Oh, OK, the pale green baby hair type stuff. Nope, I don't know what that is.
What I can tell you though, is that when I received my order of Java Moss (a small clump) there was a lot of similar baby hair type stuff on it. I assumed it was just very young growth. I got pretty annoyed at my platy fish I had at the time for eating it all. They left the more mature moss alone, so eventually it grew quite well.
I had wondered if this might be how the plant/moss propagates (if that is the right word). Since it is so fine a natural occurring current in a body of water would carry it off to a new place?
Sorry I can't be of help!
As a keeper of mosses I can say that it doesn't look like any part of any moss I know, to me. New moss looks like old moss, just skinnier. And it doesn't ever develop roots like that. Moss strands can stick to objects like velcro if they so choose, haha.