Phylogenetic position of <i>Polymorphus phippsi</i> Kostylew, 1922 and <i>Polymorphus magnus</i> Skrjabin, 1913 (Palaeacanthocephala, Polymorphidae) ascertained on the basis of molecular data

Abstract

Polymorphidae is a family of acanthocephalans, obligatory parasites with a complex life cycle involving arthropods as intermediate hosts and vertebrates of different taxa as definitive hosts. The current taxonomy of Polymorphidae seems to be equivocal. Its type genus Polymorphus has been shown to be polyphyletic based on molecular data. We obtained partial sequences of 28S rDNA gene and cox1 mitochondrial gene of two species of this genus, Polymorphus phippsi and P. magnus, and used them in a reconstruction of the polymorphid phylogeny. As a result, P. magnus was included into the same clade as the type species of the genus, P. minutus, while P. phippsi appeared to be close to Profilicollis spp. The position of P. phippsi agrees with the polyphyly of Polymorphus but does not correspond to its taxonomic status based on described phenotypic characters.