New Insights into the Taxonomy of Malacopsylloidea Superfamily (Siphonaptera) Based on Morphological, Molecular and Phylogenetic Characterization of Phthiropsylla agenoris (Malacopsyllidae) and Polygenis (Polygenis) rimatus (Rhopalopsyllidae)

Abstract

From a phylogenetic point of view, the Malacopsyllidae family and the Rhopalopsillidae family (comprising Parapsyllinae and Rhopalopsyllinae subfamilies) have been traditionally classified within the Malacopsylloidea superfamily, mostly restricted to South America. The phylogenetic relationships and taxonomic status of Malacopsyllidae and Rhopalopsillidae have never been assessed since no molecular loci of Malacopsyllidae have been sequenced by any authors, and the phylogeny provided so far was not based on any sort of formal quantitative analysis of flea morphology. Based on these precedents, the objective of this study was to carry out a comparative phylogenetic, molecular and morphological study of two different species belonging to each family, Phthiropsylla agenoris (Malacopsylla) and Polygenis (Polygenis) rimatus (Rhopalopsyllidae, Rhopalopsyllinae). In this study, we demonstrated the usefulness of several morphological features as diagnostic characters to differentiate between P. (P.) rimatus and P. agenoris. Using molecular and phylogenetic data, we easily discriminated between the two taxa (P. agenoris and P. (P.) rimatus) by comparing both nuclear and mitochondrial markers. This fact proves the usefulness of ITS2, EF1−α, cox1, cytb and cox2 as molecular diagnostic markers to characterize and identify different Siphonaptera taxa. Additionally, the phylogenetic results confirm, for the first time, the monophyly of the Malacopsyllidae family and suggest a clear paraphyletic position of the Paraspsyllinae subfamily and, consequently, the Rhopalopsyllidae family.