Marteilia spp. parasites in bivalves: A revision of recent studies.

Marteilia spp. parasites are Paramyxean organisms that affect several commercial species of molluscs, and thus have a socio-economical impact. These parasites also have an ecological impact on the biodiversity and population dynamics of natural mollusc beds. It has been over forty years since the first description of Marteilia refringens, the first Marteilia species described. Despite four decades of research, the biology, cellular development, as well as the life cycle of Marteilia parasites are not fully understood. In recent years, new studies have reported advances in knowledge of the life cycle, the description of new species, the development of new molecular detection/discrimination tools, new data on biotype geographical distribution, as well as new information on host response and defence mechanisms. Such information is summarized, reported and discussed in the present review in order to facilitate a new overview of the subject. However, numerous knowledge gaps are still unresolved and need to be prioritized in the research and funding institution agendas.