Circular spot

[reefinman]

Hello,

I was wondering what was going on with my clown tang. He has recently started to lose weight and rub against the sand. I have not seen any white spots on any of my fish. I also have a yellow eyed tang. He is also rubbed on the sand bed a few times. Yellow eyed tang is healthy. I have added a few pictures.

 

[Humblefish]

Two tangs rubbing on the sand usually means you have either an external parasite (such as ich) or flukes in play in your system. Both ich & flukes can harbor inside the gills, sight unseen. Were any of these fish QT'd? If so, can you please describe your QT protocol in as much detail as possible?

 

[reefinman]

The fish have been in the tank for a number of years.

 

[Humblefish]

The fish have been in the tank for a number of years.

When was the last fish added to your tank? Coral/invert? Any fish can be carrying ich trophonts (or flukes) inside the gills. Any coral/invert with a hard surface can serve as temporary housing for tomonts. Tangs (especially Acanthurus) have a mucous coat that is reduced in composition making them more susceptible than most other fish.