Enchodelus decraemerae, Pourjam & Pedram & Vinciguerra & Robbins, 2010

Pourjam, Ebrahim, Pedram, Majid, Vinciguerra, Maria T. & Robbins, Robert T., 2010, Enchodelus decraemerae sp. n. and Enchodorus dolichurus Vinciguerra, 1976 (Dorylaimida: Nordiidae), two rare species from Iran, Russian Journal of Nematology 18 (2), pp. 191-197 : 192-196

Enchodelus decraemerae sp. n.

( Fig 1 )

Measurements: See Table 1 .

Females: Slender nematodes of medium size. Habitus after fixation curved ventrad. Body tapering towards both ends very gradually. Cuticle 2.0-3.0 µm thick in the anterior region and at mid-body and 3.0-4.0 µm anterior to anus. Lateral chords 22.5- 24.5% of corresponding body width. Lateral pores obscure. Lip region 2.8-3.0 times as wide as high, separated from the rest of body by a shallow depression; labial and cephalic papillae very slightly protruding. Amphid fovea cup-shaped, opening at level of cephalic depression and occupying 55-60% of corresponding body diameter. Odontostyle very long and slender, slightly curved, 4.3-4.7 times as long as lip width, with furcated base. Odontophore shorter than odontostyle with distinct basal flanges. Guiding ring double, with its fixed ring located at 45-51 µm from anterior end and a guiding sheath of 9-10 µm in resting position of odontostyle. Pharynx consisting of a slender but well muscled portion expanding gradually into the basal expansion, which occupies 27-30% of neck length. Pharyngeal gland nuclei located as follows: D: 75.5-80.0%, AS1 and AS2: not seen; PS: 50.0-56.5%. Cardia as long as wide (11-15 × 12-14 µm), cylindroid. Intestine simple, containing green material in almost all examined specimens. Genital system didelphic-amphidelphic, with both branches equally and well developed. Ovaries reflexed, 243-325 µm long, with maturing oocytes in almost all examined specimens. Oviduct 230-310 µm long, consisting of a slender distal part and of a well developed pars dilatata. Sphincter clearly visible between oviduct and uterus. Uterus 105-142 µm long, tripartite, consisting of a wide proximal part with distinct lumen containing mature eggs ( Fig. 1 , C) 93-105 µm long and/or elliptic sperms in dimension of 6-7 × 2 µm, a narrower intermediate region and a well developed spheroid pars dilatata distalis. Vagina extending inwards for 22.5-24.5% of corresponding body width; pars proximalis about as long as wide, 16-25×17-25 µm; pars refringens in lateral view composed of two sclerotised pieces, each in dimension of 7-9 × 11-13 µm, and pars distalis 3-4 µm thick. Vulva a transverse slit. Prerectum 2.0-3.7 times and rectum about as long as anal body width. Tail conical with rounded tip and hyaline terminal portion of 9-14 µm.

Males: General morphology similar to that of females, with posterior region more ventrally curved. Genital system diorchic, with opposed testes. The precloacal pair of papillae located at 12- 15 µm distance from cloacal opening and a series of 10-12 irregularly spaced ventromedian supplements ending at 27-45 µm distance from cloacal opening, at spicule level. Spicules dorylaimoid, massive, 3.0- 3.8 times as long as wide. Lateral guiding pieces 9- 11 µm long. Tail ventrally curved, with rounded tip and 5-11 µm thick hyaline portion.

Differential diagnosis and relationships: Enchodelus decraemerae n. sp. is an amphimictic species with medium female body length (1.49-1.72 mm) and is characterised by having rather low and slightly set off lip region, a very long odontostyle (61-67 µm), an odontophore with developed flanges, didelphic female genital apparatus, transverse vulva, vagina with well developed pars refringens, conical tail with rounded tip, males with 10-12 irregularly spaced supplements.

The new species belongs to a group of species within genus Enchodelus with odontostyle longer than 50 µm and conical tail, which Ahmad and Jairajpuri (1980) ascribed to the subgenus Nepalus . It can be compared with two known species of this group, namely E. maximus Baqri & Jairajpuri, 1974 and E. nepalensis Zullini, 1973 . The new species can be differentiated from E. maximus by its shorter body (1.49-1.72 vs 2.48-2.60 mm), smaller a value (23.0-30.5 vs 41-45), longer odontostyle (61-67 vs 54-57 µm), posteriorly located guiding ring (45-51 vs 35-36 µm from anterior end), much shorter female tail (c’ 0.9-1.3 vs about 2) and having functional males in population vs absence of males. It also can be differentiated from E. nepalensis by having shorter body (1.49-1.72 vs 2.1-2.3 mm), smaller b value (5.0-5.7 vs 6.4-6.5), shorter female tail (c’ 0.9-1.3 vs 1.7) and by having 10-12 ventromedian copulatory supplements vs 5.

Type habitat and locality. Collected from rhizosphere of mosses on rocks, mountains of Ahar village, Tehran on March 2010.

Type material. Holotype female, 10 paratype females and 10 paratype males deposited in the Nematology Laboratory of the Faculty of Agriculture, University of Tarbiat Modares, Tehran, Iran; two paratype females and two paratype males in separate slides deposited at CABI UKCentre, Surrey, UK, and USDA Nematode Collection, Beltsville, MD, USA.

Etymology. Named in honor of Prof. Wilfrida Decraemer.

Figures

Fig. 1. Enchodelus decraemerae sp. n. A: Neck region, B: Posterior genital tract, C: A part of female genital tract and a mature egg, D-F: Lip region and the position of amphid, G: Odontostyle and odontophore in detail (fresh material), H: Posterior end of male, I-L: Female tail.