i saw a bunch of the ghost shrimp at petsmart yesterday and a few had the white worms you are talking about. it was the first time i ever saw it too. i have had all kinds of shrimp and i know it is not part of their anatomy. i wonder why there arent many discussions on it with shrimp being so popular in the hobby. they may not kill the shrimp but are probably contagious. someone must know more.