Zoas closing with bump on them

[zodiii]

There's a small group of Zoas in my Girlfriend's tank that are closing up and getting this odd, tan/brownish colored bump right on the opening of them. It doesn't look like a Nudi, and the bump is easy to pull off with tweezers. The color of the fleshy areas under the bump is lighter in color and there is a divot where the bump is removed. Other zoas in the same colony show no issues.

 

I have one photo, taken with a ghetto Macro (backwards lens).

 

Anyone have any ideas? I will try to get a better picture of one of the Zoas closed up with the bump intact.

 

[Angel<3Nanos]

Interesting. Never seen that. Can we see a pic of the infected colony?

[zodiii]

Sure:

 

 

Sorry for potato-cam.

 

You can see one in the middle, next to the open zoa, that is starting to close up.