Identification Please

[maxells]

I bought some live rock about 4 weeks ago. (see pic)
This was attached to it. Since then, it seems the top has been growing slightly (brown things in the center). Does anyone know what it is?
Also, do I need to do anything to keep it alive? It seems to be doing well so far.

 

[maxells]

No one has any ideas?

 

[dougai]

looks like a shell of some sort

 

[maxells]

Yes. I have searched online and have seen nothing like it. It is clearly alive. The orange color around the outside seemed to get brighter and there is definitely growth in the top. I really like it but want to make sure it is not going to be harmful and I don't want it to die.

 

[maxells]

I am amazed that I have something in my tank that no one here has seen before. After reading the boards for awhile this is a complete surprise.
I guess the good news is I have something that is rare.

 

[1journeyman]

Lol, that's the great thing about live rock.
Trust me, everyone who gets live rock will have things no one else has seen before. The best thing you can do is watch it closely to see what it seems to need. Does it look like it was growing on a part of the rock that was getting bright light? Does it seem to open more when you feed the tank? Is it having a hard time keeping algae from growing on it?

 

[maxells]

Thanks for the suggestions. I have been watching it closely. It has not moved at all. My plan is to add corals to the tank so there is a good light system and all of the requirements for corals tested properly so maybe that is helping it. No algae ever grows on it, even when I had that initial outbreak during the cycling of the tank.
Thanks again.