White Sponge or Tunicates competing with Zoas?

[Janoots]

Hey all! First tank is 4 months old and having a blast! I have some Interesting stuff growing on an isolated piece of rock within my zoa frag. The growth is cotton looking, but firm and has tubes coming out of it. It seems to be growing within my zoas and “pushing” them away from each other. However, when my zoas are fully extended they pretty much cover it up. What is it and any direction on what to do if anything?

 

[Tahoe61]

It looks like sponge. Simply remove to separate container and use soft tooth brush to remove and return frag. Wear gloves, avoid exposure to toxins.