? What is this?

[BriGuy]

Alright looked at tank today that I am thinking about purchasing and the live rock in the tank is covered by these things (sorry phone cam pic here) and I am trying to figure out what these things are. They are light purple in color and the largest ones are the dia of dimes. They have a hole in the center of them that appear to go all the way down to the base. They look soft\sponge like in nature and seem to be spreading\growing everywhere. Any ideas people while I score the net some more.

[BriGuy]

Oh also to note, very large yellow tank does not eat on them, nor does a 6 line wrasse bother them.

[Iplantz]

Some type of tunicate?

[BriGuy]

From looking at some pics of tunicate's they appear to be more tube shaped, these are almost dome shapped coming off the rocks.

[BriGuy]

Don't these require good lighting, sorry forgot to mention that this tank has rather poor lighting conditions. But after seeing more pic's I think that it might fall into this family.

[apedroza]

could be atype of sponge also.

[FossilReef]

I agree; they look to be a sponge. And no, most don't require good lighting; most are filter-feeders.

[d3rryc]

Yep, sponge. I've got several of them scattered around my tank -white, green, purple and deep blue.