Hi Ruth
Are the clams on the sand bed or up on the rocks. What water depth and lighting? Do you have any fish that might be either nipping the clams or picking on any possible pyramiddal snails. I often see my yellow wrasses picking on the edges of the clam shells. This causes the mantles to retract for a period of time. Often times, clams will just expire for no apparent reason. They look great one day and are dead the next. Hope your's recover.
Andy
|