The First Report on Fin Rot Disease of Cultured Turbot Scophthalmus maximus in China

Abstract Since 1998, the culture of turbot Scophthalmus maximus has spread rapidly along the coast of North China, becoming an important industry. However, fin rot disease was identified during an epidemiological study from 2001 to 2004. The infections occurred with high mortality, up to 90–100% in some cases. Young fish are sensitive to the infection. An important clinical sign is fin rot. Bacterial isolation was done in four cases, including hatcheries and farms. One dominant strain of 0.2–0.4 × 1.5–2.0 μm was identified as Vibrio anguillarum by morphology, physiological and biochemical tests, and 16S rRNA sequence analysis. Virulence assays carried out with the isolated V. anguillarum resulted in the same gross signs as in naturally infected fish, indicating that V. anguillarum was the causative agent for fin rot disease. The 14-d dose lethal to 50% of the fish was calculated as 1.7 × 103 colony-forming units/mL. Histopathological studies demonstrated that V. anguillarum could cause severe tissue chang...