魚病研究
Online ISSN : 1881-7335
Print ISSN : 0388-788X
ISSN-L : 0388-788X
57 巻, 1 号
選択された号の論文の5件中1~5を表示しています
総説
  • Yuho Watanabe, Tomoyoshi Yoshinaga
    原稿種別: Review
    2022 年 57 巻 1 号 p. 1-10
    発行日: 2022/03/15
    公開日: 2022/03/29
    ジャーナル 認証あり

    Cryptocaryon irritans is an obligate parasitic ciliate of marine teleosts and is the causative agent of cryptocaryoniasis (marine white spot disease). ​The parasite infects the skin and gills of marine teleosts and often causes mass mortality in heavily infected fish. ​Therefore, this parasite is a major threat to marine aquaculture in tropical and subtropical waters, and effective control methods are required. ​Interestingly, it was reported that fish infected with the parasite acquired protective immunity against it, and it was suggested that a vaccine strategy could be realized. ​Since then, many researchers have attempted to develop vaccines against cryptocaryoniasis. ​This review presents the current research on vaccine development against cryptocaryoniasis to provide references for future experimental studies and propose future research directions.

論文
  • Yasuhiko Kawato, Tomoki Maeda, Toyohiro Nishioka, Ikunari Kiryu, Tohru ...
    原稿種別: Research Article
    2022 年 57 巻 1 号 p. 11-19
    発行日: 2022/03/15
    公開日: 2022/03/29
    ジャーナル 認証あり

    Aquareovirus infection by hirame aquareovirus (HAqRV) is fatal in hatchery-reared Japanese flounder Paralichthys olivaceus. ​In the present study, we investigated the transmission route of HAqRV in order to develop outbreak prevention measures. ​HAqRV was isolated from six cases of Japanese founder juveniles from different locations in 2015 and 2016 and compared by molecular epidemiology. ​For three of these cases, apparently healthy broodstock that were used for Japanese flounder production were subjected to virus carrier tests using real-time PCR and ELISA targeting the viral genome and antibody against HAqRV, respectively. ​The viral genome was detected in the intestine and/or liver, with a detection rate of approximately 60% (n = 143). ​For the ELISA test, antibodies against HAqRV were detected in 100% of the examined broodstock (n = 109). ​Sequencing analysis of the RNA-dependent RNA polymerase gene indicated that the nucleotide sequences of the isolated virus, diseased juveniles, and apparently healthy adults were identical within the same case, but distinct among different cases. ​These results suggest that asymptomatically infected broodstock are a potential infection source of HAqRV outbreaks in Japanese flounder juveniles.

  • 井上 僚, 柳田 哲矢
    原稿種別: 論文
    2022 年 57 巻 1 号 p. 20-25
    発行日: 2022/03/15
    公開日: 2022/03/29
    ジャーナル 認証あり

    2019年に東京都内で養殖ヤマメの魚病診断を行ったところ,鰓に微胞子虫のキセノマが多数確認された。胞子の形態観察と計測を行ったところ,既報のLoma salmonaeのものと概ね一致した。また,リボソームDNAの遺伝子解析では 1,839 bpの塩基配列が得られ,北米のOncorhynchus spp.から得られたL. salmonaeの登録配列と99.9%一致した。以上の結果から,本研究では本微胞子虫をL. salmonaeと同定した。また,2019年10月~2021年7月までに東京都内の3養魚場でL. salmonaeの寄生が4例確認された。Loma salmonaeは北米およびヨーロッパのサケ科魚類養殖で被害をもたらしている。国内においては北海道で,Loma sp.の寄生報告が1例あるが,種同定されたのは初である。また,陸封型のヤマメを含めたサクラマスで寄生が確認されたのは世界初であり,ここに報告を行う。

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