Question about clams

[trilinearmipmap]

Just a related question as I am waiting to get my first clam which will be a Derasa.

I have read a fair bit about the ?pyramidellid snails which parasitize clams. What has people's experience been, are these snails a common problem, do I have to worry about them much? I was thinking of examining the clam carefully for these snail or eggs before placing it in the tank.