Morphological and molecular characterisation of Persinema enigmaticum gen. n., sp. n. (Nematoda, Dorylaimida), a new remarkable taxon from Iran

A new genus is proposed to accommodate an undescribed dorylaimid form collected in Iran. Persianema gen. n. is characterised by its three-layered cuticle, oral field appreciably sunken but its perioral area visibly protruding, odontostyle less than one-half of lip region diam. and with large aperture, guiding ring simple and always located in front of odontostyle, odontophore 4-5 times longer than odontostyle, dorsal gland nucleus (DN) very posteriorly located, female genital system di-ovarian with welldeveloped pars refringens vaginae, tail short and rounded in both sexes, spicules dorylaimid and 3-4 spaced ventromedian supplements with hiatus. Its type and only species, P. enigmaticum sp. n., is described and illustrated, including SEM observations. It is distiguished by its 1.45-2.03 mm long body, lip region offset by shallow depression and 15.5-17.5 mu m wide, odontostyle 6-7 mu m long with aperture occupying more than half of its length, neck 285-340 mu m long, pharyngeal expansion 38-43% of the total neck length, three gland cells present at pharyngo-intestinal junction, simple uterus 81-113 mu m or 1.7-3.1 body diam. long, transverse vulva (V = 50-54), tail 15-25 mu m long (c = 69-106, c' = 0.6-0.8) and spicules 38-48 mu m long. Molecular analysis of D2-D3 28S rDNA sequences revealed its closest similarity with Pungentus sequences, and an integrative comparison supports its belonging to Pungentinae.