title: Two new and two recharacterized species from a radiation of pristionchus (nematoda: diplogastridae) in europe.
abstract: Two new species of Pristionchus, P. lucani n. sp. and P. bulgaricus n. sp., are described from France and Bulgaria, respectively. Additionally, new morphological and morphometric data are provided for two previously described species from Europe, P. brevicauda (Kotlán, 1928) Paramonov, 1952 and P. clavus (von Linstow, 1901) Sudhaus and Fürst von Lieven, 2003. A phylogeny including these four species was inferred from a dataset including 26 ribosomal protein-coding genes, sequences of which are original for P. bulgaricus n. sp. and P. clavus. Relationships support a radiation of all sequenced European Pristionchus species from a single, gonochoristic common ancestor, and current knowledge of species ranges supports "western" and "eastern" clades. Similar diagnostic morphologies reflect the close relationships among the new and recharacterized species, especially P. bulgaricus n. sp., P. brevicauda, and P. clavus, although mating tests as well as genetic and phylogenetic separation support their identities as unique species. Our results show that Pristionchus species in Europe are more diverse than typological characters suggest, and thus biological and molecular profiling will be essential for future delimitation of Pristionchus species from the region.
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: Matthias
authors.initials: M
authors.lastname: Herrmann
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: biogeography; gonochorism; hermaphroditism; morphology; morphometrics; phylogeny; ribosomal protein genes; taxonomy