Xenoma formation during microsporidial gill disease of salmonids caused by Loma salmonae is affected by host species (Oncorhynchus tshawytscha, O. kisutch, O. mykiss) but not by salinity

Diseases of Aquatic Organisms

D. J. Speare¹  M. L. Kent¹  J. M. Ramsay¹  S. C. Dawe¹ 

关键词: Loma salmonae;    Host species;    Salinity;    Xenoma formation;    Xenoma intensity;   

DOI  :  10.3354/dao048125

学科分类：生物科学（综合）

来源: Inter-Research

【 摘 要 】

ABSTRACT: Host species and salinity often affect the development of disease in aquatic species. Eighty chinook salmon Oncorhynchus tshawytscha, 80 coho salmon O. kisutch and 80 rainbow trout O. mykiss were infected with Lomasalmonae. Forty of each species were reared in seawater and 40 in freshwater. The mean number of xenomas per gill filament was 8 to 33 times greater in chinook salmon than in rainbow trout (RBT). Coho salmon had a mean xenoma intensity intermediate tothat of chinook salmon and RBT. In contrast to the differences between species, salinity had no significant effect on xenoma intensity in any of these host species. The onset of xenoma formation occurred at Week 5 postexposure (PE) for chinook salmon andRBT, and at Week 6 PE for coho salmon. RBT had cleared all visible branchial xenomas by Week 9 PE, whereas xenomas persisted in coho and chinook salmon at Week 9 PE. Histologically, xenomas were visible in the filament arteries of the branchial arch inchinook and coho salmon gills but were absent from RBT gills. Fewer xenomas were seen in the central venous sinusoids of RBT than in chinook and coho salmon. The lower xenoma intensity, shorter duration of infection and pathological characteristics,common to microsporidial gill disease in RBT, suggest a degree of resistance to clinical disease that is not seen in coho and chinook salmon.

【 授权许可】

Unknown