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UBC Theses and Dissertations

Phylogenetic analysis of the genus Megalobatrachonema Yamaguti, 1941 (Ascaridida:Cosmocercoidea:Kathlaniidae) with field and laboratory observations of M. Waldeni Richardson, Jane P.M.


The genus Megalobatrachonema (Family Kathlaniidae; Order Ascaridida) was investigated using phylogenetic analysis. A single cladogram was produced with a consistency index of 92.6%. Six species were found valid, two of which are new. Division of the genus into subgenera Megalobatrachonema and Chabaudqolvania was not supported by the phylogenetic hypothesis. Comparison of host and parasite phylogenies suggest that at least two instances of host switching have occurred. Biogeographical analysis of parasites and hosts indicated that vicariance, rather than dispersal, best explains distribution of five of the six. Field and laboratory observations on one of the more evolved species of the genus, M. waldeni, suggests that there is probably a single generation a year, and that transmission to the definitive host occurs in spring and early summer.

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