What are these?

[sirbrently]

I had one of these pop up before and it died. It left like a "ledge" which then became overcome by some zoo's...

Now, I have two of them coming back to life.. you can see them living nice and cohesively with the others so far!

Their little fingers or whatever move with the water.. and seem to be soft.

 

[candaceswf]

oooooh! I looks like a baby plate coral They grow pretty quick when they're small like that and will eventually break off from their stem

 

[candaceswf]

and their "fingers" are tentacles really awesome!