제주도내 여윔증상 양식 넙치(Paralichthys olivaceus)의 대량 폐사 원인의 생리학적 접근법에 관한 연구

Abstract

The primary purpose of these study of physiological approach of the root of a mass death on emaciated olive flounder (Paralichthys olivaceus) in Jeju island. The experiment was executed from 4 methods (monitoring of the aquaculture farm, physiological analysis and histological examination on nutrient deficiency, potential of pathogenic bacteria, effect of hydrogen peroxide) in olive flounder. The first experiment was executed monitoring of the ten aqua farms in Jeju island at september to April 2011. According to results of standard culture method (TSA, SS, TCBS) Virus and bacteria was not found in April~May and August~September, but during June~July, bacteria was found in a few agust farms in TSA and TCBS agar media. We also investigated the effects of starvation during 5 weeks olive flounder. This study was conducted to investigate hematological analysis, blood ion concentrations, histological examination. As a results, hematological analysis, total protein, glucose concentrations in serum were no significant differences between the starvated groups and the emaciated groups in olive flounder. According to results of blood ion concentration, Na+, Cl-, Ca++ was no significant all experimental groups. According to results of histological examination were also no significant all experimental groups. Moreover, we investigated the effect of infection of pathogenic bacteria. The olive flounder (Paralichthys olivaceus), 75.2±15g used in this experiment was obtained from a commercial fish farms in Jeju island and was injected pathogenic bacteria (1: Vibrio harveyi, 2: Edwardsiella tarda, 3: Vibrio harveyi +Edwardsiella tarda). The mortality rates at 8~10days were 100% to all experimental groups. Histological result were no significant differences between the infected groups and the emaciated groups. Also hematological analysis, hematocrit, total protein, glucose concentrations were no significant differences all experimental groups. Moreover lysozyme activity (serum and mucus), and antioxidant enzymes were also no significant differences all experimental groups. Finally, we investigated the effects of hydrogen peroxide (100ppm, 300ppm and 500ppm) in olive flounder. In addition we tested the effects of physiological change by immersion of a various concentrations of hydrogen peroxide after infection of a pathogenic bacteria (1: Vibrio harveyi, 2: Edwardsiella tarda, 3: Vibrio harveyi +Edwardsiella tarda) in olive flounder. The mortality rates at 12days were 60% to infection V. harveyi of 500ppm groups, 12days were 100% to infection E. tarda of 500ppm groups , 10days were 100% to infection V. harveyi + E. tarda of 500ppm groups in olive flounder. Also hematological analysis, cholesterol were similar the emaciated flounder group. Moreover lysozyme activity (serum and mucus), and antioxidant enzymes were also no significant differences all experimental groups. These results were suggested that the showing different features to emaciated olive flounder, pathogenic bacteria and such as V. harveyi, E. tarda infections of results. The considered to possible by taking advantage the monitoring and emaciated olive flounder. the emaciated olive flounder was mass mortality by a new pathogenic infector but was not caused by pathogenic bacteria (V. harveyi and E. tarda) infector and immersion of hydrogen peroxide.