Mucus sack around mushroom

[Shad Quill]

I cant find any info on what might be going on with this mushroom. I have quite a few and this is the only one showing trouble. Inside the sack the mushroom is bright with color and looks normal. Any idea what is going on?

 

[Crabs McJones]

I cant find any info on what might be going on with this mushroom. I have quite a few and this is the only one showing trouble. Inside the sack the mushroom is bright with color and looks normal. Any idea what is going on?

Bacterial film of some sort? is it able to be blown off or is it attached to the mushroom?

 

[cloak]

I wonder if that Hammer coral on the left may have reached out and stung the mushroom?

 

[Shad Quill]

I wonder if that Hammer coral on the left may have reached out and stung the mushroom?

I'm not sure if the hammer et r could reach. The closest point is about 7 inches away. I just brushed it over with my finger tip and let loose there are some brown spots on the mushroom under the film.

 

[DSC reef]

Euphyllia sweepers can reach really far, it looks like a damaged/stung mushroom.