Two rare species of the family Tylenchidae are described and illustrated based on morphological and morphometric characters. Scanning electron microscope (SEM) studies provided details of anterior end structures, helpful in generic identification of the studied populations. Discotylenchus biannulatus n. sp. is characterized by its dorso-ventrally flattened smooth cephalic region having two proximal annuli and a rectangular perioral disc, short longitudinal amphidial slits, lateral field with four incisures, stylet 9–10 μm long, with the conus shorter than half the total stylet length and with posteriorly directed knobs, well-developed median bulb, mono-prodelphic reproductive system with rounded empty spermatheca and short postvulval uterine sac (PUS), and filiform tail with pointed end. It is compared with other species of Discotylenchus having four lines in the lateral field. The Iranian population of Labrys chinensis is characterized by its long and slender (a = 45.2–57.2) body, smooth rounded cephalic region and an offset disc-like apical labial plate, short longitudinal lateral amphidial slits, lateral field with two incisures, moderately developed stylet with the conus less than half the total length and posteriorly directed knobs, median bulb fusiform with distinct but weak valve, gradually joining the isthmus, vulva at 57.2–59.1% with small flaps, elongate conoid tail, uniformly and slightly narrowing toward end with broadly rounded terminus and rare males. The minor morphological differences of the recovered population with the type population are discussed.
Álvarez-Ortega, S. & Peña-Santiago, R. (2016) Aporcella charidemiensis sp. n. (Dorylaimida: Aporcelaimidae) from the southern Iberian Peninsula, with comments on the phylogeny of the genus. Nematology, 18, 811–821.
Brzeski, M.W. (1985) Four new species of Tylenchidae (Nematoda). Nematologica, 31, 424–432.
De Grisse, A.T. (1969) Redescription et modification de quelques techniques utilisées dans l’étude des nematodes phytoparasitaires. Mededelingen Faculteit Landbouwwetenschappen, 34, 351–369.
Geraert, E. (2008) The Tylenchidae of the World. Identification of the family Tylenchidae (Nematoda). Akademia Press, Ghent, 540 pp.
Ghaderi, R., Kashi, L. & Karegar, A. (2012) The nematodes of Iran (based on the published reports until 2011). Agricultural Extension and Education Publication, Tehran, 371 pp.
Ghaemi, R., Pourjam, E., Atighi, M.R., Pedram, M. & Karssen, G. (2012) First record of the genus Discotylenchus Siddiqi, 1980 (Nematoda: Tylenchidae) from Iran, with description of one new and data on two known species. Zootaxa, 3493, 72–82.
Mehrabian, F., Azizi, K., Bazgir, E. & Darvishnia, M. (2017) Morphological and molecular characterisation of Discotylenchus lorestanensis sp. n. (Nematoda: Tylenchidae) from Iran. Zootaxa, 4290 (1), 167–176.
Örley, L. (1880) Az anguillulidak maganrajza. A kir.m. termeszettudom. Tersulat altal a bugatdijjal jutalmazott palyamii. Természettudományi Füzetek, 4, 16–50.
Panahandeh, Y., Pourjam, E. & Pedram, M. (2014) Four new tylenchids (Tylenchina: Nematoda) for nematode fauna of Iran. Journal of Agricultural Science and Technology, 16, 461–477.
Panahandeh, Y., Pourjam, E., Aliramaji, F., Atighi, M. R. & Pedram, M. (2015a) First record of three known species of the family Tylenchidae Örley, 1880 (Nematoda: Tylenchina) from Iran with new morphological and molecular data. Journal of Agricultural Science and Technology, 17, 1903–1918.
Panahandeh, Y., Pourjam, E., Aliramaji, F. & Pedram, M. (2015b) Data on some members of the family Tylenchidae (Nematoda: Tylenchina) from Iran. Biologia, 70, 1376–1387.
Panahandeh, Y., Pourjam, E. & Pedram, M. (2016) Data on some species of the genus Coslenchus Siddiqi, 1978. Journal of Nematology, 48, 268–279.
Panahandeh, Y., Pourjam, E., Roshan-bakhsk, A. & Pedram, M. (2018) First record of the genus Sakia Khan, 1964 (Nematoda:Tylenchidae) from Iran, with proposal of Sakia arboris n. sp. Nematology. [in press]
Pedram, M., Soleymanzadeh, M., Pourjam, E. & Mobasseri, M. (2018). Observations on Malenchus geraerti n. sp. (Rhabditida: Tylenchidae), a morphological and molecular phylogenetic study. Zootaxa, 4369 (3), 406–418.
Qing, X. & Bert, W. (2018) 3D printing in zoological systematics: Integrative taxonomy of Labrys chinensis gen. nov., sp. nov. (Nematoda: Tylenchomorpha). Journal of Zoological Systematics and Evolutionary Research, 56, 35–47.
Siddiqi, M.R. (1980) Two new nematode genera, Safianema (Anguinidae) and Discotylenchus (Tylenchidae), with descriptions of three new species. Proceedings of the Helminthological Society of Washington, 47, 85–94.
Soleymanzadeh, M., Pedram, M., Pourjam, E. & Álvarez-Ortega, S. (2016) Description of Lelenchus brevislitus n. sp. (Nematoda: Tylenchidae), an example of a cryptic species from Iran and its phylogenetic relationships with other species in the family. Nematology, 18, 987–998.
Whitehead, A.G. & Hemming, J.R. (1965) A comparison of some quantitative methods for extracting small vermiform nematodes from soil. Annals of Applied Biology, 55, 25–38.
Yaghoubi, A., Pourjam, E., Álvarez-Ortega, S. Liébanas, G., Atighi, M.R. & Pedram, M. (2016) Discopersicus n. gen., a New Member of the Family Tylenchidae Örley, 1880 with Detailed SEM Study on Two Known Species of the Genus Discotylenchus Siddiqi, 1980 (Nematoda; Tylenchidae) from Iran. Journal of Nematology, 48, 214–221.