title: Calcaridorylaimus castaneae sp. n. (Nematoda, Dorylaimidae) from Bulgaria with an identification key to the species of the genus.
abstract: An unknown species belonging to the genusCalcaridorylaimus Andrássy, 1986 was collected from the litter of broadleaf forests dominated by Castanea sativa Mill. and mixed with Quercus daleshampii Ten. and Fagus sylvatica L. on Belasitsa Mountain, south-western Bulgaria. Calcaridorylaimus castaneae sp. n. is characterised by its long body (1.4-2.1 mm), lip region practically not offset, vulva transverse, short odontostyle (14.5-16 μm) and tail (75.5-110.5 μm, c=14.7-23.6; c'=2.9-4.4) in females and 38-46 μm long spicules with small spur before their distant end in males. It is most similar to C. andrassyi Ahmad & Shaheen, 2004, but differs in having transverse vs pore-like vulva and shorter spicules (38-46 μm vs 52-57 μm). An identification key to the species of the genus Calcaridorylaimus is proposed. Phylogenetic analyses were performed on 18S and D2-D3 expansion domains of 28S rRNA genes by Neighbor-Joining, Maximum Likelihood and Bayesian Inference methods. The phylograms inferred from 18S sequences showed closest relationships of the new species with some species belonging to the genus Mesodorylaimus. However, insufficient molecular data for members of both genera do not allow the phylogenetic relationships of Calcaridorylaimus and the new species described herein to be elucidated.
authors.affiliation: Faculty of Biology, University of Sofia, Bd. "Dragan Tzankov" 8, 1421 Sofia, Bulgaria.
authors.forename: Sevdan
authors.initials: S
authors.lastname: Nedelchev
authors.affiliation: Institute of Biodiversity and Ecosystem Research, Bulgarian Academy of Sciences, 2 Gagarin Street, 1113 Sofia, Bulgaria.
authors.forename: Milka
authors.initials: M
authors.lastname: Elshishka
authors.affiliation: Institute of Biodiversity and Ecosystem Research, Bulgarian Academy of Sciences, 2 Gagarin Street, 1113 Sofia, Bulgaria.
authors.forename: Stela
authors.initials: S
authors.lastname: Lazarova
authors.affiliation: Institute of Biodiversity and Ecosystem Research, Bulgarian Academy of Sciences, 2 Gagarin Street, 1113 Sofia, Bulgaria.
authors.forename: Georgi
authors.initials: G
authors.lastname: Radoslavov
authors.affiliation: Institute of Biodiversity and Ecosystem Research, Bulgarian Academy of Sciences, 2 Gagarin Street, 1113 Sofia, Bulgaria.
authors.forename: Peter
authors.initials: P
authors.lastname: Hristov
authors.affiliation: Institute of Biodiversity and Ecosystem Research, Bulgarian Academy of Sciences, 2 Gagarin Street, 1113 Sofia, Bulgaria.
authors.forename: Vlada
authors.initials: V
authors.lastname: Peneva
keywords: 18S and D2-D3 rRNA genes; Taxonomy; compendium; morphology