zoanthid parasite?

[dannygreen]

Hello all,
I have some zoas with some strange stuff growing on them and the live rock surrounding them i have attached a picture of what i'm refering to. Could you please advise me what this is and if it's bad or ok. If it's bad please advise how i might be rid of it. Thanks for the help in advance

 

[650-IS350]

looks like sponge growth... just use tweezers and chip it off...