Fungus, sponge, basal mat regrowth?

[RedFrog211]

I recently got a wild colony in, it’s been in the tank for about 4 days. Does this seem consistent with fungal or sponge growth, or necrosis? (Note: this is the first polyp to have opened since arriving)

The colony is rather delicate, so I’m trying to remain hands off if I can. Thanks

 

[Tahoe61]

I would dip in a diluted hydrogen peroxid solution and use either a very soft brush or Q-tips.
https://www.reef2reef.com/threads/hydrogen-peroxide-dip-for-zoas.989307/
I have good luck removing sponges and algae from Zoanthids. Typically the Zoanthid remain closed for a day or so post treatment.