감성돔에 기생한 Amyloodinium sp. 의 성상에 관한 연구 = Studies on the Features of Amyloodinium sp. Parasitized in Black Seabream , Acanthopagrus schlegeli

다국어 초록 (Multilingual Abstract)

To know the features of Amyloodinium sp. parasitized in Black seabream, Acanthopagrus schlegeli, morphology and reproduction type of the parasite were investigated. Infection mode and histopathology of the parasites were also studied. In the developmental and morphological observation, the parasite passed through parasitic and non-parasitic phases with three developmental stages termed trophont, tomont, and dinospore. The trophont, 30-80 ㎛ ovoidal or pyriform, for the vegetative stage had a spherical nucleus with 1.5 ㎛ in diameter, many food vacuoles and starch grains in cytoplasm. The tomont, 80-90 ㎛ spherical, for the reproductive stage resorbed a stalk, secreted a cyst wall and reproduced within it. A dinospore, small 10-15 ㎛ biflagellated, for the infestation stage had a stigma. The parasite was propagated for 15 days by serial passage in Korean rockfish (Sebastes schlegeli) at 25 ±1℃. Trophonts began to detach from the fish about 3 days after infection and was completed within 5 days at 25 ±1℃. It took from 3 to 5 days to reproduce at the same temperature. Reinfected fish showed that parasites penetrated under the epithelia of gill filament and gill lamellae causing hyperplasia and degeneration at infected area.