Abstract - We are aim to evaluate lysozyme and antibacterial activity of cultured catfish, Silurus asotus, that fed supplementally with Galla rhois extracts for eight weeks. Lysozyme activity in the spleen and serum of administrated group was higher than not administrated group, but in mucus of the lysozyme activity was no regular than other organ. The lysozyme activity of the spleen, kidney, serum of administrated fishes were increased after 2 weeks and that was highest after 8 weeks. Ht and GLU in serum of administrated fishes were gradually increased but GOT was decreased after 8 weeks. There is no significant differences in HB (Hemoglobin) and TP (Total Protein) each groups. Furthermore, there is no pathohistological changes of kidney and liver of tested fishes. The cumulative survival rates of administrated group after intraperitoneal injection of Aeromonas veronii with 6.5×106 cfu mL-1 was presented 33% in 9 days. As the Results, Galla rhois extracts has any beneficial effects for immunity elevation and antibacterial activity in catfish, Silurus asotus.

Shortfin eel (Anguilla bicolor pacifica) is a species of commercial importance and its production is greatly affected due to the infection by Heterosporis anguillarum. In this study, we evaluated the effect of H. anguillarum infection on the growth of Shortfin eel. A disease that trunk muscle of cultured shortfin eel, Anguilla bicolor pacifica, were irregular and resulted in death, breakout of the commercial eel culture farm. We observed that the trunk muscle of infected eels were irregular and represented white or yellowish externally. Histopathologically, a great numbers of large or small spores and sporophorocysts were also observed in degenerated muscle layer. The cloning of specific gene of H. anguillarum, encoding small subunit ribosomal RNA (SSU-rRNA) was amplified by the polymerase chain reaction(PCR) from the muscle lesion of diseased eel. The size of clone gene is well matched with the size of small subunit ribosomal RNA of H. anguillarum and thus confirming the infection by H. anguillarum.

최근 국내의 양식 메기에 표피 박리와 근육 괴사를 특징으로 하는 새로운 질병이 발생하였다. 그 폐사율은 낮으나 질병으로 인한 상품가치의 저하로 경제적 손실이 크다. 병어로부터 원인균을 분리하고 자연감염어와 인위감염어의 병리학적 변화를 관찰하였다. 원인균은 Aeromonas veronii로 동정되었으며, 원인균을 건강어에 인위감염시켜 폐사 및 증상의 발현을 매일 관찰하였다. 인위감염된 어류의 증상은 자연감염어와 유사하였으며 원인균을 감염시킨 후 7일 이내에 모두 폐사하였다. 병어의 조직표본을 제작하여 관찰한 결과, 자연감염어의 간, 비장, 신장의 울혈 및 간세포 변성과 비장 협조직의 초자적변성이 관찰되었으며, 특히 심장에서 염증성 변성과 세균응집체가 관찰되었다. 소화관에서의 울혈과 점막고유층의 섬유화 현상도 특징적이었다. 자연감염어에 비해 약한 경향이지만 인위감염어의 조직학적 변화도 관찰되었으며, 소화관에서의 조직학적 변성은 관찰되지 않았다.