Donut coral
 

There is something weird growing on the skeleton of my donut coral , you can only see it at night when the coral shrinks up. During the day when it's fully open it seems like the flesh lifts up a little on that side of the coral like it doesn't want to touch this weird growth. Maybe it is stinging it? I'm wondering if I should take the coral out at night and try and remove this growth.

Here's a picture

Attachment 10811

Here's a pic when it's open and you can see where it is lifted up on the side where the growth is. Attachment 10812

Ding, not sure what that is wm. ill have to do some research.

Sponge. It shouldn't bother the coral, but if it is you should remove it.