Molecular phylogeny of K alyptorhynchia ( R habdocoela, P latyhelminthes) inferred from ribosomal sequence data

• Published in: Zoologica scripta 2014-09, Vol.43 (5), p.519-530
• Main Authors: Tessens, Bart, Janssen, Toon, Artois, Tom
• Format: Article
• Language: English
• ISSN: 0300-3256; 1463-6409
• DOI: 10.1111/zsc.12066

With 556 species described to date, K alyptorhynchia includes about one‐third of all species of rhabdocoel flatworms. In this study, we present the first molecular phylogenetic analysis of this taxon. The final analysis comprises 110 species. These represent 11 of the 17 known families. The largest family (241 known species), P olycystididae, is represented by nine of 10 subfamilies and 33 of the 58 genera. Sequence data from 18 S r DNA and 28 S r DNA were analysed using maximum likelihood and Bayesian approaches. Of the two taxa traditionally recognised within K alyptorhynchia, E ukalyptorhynchia and S chizorhynchia, only S chizorhynchia is monophyletic. All eukalyptorhynch families, except C icerinidae, are monophyletic. On the other hand, two of the three schizorhynch families included are not monophyletic. Within P olycystididae, the traditional taxonomy was not reflected in our phylogenetic analyses and most subfamilies are polyphyletic. These results suggest that current classification, mostly based on characters of the genital system, suffers from homoplasy. Where possible, a revised classification, taking into account these new findings, is given.