Brad!

[Delphinus]

Are you guys absolutely sure there haven't been some kind of heat spikes in your tanks? Absolutely positive beyond all fraction of a reasonable doubt? Because I just find this to be completely odd that there is a string of this happening all at once. I don't think it's the dreaded clam plague, this is happening to clams from different sources and that have been in captivity for completely different lengths of time. The only thing that comes to my mind as being suspect, that we have in common, is that we are experiencing (or have been experiencing) unseasonably warm temps for durations longer than usual. I am pretty sure that it was heat stress from a heat spike my tank suffered a solid month before I saw this behaviour, so there is also a potential delay factor involved.

Anyways I am just rambling. This is my theory ... whether it is sound or not I am not sure.