The Epidemiology of the Trichodinid Ciliate Trichodina truttae on Hatchery-reared and Wild Salmonid Fish in Hokkaido
The Epidemiology of the Trichodinid Ciliate Trichodina truttae on Hatchery-reared and Wild Salmonid Fish in Hokkaido
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DOI：
10.3147/jsfp.51.199
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发表时间：
2016
期刊：
影响因子：
0.6
通讯作者：
S. Mizuno;S. Urawa;M. Miyamoto;M. Hatakeyama;Hayato Saneyoshi;Y. Sasaki;N. Koide;H. Ueda
中科院分区：
文献类型：
--
作者：
S. Mizuno;S. Urawa;M. Miyamoto;M. Hatakeyama;Hayato Saneyoshi;Y. Sasaki;N. Koide;H. Ueda
车轮虫是一种外寄生纤毛虫，会感染鲑鱼的体表，有时会导致日本北部孵化场饲养的幼鲑鱼 Oncorhynchus keta 的高死亡率。本研究调查了北海道野生鱼类和孵化场饲养的鲑鱼幼鱼身上的旋虫纤毛虫的情况，以确定这些寄生虫的流行病学。在 87 个检查孵化场中的 28 个孵化场中的 28 个饲养的幼鲑鱼和野生鱼类上观察到了车轮虫，包括马苏鲑鱼 O. masou、虹鳟 O. mykiss、成年鲑鱼、白点鲑 Salvelinus leucomaenis 和河流中的 Dolly Varden S. malma。所有分离的车轮虫纤毛虫都具有相同的小亚基核糖体RNA基因的核苷酸序列，并且在形态学上被鉴定为T. truttae。传播实验表明，T. truttae 从野生马苏鲑鱼水平传播到孵化场饲养的幼年鲑鱼。我们的研究结果表明，感染北海道鲑鱼的旋虫类纤毛虫的优势物种是 T. truttae，并且野生鲑鱼可能是孵化场饲养的幼鲑鱼的感染源。
Trichodinids are ectoparasitic ciliates that infect the body surface of salmonid fish and occasionally cause high mortality in juvenile chum salmon Oncorhynchus keta reared at hatcheries in northern Japan. The present study examined the occurrence of trichodinid ciliates on wild fish and hatchery-reared juvenile chum salmon in Hokkaido to determine the epidemiology of these parasites. Trichodinids were observed on juvenile chum salmon reared at 28 out of the 87 examined hatcheries and on wild fish, including masu salmon O. masou, rainbow trout O. mykiss, adult chum salmon, white-spotted char Salvelinus leucomaenis, and Dolly Varden S. malma in rivers. All isolates of trichodinid ciliates had the same nucleotide sequences of small subunit ribosomal RNA gene and were identified morphologically as T. truttae. A transmission experiment showed that T. truttae was transmitted horizontally from wild masu salmon to hatchery-reared juvenile chum salmon. Our results demonstrate that a dominant species of trichodinid ciliate infecting salmonid fish in Hokkaido is T. truttae and that wild salmonids can be an infection source of hatchery-reared juvenile chum salmon.