Description of Rotylenchus urmiaensis n. sp. (Nematoda: Hoplolaimidae) from North-western Iran with a molecular phylogeny of the genus.

A new bisexual species of Rotylenchus from North-western Iran is described and illustrated based on morphological, morphometric and molecular studies. Rotylenchus urmiaensis n. sp. is characterised by having a truncate lip region with irregular longitudinal striation, lateral field areolated only in pharynx region, stylet length 34-40 µm, vulva positioned at 53-61%, and female tail conoid-rounded to dorsally convex-conoid with 5-10 annuli. Rotylenchus urmiaensis n. sp. appears to be similar to R. striaticeps, from which it may be differentiated morphologically by a slightly shorter body length (870-1269 vs 1000-1723 µm), shorter stylet (34-40 vs 39-50 µm), female tail shape (conoid-rounded to dorsally convex-conoid vs rounded), frequency of males (rare vs common as abundant as females), shorter spicules (39-43 vs 41-50 µm) and phasmid position (varying from three annuli anterior or three annuli posterior to anus vs at level to seven annuli anterior to anus), and molecularly. The results of phylogenetic analyses based on sequences of D2-D3 expansion region of 28S, ITS-rDNA, 18S rDNA, and the partial cytochrome c oxidase subunit 1 (coxI) mtDNA, confirmed the species differentiation and the close molecular relationship between R. urmiaensis n. sp. and R. striaticeps. [ABSTRACT FROM AUTHOR]