Proleptonchus shamimi Bajaj & Bhatti, 1980

Ahad, Sumaya & Ahmad, Wasim, 2016, Three new and a known species of the genus Proleptonchus Lordello, 1955 (Nematoda: Leptonchidae) with a diagnostic compendium of the genus, Zootaxa 4189 (1), pp. 115-133 : 116

Proleptonchus shamimi Bajaj & Bhatti, 1980

( Fig. 1 )

Measurements. See Table 1 .

Description. Female: Medium size nematodes, 1.2–1.4 mm long; body cylindrical, tapering towards both extremities, generally straight or slightly curved ventrally. Cuticle with two distinct layers, 2–3 µm thick at midbody and 3–4 µm on tail. Outer layer thin; inner layer with irregular outline and loose; radial refractive elements abundant. Lateral chords occupying about 25–36% of midbody diameter. Dorsal, ventral and lateral body pores indistinct.

Lip region cap-like, offset by constriction, 2.5–2.7 times as wide as high or about one-fourth to one-third of body diameter at neck base; inner part of lips slightly raised. Amphids cup-shaped, their aperture occupying about two-thirds the lip region diameter. Stoma inverted flask-shaped, with sclerotized walls. Odontostyle attenuated, 0.7–0.8 times the lip region diameter long, with distinct lumen and fine aperture. Odontophore slightly arcuate, 1.25–1.37 times the odontostyle length. Guiding ring simple, refractive, at 0.7–0.8 times lip region diameter from anterior end. Pharynx consist of a slender and weakly muscular anterior part and a short pear-shaped constricted basal bulb, occupying about 18–20% of total neck length. Cardia short, rounded, about one-sixth of the corresponding body diameter long. Nerve ring at 43–45% of neck length from the anterior end.

Genital system monodelphic-prodelphic. Ovary reflexed, measuring 114–170 µm long, reaching the oviductuterus junction; oocytes arranged in single row except near tip. Oviduct joining the ovary subterminally, measuring 136–164 µm, consisting of a slender portion and a well developed par dilatata. Oviduct-uterus junction marked by well developed sphincter. Uterus short, tubular, measuring 75–86 µm, without refringent apophyses at its distal end,. Posterior genital branch reduced, 2.0–2.7 times the midbody diameter long, comprised of uterus measuring 65–80 µm and distinct sphincter followed by a sac-like structure representing a rudimentary oviduct and probably few cells representing vestigial ovary. Vagina cylindrical; pars proximalis vaginae 10–12 µm long, its wall encircled by muscles; pars distalis vaginae short, 1.5–2.0 µm long with slightly curved walls; pars refringens absent. Vulva apparently a transverse slit. Prerectum 5.3–6.8 and rectum 0.7–1.2 anal body diameter long. Tail short and rounded, conoid, 0.66–0.74 times anal body diameter long, with a pair of caudal pore.

Male: Not found

Voucher specimens. Four females on slide Proleptonchus shamimi /1; deposited in the Nematode Collection, Department of Zoology, Aligarh Muslim University, Uttar Pradesh, India.

Habitat and locality. Soil samples from around the roots of the unidentified grasses of Kaziranga National Park, Assam, India.

Remarks.: Bajaj & Bhatti (1980) described P. shamimi from India based on the study of large number of female and male specimens. They made detailed observations on the variability in posterior genital branch, a structure which has been quite often used in the identification of Proleptonchus species. Peralta & Peña-Santiago (1996) redescribed this species from Spain. They indicated a close relationship of this species with P. i nd i c u s Siddiqi & Khan, 1964 and P. johnsoni Goseco, Ferris & Ferris, 1974 . P. i n di c us has been described from India based on a single female specimen. The same specimen was also studied by Goseco et al. (1974) in his redescription. Although there is morphological similarity between the two species, P. shamimi differs from P. indicus in its comparatively larger body size, shape of lip region (more conoid vs rounded), larger expanded part of pharynx (35–39 µm vs 25 µm), presence of well developed sphincter in the posterior sexual branch (vs absent, neither Siddiqi & Khan (1964) nor Goseco et al. (1974) mentioned the presence of a sphincter in P. i nd i c u s), and a larger prerectum (160–185 µm vs 96 µm). The description of P. johnsoni is also based on just two female specimens. It has a comparatively slender body, a very slender odontostyle apparently with no visible aperture, odontophore as long as odontostyle and slightly sclerotized. Although this species appears very close to P. i n di cu s, it distinctly differs from the later in having slender body and its odontostyle very slender apparently with no aperture.

Figures

FIGURE 1. Proleptonchus shamimi Bajaj & Bhatti, 1980 A – C. Anterior region. D. Anterior end showing amphid. E & F. Pharyngeal bulb. G. Vulval region. H-J. Female genital system. K. Female posterior region. (Scale bar A – D, I = 10 µm; E – H, J = 20 µm).