Dorylaimellus (Dorylaimellus) parindicus, Ahmad & Naz, 2012

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 : 2793-2797

Dorylaimellus (Dorylaimellus) parindicus sp. nov.

( Figures 3 and 4 ; Table 2)

Description

Female. Body curved ventrad upon fixation, tapering towards both extremities. Cuticle finely striated, inner cuticle with more distinct striations, 1.0– 1.5 µm thick at mid body and 1.5–2.0 µm on tail. Lateral chords about two-thirds as wide as body width at mid body with distinct glandular organs. Lateral and dorsal body pores indistinct. Ventral pores distinct along entire body length, posterior ones more prominent, about 79–82 in number; 9–11 in the pharyngeal region, 26–30 from base of pharynx to vulva, 38–42 from vulva to anus and one in the caudal region. Lip region rounded, offset, about twice as wide as high or about one-third of body width at neck base. Amphids cup-shaped, their aperture about 0.8–0.9 times as wide as lip region width. Cheilostome a truncate cone, with refractive walls and well-developed cuticularized plates near oral aperture. Odontostyle robust, relatively thick walled, about 0.7–0.8 times lip region width long, its aperture about one-third of its length. Guiding ring at 0.8–0.9 times lip region width from anterior end. Odontophore rod-like, poorly flanged, about twice the odontostyle length. Nerve ring at 45–50% of neck length from anterior end. Pharyngeal expansion gradual; expanded part occupying about 38–45% of total neck length, enclosed in a thick sheath of dextrally spiral muscles. Cardia elongate-rounded to conoid, about one-third of the corresponding body width long. Genital system amphidelphic; both the sexual branches almost equally developed. Ovaries reflexed, measuring 40–85 µm (anterior) and 40–70 µm (posterior) with oocytes arranged in a single row except near tip. Oviduct joining ovary subterminally, measuring 50–130 µm (anterior) and 50–60 µm (posterior) long, consisting of a long slender part with prismatic cells and a slightly wider pars dilatata with wide lumen. Sphincter present at oviduct–uterus junction. Uterus measuring 30–65 µm (anterior) and 30–60 µm (posterior). Vulva longitudinal. Vagina extending inward, about half of the corresponding body width; pars proximalis vaginae 10–12 µm long with convex walls, encircled by circular muscles; pars refringens vaginae absent; pars distalis vaginae 3–4 µm with rounded walls. Prerectum 3.3–5.5 times anal body width long. Rectum about as long as anal body width. Tail elongate, slightly dorsally convex with obtusely rounded terminus, about 1.3–1.8 times anal body width long. Caudal pores two on each side.

Male. Not found.

Type habitat and locality

Soil from the paddy field, Nagar Basti, Tensukia , Upper Assam; 27 ◦ 30 ′ 0 ′′ N, 95 ◦ 22 ′ 0 ′′ E, altitude 116 m above sea level .

Type specimens

Holotype female on slide Dorylaimellus (D.) parindicus sp. nov. / 1; paratype females on slides Dorylaimellus (D.) parindicus sp. nov. / 2–3; deposited with the nematode collection of the Department of Zoology, Aligarh Muslim University, India. Two paratype females deposited with the nematode collection of the Universidad de Jaén, Spain.

Diagnosis and relationship

Dorylaimellus (D.) parindicus sp. nov. is characterized by having 1.2–1.5 mm long body; ventral body pores distinct along entire body length, posterior ones more prominent, about 79–82 in number; 9–11 in the pharyngeal region, 26–30 from base of pharynx to vulva, 38–42 from vulva to anus and one in the caudal region; lip region rounded, offset; odontostyle robust, relatively thick walled, 5–6 µm long; odontophore 12–µm long with poorly developed flanges; pharyngeal bulb 38–45% of neck length; longitudinal vulva; amphidelphic female genital system and short conoid tail with rounded terminus.

The new species is very close to Dorylaimellus indicus Siddiqi, 1964 in general morphology and measurements but distinctly differs from it in the shape of its lip region (vs more conoid and deeply offset), in having poorly developed basal flanges of odontophore (vs odontophore with well-developed flanges) and more importantly in the presence of distinct ventral body pores along entire body length (vs ventral body pores absent).

The new species is closely related to Dorylaimellus striatus Thorne, 1939 and Dorylaimellus occidentalis Thorne, 1939 but differs from the former in having longer and comparatively slender body (vs L = 1 mm, a = 37), expanded part of pharynx less than half of the pharyngeal length (vs expanded part half or more than half of pharyngeal length) and differently shaped tail (vs irregularly conoid to the blunt, rounded terminus). From D. occidentalis this species differs in having longer and slender body (vs L = 0.8–0.9 mm, a = 28–33), shorter pharynx (vs b = 3.0).

Figures

Figure 3. Dorylaimellus (Dorylaimellus) parindicus sp. nov. (A) Entire female, (B) anterior region, (C) anterior end showing amphid, (D) pharyngeal region, (E) expanded part of pharynx, (F) female genital system, (G) vulval region, (H) female posterior region showing prerectum, (I) female posterior region.

Figure 4. Dorylaimellus (Dorylaimellus) parindicus sp. nov. (A) Anterior region, (B,C) anterior end showing amphid, (D) expanded part of pharynx, (E) female genital branch (anterior), (F) vulval region, (G) female posterior region. Scale bars: A–C = 10 µm; D–G = 20 µm.