Shaw, Ross W.Kent, Michael L.Adamson, M. L.2020-10-062022-05-312022-05-312000Shaw, R.W., Kent, M.L.,and Adamson, M.L. (2000). Innate susceptibility differences in Chinook salmon Oncorhynchus tshawytscha to Loma salmonae (Microsporidia). Diseases of Aquatic Organisms. 43(1):49-53.https://hdl.handle.net/20.500.14078/1782Loma salmonae (Putz, Hoffman and Dunbar, 1965) Morrison & Sprague, 1981 (Microsporidia) is an important gill pathogen of Pacific salmon Oncorhynchus spp. in the Pacific Northwest. Three strains of chinook salmon O. tshawytscha were infected in 2 trials with L. salmonae by feeding of macerated infected gill tissue or per os as a gill tissue slurry. Intensity of infection was significantly higher in the Northern stream (NS) strain as compared to the Southern coastal (SC) and a hybrid (H) strain derived from these 2 strains. Both wet mount and histological enumeration of intensity of infection demonstrated strain differences. Survival in the NS strain was significantly lower than the other strains. The NS strain may represent a naive strain and be less able to mount an effective immune response against the parasite.enAll Rights ReservedLoma salmonaeMicrosporidiainnate susceptibilityArticlehttps://doi.org/10.3354/dao043049