Biomaterial Database

Haplosporidiosis of the Pacific oyster, Crassostrea gigas. 1991

C S Friedman, and D F Cloney, and D Manzer, and R P Hedrick

California Department of Fish and Game, Fish Disease Laboratory, Rancho Cordova, California 95670.

Haplosporidan parasites were observed in 10/100 spat and 1/171 adult Pacific oysters, Crassostrea gigas, reared in Matsushima Bay, Japan. Eight of the infected spat contained mild to severe plasmodial infections. The multinucleated plasmodia were 6-12 microm x 7-15 microm and were associated with an infiltration of hemocytes that occurred throughout the vesicular connective tissues of all infected oysters. Two oysters, one adult and one spat, contained advanced sporogonic infections. These were characterized by the presence of sporocysts and immature and mature operculated spores that measured 5.6-6.0 microm x 6.0-8.0 microm and were found exclusively within the digestive tubule epithelium. Electron microscopic examination revealed that mature spores contained a hinge operculum, striated and layered wall, spherule, single nucleus, and haplosporosome formative regions. Parasite morphology and infection pattern closely resemble that of Haplosporidium nelsoni, a pathogen of American oysters (C. virginica).

UI	MeSH Term	Description	Entries
D007564	Japan	A country in eastern Asia, island chain between the North Pacific Ocean and the Sea of Japan, east of the Korean Peninsula. The capital is Tokyo.	Bonin Islands
D008854	Microscopy, Electron	Microscopy using an electron beam, instead of light, to visualize the sample, thereby allowing much greater magnification. The interactions of ELECTRONS with specimens are used to provide information about the fine structure of that specimen. In TRANSMISSION ELECTRON MICROSCOPY the reactions of the electrons that are transmitted through the specimen are imaged. In SCANNING ELECTRON MICROSCOPY an electron beam falls at a non-normal angle on the specimen and the image is derived from the reactions occurring above the plane of the specimen.	Electron Microscopy
D010125	Ostreidae	A family of marine mollusks in the class BIVALVIA, commonly known as oysters. They have a rough irregular shell closed by a single adductor muscle.	Oysters,Oyster
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D013170	Spores	The reproductive elements of lower organisms, such as BACTERIA; FUNGI; and cryptogamic plants.	Spore
D016782	Apicomplexa	A phylum of unicellular parasitic EUKARYOTES characterized by the presence of complex apical organelles generally consisting of a conoid that aids in penetrating host cells, rhoptries that possibly secrete a proteolytic enzyme, and subpellicular microtubules that may be related to motility.	Sporozoa,Sporozoea,Apicomplexas,Sporozoas,Sporozoeas