title: Leptojacobus dorci n. gen., n. sp. (Nematoda: Diplogastridae), an Associate of Dorcus Stag Beetles (Coleoptera: Lucanidae).
abstract: A new species of diplogastrid nematode, Leptojacobus dorci n. gen., n. sp., was isolated from adults of the stag beetle Dorcus ritsemae (Coleoptera: Lucanidae) that were purchased from a pet shop in Japan. Leptojacobus n. gen. is circumscribed by a very thin, delicate body and by a small stoma with minute armature. A combination of other stomatal characters, namely the division of the cheilostom into adradial plates, the symmetry of the subventral stegostomatal sectors, and the presence of a thin, conical dorsal tooth, further distinguishes Leptojacobus n. gen. from other genera of Diplogastridae. Phylogenetic analysis of nearly full-length SSU rRNA sequences support the new species, together with an isolate identified previously as Koerneria luziae, to be excluded from a clade including all other molecularly characterized diplogastrids with teeth and stomatal dimorphism. Therefore, the new species will be of importance for reconstruction of ancestral character histories in Diplogastridae, a family circumscribed by a suite of feeding-related novelties.
authors.affiliation: Forest Pathology Laboratory, Forestry and Forest Products Research Institute, 1 Matsunosato, Tsukuba, Ibaraki 305-8687 Japan.
authors.forename: Natsumi
authors.initials: N
authors.lastname: Kanzaki
authors.affiliation: Max Planck Institute for Developmental Biology, Department of Evolutionary Biology, Spemannstraße 37, 72076 Tübingen, Germany.
authors.forename: Erik J
authors.initials: EJ
authors.lastname: Ragsdale
authors.affiliation: Max Planck Institute for Developmental Biology, Department of Evolutionary Biology, Spemannstraße 37, 72076 Tübingen, Germany.
authors.forename: Vladislav
authors.initials: V
authors.lastname: Susoy
authors.affiliation: Max Planck Institute for Developmental Biology, Department of Evolutionary Biology, Spemannstraße 37, 72076 Tübingen, Germany.
authors.forename: Ralf J
authors.initials: RJ
authors.lastname: Sommer
keywords: dimorphism; evolution; morphology; new genus; new species; novelty; phylogeny; stoma; taxonomy