What the Heck is this Thing?

[Hugh Mann]

What I am referring to is the spiky white blob thing to the bottom right of the red turf algae.

 

[Mr_Knightley]

Seems to me like a sponge of some sort, not identifiable by me. Does it react to touch?

 

[ReefReadyYouTube]

I agree. Maybe a sponge.

 

[KJ]

What I am referring to is the spiky white blob thing to the bottom right of the red turf algae.

Sponge.

 

[Hugh Mann]

I think it is a sponge. No reaction to being touched. Soft, pulled off the rock very easily.