Emperor Angel fish...should I be concerned?

[lagatbezan]

I have an adult Emperor angelfish that has been in my dt for over a year which is recently acting a little strange (at least to me). All fish including the emperor went through a full qt with cupramine and prazipro and the emperor was the last fish added to the tank. nothing new has been added to the tank in over a year.
Within the last week, it tends to spend a lot of time staying in a couple of locations in the tank for 3-5 minutes at a time. it is more active when the lights are off but during lights on, not that active. I have seen it yawn occasionally as well. all other fish are acting normal.
i'm thinking maybe flukes but is it possible after such a long time in my tank? I dont see anything in his eyes and they are crystal clear. Is it possible for it to be flukes? how long can a fish live with flukes? If it is flukes would treating the tank with prazipro be risky since it would mean he is heavily infected?
any advice would be appreciated.

 

[Newsmyrna80]

Are any of the other fish showing signs of flukes? Have you added any coral, inverts or LR without quarantining?

 

[lagatbezan]

all other fish are acting fine. no, nothing new added to the tank at all.
other fish in the tank are: Powder blue tang, hippo tang, 2 clowns, 2 yellow tang, foxface and scopas tang.

 

[lagatbezan]

Okay so tonight I noticed him only using one of his gills and breathing rather fast. After feeding he started using both gills but now I'm really concerned. Any suggestions??

 

[HumbleFish]

If you wanted to confirm (or rule out) flukes, you could give him a f/w dip for 5 mins. At around the 3 or 4 min mark you should see tiny white worms fall off/out of him (especially the gills) if he has flukes. But honestly, unless you cross contaminated somehow I don't see a fish just living with flukes for over a year.

Another possibility (thinking outside the box) is Lymphocystis. Internal organs can be affected, so nodules could be inside his gills.

Source: http://edis.ifas.ufl.edu/fa181

 

[snorvich]

And depending on the size and maturity of his tank mates, there could be aggression issues.

 

[MrTuskfish]

And depending on the size and maturity of his tank mates, there could be aggression issues.

Very possible, especially with 5 tangs in a 180. The alpha tang may not limit his aggression to just the other tangs.

 

[lagatbezan]

He is actually the biggest and the most dominant one in the tank. all the other fish just move out of his way and I have not seen any aggression toward him. The only aggression I have noticed in the tank is usually a little chasing between the two yellow tangs.