This study was carried out to investigate an infectious disease which induced high mortalities (daily 5%) in the culture sea bass farm in the Bodrum peninsula in May, 2003.
Sick fish obtained from the farm showed darkening of the skin, anorexia, haemorrhagie on the operculum, inflammation on the gills and respiratory distress. Internally, pale liver, haemorhagic spleen, pale kidney and there was no food in the stomach. Parasitological and bacteriological diagnostic methods applied to ten sick fish (80 ± 5 g.). For parasitological diagnosis, gills, skin, internal organs and blood of fish were examined. Samples from visceral organs such as liver, spleen and kidney of the moribund fish to 1,5 NaCl added Tryptic Soy Agar (TSA) and Thiosulphate Citrate Bile Salt (TCBS) agar plates were inoculated and incubated at 22 0 C for up lo 24-48 hours.
A parasitic isopod Ceratothoa oestroides was determined in buccal cavities and on the silis of the infected fish. But there was not any endoparasite in the visceral organs and blood of the sick fish. The isolates grown on TSA were identified as Vibrio harveyi because of morphological, physiological and biochemical features.