• Journal of fish pathology
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• v.19 no.2
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• pp.173-181
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• 2006

Miamiensis avidus is a scuticociliate causing mortality in olive flounder Paralichthys olivaceus. To evaluate immune response of olive flounder against M. avidus, 2.6×106cells/fish of Formalin killed cell (FKC) was intraperitoneally (i.p.) injected, and 2.4 × 106cells/㎖ of sonicated FKC was immersion immunized to 14.9 cm (26.8g) fish. Fish were immunized 2 times with 2 weeks intervals. Antiserum from immunized fish caused agglutination and immobilization of the ciliate. In ELISA test, immunized group exhibited higher titers than control group. In addition, i.p. immunized fish showed higher phagocytic ratio, phahgocytic index and chemotaxic activity. To evaluate in vivo efficacy of FKC on fish, 1.43 × 105cells/fish was i.p.. injected, and 2.2 × 105 cells/㎖ of sonicated cell was immersed into 8.6cm (6.3g) fish. After 2 times immunization with 2 weeks intervals, fish were infected with 2.0 × 104 and 2.0 × 103 cells/ml of live ciliates by immersion. After 3 weeks, cumulative mortality was lower in the i.p. immunized group and mortality was delayed in immersion immunized group. In conclusion, specific immune response of oliver flounder against M. avidus was elevated after immunization and these immune response may prevent and/or delay for the M. avidus infection to olive flounder.