Clam killing bristol worms!!!!

[whatcaneyedo]

Skimmer King You're thinking of pyram snails. Stomatella are highly beneficial herbivores.

My vote is for a protozoan infection as what you've described sounds more like the 'pinched mantle' condition. I had it happen this spring, on a Monday my big maxima looked like this and by Friday it was dead. There were many bristle worms all over it as soon as it was dead. Yet I have a smaller maxima that was sitting right next to it in the sand which is still there, fine and healthy as always. I actually have 6 clams in the tank still, 4 of which are in the sand.

This picture is from that Monday after I transferred the clam to another part of the system because I thought that maybe it was one of my fish that were bothering it.