heart looking thing-Purple

[timeless1]

Hello All,
I'm not sure what this is, I have had this in my tank for about 6 months, It has been the same size. It looks like a heart, two holes/vents. Closes up only when I tap on the glass. Any help would be great.
http://aquariacanada.com/PhotoPost/s...o=4192&cat=525

 

[cranberry]

Tunicate.

 

[timeless1]

Thanks so much Cranberry. Exactly what it is. Funny enough I found some pictures of this late last night but did not think that it was that.
Timeless.