Does anyone know what this is?

[kalymnos1971]

This was on some live rock I acquired a week ago. Thanks

 

[teddscau]

I can't enlarge your photo, but from the thumbnail it looks like either a sponge or, more likely, green star polyps with their polyps hiding.

 

[Daddi0]

Gsp

 

[kalymnos1971]

The picture is inaccurate showing a purple tint. It is primarily white. Is that because it is trying to make a comeback? This rock is new to my aquarium.

 

[waterman78]

GSP- Green Star Polyps

 

[noy]

Can't really tell much from the photos - all you can see is some sort of encrusting - could be anything. Can you take a photo with polyps extended.

If the polyps are white - I have something similar. Still have not ID'ed it.

uknowncoral by n, on Flickr