Help identifying

[gilly1969]

I had set up my tank with live rock and these white straw like things were on the rocks at the time. But now it looks like a soft coral is coming out of a couple of them. Any ideas of what they might be I like them and would like to try and have more. Any help would be greatly appreciated.

 

[explorer07]

They are mini feather dusters and they are fine. They come in most liverock.

 

[gilly1969]

Will they spread and grow?

 

[explorer07]

They can but they easily break off and they will not get much bigger. Nothing to worry about really.