Dorylaimellus (Jamilius) salvus Siddiqi, 1968

Ahmad, Wasim & Naz, Tabbasam, 2012, Four new and six known species of the genus Dorylaimellus Cobb, 1913 (Nematoda: Belondiridae) from India, Journal of Natural History 46 (45 - 46), pp. 2787-2828 : 2819-2822

Dorylaimellus (Jamilius) salvus Siddiqi, 1968

( Figures 16 , 17 ; Table 9)

Description

Female. Body slightly curved ventrad upon fixation, tapering towards both extremities. Cuticle with fine transverse striations, 1.0– 1.5 µm thick at mid body and 1.5 µm on tail. Lateral chords about one-quarter as wide as body width at mid body with indistinct glandular organs. Lateral, dorsal and ventral body pores indistinct. Lip region distinctly offset, about twice as wide as high or about one-quarter to onethird as wide as body width at neck base, with a distinct peri-oral disc and well developed papillae. Cheilostome a truncate cone with refractive walls and distinct cuticularized plates around oral aperture. Amphids cup-shaped, their aperture about 0.8–1.0 times as wide as lip region width. Odontostyle about 0.8–1.0 times lip region width long, its aperture about one-third of its length. Odontophore rod-like with basal flanges, 1.6–2.1 times the odontostyle length. Nerve ring at 38–40% of neck length from anterior end. Pharyngeal expansion abrupt; expanded part occupying about 33–38% of total neck length, enclosed in a thick sheath of dextrally spiral muscles. Cardia short, rounded, slightly more than half to one-third of corresponding body width long. Genital system amphidelphic; both the sexual branches almost equally developed. Ovaries reflexed, measuring 55–60 µm (anterior) and 58–65 µm (posterior), with oocytes arranged in a single row except near tip. Oviduct joining ovary subterminally, measuring 65–70 µm (anterior) and 55–60 µm (posterior) long; consisting of a long slender part with prismatic cells and a slightly wider pars dilatata with wide lumen and filled with spermatozoa. Weakly developed sphincter present at oviduct–uterus junction. Uterus an undifferentiated simple tube, measuring 75–80 µm (anterior) and 55–60 µm (posterior). Spermatozoa present in uterus. Vulva a large pore. Vagina extending inward, about half of corresponding body width; pars proximalis vaginae 13–15 µm with convex walls; pars refringens vaginae absent; pars distalis vaginae 3–4 µm with rounded walls. Prerectum about 7.3 times anal body width long. –Rectum about as long as anal body width. Tail long filiform, 8–9 times anal body width long, hyaline part about 15–18%. Caudal pores two on each side.

Male. Similar to female in general morphology, except the posterior region being more curved ventrad because of the presence of copulatory muscles. Supplements, an adcloacal pair and five to seven ventromedians. Spicules dorylaimoid, cylindrical, about 1.5–1.6 times cloacal body width long. Lateral guiding pieces about one-third of spicule length. Prerectum 7.1–7.3 times cloacal body width long. Tail similar to female, long filiform, 5.7–8.4 times cloacal body width long, hyaline part about 13–16%. Caudal pores two on each side.

Habitat and locality

Soil from the forest area of Belsiri canal, Bomdilla, Arunachal Pradesh; 27 ◦ 15 ′ 0 ′′ N; 92 ◦ 25 ′ 0 ′′ E; altitude 2217 m above sea level.

Remarks

Siddiqi (1968) described this species from Assam, India. In having peri-oral disc, porelike vulva and elongate attenuated tail it fits under the subgenus Jamilius ( Siddiqi, 1983) Jairajpuri and Ahmad, 1992 . The present population confirms well with the original description except for having slightly longer body (L = 1.3–1.5 vs 1.1–1.2 mm) and longer prerectum (7.1–7.3 vs 5–6 times anal body width). In the presence of long filiform tail, this species has close resemblance with D. (J). filamentosus ( Siddiqi, 1983) Jairajpuri and Ahmad, 1992 but differs in having slightly shorter odontostyle (6–7 vs 7.5–8.5 µm), comparatively shorter tail (c = 9.1–9.4 vs 5.4–6.6; c′ = 8.0–9.4 vs 11–14), longer prerectum (7.1–7.3 vs 4–5 times anal body width long) and in the presence of males (vs absence).

Figures

Figure 16. Dorylaimellus (Jamilius) salvus Siddiqi, 1968. (A) Entire female, (B) entire male, (C) anterior region, (D) anterior end showing amphid, (E) pharyngeal region, (F) female genital system, (G) vulval region, (H) female posterior region, (I) male posterior region.

Figure 17. Dorylaimellus (Jamilius) salvus Siddiqi, 1968. (A) Anterior region, (B) anterior end showing amphid, (C) expanded part of pharynx, (D) vulval region, (E) female tail tip, (F) male posterior region showing spicules. Scale bars: A–F = 20 µm.