Nothotylenchus siddiqii, Hashemi & Karegar, 2020

Hashemi, Kobra & Karegar, Akbar, 2020, New and known species of Nothotylenchus Thorne, 1941 (Nematoda: Anguinidae) from Iran with an updated list of species, Zootaxa 4729 (4), pp. 482-500 : 487-489

Nothotylenchus siddiqii n. sp.

( Figures 3 & 4 )

Measurements: Table 2.

Female: Body straight or slightly curved ventrally. Cuticular annulation distinct, about 1 µm wide; lateral fields with six to nine incisures, 5–7 µm wide and occupying 31.2–42.1% of body width. Head low, with rounded margins, not offset, with two or three fine annuli, 1.5–2 µm high and about 5.5 µm wide. Cephalic skeleton moderately developed, outer margin of basal plate extending two to three annuli inside body. Stylet delicate, conus 26.3–39.7% of total stylet length, knobs medium-sized or small and rounded, 1–2 µm wide. DGO 0.5–1 µm posterior to stylet knobs. Median pharyngeal bulb elongated and spindle shape, wider than procorpus, 4.5–6 µm wide, valveless. Isthmus cylindrical and more slender than procorpus. Nerve ring surrounding isthmus almost at its middle, 69 (65.5–71.5) µm from anterior end. Hemizonid about two to three cuticular annuli long, 82 (79.5–88.5) µm from anterior end, two annuli anterior to S-E pore. S-E pore located from posterior half of isthmus to junction of isthmus and basal bulb. Deirids at the level of S-E pore. Basal pharyngeal bulb pyriform to slightly elongate and offset from intestine, length to width ratio 2.3 (1.8–2.8), with the two anterior-most intestinal cells appearing hyaline. Oocytes in single row, spermatheca elongate, filled with round sperms or empty, uterus quadricolumellar, sometimes with a valve between spermatheca and uterus, vagina 4–6 µm in length, 27.0–34.9% of VBW. PUS well developed, 26.5–40 µm, 2.2 (1.9–2.4) VBW, 54.2 (46.3–61.3) % V-A and 3.1 (2.6–3.6) ABW. Post-vulval body length 10.6 (10.5–10.9) ABW. Tail conical with usually rounded or seldom dull terminus.

Male: General morphology, stylet, pharynx and tail shape similar to females. Spicules ventrally arcuate, gubernaculum simple and crescent-shaped, bursa 12–23.5 µm long and enveloping 25.7–48.6% of tail length. Tail conical with rounded terminus.

Habitat & locality. Type population collected in 2014 from rhizosphere of alfalfa in Darab region, Fars province, Iran (GPS coordinates: 28°41.167′N, 54°16.056′E, elevation 1367 m.).

Type material. Female holotype, three female paratypes and six male paratypes on six glass slides kept in the nematode collection of the Department of Plant Protection, School of Agriculture, Shiraz University, Iran, and two female paratypes and three male paratypes on two glass slides deposited in the Nematode Collection of the Plantenziektenkundige Dienst, Wageningen, The Netherlands.

Diagnosis and relationships. Nothotylenchus siddiqi n. sp. is characterised by its short body, 573–645 µm in length, six to nine lateral field incisures, short, delicate stylet (6.5–7.5 µm) with rounded knobs, pyriform or slightly elongate and offset basal pharyngeal bulb, posterior vulva position (V = 79.3–81.0), PUS = 26.5–40 µm, short spicules, 14.5–16.5 µm long, and tail with rounded terminus.

N. siddiqii n. sp. resembles N. affinis , N. hexaglyphus , N. persicus , N taylori Husain & Khan, 1974 ; N. geraerti and N. medians . But it can be distinguished from all these species by having 6–9 incisures in lateral fields (vs. 6). Moreover N. siddiqii n. sp. differs from N. affinis by greater PUS/VBW ratio (1.9–2.4 vs. 1.1–1.3), from N. hexaglyphus by shorter spicules (14.5–16.5 vs. 19–22 μm) and greater PUS/VBW ratio (1.9–2.4 vs. 0.5–1.3), from N. taylori by relatively shorter spicules (14.5–16.5 vs. 16.5–20 μm) and from N. persicus by shorter spicules (14.5–16.5 vs. 21–22 μm), position of the S-E pore (posterior half of isthmus to its junction with basal pharyngeal bulb vs. after basal pharyngeal bulb) and the tail terminus shape (rounded vs. pointed).

Etymology. The species is named in honor of Dr. Mohammad Rafiq Siddiqi for his outstanding contributions to the science of nematology.

Figures

FIGURE 3. Nothotylenchus siddiqii n. sp. A, C, E-H, J & K: Female. B, D, I: Male. A & D: General morphology; B & C: Head & stylet; E: Pharynx; F: PUS; G: Basal pharyngeal bulb; H-J: Tail; K: Lateral fields.

FIGURE 4. Nothotylenchus siddiqii n. sp. A-L: Female. M: Male. A: Head & stylet; B-D: Lateral fields; E: Median bulb; F & G: Basal pharyngeal bulb; H: PUS; I: Post-vulval body length; J-L: Tail; M: Spicules, gubernaculum & bursa (All scale bars = 10 µm, except I = 20 µm).

Tables

TABLE 2. Morphometrics of Nothotylenchus siddiqii n. sp. from Iran. All data of female and male paratypes are in the form of mean ± s.d. (range), and the measurements are in μm.

Character\Population		Female	Male
	Holotype	Paratypes	Paratypes
n	1	5	9
L	610	604 ± 33 (573–645)	523 ± 39 (454–587)
L′	559	556 ± 37 (523–593)	476 ± 36 (415–533)
a	36.5	36.0 ± 2.7 (32.1–39.3)	38.1 ± 3.1 (34.8–43.1)
b	5.5	5.6 ± 0.3 (5.2–6.0)	4.9 ± 0.3 (4.5–5.3)
c	12.0	11.6 ± 1.0 (10.4–12.5)	11.1 ± 0.6 (10.5–12.1)
c′	4.4	4.9 ± 0.5 (4.4–5.5)	4.6 ± 0.4 (4.0–5.3)
V	79.3	80.3 ± 0.6 (79.5–81.0)	-
V′	86.5	88.2 ± 0.7 (87.4–88.9)	-
Stylet	7.5	7.1 ± 0.5 (6.5–7.5)	6.8 ± 0.5 (6.5–7.5)
Pharynx	111	108 ± 4 (102–112)	107 ± 4 (101–112)
Anterior end to center of median bulb	44.5	43.5 ± 1.4 (42–45)	42.2 ± 2.0 (38.5–45)
MB	40.1	40.3 ± 2.3 (38.1–43.5)	39.5 ± 0.7 (38.2–40.2)
Basal pharyngeal bulb length	20.5	17.9 ± 1.0 (16.5–19)	17.4 ± 2.6 (14–23)
Basal pharyngeal bulb width	8.5	7.8 ± 1.0 (6.5–9)	6.7 ± 0.6 (5.5–7.5)
S-E pore	92	85.3 ± 3.9 (82.5–92)	80.2 ± 3.1 (74–85)
Deirids	95	89.6 ± 7.9 (84 –95)	82.6 ± 3.6 (76–87)
Anterior end to vulva	483	486 ± 27 (464–518)	-
V-A	75	62.3 ± 6.7 (56.5–70.5)	-
Tail length	51	52.5 ± 2.6 (50.5–56.5)	47.4 ± 3.9 (39.5–53.5)
V-A/Tail	1.5	1.2 ± 0.2 (1.0–1.4)	-
BW	16.5	16.8 ± 1.1 (15.5–18.5)	13.8 ± 1.0 (12.5–15.5)
VBW	15.5	15.8 ± 1.4 (14–17.5)	-
ABW	11.5	10.9 ± 0.7 (10.5–11.5)	10.4 ± 1.0 (9–12)
Spicules	-	-	15.6 ± 0.6 (14.5–16.5)
Bursa/ABW	-	-	1.6 ± 0.3 (1.2–2.2)
Gubernaculum	-	-	5.1 ± 0.5 (4.5–6)