Ecological study on Microcotyle sebastisci of parasiting of cultured rocfish, Sebastes schlegeli, in Korea

남해안 양식산 조피볼락에 기생한 Microcotyle sebastisci의 감염률 변동

  • Choi, Sang-Duk (South Sea Fisheries Research Institute, National Fisheries Research and Development Agency) ;
  • Sim, Doo-Saing (Pathology Division, National Fisheries Research and Development Agency) ;
  • Gong, Yong-Gun (South Sea Fisheries Research Institute, National Fisheries Research and Development Agency) ;
  • Paek, Jai-Min (South Sea Fisheries Research Institute, National Fisheries Research and Development Agency) ;
  • Bang, In-Chul (South Sea Fisheries Research Institute, National Fisheries Research and Development Agency)
  • 최상덕 (국립수산진흥원 남해수산연구소) ;
  • 심두생 (국립수산진흥원 병리과) ;
  • 공용근 (국립수산진흥원 남해수산연구소) ;
  • 백재민 (국립수산진흥원 남해수산연구소) ;
  • 방인철 (국립수산진흥원 남해수산연구소)
  • Published : 1996.12.30

Abstract

We report on the variation of infection and histopathological change of Microcotyle sebastisci parasitic on cultured rockfish, Sebastes schlegeli, in Namhae Islands and Kamak Bay from April to October in 1995. Microcotylosis due to Microcotyle sebastisci occurred among cultured rockfish, Sebastes schlegeli. This parasite was not found on the host fish from June to July. Parasite sites were mainly consist of 2nd and 3rd gill arch`s filaments of rockfish. Also, the sites were secreted in large quantity of mucus with a very small bleeding. In Namhae Islands, maximum values of prevalence, relative density and mean intensity were found on September 1995, as 40.0%, 30.7 and 76.8, respectively. In Kamak Bay, maximum values of prevalence, relative density and mean intensity were obtained on October 1995, as 46.0%, 40.5 and 88.0, respectively. Histopathological changes of the heavily infested gills were showed necrosis, epithelium of the gill filaments underwent hyperplasia with fusion of the lamella and filamental clubbing. And a bacterial colony is invaded on the surface of lamella epithelium.

1995년 4월부터 10월까지 전남 가막만과 경남 남해 해역에서 양식하는 조피볼락에 기생하는 아가미흡충 Microcotyle sebastisci의 기생률 변동 및 병리조직학적 변화를 조사하였다. M. sebastisci는 6~7월에 나타나지 않았고, 주로 새엽 II~III에 기생하였다. 기생된 부위는 미세한 출혈과 함께 점액이 다량 분비되었다. 남해의 경우 9월에 있어서 감염률, 상대 감염밀도, 평균 감염강도는 각각 40.0%, 30.7, 76.8을 나타내었다. 또한 가막만의 경우는 10월에 감염률, 상대 감염밀도, 평균 감염강도는 각각 46.0%, 40.5, 88.0으로 조사기간 중 가장 높게 나타났다. 병리조직학적 소견으로는 호흡상피세포의 증생, 비후, 새박판간상피세포의 중생과 새변의 곤봉화가 일어났다. 2차적으로 세균의 감염에 의한 아가미 부식도 관찰되었다.

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