Abstract
Eight Fusarium strains were isolated from five prawns showing black gills at a farm in Kagoshima Prefecture, Japan in December 2001. On the other hand, no fungi were isolated from five prawns without black gills. Two out of the eight strains were morphologically identified as F. oxysporum and the other six strains as F. solani. Morphological characteristics of F. oxysporum were described and illustrated. The fungus showed pathogenicity when injected to juvenile kuruma prawns. This is the first case of F. oxysporum infection of kuruma prawn in Japan.