Molecular phylogenies as a tool to understand diversity in rotifers

Over the past decade, the availability of DNA sequence data from rotifers and the development of statistical and analytical tools linked to phylogenetic reconstructions allowed researchers to deepen our knowledge of patterns and processes in rotifer diversity. Here, I review the recent rotifer literature regarding: (i) the position of rotifers in the animal kingdom, with the wide consensus being within Spiralia, in a clade called Platyzoa together with Acanthocephalans, Gastrotricha, Gnathostomulida, Micrognathozoa, and Platyhelminthes; (ii) the still unresolved phylogenetic relationships within rotifers and the disputed position of Acanthocephala; (iii) the discovery of extensive hidden diversity through DNA taxonomy; (iv) phylogeography; and (v) the phylogenetic structure of rotifer communities. In order to facilitate the further discovery of hidden diversity in rotifers, I provide a simple tutorial on the currently available methods in DNA taxonomy from single locus data using a previously published rotifer dataset as an example. Moreover, I outline a brief perspective on the potentiality of the use of phylogenetic approaches in future rotifer studies.