Phylogenetic affinities and systematic position of Entomelas sylvestris Baker, 1982 (Nematoda: Rhabdiasidae), a parasite of Breviceps sylvestris FitzSimons (Amphibia: Brevicipitidae) in South Africa Vasyl V. Tkach • Ali Halajian • Yuriy Kuzmin Received: 28 November 2012 / Accepted: 2 January 2014 Ó Springer Science+Business Media Dordrecht 2014 Abstract The genus Entomelas Travassos, 1930 currently includes nine species of rhabdiasid nema- todes, eight of them parasitic in lizards and only one, Entomelas sylvestris Baker, 1982, parasitic in amphib- ians. Entomelas sylvestris was originally described from the Forest Rain Frog Breviceps sylvestris Fitz- Simons in South Africa and was not reported since. It was placed in the genus Entomelas without any specific arguments for this taxonomic decision, pre- sumably mainly based on details of the buccal capsule morphology. We have found this species in the same host in Limpopo province, South Africa. Molecular phylogenetic analysis based on the newly-obtained sequence of complete ITS region and partial nuclear large ribosomal subunit (28S) gene of E. sylvestris and previously published sequences of a variety of other rhabdiasid taxa, has convincingly demonstrated that this species does not belong in Entomelas. Instead, it clustered together with the members of Rhabdias Stiles & Hassall, 1905 from amphibian hosts. There- fore, we transfer E. sylvestris into Rhabdias as Rhabdias sylvestris (Baker, 1982) n. comb. In our analysis E. sylvestris appears, albeit with weak support, as a basal/sister taxon to the rest of Rhabdias spp. which explains to some extent the differences in the buccal capsule morphology between this species and other Rhabdias spp. Introduction The family Rhabdiasidae Railliet, 1915 is a relatively small group of nematodes that currently includes eight genera of nematodes parasitic in lungs, oesophagus and mouth of amphibians and reptiles worldwide. The vast majority of the rhabdiasids belongs to Rhabdias Stiles & Hassall, 1905 and are parasitic exclusively in lungs of their hosts. Another large genus, Entomelas Travassos, 1930, includes nine species of rhabdiasid nematodes (Kuzmin & Tkach, 2002–2013: http://izan. kiev.ua/ppages/rhabdias/list.htm). Eight of them are parasites of lungs and oesophagus of several groups of lizards and only one, Entomelas sylvestris Baker, 1982, is a parasite of amphibians. Entomelas sylvestris was originally described from the Forest Rain Frog Breviceps sylvestris sylvestris FitzSimons (Anura: Brevicipitidae) in Transvaal, South Africa. It was placed in the genus Entomelas without any specific arguments for this taxonomic decision, presumably V. V. Tkach (&) Department of Biology, University of North Dakota, 10 Cornell Street, Grand Forks, ND 58202, USA e-mail: vasyl.tkach@email.und.edu A. Halajian Department of Biodiversity (Zoology), University of Limpopo, Turfloop Campus, Private Bag X1106, Sovenga, Polokwane 0727, South Africa Y. Kuzmin Department of Parasitology, Institute of Zoology, 15 Bogdan Khmelnytskyi Street, Kiev 01601, Ukraine 123 Syst Parasitol (2014) 87:293–298 DOI 10.1007/s11230-014-9469-4