Candy cane issue

[ReefRookie22]

Are these menenterial filaments at the base of my candy cane?
Or is it come kind of fungus/disease?
I've only just noticed it and put new corals in the tank this morning so it could be a defence response. But would it happen this quickly?
Any ideas greatly appreciated.

 

[bubbgee]

looks like a sponge to me. Can you take it out and brush it off? Or just try to brush it off inside the tank?