"These "GloFish" DO NOT glow in the dark. They fluoresce red under a black light (UV radiation, for those of us who care). But from everything I've read, they don't emit any light at all in the absence of external UV. None. So, that pretty much makes them "Glow-in-the-LIGHT fish."
Surely the poll should have asked how many pets we have that fluoresce red under a black light. Please note those who ask about Paris Hilton, the question is pets that fluoresce red under a black light, not pets that black out under a fluorescent red light!