Are these baby trochus snails or should I be worried?

[MikeTheNewbie]

Hi, I introduced Trochus snails to my tank a couple of weeks ago and they are doing a wonderful job cleaning up the glass. A few moments ago I noticed little white critters on the shells of some of them. I'm not sure if I'm going to be a lucky grandpa or if its something to worry about. I never saw rows of eggs on them. Can any one confirm?
Thanks in advance!

 

[eggplantparrot]

spirorbid worms. harnless filter feeders

 

[MikeTheNewbie]

Hi thanks for the help. I was starting to get excited about getting more Trochus.