Dorylaimellus belondirelloides Siddiqi, 1968

Kumar, Sumit & Ahmad, Wasim, 2024, Description of five new and four known species of Dorylaimellus Cobb, 1913 with perioral disc (Nematoda: Belondiroidea) from the Western Ghats of India, European Journal of Taxonomy 925 (1), pp. 1-45 : 11-12

Dorylaimellus belondirelloides Siddiqi, 1968

Fig. 4 , Table 3

Dorylaimellus belondirelloides Siddiqi, 1964: 250–253 .

Material examined

INDIA • 21 ♀♀; Karnataka State, Shimoga district, village Dummalli ; 13°55′53.65″ N, 75°34′4.48″ E; 10–15 cm deep; 26 Oct. 2018; soil samples collected from around the roots of plants (unidentified); slide reference number AMU/ZD/NC / Dorylaimellus belondirelloides /1–10 .

Description

Female

Body slightly curved ventrad upon fixation, 0.8–0.9 mm long. Cuticle with distinct transverse striations, about 1 µm at anterior and mid-body, 2 µm on tail tip. Lateral chords 4–6 µm or about one-fifth to one-third (20–30%) of body diameter at mid-body, glandular bodies indistinct. Lateral, dorsal and ventral body pores indistinct. Lip region cap-like, offset by constriction, 2.0–2.3 times as wide as high, or about two-sevenths to two-fifths (28–37%) of body diameter at neck base. Lips rounded, amalgamated; perioral disc distinct. Cheilostome a truncate cone with refractive walls and distinct cuticularized pieces near oral aperture. Amphids fovea cup-shaped, their aperture occupying about 0.6–0.7 times lip region diameter, fusus almost at level of odontophore base. Guiding ring single, weakly developed, at 0.7–1.0 times lip region diameter from anterior end. Odontostyle robust, slightly fusiform, 5–6 times as long as wide, or about 0.8–1.0 times as long as lip region diameter, its aperture occupying about one-third of length. Odontophore with weakly developed basal flanges, 1.7–2.2 times as long as odontostyle. Nerve ring encircling anterior slender part of pharynx at about 34–40% of neck length from anterior end. Pharyngeal expansion gradual; expanded part 5.9–8.4 times as long as wide, or about 3.7–4.9 times body diameter at neck base, occupying about 37–47% of total neck length, enclosed in thick sheath of dextrally spiral muscles. Anterior portion of expanded part of pharynx with prominent small globules, rarely indistinct. Only dorsal pharyngeal gland and orifice visible: DO = 57–65; DN = 59–66; DO–DN =1.0–2.0 (n = 8). Cardia short, elongate-rounded, 1.0–1.6 times as long as wide, occupying about one-fourth to two-fifths (24–42%) of corresponding body diameter.

Genital system amphidelphic, both branches almost equally developed. Ovaries reflexed, not reaching oviduct-uterus junction, measuring 21–45 µm (anterior) and 21–56 µm (posterior) long, with squamous shaped oocytes arranged in single row except near tip. Oviduct joining ovary subterminally, anterior 22–40 µm or 1.1–1.9 times, and posterior 20–37 µm or 1.0–1.8 times as long as mid-body diameter, consisting of a slender part with prismatic cells and wide pars dilatata with distinct lumen; oviduct-uterus junction marked with sphincter. Uterus small tube, anterior 8–12 µm or 0.4–0.6 times, and posterior 7–13 µm or 0.3–0.7 times as long as corresponding body diameter; sperms not observed. Vulva longitudinal. Vagina extending inwards about two-fifths to one-half (40–50%) of corresponding body diameter; pars proximalis vaginae longer than wide, 5–7 ×4.0 µm, with convex walls; pars refringens absent; pars distalis 2–3 µm. Prerectum 7.2–10.6 and rectum 1.4–2.1 times as long as anal body diameter. Tail cylindroid-subclavate with thick cuticle at terminus. Caudal pores two on each side.

Male

Not found.

Remarks

Siddiqi (1968) described D. belondirelloides from around the roots of Lagenaria siceraria plants (Bottle gourd) from Assam, India, and differentiated it from D. caffrae Kruger, 1965 and D. projectus Heyns, 1962 in having a comparatively anterior located vulva, a longer prerectum and a longer tail. The present population conforms well with the original description except for having a comparatively longer and slender body (L= 0.8–0.9 vs 0.73–0.76 mm; a = 40.4–47 vs 37–40), a cuticle with distinct transverse striations (vs fine transverse striation and hypodermis coarsely striated), in the nature of the odontostyle (slightly fusiform vs linear), in the presence of small globules in the anterior region of the expanded part of the pharynx (vs absent) and a longer tail (c= 16–19 vs 21–23 or c′ = 4–5 vs 3).

Figures

Fig. 4. Dorylaimellus belondirelloides Siddiqi, 1968 (LM photographs).A.Anterior region, arrow indicating fusiform thickening. B. Arrow indicating basal flanges. C. Anterior end showing amphid. D. Expanded part of pharynx, arrows indicating small globules. E. Vulva region. F. Female genital system. G. Posterior region. Scale bars: A–G= 10 µm.