Purple tang with white C

[121a]

I have a purple tang in my 75g, and just noticed this...

 

 

I run a UVs also. I have not had ick in the tank for a very long time as well. The tang has been doing well for the past 2 months and continues to eat and swim normaly.

 

Anyone have an idea on what this is?

[Brian5280]

Try going to Reef Central and asking them what it is. I don't think many people on here have much experience with tangs.