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DNA sequences for the gene encoding mitochondrial cytochrome oxidase I in a group of rodents (pocket gophers) and their ectoparasites (chewing lice) provide evidence for cospeciation and reveal different rates of molecular evolution in the hosts and their parasites. The overall rate of nucleotide substitution (both silent and replacement changes) is(More)
The close correspondence often observed between the taxonomy of parasites and their hosts has led to Fahrenholz's rule, which postulates that parasites and their hosts speciate in synchrony. This leads to the prediction that phylogenetic trees of parasites and their hosts should be topologically identical. We report here a test of this prediction which(More)
Individual specimens of Anisakis, Pseudoterranova, and Contracaecum collected from marine mammals inhabiting northern Pacific waters were used for comparative diagnostic and molecular phylogenetic analyses. Forty-eight new sequences were obtained for this study of 14 Anisakis taxa, 8 Pseudoterranova taxa, 4 Contracaecum taxa, and 4 outgroup species. Partial(More)
BACKGROUND The orders Ascaridida, Oxyurida, and Spirurida represent major components of zooparasitic nematode diversity, including many species of veterinary and medical importance. Phylum-wide nematode phylogenetic hypotheses have mainly been based on nuclear rDNA sequences, but more recently complete mitochondrial (mtDNA) gene sequences have provided(More)
Advances in morphological and molecular studies of metazoan evolution have led to a better understanding of the relationships among Rotifera (Monogononta, Bdelloidea, Seisonidea) and Acanthocephala, and their relationships to other bilateral animals. The most accepted morphological analysis places Acanthocephala as a sister group to Rotifera, although other(More)
Reverse transcription of cellular RNA was used to obtain sequences from regions of 18S and 26/28S ribosomal RNA for eight species of ascaridoid nematodes. Phylogenetic relationships among these species were inferred from the aligned sequences by maximum-parsimony and maximum-likelihood methods. Seventy-nine of the 168 sites that varied were phylogenetically(More)
We conducted an extensive literature review on studies that have used DNA sequences to detect cryptic species of parasites during the last decade. Each literature citation that included the term "cryptic" or "sibling" species was analyzed to determine the approach used by the author(s). Reports were carefully filtered to retain only those that recognized(More)
Molecular phylogenetic analyses of 113 taxa representing Ascaridida, Rhigonematida, Spirurida and Oxyurida were used to infer a more comprehensive phylogenetic hypothesis for representatives of 'clade III'. The posterior probability of multiple alignment sites was used to exclude or weight characters, yielding datasets that were analysed using maximum(More)
Nuclear-encoded large-subunit ribosomal DNA sequences were used to infer a phylogenetic hypothesis for 17 taxa (16 nominal species) of the genera Contracaecum and Phocascaris. Phylogenetic trees based on these data have been used to assess the validity of the taxonomic distinction between these genera, which was based on the presence or absence of certain(More)
The peritoneal cavity (PNC) and intestine of northern fur seal (Callorhinus ursinus) pups and California sea lion (Zalophus californianus) pups that died in late July and early August, 2003, on San Miguel Island, California, were examined for hookworms. Prevalence and morphometric studies were done with the hookworms in addition to molecular(More)