Neodolichodorus hainaensis, Xu & Xie & Li, 2012

Xu, Chun-Ling, Xie, Hui & Li, Yu, 2012, Description of Neodolichodorus hainanensis n. sp. (Nematoda: Dolichodoridae) from rhizosphere soil of golf turf in China, Zootaxa 3236 (1), pp. 62-68 : 63-67

Description of Neodolichodorus hainaensis n. sp.

( Figs 1–3 )

Measurements. Table 1.

Description. Female. Body arcuate ventrally, C-shaped, cylindrical over most of its length, tapering from pharyngeal glands to head and from anus to tail tip. Cuticle with deep transverse striae forming very distinct annuli, about 1.0–1.2 µm wide from first to second striae behind lip region, 1.5–1.8 µm wide for second annuli, then becoming gradually coarser, broadest at 4.5–6.0 µm wide in pharyngeal region, then becoming abruptly finer after pharyngeal gland bulb toward distal end of body, about 3.0–3.5 µm wide (except some annuli 2.6–3.0 µm wide at vulval region and 3.5–4.0 µm wide at tail region). Lateral field marked by 4 incisures for most of length, about 12– 13 µm in width, one third body width near middle, arising from fifth to ninth annuli behind lip region with 2 incisures forming one band crossed by external transverse striae, with 3 incisures from 14th to 18th annuli forming areolated bands, and with 4 incisures at level of knobs of stylet, ending on tail; forming 3 bands crossed regularly by every second external transverse stria but middle band partly or wholly irregularly crossed. Cephalic region hemispherical, 4 µm high, 3 µm wide, with small oral disc; bearing 7–8 striae, offset by a constriction 0.8–1.2 µm deep, divided into 4 lobes by obvious shallow indentations, cephalic framework heavily sclerotized. Stylet elongate, straight or slightly bent ventrally, with elongated tubular stylet guide, conus obviously longer than shaft, 57–64% of total stylet length, basal knobs sloping posteriorly, 3 µm high and 6 µm wide. Hemizonid between isthmus and gland, 3 annuli wide in lateral view, 7–11 annuli (about 34 µm) posterior to excretory pore. Hemizonion visible. Precorpus cylindrical with convoluted lumen, 33–53 µm long, median bulb large, oval, with sclerotized hemispheroid valves (5–6 µm wide, 7–9 µm long), followed by narrower isthmus (7 µm wide, 16–38 µm long) encircled by nerve ring; and elongate pyriform gland bulb (18 µm wide and 44–60 µm long), bearing one subdorsal nucleus and two subventral nuclei. Pharyngeal-intestinal valve 24.5–27 µm wide and 17 µm long in lateral view. Reproductive system didelphic, ovaries outstretched. Vulva epiptygma absent, vulva a transverse slit, 0.8–1.0 µm high, depressed, occupying 37–44% of vulval body diameter; vagina having heavy sclerotisation in the form of a ‘yellowish mass’, 6–7 µm wide and 3 µm high, about two fifths body-width in lateral view. Spermatheca subcylindrical, containing sperm. Intestine 20–30 µm long, post-rectal intestinal sac absent, intestinal fasciculi absent. Tail with 9–10 annuli, subconoid, tail terminus rounded with 3–5 striae. Phasmid dot-like, adanal.

Male. Similar to female except for reproductive system, associated structures and tail. Paired spicules slightly curved ventrally, well developed, without distal flanges, slightly protrusible. Gubernaculum strong, with an almost straight corpus, slightly protruding from cloaca with spicules when fixed. Tail short, pointed in lateral view, enveloped by bursa; trilobed with two large lateral lobes and a small terminal lobe with a bifid extremity in ventral view, lateral lobes round, prominently striated externally in lateral view.

Type locality and habitat. Rhizosphere soil of turf from golf course in Xiuying district , Haikou city, Hainan province, China (20º1’50.35’’N, 111º14’42.54’’E). Collected by Hui Xie and Mu-tao Wu on 7 June 2001 .

Type material. Holotype: one female on slide HNN1 . Allotype: one male on slide HNN1 . Paratypes: for adult females, two on slide HNN2 , one on slide HNN3 , five on slide HNN5 ; for adult males, three on slide HNN2 , one on slide HNN3 , four on slide HNN4 and one on slide HNN5 . All specimens except HNN2 are deposited in Laboratory of Plant Nematology , South China Agricultural University, Guangzhou, P. R . China, and HNN 2 specimen is deposited in Nematode Collection at University of California, Riverside, California, USA ( UCRNC) .

Etymology. The species is named after the geographic location, Hainan province.

Diagnosis. Neodolichodorus hainanensis n. sp. is characterized by having a conspicuous offset head with 6–7 striae, divided into 4 lobes; stylet a little shorter (82–100 µm) than most species of Neodolichodorus ; lateral field with four incisures, areolated, outer lateral field regularly crossed by every two external striae at most body length, and inner lateral field partly or wholly irregularly crossed by extending external striae; subconoid tail with rounded terminus; gubernaculum and spicule slightly protruding from cloaca, middle bursa lobe small with a bifid extremity in ventral view.

Figures

FIGURE 1. Neodolichodorus hainanensis n. sp. Female. A: Head region. B: Posterior part of pharynx. C: Head region with incisures and annuli. D: Lateral field. E, H: Vulva region, lateral and sub-ventral views; F: Anterior with pharynx; G, L, M: Tails. I, J. Lip region. Male. K: Lip region. N: Spicule and gubernaculum. O, P, R: Tails in lateral view. Q: Tail in ventral view.

FIGURE 2. Digital photomicrographs of N. hainanensis n. sp. A. Whole female; B. Female cephalic region; C. Vulva region in lateral view; D. Vulva region in ventral view. E. Female anterior part; F. Whole male; G. Male anterior part; H. Incisures in median bulb region; I, J. Female tails in lateral view; K. Incisures on female tail in lateral view, the arrow shows phasmid; L. Male tail in lateral view; M, N. Male tails in ventral view.(Scale bars: A, F=70 µm; B=10µm; C,D=25 µm; E, I–K, N= 20 µm; F=120 µm; G, H, L, M=30 µm; H=25 µm).

FIGURE 3. SEM micrographs of N. hainanensis n. sp. A, B. Lip region of female in lateral view; C. Lateral field; D, E. Male tails in lateral view.