Phylogenetic Relationships of Cardiocephaloides spp. (Digenea, Diplostomoidea) and the Genetic Characterization of Cardiocephaloides physalis from Magellanic Penguin, Spheniscus magellanicus, in Chile.

Cardiocephaloides as represented in the currently available dataset is monophyletic with C. physalis parasitism in penguins likely resulting from a secondary host-switching event. Identical 28S sequences of C. physalis from South America and Africa cautiously confirm the broad distribution of this species, although comparison of faster mutating genes (e. g., CO1) is recommended for a better substantiated conclusion.