Anyone know what this is?

[howser]

And if I can get it healthy?

I have a few Red Mithrax crabs that like to look for food in the bare area. Not sure if they're making it worse or not. The other blue legged crabs do it too.

Any ideas are appreciated.

Thanks

 

[kingfisher62]

Have you figured out what it is yet?

 

[endlessblue]

Looks like it could be a favia that has encrusted around a rock. That's a different one tho I'm following along

 

[endlessblue]

Or a micromussia

 

[organism]

Can you get a closer picture of the polyps?