filament

Hi everyone, When I was setting up my tank I saw this floating plant at the LFS and liked how it looked. The guy couldn't tell me what it was. It came with a fake plastic ludwigia that works as an "anchor" for it. I'd like to know what it is, I actually haven't seen it in any of the "big...

does anyone know what that hairy mass is? Is it growth from a morimo moss ball?