Marteilia cochillia sp. nov., a new Marteilia species affecting the edible cockle Cerastoderma edule in European waters

Marteilia “type C” was recently identified, by molecular characterization, in the cockle Cerastoderma edule from the Ebro Delta in southern Catalonia (Spain) where it caused high mortalities during the summer of 2008. The present paper provides a transmission electron microscopic morphological description and additional molecular analyses. Specific ultrastructural diagnosis is based in TEM observations of mature stages of the parasite characterized by four secondary cells which subdivide into three “proteic masses”. Each proteic mass contained two spores and thus six spores per secondary cell were suspected. The number of secondary cells and number and nature of spores define the morphological taxobasis to distinguish different members of the Phylum Paramyxea. New sequences included in the phylogenetic analysis place Marteilia “type C” in a well-defined cluster proximal to Marteilia refringens. The new data thus corroborate previous results and lead us to formally describe Marteilia “type C” as a new species, Marteilia cochillia n. sp. affecting bivalves in Europe.