عنوان مقاله [English]
Two populations of Paurodontella longicaudata n. sp. were recovered from natural forests of Golestan province, northern Iran. The new species was characterized with 405-579 μm long females having 7.5-8.4 μm long stylet with asymmetrical knobs, four lines in the lateral fields, basal pharyngeal bulb with long stem-like extension projecting into the lumen of intestine, small post-vulval uterine sac (PUS) 4.0-4.8 μm long, elongate conoid tail with 84-96 μm length and finely rounded tip. Males were not recovered, but spheroid sperm cells were observed inside female genital tract. Morphological differences between the new species and seven known species of the genus, mainly having conical tail, namely P. asymmetrica, P. balochistanica, P. gilanica, P. minuta, P. myceliophaga, P. parapitica and P. persica, were discussed. The new species is the morphologically closest species to P. gilanica, forms a tentative cryptic species showing remarkable nucleotide differences in two small and large subunit ribosomal RNA gene markers. In Bayesian phylogenetic analyses using the SSU and LSU, it formed a clade with Paurodontella gilanica. This is new evidence on cryptic speciation in nematodes indicating "apparently minor" morphological differences which corroborated with the remarkable molecular differences.