I'm sure someone knows what this it is !

[nutoit]

I'll do my best to discribe this. I'm new to this board and haven't figuured out how to post pictures yet. Maybe somebody can help me with that as well.
They have the base almost like a mushroom. The top looks like an anenome with long thin spikes.They seem to be spreading pretty quickly.It's light brown or flesh color. I know these are seen quite often just don't know if I should be getting rid of them, if they have the potential to sting,if I should worry about them taking over....seem to be popping up in a few places.
Thanks for the help.

 

[banshee]

Aptasia?

 

[karlas]

does it look like this
<a href="http://www.reefsource.com/Database/aptasia.htm" target="_blank">aptasia</a>
its someting you definitly dont want if thats it it is a pest anemone and will spread and overtake a tank. they are very hard to get rid of here are a few ideas
<a href="http://www.reefsource.com/aptasia1.htm" target="_blank">rid aptasia</a>

 

[lerch]

I think I am suffering from a aptasia outbreak right now. A girl at my LFS told me that it was a button polyp when I bought the piece of live rock when I bought it, she did not say it was aptasia so I was am pretty mad at her now. I have had this rock for nearly 4 months now and it has really spread. I talked to another dealer at my LFS and he told me it was aptasia and instructed me to but a saron shrimp to get rid of it. I would tell you to get a saron shrimp to if you want to get rid of the aptasia. My shrimp has alreay killed 5 of the aptasia that I can see and I don't know how many else. He has not killed the big aptasia yet, but he is doing a good job. I have heard these shrimp will kill polyps also but mine has not yet. If you want to get rid of the aptasia get a saron shrimp, they work great and they are REALLY cool looking.