Previously unknown apicomplexan species infecting Iceland scallop, Chlamys islandica (Müller, 1776), queen scallop, Aequipecten opercularis L., and king scallop, Pecten maximus L.

► Previously unknown apicomplexan species infecting three different scallops species. ► Unlike other species known to infect bivalves. ► Common in muscular tissues and inside haemocytes. ► Sexual and asexual forms in an apicomplexan life cycle detected. ► At present, its systematic position within the phylum Apicomplexa cannot be ascertained.