I have these skinny white specks on the back glass panel.
They're attatched by one end, the other points into the tank. They're probably 1/8" long or so.
I've two adult feather dusters in the tank, and I used to have a flame angel before he died. I know flame angels eat baby feather dusters, so I likely wouldn't have had any before that lived long enough to see what they look like.
I'm hoping someone has pics of baby feather dusters, as I can't get a clear pic of them, try as I have.