While no one has questioned my identification of the host shell as being a Mercenaria, I thought I should at least raise the question since I am not an expert at shell id. The shell portion that has the large blister pearl may not be identifiable but there is a whole half shell that has multiple “pearl warts. I will attach pictures showing both sides as well as one showing the shell valves with the large blister. Is my id of Mercenaria correct? Thanks Tom