out about a new addition before and not eat as much as they used to. It can definitely be frustrating for sure!

Some of the things I have done in the past that have worked for me is to feed fish in different parts of the tank at the same time, this can help curb some aggression or territory issues. I've also made sure to feed less per feeding but feed multiple times a day. This helps new and adjusting fish get used to feedings but also helps your original fish get used to the new guys eating with them. If there's something that you feed that your fish absolutely goes crazy over, I would feed more of that but still offer a variety of foods for them. Also, with herbivores, I like to keep some nori in the tank most of the time, like put a good piece in when you leave for work and take whatever is left out of the tank when you come home and replace it.

If none of that worked, I would do like you're thinking and set up a QT/rehab tank for the fish in question and get them back into prime condition. Wouldn't necessarily medicate anything, just feed it some good food and give it a low-stress environment.

 

[revaltion131]

I would go with highly focused feeding of the tang specifically in the next few days and go to QT if you don't get anywhere. Is the fish hiding or acting differently other than not eating regularly?

I have lost fish due to a new introduction so it's certainly not impossible for the new additions to be the cause of the diminished appetite. While the new guy was never openly aggressive towards the existing fish (that I saw) the old fish slowly went into hiding and stopped coming out to eat. I didn't see him for a few days so finally tracked him down and tried to focus-feed just him for a week and he did eat, but it was too late.

 

[Brew12]

I would go with highly focused feeding of the tang specifically in the next few days and go to QT if you don't get anywhere. Is the fish hiding or acting differently other than not eating regularly?

He normally just cruises around the tank really slowly now. He used to swim much more energetically. He doesn't hide much. That is one reason I thought age might be a factor.

Here is a picture of my buddy from the side so you can get an idea how thin he has gotten. The picture I took from the side is too blurry.