Virginia Institute of Marine Science
Journal of Parsitology
A new species of oyster pathogen, Marteilia sydneyi, from Australian oysters, Crassostrea commercialis, is described incorporating light and electron microscope observations. The pathogen is a haplosporidan which exists as a plasmodium in the oyster hepatopancreas. Upon sporulation, 8 to 16 uninucleate sporangial primordia are internally cleaved (endogenously budded) from each plasmodium; thus conversion to a sporangiosorus occurs. Each sporangium enlarges and internally cleaves into 2 or 3 spore primordia each of which, in turn, internally cleaves into 3 uninucleate sporoplasms of graded sizes, the largest containing the smaller 2 in a vacuole and the intermediate-sized one containing the smallest in a vacuole. The spore wall is continuous without an orifice or operculum.
Perkins, Frank O. and Wolf, Peter H., Fine Structure of Marteilia sydneyi sp. n.: Haplosporidan Pathogen of Australian Oysters (1976). Journal of Parsitology, 62(4), 528-538.