Is this a mushroom?

[regina filange]

Above the Clown fish, there is some sort of mushroom?
It never seems to open or close, or change in anyway.
It is a mushroom of some kind?
Thanks!

 

[regina filange]

Anyone?
Or am I asking a very obvious question, that yes it's a type of mushroom.
Or does no one know what the heck it is?

 

[mushroomss]

it looks like a mushroom in really poor condition.You can see it has an oral disk (mouth) so thats what im guessing