Weird yellow ribbon stuff on Duncans!

[KVYA]

I have an Aussie Duncan frag of about 8 heads and have had it for about 10 months.
Yesterday I noticed it a little closed up and now today there is this yellow ribbon stuff on it and I think it's oozing from the coral itself. And it's now all closed up and nothing is opening. There are two spots where it's on but it's in between the polyps. It basically looks like 2x 1mm yellow lettuce nudibranchs on it.
The Duncan colony that is about 2 inches downstream from the Aussie is doing just fine though and is opening up more than usual.

I got these two around the same time and they have grown so many new heads.

What is this?

 

[saltyphish]

Any pics?

 

[KVYA]

Any pics?

It's too blurry. But it looks exactly like 1mm yellow lettuce nudibranchs.

 

[Meccaman96]

Its its stomach probably

 

[KVYA]

Its its stomach probably

It's stomach?

 

[saltyphish]

When some corals get stressed they can expel their guts. It would be coming out from their mouths if that is the case. Your saying its in-between the heads though, correct?

 

[KVYA]

When some corals get stressed they can expel their guts. It would be coming out from their mouths if that is the case. Your saying its in-between the heads though, correct?

Yes. It's in between the heads.

 

[saltyphish]

try to take a clear pic and post it for better help please.

 

[KVYA]

try to take a clear pic and post it for better help please.

I just got home and the Duncans are fully open right now and the yellow stuff is gone