what is this, and does it live?

[mr_X]

is this some kind of coral?...and if so, since the color is brilliant, does this mean it's alive?

 

[bleedingthought]

From the picture, it looks like coralline.

 

[mr_X]

but it has stalks ...like little trees

 

[bleedingthought]

Yeah, it does that sometimes.

 

[Anonymous]

DP

 

[Anonymous]

Those are Foraminiferans, aka forams. One of the most common items on live rock I have found.

Check out down the bottom of the page.
http://www.reefs.org/hhfaq/pages/main_p ... _rock3.htm

 

[Anonymous]

Was going to say foraminferans - Laura beat me to it. If you look very close you will occasionally see them extend a small filament - not sure if it's for food capture or what.