that thing in the center is its mouth. however it is not necessary to feed. my coral looks exactly like yours when it is disturbed. its my favorite mushroom ive seen. i gust got a similar one to this except the colors are reversed. pink base with green bumpbubble things.
HTH
BB
ohh yeah i forgot that the coral looks the same when its splitting as it does when its disturbed. if it has been healthy for a while and nothing has changed, it may be splitting.
HTH
BB