Ultrastructural study of sporulated instars of a haplosporidian parasitizing the clam Ruditapes decussatus

In 1951, Vilela pointed out the presence of a haplosporidian parasitizing Ruditapes decussatus from Portuguese waters and created the species Haplosporidium tapetis. Later, a haplosporidian was found in the same species originating from the pound of Thau (France).