Infectivity of Mikrocytos mackini, the causative agent of Denman Island disease in Pacific oysters Crassostrea gigas, to various species of oysters

In addition to Crassostrea gigas, Mikrocytos mackini Farley 1988, a pathogenic intracellular protistan of unknown taxonomic affiliations, produces disease and mortalities in other species of economically important oysters (Crassostrea virginica, Ostrea edulis and Ostrea conchaphila).Preliminary evidence suggests that these alternate species may be more susceptible to infection and the resulting disease than the usual host C. gigas.M. mackin1 ~solated from C. vlrginica and 0. edulis were infective for oysters.Warm temperatures (above 15°C) prevented the development of M. mackini in C. gigas, C. virginica and 0. edulis.