Phylogeography of the cosmopolitan marine parasite Kudoa thyrsites (Myxozoa: Myxosporea).

TitlePhylogeography of the cosmopolitan marine parasite Kudoa thyrsites (Myxozoa: Myxosporea).
Publication TypeJournal Article
Year of Publication2006
AuthorsWhipps CM, Kent ML
JournalThe Journal of eukaryotic microbiology
Volume53
Issue5
Pagination364-73
Date Published2006 Sep-Oct
ISSN1066-5234
KeywordsAnimals, Australia, British Columbia, DNA, Protozoan, DNA, Ribosomal, DNA, Ribosomal Spacer, England, Eukaryota, Fish Diseases, Fishes, Geography, Japan, Molecular Sequence Data, Oregon, Phylogeny, Polymerase Chain Reaction, Protozoan Infections, Animal, Seawater, Sequence Analysis, DNA, South Africa, Spores, Protozoan
Abstract

Kudoa thyrsites (Myxozoa: Multivalvulida) is a cosmopolitan marine parasite of fishes associated with post-mortem tissue degradation. Financial losses incurred as a result of these infections are of concern to commercial fisheries. There is conflicting evidence whether K. thyrsites represents a cryptic species complex. Myxospore morphology is very similar for K. thyrsites across its range, but preliminary genetic analyses show some differences. Kudoa thyrsites and the morphologically similar Kudoa histolytica were examined from hosts in British Columbia, Canada, Oregon, USA, Chile, England, South Africa, Australia, and Japan. We compared myxospore morphology and DNA sequences of heat shock protein 70 and the small subunit, large subunit, and internal transcribed spacer 1 of the ribosomal DNA. There was some morphological variation between regional representatives, inconsistent with genetic analyses. Phylogenetically, major separations correlated to four broad geographic regions: Japan, Australia, eastern Pacific, and eastern Atlantic. Within these regions there was little additional genetic structure. These data are evidence for regional subdivision of K. thyrsites suggesting global transplantation of fishes has yet to homogenize these distinctions. Within regions, parasite gene flow appears to be high between host species, suggesting little host specificity and minimal cryptic speciation. Our data also indicate that K. histolytica is not a valid species, as it was morphologically and genetically indistinguishable from K. thyrsites.

DOI10.1111/j.1550-7408.2006.00114.x
Alternate JournalJ. Eukaryot. Microbiol.