Abstract
From October 1981 to January 1982, a bacterial disease occurred among O-age cultured flounder Paralichthys olivaceus in the Kunda Bay, Kyoto Prefecture, Typical symptoms of the diseased fish were hemorrhage of the opercle, corneal opacity, exophthalmos and hemorrhage of the eyes.
The causative organism isolated from diseased fish was found to be a β-hemolytic Streptococcus. This bacterium could not be identified with any known Streptococcus species listed in Bergey's Manual 8th ed., however, there was a close resemblance between this isolate and Streptococcus sp. reported by KITAO et al. (1981), OHNISHI and Jo (1981), and UGAJIN (1981) from various freshwater fishes.
