Nygolaimoides albus, Asl, Ebrahim Zahedi, Niknam, Gholamreza, Jabbari, Habibeh & Pena-Santiago, Reyes, 2016

Asl, Ebrahim Zahedi, Niknam, Gholamreza, Jabbari, Habibeh & Pena-Santiago, Reyes, 2016, Two new species of the rare genus Nygolaimoides Meyl in Andrássy, 1960 (Nematoda, Dorylaimida, Thorniidae) from Iran, with a compendium of its species, Zootaxa 4150 (1), pp. 61-72 : 65-68

Nygolaimoides albus sp. n.

( Figs 3 D–F, 4 & 5)

Material examined. Twenty females, 15 males and 10 juveniles, in good condition.

except for ratios).

N. zarrinensis sp. n. N. albus sp. n.

Species Holotype Paratypes Holotype Paratypes

Character female 7 females 6 males female 20 females 15 males

820 868±80(734 – 944) 818±49(772 – 881) 770 849±89(678 – 950) 705±37.5(640 – 762) 31 32±2(29 – 35) 33±2(31 – 35) 46 46±4(40 – 51) 47±3(43 – 50) 4.6 4.5±0.3(4.2 – 5) 4.5±0.2(4.2 – 5) 4.7 4.5±0.3(4 – 5) 4±0.2(3.7 – 4.2) 73 68±7.5(63 – 84) 49±4(43 – 55) 195 181±34.5(120 – 233) 69±6.5(58 – 78) 0.8 0.8±1(0.7 – 0.9) 1±0.1(0.9 – 1.1) 0.5 0.5±0.07(0.4 – 0.7) 0.8±0.07(0.7 – 1.0) 48 47±1.3(46 – 50) - 48 48±2(43 – 51) -

region width 10.3 10±0.7(9.5 – 10.5) 10±2(10 – 12) 8.7 9±0.6(8 – 10) 9±0.5(8.0 – 9.5)

Odontostyle length 10.2 10±0.6(9.5 – 11) 10.5±0.5(10 – 11) 10 10±0.6(9.5 – 11) 10±0.7(9.0 – 10.5)

Odontophore length 15 15.5±1.0(14 – 17) 15±1.1(14 – 17) 14 13±0.9(12.5 – 15) 12±1.1(10 – 14)

Neck length 175 186±6(162 – 194) 177±13(162 – 194) 190 188±10(164 – 200) 180±0.9(169 – 194)

Pharyngeal bulb length 79 81±2.5(78 – 83) 75±5(79 – 90) 68 69±3(66 – 72) 66±4(60 – 71)

Body diameter at neck base 27 27±4.3(22 – 33) 23±1.3(22 – 25) 18.2 18.5±0.7(17 – 19) 14.5±1.4(12 – 17) mid-body 28 27±4.0(21 – 32) 25±2(22 – 28) 19 18±1(17 – 21) 15±0.9(14 – 16) anus 16 16±2.0(12 – 19) 17±0.8(16 – 18) 11.5 10±1.3(9 – 13) 12±0.8(11 – 14)

Distance vulva - anterior end 415 410±34(347 – 437) - 394 403±39(347 – 472) -

Prerectum length 28 32±8(23 – 40) - 32 30±3(29 – 35) -

Rectum length 17 16.5±2.5(12 – 20) - 11.8 12±1(11 – 13) -

length 14 13±0.5(11 – 15) 17± 1.5(14 – 18) 5 5±0.5(4.0 – 5.5) 10±0.9(9 – 12)

Spicules - - 23.5±1.7(21 – 25) - - 15±1.3(13 – 17)

Gubernaculum - - 4±0.4(3.5 – 4.5) - - 4±0.3(3.5 – 4.5) Measurements. See Table 1.

Description. Adult: Slender to very slender (a = 40–51) nematodes of small size, 0.64–0.95 mm long. Body cylindrical, tapering towards both ends, but more so towards the anterior end as the tail is short and rounded. Habitus upon fixation regularly curved ventrad, more in the posterior body region, J- or G-shaped. Two-layered cuticle, 1.0–1.5 µm thick throughout most body. Body pores indistinct. Lip region continuous with the adjacent body, one-half to three-fifths of body diameter at neck base, and with the perioral area distinctly protruding or elevated; lips (under SEM) totally fused; labial and cephalic papillae button-like, each surrounded by a ring-like, visibly elevated annulus, and with a large pore at the center; inner labial papillae visibly larger than the outer ones, situated at the margin of oral field, very close to outer labial papillae; oral field wide, consisting of five concentric incisures around the oral aperture. Amphid fovea aperture a narrow elliptical transverse slit occupying less than one-fourth of lip region diameter. Cheilostom a truncate cone 5 µm long. Odontostyle typical of the genus, approximately 1.1 times longer than lip region diameter, 6–7 times longer than wide, and with aperture occupying about two-fifths its total length. Guiding ring simple, distinct. Odontophore rod-like, lacking any differentiation, 1.3 times the odontostyle in length. Pharynx consisting of a slender but muscular anterior section gradually enlarging into the basal expansion, which is 5.8–6.2 times longer than wide, 3.8–4.6 times longer than body diameter at neck base, and occupies 37–38% of total neck length; gland nuclei very distinct in some specimens, located as follows (n = 2): DO = 66–68, DN = 71–74, S1N1 = 82–84, S1N2 = 84–85, S2N = 87–88. Pharyngointestinal junction consisting of short and rounded cardia surrounded by three moderately developed cardiac cells. Prerectum ca 3.0, rectum ca 1.2 body diameters long.

Female: Genital system didelphic-amphidelphic, with both branches well developed, 114–243 µm long or 13– 28% of total body length each. Ovaries variable in size, 41–95 µm long, often reaching and surpassing the oviductuterus junction. Oviduct 66–83 µm or 3.7–4.7 times the corresponding body diameter in length, consisting of a slender, distal portion made of prismatic cells and more than twice longer than wide, pars dilatata often containing ellipsoid sperm (2.5–4 ×1.3 µm) cells. Uterus a simple tube-like structure 21–24 µm or 1.0–1.3 times the body diameter in length and eggs not seen. Vagina extending inwards to about one-third body diameter, poorly differentiated but with its pars distalis being distinctly refringent. Vulva a short longitudinal slit. Tail very short, tip hemispheroid.

Male: Genital system diorchic, with opposite testes. In addition to the adcloacal pair, there are two (very occasionally one or three) ventromedian supplements outside the range of the spicules, the posterior one 21–27 µm from the adcloacal pair, the anterior one 14–21 µm from the posterior.

Spicules dorylaimoid, hardly curved ventrad, about 5.0 times longer than wide and 1.2 times longer than body diameter at level of the cloacal aperture; ventral side lacking a distinct hump and hollow; median piece occupying one-half of maximum spicule width, reaching the posterior tip; posterior end 2 µm wide. Lateral guiding pieces straight, tapering at the end, about 3 µm long and four times longer than wide. Gubernaculum about 2.5 µm long. Tail conoid, dorsally convex, ventrally almost straight.

Diagnosis. The new species is characterized by its slender to very slender (a = 40–51), 0.64–0.95 mm long body, lip region continuous and 8–10 µm broad, odontostyle 9.5–11.0 µm long, neck 164–200 µm long, pharyngeal expansion 66–72 µm long, V = 43–51, female tail hemispheroid (4.0–5.5 µm, c = 120–233, c’ = 0.4–0.7), male tail conoid (9.0–12.0 µm, c = 58–78, c’ = 0.7–1.0), spicules 13–17 µm long, and two (very occasionally one or three) ventromedian supplements bearing hiatus.

Relationships. The new species is easily recognizable by its very short, hemispheroid female tail and small spicules. See the key to species below for additional information.

Type locality and habitat. Iran, West Azarbaijan province, Miandoab County, Garyaghdi region (GPS Coordinates N: 36˚55ˈ45.6 ̎– E: 46˚11ˈ06.0), in soil and stump samples of an old Populus alba nursery.

Type material. Female holotype, 15 female paratypes, 10 male paratypes and seven juveniles, deposited with Nematode Collection , Nematology Lab., Faculty of Agriculture , University of Tabriz, Iran . Four female and four male paratypes with Nematode Collection , University of Jaén, Spain .

Etymology. The specific epithet refers to Populus alba as the new species was collected from the rhizosphere of this tree species.

Abbreviations: lrw—lip region wiđth; ođont.—ođontostyle length; neck—neck length; ph. bulb—pharyngeal bulb length; tail—tail length; spicul.—spicule length; ve. sup.—number

ventromeđian supplements; ref.—reference.

References: 1—Present paper. ƻ—Ahmađ et al. (ƻ003). 3— Anđrássy (1987). 4— Anđrássy (1957). 5—Anđrássy (ƻ009). 6—Mushtaq anđ Ahmađ (ƻ007). 7— Paetzolđ (1958).

The papers by Anđrássy (1987, ƻ009) are herein consiđeređ the references characterizing N. borborophilus for comparative purposes, as other đescriptions (for instance: đe Man,

1876; Thorne, 1939; Meyl, 1954; Goođey, 1963; Bongers, 1988; Chizhov, 1996) are less complete.

As Dorylaimus meyli .

Figures

FIGURE 3. A – C: Nygolaimoides zarrinensis sp. n. (SEM). A: Lip region, ventral view. B: Same, lateral view. C: In face view. D-F: Nygolaimoides albus sp. n. (SEM). D: Lip region, subventral view. E: Lip region, sublateral view. F: Caudal region, ventral view. (Scale bar = 2 µm.)