Duncan with yellow spots on base

[Gone Tidepoolin]

My Duncan wasn't open today, upon inspection it had yellow spots on the base.
Can anyone tell me what it is, what to do?
Everything else in the tank is fine.
Thanks!

 

[Gone Tidepoolin]

Here is a photo

 

[AlSimmons]

It kind of looks like Mesenterial Filaments. Sometimes these are used as a defence mechanism, other times it could just be an indication that coral is upset. Has anything changed recently? What are you parameters?

 

[Gone Tidepoolin]

The water parameters are normal, its a 100 gallon aquarium. I fragged a head off about a month ago. The frag, which is placed next to it doesn't have any of the spots.
Could a hermit crab cause it? I added a few new small ones. I did add a new Acro, but it isn't close to it, otherwise nothing else has changed.
As a "panic" measure, I dipped it in Coral RX, even though it had been in the tank for 2+ years, and the tank has been up for 10+years.
Should I scrape the spots off?
Thanks for your help!

 

[AlSimmons]

As long as your parameters are within reason and your other corals look OK you might want to just wait it out. Give it another day or so and see what happens before you do anything else. Don't touch it, don't dip it etc. GL.

 

[Gone Tidepoolin]

It seems to be opening back up, I dipped it before I got your message.

 

[R1ant04]

I had 1 do this as well....While it was there, had no visible issues with the Duncan. Eventually it jus went away on its own.

 

[Fylerb]

Dipping wouldn't hurt