Description of a New Anguinid Nematode, Nothotylenchus phoenixae n. sp. (Nematoda: Anguinidae) Associated with Palm Date Trees and Its Phylogenetic Relations within the Family Anguinidae.

Nothotylenchus phoenixae n. sp. is described and illustrated from soil samples of palm trees in Kermanshah Province, western Iran. The new species is characterized by a body length of 784 (663 to 925) μm in females and 677 to 715 μm in males; a delicate stylet 6 (5 to 7) μm long and six lines in the lateral field; median bulb of pharynx fusiform, nonmuscular, and nonvalvate; isthmus elongate, slender ending to a pyriform basal pharyngeal bulb not overlapping intestine; postvulval uterine sac well developed, 15 (14 to 17) μm long, female tail elongate-conoid with pointed terminus; and male with adanal bursa and spicules 21 to 22 μm long (n = 2). The new species comes close in morphology and morphometrics to five known species of the genus, namely N. affinis, N. hexaglyphus, N. persicus, N. taylori, and N. uniformis. Molecular analyses of the partial 18S, D2/D3 expansion segments of the partial 28S and internal transcribed spacer (ITS) revealed this as a new species. The sequences of the partial 18S and 28S D2/D3 regions confirmed the close phylogenetic relationship between N. phoenixae n. sp. and other anguinids, but Nothotylenchus is clearly separated from Ditylenchus species and should be considered as a valid genus.