title: An intranuclear microsporidium associated with acute anemia in the chinook salmon, Oncorhynchus tshawytscha.
abstract: An intranuclear microsporidium is described from hemoblastic cells of the chinook salmon, Oncorhynchus tshawytscha. The infection is associated with an acute anemia in the fish. Up to 47% of the hemoblast nuclei were infected in anemic fish. The organisms, found only in spleen and kidney tissues, were 1-2 microns in diameter and consisted of vegetative and early sporulation forms. This microsporidium differs from known species which parasitize fish in its tissue location; however, the absence of mature spores and other life cycle stages precludes determination of its precise taxonomic identity.
mesh_terms: D000740:Anemia / Q000469:parasitology / Q000662:veterinary*; D000818:Animals; D016782:Apicomplexa / Q000648:ultrastructure*; D002467:Cell Nucleus / Q000469:parasitology; D005393:Fish Diseases / Q000209:etiology / Q000469:parasitology*; D007668:Kidney / Q000469:parasitology; D008854:Microscopy, Electron; D011528:Protozoan Infections / Q000469:parasitology; D011529:Protozoan Infections, Animal; D012474:Salmon / Q000469:parasitology*; D013154:Spleen / Q000469:parasitology