Enchodelus liangi, W.Ahmad & Wu & Shaheen, 2001

W. Ahmad, Wu, J. & Shaheen, A., 2001, Studies on the genus Enchodelus Thorne, 1939 (Dorylaimida: Nordiidae) from China, Journal of Nematode Morphology and Systematics 4 (2), pp. 83-90 : 86-88

Enchodelus liangi sp. n.

( Figure 2 )

Measurements: Table I

Female: Body slightly ventrally curved upon fixation. Cuticle finely transversely striated, 1.5 — 2.0 m thick at midbody. Cuticle thickness on tail varies from 2.3 m on dorsal side, 3.0 m on ventral side and 7.7 — 8.5 m at tip. Lateral hypodermal chords about one­fifth to one­fourth of the body width at midbody. Body pores indistinct. Lip region slightly offset, about one­fourth of body width at neck base. Vestibule thick­walled, almost funnel­shaped. Amphids stirrup­shaped with slit­like aperture, occupying about 0.6 — 0.7 lip region width; fusus at level near middle of odontophore. Odontostyle fine, attenuated, 1.3 — 1.4 lip region widths long; its aperture 2.5 — 3.0 m. Odontophore rod­like, 1.3 — 1.4 times the odontostyle length. Nerve ring encircling the anterior slender part of pharynx at 95 — 100 m from anterior end. Pharyngeal expansion gradual; expanded portion occupying about 39 — 42% of the total neck length. Dorsal pharyngeal gland nucleus exceptionally enlarged, 6 — 8 x 5 — 7 m; first pair of subventrals inconspicuous; second pair also with large nuclei measuring 4 x 4 m, located near middle (55 — 56%) of the expanded portion. Cardia short, hemispheroid. Pharyngeal gland nuclei are located as follows: D = 64 — 67; PS1 = 41 — 46; PS2 = 43 — 46. Vulva transverse; vagina 21 — 23 m or about half of the corresponding body width deep. Pars proximalis oaginae 15 x 13 m, slightly longer than wide with weakly sigmoid, somewhat convergent contour, encircled by well developed musculature. Pars refringens oaginae in optical section consisting of two well developed triangular sclerotizations with proximal smooth surface, measuring 4.5 x 3.0 m and with a combined width of 10 m and an extent along the lumen 4 m. Pars distalis oaginae 1.5 — 2.0 m long with rounded walls.Reproductive system amphidelphic; ovaries well developed, reflexed, reaching almost upto oviduct­uterus junction; oocytes initially arranged in multiple rows and then in a single row. Sphincter present at oviduct­uterus junction. Uterus about 2 — 3 times as long as corresponding body width. No sperm seen in the uterus. Prerectum about 6 — 8 anal body widths long. Tail short, conoid, slightly ventrally arcuate with bluntly rounded terminus, 1.2 — 1.4 anal body widths long, with a pair of caudal pores on each side.

Male: Not found

Diagnosis and relationships: E. liangi sp. n. is characterized by having 1.1 — 1.3 mm long body; offset lip region; 13 m long, attenuated odontostyle; exceptionally enlarged dorsal pharyngeal gland nucleus; second pair of subventral pharyngeal glands almost in the middle of the expanded part; amphidelphic reproductive system and short, conoid, bluntly rounded tail.

The new species though very close to E. lushani sp. n. distinctly differs in the shape of lip region, in having smaller odontostyle, enlarged dorsal pharyngeal gland nucleus; comparatively longer prerectum and slightly differently shaped tail.

The two species were recorded in the same soil sample and show very close resemblances, but still differ in certain basic features such as shape of lip region, size of odontostyle and of pharyngeal gland nuclei. The body is strongly ventrally curved in all the specimens of E. lushani sp. n., whereas, it is slightly ventrally curved in E. liangi sp. n.

Type habitat and locality: Same as for E. lushani sp. n.

Type material: Collected in June 1999. Holotype female on slide Enchodelus liangi sp. n. /1; paratype females on slides Enchodelus liangi sp.n. /2­3; deposited in the nematode collection of the Department of Zoology, Aligarh Muslim University, Aligarh, India. A paratype female deposited with the nematode collection of the Universidad de Ja n, Spain .

Etymology: The species is named after Prof. Yanling Liang of the Institute of Hydrobiology, Chinese Academy of Science, Wuhan, for his kind help in making this collection possible.

Figures

FIGURE 2: Enchodelus liangi sp. n. A: Entire female. B: Anterior region. C: Expanded part of pharynx. D: Vulval region. E: Female posterior region. F: Female posterior end.