Nothotylenchus brzeskii, 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 : 483-487

Nothotylenchus brzeskii n. sp.

( Figures 1 & 2 )

Measurements: Table 1 .

Female: Body slightly or completely curved ventrally. Cuticular annulation distinct, 1–1.5 µm wide; lateral fields with four incisures, 5.5–7.5 µm wide and 18.8–33.3% of the body width, two outer ones sometimes crenate. Head wide and low, 1.5–2.5 µm high and 6.5–7.5 µm wide, with rounded edges and two or three fine annuli, not offset. Cephalic skeleton weak, the outer margin of basal plate extending two annuli into body. Stylet delicate, conus 33.3–40.0% of total stylet length, knobs small and rounded, 1.5–2 µm wide. DGO 1–1.5 µm posterior to stylet knobs. Median bulb elongated and fusiform, slightly wider than procorpus, 5–6 µm wide, without thickenings of lumen walls. Isthmus cylindrical and more slender than procorpus. Nerve ring surrounding isthmus near middle or in its posterior half, sometimes at the junction of isthmus and basal pharyngeal bulb, 90 (84–93) µm from anterior end. Hemizonid two to three cuticular annuli long, 112 (109–117) µm from anterior end, one to three annuli anterior to S-E pore. S-E pore opposite the anterior or posterior half of the basal bulb. In one specimen two pairs of hemizonid and S-E pore were observed. The first pair located opposite the anterior half and the second pair near the end of basal pharyngeal bulb. Deirids at the level of S-E pore. Basal pharyngeal bulb pyriform and offset from intestine or with slight overlap, up to 7.5 µm, 2.1 times (1.6–2.8) longer than wide, with the two anterior-most intestinal cells appearing hyaline. Reproductive system characteristic of Nothotylenchus : reproductive tract mono-prodelphic, oocytes in single row, cylindrical, inline spermatheca filled with large rounded sperms or sometimes empty, uterus quadricolumellar, vagina 6.5–9.5 µm in length and 25.6–46.6% of VBW. PUS short, 16.5–24 µm long, 0.9 (0.6–1.2) of VBW or 28.1 (20.2–35.3) % V-A and 1.3 (0.9–1.8) ABW. Post-vulval body length 8.3 (7.6–8.9) ABW. Tail thick, conical and narrowed gradually from anus, ventrally arcuate at the end, with rounded to sometimes dull terminus.

Male: General morphology, stylet, pharynx and tail shape similar to females. Spicules slightly or completely ventrally arcuate, gubernaculum simple and crescent-shaped, bursa 27–36.5 µm long and enveloping 51.2–74.1% of tail length. Tail 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, two female paratypes and two male paratypes on three glass slides kept in the nematode collection of the Department of Plant Protection, School of Agriculture, Shiraz University, Iran, and two female paratypes and two male paratypes on two glass slides deposited in the Nematode Collection of the Plantenziektenkundige Dienst, Wageningen, The Netherlands.

Diagnosis and relationships. Nothotylenchus brzeskii n. sp. is characterised by a body length of 774–922 µm, lateral fields with four incisures, delicate, short stylet (7–8 µm) with small rounded knobs, pyriform, offset from intestine or slightly overlapping basal pharyngeal bulb, posterior vulva position (V = 83.4–84.4), short PUS (16.5–24 µm), spicules 20.5–23 µm in length, and thick tail with rounded to dull terminus.

N. brzeskii n. sp. resembles N. basiri , N. cylindricollis Thorne, 1941 , N. cylindricus Khan & Siddiqi, 1968 , N. singhi Das & Shivaswamy, 1980 , N. thornei Andrássy, 1958 and N. websteri Kumar, 1983 . It differs from N. basiri by longer spicules (20.5–23 vs. 13–15 µm), from N. cylindricollis by different tail terminus (rounded to dull vs. pointed) and different basal pharyngeal bulb (pyriform vs. elongate and cylindroid), from N. cylindricus by the longer spicules (20.5–23 vs. 14 µm), and different basal pharyngeal bulb (pyriform vs. elongate and cylindroid), from N. singhi by longer spicules (20.5–23 vs. 13–15 µm) and lower PUS/VBW ratio (0.6–1.2 vs. ˃ 1.5), from N. thornei by different tail terminus (rounded to dull vs. mucronate) and lower c′ value (3.3–4.0 vs. 7.6–9.0) and from N. websteri by longer spicules (20.5–23 vs. 11–13 µm) and different tail terminus (rounded to dull vs. pointed).

Etymology. The species is named in honor of Dr. Michal W. Brzeski for his outstanding contributions to the science of nematology.

Figures

FIGURE 1. Nothotylenchus brzeskii n. sp. A, C-G, I & J: Female. B & H: Male. A & B: General morphology; C & G: Basal pharyngeal bulb; D: Head & stylet; E: Pharynx; F: PUS; H & I: Tail; J: Lateral fields.

FIGURE 2. Nothotylenchus brzeskii n. sp. A-C & E-H: Female. D: Male. A: Head & stylet; B: Median bulb; C: Tail; D: Spicules, gubernaculum & bursa; E: Lateral fields; F: PUS; G & H: Basal pharyngeal bulb (Scales bars in A & E = 10 µm; B = 30 µm; C, D, F & G = 20 µm)

Tables

TABLE 1. Morphometrics of Nothotylenchus brzeskii 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	4	4
L	781	824 ± 66 (774–922)	770 ± 31 (741–811)
L′	726	766 ± 63 (720–860)	719 ± 32 (689–761)
a	27.9	34.0 ± 6.5 (27.5–42.3)	35.8 ± 2.9 (33.2–38.8)
b	6.4	6.6 ± 0.6 (6.2–7.4)	6.2 ± 0.2 (5.9–6.4)
b′	6.0	6.4 ± 0.7 (5.8–7.4)	5.9 ± 0.1 (5.8–6.0)
c	14.0	14.3 ± 0.8 (13.3–15.0)	15.2 ± 1.0 (14.2–16.5)
c′	3.2	3.7 ± 0.3 (3.3–4.0)	3.4 ± 0.2 (3.1–3.5)
V	84.2	84.0 ± 0.4 (83.4–84.4)	-
V′	90.7	90.3 ± 0.3 (90.1–90.8)	-
Stylet	8	7.1 ± 0.5 (7–8)	7.1 ± 0.6 (6.5–7.5)
Pharynx	123	125 ± 3 (121–130)	125 ± 4 (121–128)
Anterior end to end of glands	129	129 ± 6.4 (123–137)	130 ± 4 (127–135)
Basal pharyngeal bulb overlapping	6.5	5.2 ± 3.2 (1.5–7.5)	5.4 ± 1.9 (3.5–7)
Anterior end to center of median bulb	56	55.7 ± 5.8 (51.5–64)	55.3 ± 1.8 (54–57.5)
MB	45.5	44.4 ± 3.4 (42.3–49.5)	44.4 ± 0.8 (43.6–45.0)
Basal pharyngeal bulb length	32	22.5 ± 5.7 (17.5–29.5)	19.6 ± 4.2 (16–24)
Basal pharyngeal bulb width	13.5	10.9 ± 0.5 (10.5–11.5)	10.3 ± 1.1 (9.5–11.5)
S-E pore	112	117 ± 4 (114–122)	110 ± 1 (109–111)
Deirids	112	120 ± 1.5 (119–122)	111 ± 0.0 (111–112)
Anterior end to vulva	658	692 ± 56 (653–775)	-
V-A	67	71.9 ± 6.1 (67–80.5)	-
Tail length	55.5	57.5 ± 3.9 (53.5–61.5)	50.7 ± 1.8 (49–52.5)
V-A/Tail	1.2	1.3 ± 0.0 (1.2–1.3)	-
BW	28	25.0 ± 6.3 (19–33.5)	21.5 ± 1.0 (20.5–22.5)
VBW	24.5	23.0 ± 3.8 (20.5–28.5)	-
ABW	17.5	15.8 ± 2.2 (13.5–19)	15.0 ± 0.7 (14.5–16)
Bursa/ABW	-	-	2.1 ± 0.4 (1.8–2.5)
Spicules	-	-	22.1 ± 1.2 (20.5–23)
Gubernaculum	-	-	6.7 ± 0.6 (6–7.5)