Histopathological and electron microscopy studies on sleepy disease of koi Cyprinus carpio koi in Japan

Diseases of Aquatic Organisms

Hori Katsuyuki¹  Tadashi Isshiki¹  Teruo Miyazaki¹ 

关键词: Koi;    Cyprinus carpio koi;    Koi sleepy disease;    Pox-like virus;    Carp edema virus;    Respiratory epithelial cells;    Clubbed gill filament;    Hypoxia;    Kinetic disturbance;   

DOI  :  10.3354/dao065197

学科分类：生物科学（综合）

来源: Inter-Research

【 摘 要 】

ABSTRACT: Koi sleepy disease (KSD) usually occurs when koi Cyprinus carpio koi are taken from nursing earthen ponds and placed in cement-lined ponds containing fresh water in spring and autumn in Japan. We transfered koi from an earthen pond to tanks containing fresh water and 0.5% salt water in an attempt to replicate KSD and prevent the onset of KSD, respectively, in the laboratory. KSD broke out after 4 to 5 d, followed by mass mortality (76%: 95/125 fish) within 17 d, in the fresh water.Diseased fish died within a few days. Examination revealed enlarged cells in the respiratory epithelia of gill lamellae; hyperplasia of interlammellar epithelia resulted in clubbing of gill filaments, which caused hypoxia when severe. Electron microscopy showed that enlarged cells contained immature particles (416–450 nm diameter) or mature virions (333–400 × 400–413 nm) of a pox-like virus in the cytoplasm. Mature virions were transported to the periphery of the cells. Hepatocytes, renal tubular epithelial cells, muscle cells of the lateral musculature and cardiac muscle cells were cloudy with mitochondrial degeneration. PCR assay using primer sets for a pox-like virus causing ‘carp edema’ determined that KSD-virus is the same as the carp edema virus.None of the koi held in 0.5% salt water showed sleepy disease during a 25 d experimental period; PCR assay revealed no KSD-virus in gills of koi in the same treatment.

【 授权许可】

Unknown