title: Taxonomy and molecular phylogeny of Myxobolus bilobus n. sp. (Myxozoa) parasitizing Notemigonus crysoleucas (Cyprinidae) in Algonquin Park, Ontario, Canada.
abstract: Myxobolus bilobus n. sp. (Myxozoa) is described from golden shiner Notemigonus crysoleucas in Algonquin Park, Ontario, Canada. Plasmodia develop at the distal end of gill filaments, where they form a novel-shaped plasmodium made up of 2 side-by-side hemispheres joined at a central pore. Surrounding gill tissue is vacuolated, necrotic, and hemorrhagic. Spores of M. bilobus n. sp. resemble those of M. aureatus Ward, 1919, M. angustus Kudo, 1934, M. spalli Landsberg & Lom, 1991, and M. pseudokoi Li & Desser, 1985 in parasitizing cyprinids and in their pyriform shape. Spores of M. bilobus n. sp., however, are much larger (20 to 22.1 microm long, 7.5 to 9.3 microm wide, and 6 microm thick) than those of these other species, and the plasmodium is bi-lobed rather than the typical hollow sphere. A phylogenetic analysis of the 18S rDNA (2014 bp) reveals that M. bilobus n. sp. is a member of a clade that includes 11 species of Myxobolus, all of which are parasites of cyprinid fishes in North America or Eurasia. The study concludes that M. bilobus n. sp. is a member of a clade that has undergone radiation within cyprinid fishes of the 2 continents and that this evolution has involved both host and site switching.
authors.affiliation: Department of Biology, Saint Mary's University, Halifax, Nova Scotia, Canada. david.cone@smu.ca
authors.forename: David K
authors.initials: DK
authors.lastname: Cone
authors.forename: Jing
authors.initials: J
authors.lastname: Yang
authors.forename: Genlou
authors.initials: G
authors.lastname: Sun
authors.forename: Russell
authors.initials: R
authors.lastname: Easy
mesh_terms: D000818:Animals; D001483:Base Sequence; D016000:Cluster Analysis; D003530:Cyprinidae; D017931:DNA Primers; D056890:Eukaryota / Q000145:classification / Q000235:genetics*; D005393:Fish Diseases / Q000469:parasitology* / Q000473:pathology; D005880:Gills / Q000469:parasitology / Q000473:pathology; D016013:Likelihood Functions; D008957:Models, Genetic; D008969:Molecular Sequence Data; D009864:Ontario; D010802:Phylogeny; D011529:Protozoan Infections, Animal / Q000473:pathology*; D012337:RNA, Ribosomal, 18S / Q000235:genetics; D017422:Sequence Analysis, DNA / Q000662:veterinary; D033761:Spores, Protozoan / Q000166:cytology
chemical_list: D017931:DNA Primers; D012337:RNA, Ribosomal, 18S