Basirotyleptus nindei Siddiqi, 1970

Islam, Md Niraul & Ahmad, Wasim, 2022, Description of five new and six known species of the genus Basirotyleptus Jairajpuri, 1964 (Nematoda: Dorylaimida: Tylencholaimoidea) from the Western Ghats, India, European Journal of Taxonomy 791 (1), pp. 1-57 : 10-13

Basirotyleptus nindei Siddiqi, 1970

Fig. 3 , Table 3

Basirotyleptus nindei Siddiqi, 1970: 203–205 .

Material examined

INDIA – Kerala State • 11 ♀♀; Pathanamthitta district, Thannithodu forest ; 9º15′21.6″ N, 76º55′19.2″ E; 5–15 cm depth; 1 Nov. 2017; soil samples collected from around the roots of shrubs (unidentified); slides reference number AMU/ZD/NC/ Basirotyleptus nindei /1–4 • 7 ♀♀; Ernakulum district, Manikandanchal ; 10º09′28.8″ N, 76º47′56.4″ E; 5–15 cm depth; 28 Oct. 2017; soil samples collected from around the roots of shrubs (unidentified); slides reference number AMU/ZD/NC/ Basirotyleptus nindei /5–7 .

Description

Female

Small sized nematodes, slightly curved ventrad or open C-shaped upon fixation; body cylindrical tapering gradually towards both extremities but more so towards the anterior end. Cuticle with two distinct layers, 1.0–1.5 µm thick at anterior region, 1.5–2.0 µm at midbody and 2.5–3.0 μm on tail. Outer cuticle thin, with fine transverse striations; inner layer thick, finely striated, loose, its outline irregular, with distinct radial refractive elements. Lateral chords occupying about 29–35% of midbody diameter. Lateral body pores distinct; 1–2 in neck region; 1–2 from pharyngeal base to vulva; 2–4 in post-vulval region. Dorsal and ventral body pores indistinct. Lip region cap-like, offset by constriction, 1.8–2.1 times as wide as high or about one-third to two-fifths of the body diameter at neck base. Lips angular, separate, inner part elevated. Labial and cephalic papillae distinct but not interfering with labial contour. Amphids stirrupshaped, their aperture about two-fifths to one-half as wide as lip region diameter. Stoma a long, slender truncate cone, slightly sclerotized in the perioral region. Odontostyle slender, solid, needle-like, 1.4–1.5 times the lip region diameter long. Odontophore sclerotized, with prominent basal flanges, about 1.0–1.2 times the odontostyle length. Guiding ring simple, refractive, at 1.2–1.7 times the lip region diameter from anterior end. Pharynx consisting of a slender anterior part, expanding abruptly into a short pearshaped basal bulb, with a perceptible thickening at the posterior part of its inner lining, occupying about 14–18% of total neck length. Nerve ring located at 53–60% of neck length from anterior end. Cardia rounded to conoid, about one-fourth to one-third of the corresponding body diameter long.

Genital system monodelphic-opisthodelphic. Ovary reflexed, measuring 37–84 μm; oocytes arranged in single row except near tip. Oviduct joining the ovary subterminally, measuring 39–81 μm, consisting of a slender distal portion and a well-developed pars dilatata. Oviduct-uterus junction marked by weak sphincter. Uterus short and muscular, measuring 16–25 μm. Anterior genital branch absent or rarely present (n = 7), reduced to a very small sac, about one-fifth to one-fourth midbody diameter long. Sperm cell absent. Vagina cylindrical, extending inwards, 8.5–9.5 μm or about two-fifths to one-half (43–52%) of midbody diameter; pars proximalis vaginae 5.0–7.0 × 4.0–5.0 μm, encircled by circular muscles; pars distalis vaginae 3.0–4.0 μm with slightly curved walls; pars refringens absent. Vulva apparently a transverse slit. Prerectum 2.0–3.1 and rectum 1.0–1.4 times anal body diameter long. Tail short, rounded to conoid, with a pair of caudal pores on each side.

Male

Not found.

Remarks

Siddiqi (1970) described this species from the Malawi. During the present study eighteen females were collected from two different localities of the Western Ghats, India. The morphometrics of present populations conform well with the type population except in having differently shaped amphids (stirrupshaped vs cup-shaped), slightly shorter odontostyle (9.0–10.5 vs 11.0 µm), slightly longer odontophore (10.5–12 vs 10 µm); nerve ring located more posteriorly (53–60 vs 50% of total neck length); sometimes presence of small anterior uterine sac about one-fourth to one-third midbody diameter long (vs anterior sac completely absent) and slightly shorter prerectum (2.0–3.1 vs 3.0–4.0 times anal body diameter). These slight differences are considered as intraspecific variability. This species is reported here for the first time from the India.

Figures

Fig. 3. Basirotyleptus nindei Siddiqi, 1970, ♀ (AMU/ZD/NC/Basirotyleptus nindei/1–4) (LM photographs). A–C. Anterior region. D. Anterior region showing amphid. E. Pharyngeal region. F–G. Pharyngeal bulb. H. Genital system. I–J. Vulval region. K–L. Posterior region. Scale bars = 10 µm.

Tables

Table 3. Measurements of Basirotyleptus nindei Siddiqi, 1970. All measurements are in μm and in the form: mean ± s.d. (range).

Localities	Pathanamthitta population	Ernakulum population
Characters	Females	Females
n	11	7
L	415.4 ± 13.9 (393–438)	432.8 ± 19.8 (391–448)
Body diameter at neck base	16.1 ± 0.48 (15.5–16.5)	16.6 ± 0.90 (14.5–17.5)
Body diameter at mid body	19.1 ± 1.6 (16.5–21.5)	17.9 ± 1.1 (16.5–19.5)
Body diameter at anus	11.4 ± 0.43 (10.5–11.5)	11.4 ± 0.68 (10.5–12.5)
a	21.8 ± 1.6 (19.1–24.3)	24.0 ± 0.65 (22.9–25.0)
b	3.9 ± 0.16 (3.6–4.1)	3.9 ± 03.0 (3.5–4.5)
c	34.1 ± 1.9 (30.3–36.8)	35.3 ± 2.6 (30.5–38.1)
c’	1.02 ± 0.07 (1.0–1.2)	1.03 ± 0.06 (1.0–1.1)
V	42.4 ± 1.6 (39.6–45.1)	42.5 ± 1.2 (40.9–44.3)
G1	1.3 ± 0.17 (1.1–1.6)	1.2 ± 0.12 (1.0–1.4)
G2	22.1 ± 2.2 (17.6–25.7)	23.0 ± 2.6 (19.4–26.9)
Lip region diameter	6.2 ± 0.30 (6.0–7.0)	6.7 ± 0.17 (6.5–7.0)
Lip region height	3.2 ± 0.22 (3.0–3.5)	3.2 ± 0.22 (3.0–3.5)
Amphidial aperture	3.1 ± 0.24 (3.0–3.5)	3.2 ± 0.22 (3.0–3.5)
Odontostyle length	9.5 ± 0.38 (9.0–10)	9.8 ± 0.31 (9.5–10.5)
Odontophore length	10.7 ± 0.29 (10.5–11.5)	11.03 ± 0.35 (11–12)
Total stylet length	20.3 ± 0.56 (19–21)	20.9 ± 0.50 (20.0–21.5)
Guiding ring from anterior end	8.5 ± 0.24 (8.5–9.0)	8.6 ± 0.22 (8.5–9.0)
Nerve ring from anterior end	61.7 ± 2.3 (58–66)	61.0 ± 2.4 (55–63)
Neck length	106.6 ± 4.2 (97–113)	109.3 ± 4.4 (98–112)
Expanded part of pharynx	16.9 ± 0.78 (15.5–18.0)	18.0 ± 1.1 (15.5–19.5)
Cardia length	4.2 ± 0.39 (4.0–5.0)	4.4 ± 0.37 (4.0–5.0)
Anterior genital branch	5.6 ± 0.69 (5.0–6.0)	5.3 ± 0.40 (4.5–6.0)
Posterior genital branch	94.0 ± 10.2 (74–112)	102.2 ± 14.3 (78–120)
Vaginal length	9.3 ± 0.44 (8.5–9.5)	9.5 ± 0.35 (8.5–9.5)
Vulva from anterior end	176.3 ± 10.8 (160–197)	184.2 ± 7.2 (173–195)
Prerectum length	29.5 ± 2.7 (25–36)	30.5 ± 4.7 (24.0–37.0)
Rectum length	14.3 ± 0.86 (12.5–15.5)	14.1 ± 1.2 (11.5–15.5)
Tail length	12.2 ± 0.76 (11.0–13.5)	12.3 ± 1.0 (11.0–13.5)