Something on my Goni?

[HandofThanatos]

I have two goniapora and this one has these weird... nodules... on it for lack of a better term.

It is the back end of the frag, and it is on the actual skeleton of it, not the flesh.

Is this a hitchhiker, some kind of algea, or just how goniapora grows?

Thanks in advance for the help!

 

[KJ]

Valonia. Bubble algea.