Laimydorus baldus Baqri & Jana, 1982

Sen, Debabrata, Chatterjee, Amalendu & Manna, Buddhadeb, 2012, One new and two known species of Dorylaimoidea (Nematoda) from West Bengal, India, Zootaxa 3258, pp. 46-57 : 51-53

Laimydorus baldus Baqri & Jana, 1982

( Figure 3 )

Measurements: See Table 2 .

Females. Body almost straight or slightly ventrally curved when fixed, tapering towards ends. Cuticle with fine transverse striations, 4 Μm thick at anterior end at the level of middle of the odontostyle, 2.5–4 Μm at midbody and 3.5–5 Μm on tail. Lateral chords 1/4–1/3 of the body width near midbody. Lip region set off by slight depression, 5 Μm high and 13–14 Μm or 0.9–1 adjacent body-widths wide. Amphids stirrup-shaped, apertures 6.5 Μm or 46–50% of the corresponding body width and at 5.5–6 Μm from the anterior end. Odontostyle 1.6–1.8 lip region-widths long, 4–4.5 Μm thick, aperture occupying 8.5–10 Μm or 35–38% of the odontostyle length. Guiding ring at 14.5–17 Μm from anterior end. Odontophore 1.2–1.5 times the odontostyle length. Nerve ring at 125–147 Μm from anterior end or 30–35% of pharynx length. Cardia elongate conoid, wide at pharyngo-intestinal junction and then narrow, 17–19.5 Μm long. Expanded portion of pharynx 3.4–4.1 times the neck base-width long or 45–48% of the pharyngeal length. Location of pharyngeal gland nuclei are as follows: D = 54.4–55.7%, AS 1 = 23.7–28.0%, AS 2 = 28–29.9%, PS1 = 66.8–76.8%, PS2 = 71.7–82.6%. Female reproductive system didelphic-amphidelphic, with both genital branches well developed, posterior branch longer than the anterior–anterior branch 549–580 Μm and the posterior branch 581–697.5 Μm long. Ovaries large, reflexed, occasionally almost up to the sphincter level, anterior ovary 174–220 Μm long and posterior ovary 213–330.5 Μm long. Oocytes arranged in a single row except at the growth region. Oviduct long, tubular, joining the ovary subterminally. Sphincter separating oviduct from uterus, but not very marked. Uterus tubular, muscular, short and simple, fusiform or spindle-shaped sperms present in both uteri. Vulva transverse, slightly pre-equatorial. Vaginal length 21–25.5 Μm or 31–42% of the corresponding body width. The length of pars proximalis vaginae 14–16.5 Μm, pars refringens vaginae 4–5 Μm, sclerotised pieces almost oval or triangle-shaped, combined width of pars refringens vaginae 8–9 Μm and length of pars distalis vaginae 2–5 Μm. Prerectum 3.9–5.2 and rectum 1–1.3 anal body widths long. Tail elongate filiform, 5.6–6.9 anal body-widths long, in some specimens ventrally curved.

Males. Similar to female in general morphology except in tail and prerectum length. Testes outstretched. Spicules 1.5–1.7 anal body widths long, lateral guiding pieces 9–12Μm long. Prerectum longer than in female, 7.9– 9.2 anal body widths in length. Tail short, ventrally curved, bluntly rounded, 0.8–0.9 anal body –widths long. 24– 28 contiguous ventromedian supplements, preceded by an adanal pair.

Habitat and Locality: Collected from the soil around the roots of guava at Dakshin Ghoshpara, Sonarpur block (latitude 22.43° east and longitude 88.43° north), South 24-Parganas on 24.07.2005.

Remark. The present specimens agree well with the type specimens described by Baqri and Jana (1982) from soil around the roots of paddy rice ( Oryza sativa ) at Coochbehar district, West Bengal except for some variations in lengths of body, odontophore, prerectum and tail (L = 2.11–2.44 mm, odontophore = 29–30 Μm, rectum = 40–45 Μm and tail length = 190–224 Μm in type specimens). In the single male paratype treated in the original description, the body length was reported as 1.83 mm, slightly shorter than in the present specimens. Other characters, such as odontostyle, spicule and prerectum lengths, and the number of ventromedian supplements fit the ranges of the studied material (odontostyle 24 Μm, spicules 53 Μm and prerectum 236 Μm, 24 contiguous supplements preceded by an adanal pair). Bohra and Baqri (2004) and Bohra et al. (2005) reported this species from different localities of Gujarat state, India. The species is being reported for the first time from South 24-Parganas district.

Figures

FIGURE 3. Laimydorus baldus. Female: A. Entire body, C. Anterior end showing amphid, guiding ring and odontostyle, D and E. Pharyngo-intestinal junction and difference in shape of cardia, F. Vagina and part of gonad (anterior branch), G. Tail. Male: B. Entire body, H. Posterior portion showing ventromedian supplements, spicules and tail.

Tables

TABLE 2. Morphometrics of Laimydorus baldus. [All measurements are in Μm except L and body ratios, L in mm; Mean ± SD (Range)].

Characters	Females	Males
n	4	5
L	2.0 ± 0.10 (1.9–2.1)	1.96 ± 0.11 (1.9–2.1)
a	32.4 ± 1.7 (31.0–34.4)	31.3 ± 0.2 (31.1–31.6)
b	4.6 ± 0.3 (4.2–4.9)	4.3 ± 0.1 (4.2–4.5)
c	11.8 ± 0.6 (11.5–12.6)	78.8 ± 1.0 (77.8–79.8)
c’	6.1 ± 0.7 (5.6–6.9)	0.8 ± 0 (0.8–0.9)
V %/ T%	45.8 ± 1.8 (44.1–47.8)	61.0 ± 3.9 (56.5–63.5)
G1%	27.1 ± 0.9 (26.3–28.1)	--
G2 % Odontostyle length	30.0 ± 3.4 (27.6–32.5) 25.6 ± 1.4 (24–26.5)	-- 25.6 ± 1.4 (24–26.5)
Odontophore length	36.3 ± 4.0 (34–41)	35.8 ± 1.5 (34–36.5)
Maximum body width	63.6 ± 4.6 (61–69)	63.6 ± 4.6 (61–69)
Body width at neck base	57.1 ± 5.6 (54–64)	62.0 ± 1.5 (61– 63.5)
Body width at vulva	63.5 ± 4.3 (61–68.5)	--
Pharynx length	445.0±19.6 (424–463)	456.6±17.0 (439–473)
Expanded part of pharynx	217.4±3.1 (215.5–221)	225.3 ± 6.4 (218–230)
Glandularium	196.3±10.5 (185–206)	--
Length of anterior gonad	560.0±17.3 (549–580)	--
Length of posterior gonad	639.2±82.3 (581– 697.5)	--
Anterior end to vulva	946.6±28.8 (929–980)	--
Tail length	174.0±10.4 (167–186)	25.3 ± 1.4 (24.5–27)
Anal body width	28.3 ± 3.6 (24.5–32)	29.5 ± 0 (29.5)
Length of prerectum	133.8±17.5 (122.5 –154)	251.3 ± 18.8 (235–272)
Length of rectum	32.6 ± 1.1 (32–34)	31.0 ± 1.7 (29–32)
Total length of testis	--	1220 ± 7(1213–1227)
Length of spicules	--	49.3 ± 2.5 (47–52)
Ventromedian supplements	--	25.6 ± 2 (24–28)