Should I be concern?

[David Nguyen]

What's that black worm like thing coming out of the mouth of the zoa?

 

[Cary]

I have never seen anything like that. I am interested to read what other have to write. That being said, I have never heard of a worm that hurts zoas.

 

[Pinback]

I think they are pooping

 

[thejuice24]

Definitely expelling zooxanthellae

 

[DSC reef]

Nothing to worry about. Just expelling.

 

[Ice]

Just let it naturally remove, the current will take it off or a fish will eat it. Tangs nibble on that all the time.