anemone?

Hey guys!

here's another thing going on in my tank...

a friend of mine gave me a little anemone (i guess!?) and it seems like its bubbles wont come out?! and it actualy got a little '' smaller '' if i can say..

I just wonder if the coral needs something specific i mean... is there too much light? not enough light?

I have been told that I can feed my corals with some PhytoPlancton ( i give them some, twice a week)

i'm gonna show you guys a picture so maybe someone can actually confirm what is this coral and maybe figure out what the problem can be?

thanks!