Abstract
Recently, cultured yellow tails with black spots, less than some mm in diameter oll thefins and the dody surface have been noticed in culture farms in Shizuoka, Ehime and Kochiprefectures.
The condition is named“Black Spot Disease”. Histylogical examinations of affected fishesshowed that the condition is lymphocystis, and the black spots are caused by the developmentof melanophore cells around lymphocystis cells.
