Who ate my Sponge - Bob?

[trybry5]

Last month my Dragon's Eye Zoa's had a feathery boa around it.

The group informed that it was a sponge and under the right conditions, it would continue to grow immensely and it did.

Now the sponge is all but gone over night. Who ate it? All I have in the tank is a CUC (clean-up crew). I also had a very small patch of Hair Algae on two closed Green star polyps and that is all gone too.

I don't mind losing the hair algae, but who at the sponge and why now.
I don't want any non reef safe cleaners in my tank.

Here's the before and after pic's:

 

[khmerspec]

No help here, but I hate when things disappear/appear over night. Makes me go crazy wondering what I did wrong.

 

[trybry]

No help here, but I hate when things disappear/appear over night. Makes me go crazy wondering what I did wrong.

Me too, but lucky me, the sponge has gone back into hiding. I do see a few shoots protruding from a large shell, that I tried to spread it to. I guess that worked.