Jones Simon, Fiala Ivan, Prosperi-Porta Gina, House Marcia, Mumford Sonia
Pacific Biological Station, Fisheries and Oceans Canada, 3190 Hammond Bay Road, Nanaimo, British Columbia V9T 6N7, Canada.
Folia Parasitol (Praha). 2011 Jun;58(2):87-94. doi: 10.14411/fp.2011.009.
A new species of sphaerosporid myxosporean, Sphaerospora elwhaiensis sp. n., is described from kidney of non-anadromous sockeye salmon (kokanee) Oncorhynchus nerka (Walbaum) from Lake Sutherland in the northern Olympic Peninsula, Washington, USA. Infection with the parasite was detected in 45% of 177 kokanee examined over 5 years. While conforming to the morphological criteria by which members of the genus are defined, the parasite is distinguished from congeners in salmonids of western North America by a unique combination of valvular sculpting of the myxospore, the relatively large size of the myxospore and monosporous development within the pseudoplasmodium. In addition, nucleotide sequences of the parasite's small and large subunit ribosomal RNA gene are unique. Phylogenetic analyses of these sequences suggested that the parasite is most closely related to freshwater Myxidium spp. and Zschokkella spp. The molecular data have provided further evidence for a polyphyletic association previously recognized among members of the genus and emphasize the need for a taxonomic revision of Sphaerospora Thélohan, 1892 and related genera.
一种新的球孢虫属粘孢子虫，即艾氏球孢虫（Sphaerospora elwhaiensis sp. n.），是从美国华盛顿州奥林匹克半岛北部萨瑟兰湖的非溯河产卵型红大麻哈鱼（红大麻哈鱼陆封型）Oncorhynchus nerka（Walbaum）的肾脏中发现并描述的。在5年期间检查的177条红大麻哈鱼陆封型中，45%检测到感染了这种寄生虫。虽然该寄生虫符合球孢虫属成员的形态学标准，但它与北美西部鲑科鱼类中的同属物种不同，其独特之处在于粘孢子的瓣状纹饰、粘孢子相对较大的尺寸以及假原质体内的单孢子发育。此外，该寄生虫的小亚基和大亚基核糖体RNA基因的核苷酸序列也是独特的。对这些序列的系统发育分析表明，该寄生虫与淡水的Myxidium属和Zschokkella属关系最为密切。分子数据为该属成员之间先前公认的多系关联提供了进一步证据，并强调了对1892年的球孢虫属（Sphaerospora Thélohan）及相关属进行分类修订的必要性。
