Molecular phylogeny of Gyrodactylus(Monogenea) parasitizing fishes in fresh water, estuarine, and marine habitats in Canada

• Published in: Canadian Journal of Zoology
• Main Authors: Gilmore, S.R., Cone, D.K., Lowe, G., King, S.K., Jones, S.R.M., Abbott, C.L.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Canadian Science Publishing 2012
• Subjects: Canada; Atlantic salmon
• Online Access: http://dx.doi.org/10.1139/z2012-040; http://www.nrcresearchpress.com/doi/full-xml/10.1139/z2012-040; http://www.nrcresearchpress.com/doi/pdf/10.1139/z2012-040

Gyrodactylus Nordmann, 1832 is a genus of monogenean flatworms that is well-studied in Europe and best known for the destructive pathogen of Atlantic salmon, Gyrodactylus salaris Malmberg, 1957. However, there is a paucity of information on species of Gyrodactylus occurring elsewhere despite that the genus is thought to be extremely speciose. Here we present the first major molecular phylogeny of Gyrodactylus using samples from host fishes in North America. Our aims were to characterize species and molecular diversity of North American Gyrodactylus to allow a determination of their evolutionary relationship with congenerics sampled from Europe. Specimens belonging to 25 species of Gyrodactylus and closely related species from Canada and the northern United States of America were identified using morphology and sequenced at 18S rDNA and ITS2 rDNA (totaling ca. 1430 bp). Significant molecular groups in North American Gyrodactylus were found to correspond to a major division in the genus based on the structure of the male copulatory organ. Results corroborate earlier findings suggesting that the genus Fundulotrema Kritsky and Thatcher, 1977, traditionally thought to be distinct from Gyrodactylus owing to the presence of a peduncular bar, falls within Gyrodactylus. The usefulness and application of the broadly conserved 18S primers as a standard tool for Gyrodactylus taxonomy is discussed and advocated.