Need ID- not apistasia I think

[Steverino]

Any help on this is appreciated:
I have a brown plant growing that I need identifying, apparently it was living on a piece of live rock that I got with a frag....(I have 2 little Apistasia growing on another rock that I am trying to exterminate so I know what they look like.) This new growth has a long stem (3/4" long), a round structure on the top that looks like an umbrella that has been blown inside-out due to the wind. It is small, and I noticed a line of them, about 12 or so stalks growing in a row. It shrinks at night when the lights are off and the moonlights are on. I'm not ruling out that it might be a soft coral, but it popped up so fast that I am leaning away from that.

If you know what Caulerpa verticallata looks like, this new plant looks like a brown version of it, but with only a single disc-like growth at the top, whereas Verticallata has several discs/rings going up the stem.

Below is a link to show what the Verticallata looks like, but keep in mind my new growth is brown, single stalks, and a single round disk at the end of the stalk.

http://images.search.yahoo.com/sear...a.&fr=yfp-t-501&toggle=1&ei=UTF-8&fr2=tab-web

 

[Steverino]

I meant Aiptasia!

 

[graveyardworm]

I wanna say acetabularia, but you say its brown, and I've only known it to be green. A pic would really help alot.

 

[Steverino]

acetabularia: I did a search on that and it is getting close...but mine is brown, and also, mine has just the "metal bars of the umbrella, not the nylon", like an umbrella skeleton if you know what I mean. I'll try for a photo, but it is kinda small and towards the back of the tank. Any other ideas?