Aquariums: Are these eggs or worms on my aquatic snails shell?

I just got the snail from PetSmart about three days ago and these little tubes just appeared on his shell tonight. They were not there this morning. I am wondering if it’s a parasite I need to take care of or if it is just eggs or harmless worms? Please help! I have four small tropical fish and one snail in a 10 gallon tank.