참장어 ( 뱀장어 ) Anguilla japonica 양어장에서의 아질산 중독에 의한 Methemoglobin 증과 병리조직학적 변성 = On the Histopathological Changes and Methemoglobinemia to Nitrite Toxicity in the Culture Farms of Eel , Anguilla japonica

다국어 초록 (Multilingual Abstract)

Histopathological changes and methemoglobinemia of the eels (Anguilla japonica) reared at six culture farms in the vicinity of Yoˇsu city were investigated under the conditions of 22.0∼29℃, 4.33∼7.33ppm of D.O., pH 6.1∼8.2 and 0.03∼10.1ppm of nitrite from December, 1989 to June, 1990. All of the eels showed no any abnormal state in action, color and blood, but the eels reared in pH 6.0 had planty of mucus and stickiness on their body surface. Methemoglobin levels were 1.03∼9.86% of total erythrocyes in Dec. and 5.05∼25.69% in June, and poikilocyte levels were 5.8∼30.17% in Dec. and 8.67∼74.45% in June. These results indicate the fact that the water management of the culture farms was worse in summer than in winter, even though not good in winter. Hypertrophy was found in the gill, hepatic and kidney tissue of the eels in all the culture farms. In March and June, Fish of all culture farms appeared the detachment of gill lamella epithelium cells, pyknosis and sinusoids of nucleus in the hepatic tissue and hemosiderosis in the kidney tissue. The trend of increase in methemoglobin levels appeared in the fish of culture farms with high nitrite concentration, which didn`t appear equally in all the culture farms. However, in the culture farms of pH 6.0, methemoglobin and poikilocyte levels were increased independently of concentration of nitrite, and degeneration in the tissue of the gill, liver and kidney was also appeared.