R8 FAC Polychaete Survey 2019 WFL1

<p style='text-align: justify;'><em>C. shasta</em> (<em>Ceratonova shasta)</em> is a parasite that can adversely affect salmonids and in some instances maybe fatal. This parasite completes its life cycle by infecting polychaete worms (<em>Manayunkia speciosa</em>) in their myxospore stage; then is released as a actinospore which infects salmonids. Steelhead (<em>Oncorhynchus mykiss</em>), Chinook (<em>Oncorhynchus tshawytscha</em>) and Coho (<em>Oncorhynchus kisutch</em>) are species of concern regarding <em>C</em>. <em>shasta</em> infection in the Klamath River.</p><p style='text-align: justify;'><br /></p><p style='text-align: justify;'>U.S. Fish and Wildlife Service Fish and Aquatic Conservation program's Arcata office in coordination with Oregon State University's John L. Fryer Aquatic Animal Health Laboratory  annually collects information on abundance of polychaete worms and infection rates of <em>C. shasta</em> for three reaches on the Klamath River from below the Shasta River confluence to the Scott River confluence.</p>

沙斯塔角孢虫（*Ceratonova shasta*，常缩写为C. shasta）是一种可对鲑科鱼类（salmonids）造成不利影响的寄生虫，部分情况下可导致宿主死亡。该寄生虫的生命周期需通过在黏孢子阶段（myxospore stage）感染多毛类蠕虫（polychaete worms）*Manayunkia speciosa*来完成；随后以放射孢子（actinospore）的形式释放，进而感染鲑科鱼类。在克拉马斯河（Klamath River）流域，受沙斯塔角孢虫感染威胁的重点关注物种包括硬头鳟（*Oncorhynchus mykiss*，俗称steelhead）、奇努克鲑（*Oncorhynchus tshawytscha*，俗称Chinook）以及银鲑（*Oncorhynchus kisutch*，俗称Coho）。

美国鱼类和野生动物管理局（U.S. Fish and Wildlife Service）鱼类与水生保护项目的阿卡塔办事处，与俄勒冈州立大学约翰·L·弗莱尔水生动物健康实验室（John L. Fryer Aquatic Animal Health Laboratory）开展协作，每年针对克拉马斯河沙斯塔河汇流处下游至斯科特河汇流处的三个河段，收集多毛类蠕虫的种群丰度以及沙斯塔角孢虫的感染率数据。