Is this clam in trouble?

[Proteus]

I have 4 clams and also have pyrimid snails. I've kept then in check buy manual removal
Like Denny said a few wont do much damage but left unchecked will multiply.
Once a week I pick clams up and loo at the foot and very edge of the shell I pick off snails and brush with toothbrush to remove eggs, of coarse in dif water.

Mystery, coris, melonarous wrasses are your best bet for long term.