Clams

[will l]

I was wondering if it is worth while to keep tiny clams in my tank, a 30gal fowlr. The only problem is that my hermits have a fiest everytime I add more. The ones im talking about are 1/4in. Heres a comparison with a normal cleaning clam.

 

[will l]

Maybe Well they seem to be doin ok, last time i must of put 20 in there, they lasted and did ok for like 2 weeks untill my crabs got them 1 by 1. I felt bad for the poor little buggers. Tiny little shells all over the place. What clams would you suggest? (that r big enough to survive those crabs)