Eudorylaimus caudatus Mushtaq & Ahmad 2006
Creators: name: Liang, Siwei
name: Islam, Md Niraul
name: Du, Xiaofang
name: Li, Ying bin
name: Liang, Wenju
name: Ahmad, Wasim
name: Zhang, Xiaoke
name: Mahamood, Mohammad
name: Alhewairini, Saleh
name: Li, Qi
Publisher: name: Zenodo
Year: 2025
Subjects: Biodiversity
Taxonomy
Animalia
Nematoda
Enoplea
Dorylaimida
Dorylaimidae
Eudorylaimus
Eudorylaimus caudatus

description: Eudorylaimus caudatus Mushtaq & Ahmad, 2006
Fig. 3, Table 2
Eudorylaimus caudatus Mushtaq and & Ahmad, 2006: 20–24, figs 6, 7.
Type specimens.
Holotype • India (slide no. E. caudatus 1) – Kashmir, Verinag; soil samples collected from around the roots of plants (unidentified); Paratypes • same data as holotype (slide no. E. caudatus 2–4). Not examined.
Material examined.
China • 5 ♀ / 1 ♂ (IAE / NC / EU / E. caudatus / 1–4), Liaoning Province, Huludao City, Xingcheng, 40.640209°N, 120.729788°E; soil samples collected from around the roots of Black locust (Robinia pseudoacacia L.) • 2 ♀ (IAE / NC / EU / E. caudatus / 5), Liaoning Province, Jinzhou City, Linghai; 40.974492°N, 121.101014°E; soil samples collected from around the roots of grasses (unidentified).
Description.
Female. Slender nematodes of small-size, 0.88–0.93 mm long body; curved ventrally or open C-shaped upon fixation. Body cylindrical, tapering gradually towards both extremities but more so towards the posterior region. Cuticle with two distinct layers, 1.5–2.0 μm thick at the anterior region, 2.0–3.5 μm at midbody, and 3.0–4.0 μm on tail. Outer cuticle smooth or finely striated, inner layer thin with fine transverse striations. Lateral, dorsal and ventral body pores indistinct. Lateral chords 9–10 μm wide at midbody, occupying ~ 1 / 3 (27–32 %) of the corresponding body diameter. Lip region offset from the body by constriction, 2.0–2.3 times as wide as high or ~ 1 / 3 (33–37 %) of the body diameter at the pharyngeal base. Lips angular, separated; labial papillae slightly raised from labial contour. Amphidial fovea cup-shaped, aperture slit-like, 5.5–6.0 μm wide or occupying ~ 1 / 2 (50–54 %) of lip region diameter. Cheilostom a truncate cone. Odontostyle typical dorylaimoid, 5.0–6.5 times as long as wide, 1.1–1.2 times the lip region diameter long or 1.3–1.5 % of total body length, its aperture 5.0–6.0 μm or ~ 2 / 5 (38–44 %) of its length. Odontophore linear, rod-like, 1.2–1.4 times the odontostyle length. Guiding ring simple, at 0.59–0.66 times lip region diameter from anterior end. Pharynx consisting of a weakly muscular anterior part, expanding gradually into a cylindroid part, occupying ~ 40–43 % of the total neck length; expanded part of pharynx 5.6–7.1 times as long as wide, 3.5–4.2 times the body diameter at neck base. Pharyngeal gland nuclei and their orifices are located as follows: DO = 60.9–64.1, DN = 64.1–66.8, DO – DN = 2.4–4.1, S 1 N 1 = 76.1–78.3, S 1 N 2 = 80.0–82.5, S 2 N = 90.0–91.7, S 2 O = 91.1–92.7. Nerve ring encircling the pharynx at 37–40 % of the neck length from the anterior end. Cardia rounded to conoid, ~ 2 / 5 to 1 / 2 (37–50 %) of the corresponding body diameter long. Genital system didelphic-amphidelphic; both the genital branches almost equally developed. Anterior genital branch 11.4–15.1 % and the posterior genital branch 10.3–13.5 % of body length. Ovaries reflexed, not reaching the oviduct-uterus junction; measuring 48–87 μm or 1.6–1.9 (anterior) and 49–65 μm or 1.6–1.8 (posterior) times the corresponding body diameter long; oocytes arranged in a single row except near the distal end. Oviduct joining the ovaries sub-terminally, measuring 48–65 μm or 1.6–1.9 (anterior) and 45–82 μm or 1.3–1.8 (posterior) times the corresponding body diameter long, consists of a slender distal portion and a well-developed pars dilatata. Oviduct-uterus junction marked by a well-developed sphincter. Uterus long, measuring 48–58 μm or 1.3–1.8 (anterior) and 40–57 μm or 1.2–1.8 (posterior) times the corresponding body diameter long, tripartite, consists of a well-developed muscular proximal part, a short slender median part, and a short, somewhat spheroid distal part. Vagina cylindrical, extending inwards, 14–16 μm or ~ 2 / 5 to 1 / 2 (43–47 %) of midbody diameter; pars proximalis 9.5–12 × 7.0–9.0 μm, with somewhat sigmoid wall encircled by circular muscles; pars refringens with two small triangular sclerotized pieces, measuring 3–4 × 2–3 μm with the combined width 5–6 μm; pars distalis 1.5–2.0 μm. Vulva a transverse slit. Prerectum 1.6–2.2 and rectum 0.9–1.1 anal body diameter long. Tail short conoid, ventrally arcuate with clavate to rounded tip, 1.3–1.5 times anal body diameter long, with characteristic series of thickening (blisters) on ventral side; hyaline portion of tail always perceptible, ~ 1 / 6 to 1 / 3 anal body diameter long with a pair of caudal pores on dorsal side.
Male. General morphology similar to that of female except for the posterior region being more ventrally curved. Genital system diorchic, testes opposed, sperm cells spindle-shaped, 4.0–5.0 μm long. In addition to the adcloacal pair, situated at 7 µm from the cloacal aperture, there are five irregularly spaced ventromedian supplements, first ventromedian supplement located beyond the range of spicules, 33 μm from the adcloacal pair. Spicules typically dorylaimoid, curved ventrad, relatively robust, 4.9 times as long as wide and 1.6 times as long as body diameter at the level of cloacal aperture, dorsal contour regularly convex, ventral contour bearing a moderately developed hump, curvature of 125 °. Head occupying 15.6 % of total spicule’s length, its dorsal side longer than ventral side, both sides slightly curved. Median piece 8.7 times as long as wide or occupying ~ 46 % of the spicules’ maximum width, reaching the spicule tip, posterior end 2.5 μm wide. Lateral guiding pieces distinct, and rod-like with bifid distal tip, ~ 5.0 times as long as wide or ~ 1 / 3 of the spicules length. Prerectum 3.2 and rectum 1.9 cloacal body diameter long. Tail similar to female, short conoid, ventrally arcuate with clavate to rounded tip, 1.8 times cloacal body diameter long, with characteristic series of thickening (blisters) on ventral side; hyaline portion of tail always perceptible, 1 / 3 anal body diameter long with a pair of caudal pores on dorsal side.
Remarks.
Mushtaq and Ahmad (2006) described this species from Verinag, Jammu and Kashmir, India. They named this species E. caudatus because of the presence of ventral thickenings (blisters) on the tail. In the present study, we have recorded seven females and one male of E. caudatus from the Liaoning Province of China. The morphology and morphometric values are similar to the type population except in having slightly longer body size (L = 0.88–0.93 vs 0.79–0.85 mm); longer pharynx (282–291 vs 210–245 μm) and its expansion (115–122 vs 99–113 μm), slightly lower b value (3.1–3.3 vs 3.4–3.7); slightly posteriorly located nerve ring (105–1117 vs 77–87 μm); slightly shorter rectum (19–24 vs 24.5–26.5 μm) and presence of male (vs male absent). These variations should be considered as intraspecific as well as geographical variability. The male is reported here for the first time for this species. This species is recorded here for the first time from China.
description: Published as part of Liang, Siwei, Islam, Md Niraul, Du, Xiaofang, Li, Ying bin, Liang, Wenju, Ahmad, Wasim, Zhang, Xiaoke, Mahamood, Mohammad, Alhewairini, Saleh & Li, Qi, 2025, Two new and two known species of the genus Eudorylaimus Andrássy, 1959 (Nematoda, Dorylaimoidea, Qudsianematidae) from Northeast China, pp. 41-74 in ZooKeys 1238 on pages 41-74, DOI: 10.3897/zookeys.1238.138550