Treatments of Neoheterobothrium Infection in Japanese Flounder by 8% NaCl-supplemented Seawater Bathing

Abstract

This paper aimed to report successful cases of treatment of Neoheterobothrium infection in Japanese flounder, Paralichthys olivaceus with 8% NaCl-supplemented seawater. In a hatchery in Kagawa Prefecture, Japan in 1999 and 2000, brood stocks of Japanese flounder underwent severe anemia. To maintain the seed production, the naturally infected flounder with the causative parasite, Neoheterobothrium hirame, were treated by 8% NaCl-supplemented seawater bathing for 5 min at 17 and 20°C, resulting in detachments of both immature and adult worms, and recovery from anemia in the host fish, with no death of the host fish during and after the treatment. These observations assumed that the NaCl-supplemented seawater bathing is an effective treatment of Neoheterobothrium infection in Japanese flounder.