I recently aquired a small bubble tip anenome. Its been in my 30 gallon tank for 1 week and seemed to be thriving. My false percula clownfish loves it, and the anenome even seems to be growing. However, when I woke this morning the anenome had pulled all of its tentacles into its 'stalk' or 'base'. Slowly its opening up, but is this 'normal'. Is it unhappy? Is this a warning sign of a premature death? Help!