title: Sphaerospora elwhaiensis sp.n. (Myxosporea: Sphaerosporidae) from landlocked sockeye salmon Oncorhynchus nerka (Salmoniformes: Salmonidae) in Washington State, USA.
abstract: 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.
authors.affiliation: Pacific Biological Station, Fisheries and Oceans Canada, 3190 Hammond Bay Road, Nanaimo, British Columbia V9T 6N7, Canada. simon.jones@dfo-mpo.gc.ca
authors.forename: Simon
authors.initials: S
authors.lastname: Jones
authors.forename: Ivan
authors.initials: I
authors.lastname: Fiala
authors.forename: Gina
authors.initials: G
authors.lastname: Prosperi-Porta
authors.forename: Marcia
authors.initials: M
authors.lastname: House
authors.forename: Sonia
authors.initials: S
authors.lastname: Mumford
mesh_terms: D000818:Animals; D001483:Base Sequence; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D005393:Fish Diseases / Q000469:parasitology*; D005618:Fresh Water; D007668:Kidney / Q000469:parasitology; D008969:Molecular Sequence Data; D055764:Myxozoa / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification* / Q000648:ultrastructure; D010273:Parasitic Diseases, Animal / Q000453:epidemiology / Q000469:parasitology*; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D012474:Salmon / Q000469:parasitology*; D017422:Sequence Analysis, DNA / Q000662:veterinary; D013170:Spores / Q000648:ultrastructure; D014861:Washington / Q000453:epidemiology
chemical_list: D004275:DNA, Ribosomal