Description of a new species of Aplectana (Nematoda: Ascaridomorpha: Cosmocercidae) using an integrative approach and preliminary phylogenetic study of Cosmocercidae and related taxa

Abstract Background Nematodes of the family Cosmocercidae (Ascaridomorpha: Cosmocercoidea) are mainly parasitic in digestive tract various amphibians and reptiles worldwide. However, our knowledge molecular phylogeny is still far from comprehensive. The phylogenetic relationships between other two families, Atractidae Kathlaniidae, superfamily Cosmocercoidea under debate. Moreover, systematic position some genera within remains unclear. Methods collected Polypedates megacephalus (Hallowell) (Anura: Rhacophoridae) were identified using morphological (light scanning electron microscopy) methods [sequencing small ribosomal DNA (18S), internal transcribed spacer 1 (ITS-1), large (28S) mitochondrial cytochrome c oxidase subunit ( cox 1) target regions]. Phylogenetic analyses cosmocercoid nematodes 18S + 28S sequence data performed to clarify Cosmocercidae, Kathlaniidae genus Aplectana Cosmocercidae. Results Morphological genetic evidence supported hypothesis that nematode specimens P. represent a new species (Cosmocercoidea: Cosmocercidae). Our results revealed monophyletic group, but not basal group as traditional classification. paraphyletic because subfamily Cruziinae (including only Cruzia ) formed seperate lineage. also showed has closer relationship Cosmocerca Conclusions suggested should be moved hitherto-defined elevated separate family, closely related present study provided basic framework for based on first time knowledge. species, A. xishuangbannaensis n. sp., was described integrative approach. Graphical abstract