Is this sponge?

[Elfie22]

Hey Reefers! I was cleaning my tank last night and noticed my ancantho hasn't been his puffy self lately. When I picked it up I noticed this weird, jelly like substance on its base. Is this sponge and should I clean it off or dip it?

Never seen this before (sorry for the not so awesome pics)!

 

[Dan_P]

Looks like sponge growth.