Sponge or tunicate?

[Besieged]

I'm pretty sure this is a sponge growing on the bottom of this favia frag?

If so, I'm okay with it.. but I have questions, and a problem:

How did it survive being removed from shipping water into open air, submerged for three minutes in Reef Primer, removed again, dipped in clean tank water, removed again and placed in the tank? Is this some exceptionally hardy species?

And, the big thing - this frag as a lot of GHA on it. I was going to put it in an H2O2 dip... but I guess I can't do that now if I want to save the sponge? Is there a way to safely remove it without killing it? Aside from wanting to dip the frag, I wasn't intending on leaving it in this spot in the tank much longer. I'd also just as well prefer to have the sponge living in my fuge, where it'll be safe from further changes in the display. Does anyone have a specific species ID that might help me find out more about it?

 

[Tahoe61]

Sponge.

It's an old urban myth that all sponge exposed to air is a death sentence to said sponge.
It's a cool sponge. I would dip only the part infected with algae in a diluted hydrogen peroxide dip. Google diluted ratio.

 

[Besieged]

Would anyone happen to have experience with relocating one? I'd like to trim it off this frag if I can.