Sporonchulus vagabundus Jairajpuri, 1971

Tahseen, Qudsia, Asif, Mohammad, Mustaqim, Malka, Ahlawat, Shikha & Bert, Wim, 2013, Descriptions of ten known species of the superfamily Mononchoidea (Mononchida: Nematoda) from North India with a detailed account on their variations, Zootaxa 3646 (4), pp. 301-335 : 323-327

Sporonchulus vagabundus Jairajpuri, 1971

( Figs. 12 , 13 )

Measurements. Table 1

Description. Adult: Body J-shaped upon fixation, tapering gradually towards posterior extremity with long conoid tail. Cuticle smooth, 3–4 µm thick. Lateral chord about one-third of body width at mid body. Body pores indistinct. Lip region slightly rounded to truncate, distinct and wider than adjoining body ca three times as wide as high and about two-thirds of the corresponding body diameter. Amphids cup-shaped with slit-like aperture, about 8–9 µm from anterior end located slightly posterior to labial base. Buccal cavity with converging, arched walls, 1.4–1.6 times as wide as long. Dorsal wall bearing a medium-sized, 4 µm long and 5 µm wide tooth, with apex straight or perpendicular to longitudinal body axis; its tip at about 64–70 % of buccal cavity from its base. Subventral walls with 18–24 irregularly placed denticles arranged roughly in 4 vertical rows. Pharynx muscular, cylindrical with thick lumen. Nerve ring encircling pharynx at ca 33–40% and a faintly visible excretory pore at ca 42–49% of pharyngeal length from anterior end. Orifices of the pharyngeal glands, DO located at ca 53–66%, SV1O1 and SV1O2 at ca 70–76%, SV2O1 and SV2O2 at ca 95–97% of pharyngeal length. Pharyngo-intestinal junction non-tuberculate. Rectum 0.8–1.0 times anal body diameter long. Tail long, conoid, ventrally arcuate, tapering evenly to a narrow rounded terminus. Caudal glands well developed, arranged in tandem. Spinneret terminal, occasionally sclerotised.

Female: Genital system didelphic, amphidelphic; short and compact with reflexed ovaries measuring 110–139 µm. Each ovary with a large proximal oocyte, 4–5 ocytes singly or alternately arranged with very small proliferating ones near distal tip. Oviduct with distinct pars dilatata. No trace of sperms either in uterus or in pars dilatata. Vagina thick-walled, about two-fifths of the corresponding body diameter long; pars refringens vaginae trapezoid, conspicuous, 2 × 2 µm in size. Vulva a transverse slit; vulval papillae absent.

Male: Not found.

Locality and habitat: A soil sample containing S. vagabundus was collected from Bina coal field at Sonebhadra, Uttar Pradesh, India. S. vagabundus was also recovered from a soil sample collected from a ditch at Dehradun, Uttar Pradesh, India, at 30°19'22"N 78°1'20"E coordinates.

Voucher specimens. Five females on slide Sporonchulus vagabundus Jairajpuri, 1971 no. BS-05/1-2 deposited in the Nematode Collection, Department of Zoology, Aligarh Muslim University, Aligarh, Uttar Pradesh, India. One female deposited at USDANC, Beltsville, MD, USA.

Three females on slide Sporonchulus vagabundus Jairajpuri, 1971 no. DJ/1-2 deposited in the Nematode Collection, Department of Zoology, Aligarh Muslim University, Aligarh, Uttar Pradesh, India. One female deposited at USDANC, Beltsville, MD, USA.

Salient characters. Medium-sized species with buccal cavity having converging and arched walls, about 1.4– 1.6 times as long as wide; dorsal tooth medium-sized, situated in anterior half of buccal cavity; subventral walls bearing four vertical rows with a total of 18–24 denticles; subventral teeth more or less of equal size; female genital system amphidelphic; tail conoid, ventrally arcuate, gradually tapering to a truncate terminus; caudal glands arranged in tandem; spinneret conspicuous, terminal, usually sclerotised.

Remarks. S. vagabundus was first described by Jairajpuri, 1971 from Rishikesh, Saharanpur, Bareilly and Aurangabad localities of India. It was later recorded from several other Indian localities (Jairajpuri & Khan, 1982). The present specimens conformed well to those described from other localities in India except for having smaller body length (0.9–1.0 µm vs 1.2–1.8 µm). The spinneret also varied from conspicuous and well-sclerotised to nonsclerotised ( Fig. 12 R–U; 13 M, N). A great degree of intraspecific variability was observed in the shape of the buccal cavity and in the arrangement of teeth ( Fig. 12 A–H; 13C, D; F–H).

Figures

FIGURE 12. Sporonchulus vagabundus Jairajpuri, 1971 (Sonbhadra population). A, F – H: Anterior end with buccal armature. B – E: Subventral wall. I: Anterior end showing amphids. J – L: Pharyngo-intestinal junction. M, N: Anterior genital branch. O: Vulval region. P, Q: Posterior genital branch. R – U: Posterior body region. (Scale bar = 10 µm).

FIGURE 13. Sporonchulus vagabundus Jairajpuri, 1971 (Dehradun population). A – F: Anterior end with buccal armature. G, H: Subventral wall. I, J: Pharyngo-intestinal junction. K: Anterior genital branch. L: Posterior genital branch. M: Posterior body region. N: Tail tip (Scale bar = 10 µm).