White String like spots on Ricordea Mushroom

[cdarcy]

Hello, does anyone know what these white string like spots are on my ricordea?
I have seen them before, as they seem come and go, but this is the biggest one I have ever seen on it.
Wondering if it’s starting to split, but really curious what these white string light spots are? Why do they occur and ks this normal?
Couldn’t really find anything via Google, curious if you all have seen this on yours? Know what it is?

Thank you!

 

[Reefer Matt]

Looks like Mesentrial filaments. Mine get them when I do water changes or feed the tank, etc. They go away on their own, in my experience.