Identify anemone

[kmatwill]

Please help me identify this. I have 4 of them on some live rock I just bought. Didn't realize they were anemone until I woke up this morning to find this one on the glass. Am I in trouble?

[Vert20]

Is that the backside or Frontside? Moves pretty quick huh? Are the "tenticles" soft and flowy or stiff?

Looks kinda like the backside of an urchin...hard to tell.

[Aquaman]

Thats a real fuzzy picture but, I think its a Rock anemone, which is a pest.

[kmatwill]

Are they as bad as apstasia?

[saltybp]

I just found a couple of those in my tank as well, they are out of direct light (actually pretty much in the dark) and only open fully when the lights go out. I would like some additional info on this as well.

Thanks,
Bill

[spfmatt]

I'd have to agree with Vert20 it looks like an urchin or a starfish. Maybe if you can get a better picture, that might help.

[kmatwill]

One of our local reefers came over and id'd as a rock anemone. Thanks!

[saltybp]

So is it a pest? will it take over the tank or is it harmless?