Remember the grinch with Jim Cary a couple years back? There was a scene where he used his lips as a suction to help him remove the glass from a window. Well, I can touch the side of the tank with my finger, and he'll zip over and "kiss" the glass where my finger is. If you remember that scene, that's what the fish lips looked like. I'm sure he thinks it's something to eat!
Okay, ignore me, I'm amusing myself.