The genus Marteilia includes protozoan species with repeated endogenous budding sporulation and spores that corise three cells.mp All of these species are parasitic for marine invertebrates. Most species in this genus are observed in the digestive tissue of bivalves. One of the st important species, mo Marteilia refringens, has been observed in the European flat oys-ter, Ostrea edulis (Grizel et al., 1974); mussels, Mytilus edulis and Mytilus galloprovincialis (Tige and Rabouin, 1976; Villalba et al., 1993); razor clam, Solen margina-tus and the striped venus cla Chamalea gallinam,(Lopes-Flores et al., 2008a, 2008b) in Europe. Because of the econoc impact of M. refringensmi on the flat oyster industry, this species is listed as a notifiable pathogen by World Organization for Animal Health (OIE, 2012). Another species, Marteilia sydneyi, hasdetrimental impacts on the Sydney rock oyster, Saccos-trea glomerata, in Australia (Perkins and Wolf, 1976; Green et al., 2011). The recently identified species Marteilia cochillia was involved in rtality of the edible mocockle, Cerastoderma edule, in Spain (Carrasco et al., 2013). Although relatively less information is available, M. lengehi (Comps, 1976) and M. christenseni (Comps, 1985) have also been observed in Saccostrea cucullata and Scrobicularia piperata In Asian , respectively.