I have a sailfin tang that is acting normally and eating well. But he has some faded discolorations on most of his body. What can this be? This just came up a couple of days ago.
How long have you had him? How do you feed him? It's important to provide a nutritious and varied diet to captive marines. Usually fading color means he's missing something from his diet.
I feed all my tangs nori (in the tank for their grazing pleasure 24/7), as well as spirulina flake and various frozen cube food. Everything gets soaked in Selcon before going into the tank.
If you're not using Selcon or some other fish vitamins, you might try that and see if he'll color up again.
Hopefully you'll hear from David Mohr on this one as well, as he could give you a better idea if it might be some kind of disease. My guess is that it's a nutrition issue, but I'll defer to the livestock experts for further comments.
IME your sailfin tang is not a happy camper.
She may need better food as jdeets has stated. Tangs like to nibble on algae throughout the day.
In addition barely adequate water conditions or the size of tank may be the cause.
IF your tank is small consider trading it in only a more suitable fish as all tangs like to swim briskly.
Consider placing a strong powerhead in an area where they swim as they like water movement.
