Longidorus pacensis, Archidona-Yuste & Cantalapiedra-Navarrete & Castillo & Palomares-Rius, 2019

Archidona-Yuste, Antonio, Cantalapiedra-Navarrete, Carolina, Castillo, Pablo & Palomares-Rius, Juan E., 2019, Molecular phylogenetic analysis and comparative morphology reveals the diversity and distribution of needle nematodes of the genus Longidorus (Dorylaimida: Longidoridae) from Spain, Contributions to Zoology 88, pp. 1-41 : 22-30

publication ID	https://doi.org/ 10.1163/18759866-20191345
publication LSID	lsid:zoobank.org:pub:E75A42B9-4722-41E7-B8ED-8ABCC5A64C30
persistent identifier	https://treatment.plazi.org/id/2C6CEF20-FF9C-9D61-FD51-FF5169DFFCB7
treatment provided by	Felipe
scientific name	Longidorus pacensis
status	sp. nov.

Treatment

Longidorus pacensis View in CoL sp. nov.

http://zoobank.org/ urn:lsid:zoobank.org:act:10E0F15B-7C7B-4B1D-B063-1A041F77EFFB

( figs. 7 View FIGURE 7 , 8 View FIGURE 8 and 9 View FIGURE 9 , table 3)

Material examined. Holotype. Adult female, collected from fallow by P. Castillo, May 6, 2016; mounted in pure glycerine and deposited in the nematode collection at Institute for Sustainable Agriculture ( IAS) of Spanish National Research Council ( CSIC), Córdoba, Spain (collection number INB32-03).

Paratypes. Female , male and juvenile paratypes extracted from soil samples collected from the same locality as the holotype; mounted in pure glycerine and deposited in the following nematode collections: Institute for Sustainable Agriculture ( IAS) of Spanish National Research Council ( CSIC), Córdoba , Spain (collection numbers INB32-01-INB32-12); two females at Istituto per la Protezione Sostenibile delle Piante ( IPSP), Consiglio Nazionale delle Ricerche ( CNR), Bari, Italy ( INB32-14 ); and one female and one male at USDA Nematode Collection, Beltsville, MD, USA (T-6985p); collected by P. Castillo, May 6, 2016 .

Type locality. Badajoz , Badajoz province, Spain: 38° 49'24.85"N, 7°1'42.36"W; 187 m above sea level GoogleMaps (a.s.l.).

Etymology. The species name is derived from the Latin word “ Pacensis ” the Roman name of Badajoz, where the type specimens were found.

Diagnosis. Longidorus pacensis sp. nov. is an amphimictic species characterised by a moderately long body (6.7–8.3 mm), assuming a ventrally curved open C-shape upon fixation; lip region conoid-narrowed continuous with body contour, 11.0–12.5

μm wide; guiding-ring located 36.5–40.5 μm from anterior end; moderately long odontostyle (115.0–

129.0 μm); amphidial fovea pocket-shaped, asymmetrically bilobed; vulva almost equatorial; female tail short, bluntly Downloaded conoid from, Brill and.com bearing 08/29/2023 between05:44:51PM via free access two and three pairs of caudal pores; c’ ratio (0.7– 0.9); males less frequent than females, with long spicules (62.0–79.0 μm) and 15–20 ventromedian supplements; According to the polytomous key by Chen et al. (1997), the supplement by Loof & Chen (1999), and additional codes (Peneva et al., 2013; Archidona et al., 2016), the new species has the following code: A4(5)-B1-C3-D1-E3-F4-G1-H1- I2-J1–K1. Specific D2–D3 region, ITS1 rRNA, partial 18S rRNA and partial CoxI sequences (GenBank accession numbers MH430014-MH430015, MH429989-MH429990, MH430004-MH430005, and MH430066-MH430067, respectively).

Description. Female. Body moderately long, cylindrical, tapering towards anterior end, and assuming a ventrally curved open C-shape upon fixation. Cuticle thin appearing smooth under low magnifications, 3.6 ± 0.7 (3.0–4.5) μm thick at mid body, but thicker (19.3 ± 2.4 (16.5–24.0) μm) and marked by very fine superficial transverse striae mainly in tail region. Lateral chord 18.0 ± 1.5 (16.5–19.5) μm wide at mid-body or 23–25% of corresponding body diameter. Lip region conoid-narrowed, anteriorly rounded, and continuous with body contour. Amphidial fovea pocket-shaped asymmetrically bilobed with lobes extending approximately 3/4 of distance between oral aperture and guiding-ring, openings obscure appearing as minute pores (not illustrated), not slit-like. Stylet guiding-ring single, located 3.3 ± 0.2 (2.9–3.7) times lip region diameter from anterior end. Odontostyle moderately long, straight or slightly arcuate, 3.2 ± 0.2 (2.9–3.5) times as long as distance between anterior end to guiding-ring, odontophore approximately 1/2 part of the odontostyle length, weakly developed. Nerve ring encircling cylindrical part of pharynx, located 208.3 ± 23.2 (189.0–234.0) μm from anterior end. Anterior slender part of pharynx usually coiled in its posterior region. Basal bulb long and cylindrical, 129.9 ± 14.8 (112.0–153.0) μm long or approximately one-fourth of neck length, and 21.0 ± 1.6 (19.0–23.0) μm in diameter. Glandularium 116.3 ± 6.9 (109.0–125.0) μm long. Normal arrangement of pharyngeal glands (Chen et al., 1997; Loof & Chen, 1999): nuclei of DN and SVN glands situated at 14.6% ± 2.8 (12.9–17.8%) and 47.8% ± 0.9 (47.3–48.9%) of the distance from anterior end of pharyngeal bulb, respectively. Dorsal gland nucleus slightly larger than nuclei of two SVN (4.0–5.0 vs 3.0–4.0 μm in diameter). Cardia conoid-rounded, 16.3 ± 1.5 (15.0– 18.0) μm long. Reproductive system with both genital branches equally developed, ranging between 391–615 μm long, (G1) 6.9 % ± 1.1 (5.7–8.9), (G2) 6.8% ± 1.0 (5.8–8.8%) of body length, respectively. Vulva in form of a transverse slit, located about mid-body, vagina perpendicular to body axis, extending to approximately 2/3 of corresponding body width, surrounded by well-developed muscles. Uterus filled with sperm cells in most female specimens observed; well-developed sphincter between uterus and oviduct, usually containing numerous sperm cells too. Prerectum variable in length, 560 ± 164 (440–839) μm long, and rectum 37.7 ± 2.3 (35.0–39.0) μm long, anus a small round- ed slit. Tail short, dorsally convex and terminus bluntly rounded to almost hemispherical, bearing between two and three pairs of caudal pores.

Male. Less frequent than female (1:2 ratio). Morphologically similar to female except for genital system and posterior region considerably curved ventrally. Tail convex conoid, ventrally concave with broad blunt terminus, a deep depression posterior to anus and the thickened outer cuticular layer. Male genital tract diorchic with testis opposed, containing multiple rows of spermatogonia in the germinal zone. Spicules arcuate, robust, 1.5–2.1 times longer than tail length, lateral guiding pieces more or less straight. One pair of adanal supplements preceded by a row of 14–19 ventromedian supplements.

Juveniles. All four juvenile stages (first-, second-, third- and fourth-stage) were distinctly separated by morphological characters, such as body length, length of replacement and functional odontostyle (Robbins et al., 1996). Juveniles similar to adults apart Downloaded from developed from Brill.com reproductive 08/29/2023 system 05:44:51, PM via free access

n 1 L 4.1

a (body length/maximum body width) 147.9

b (body length/pharyngeal length) 13.5

c (body length/tail length) 95.7

c´ (tail length/body width at anus) 2.3

V or T ((distance from anterior end to 52 vulva or male gonad length/body length)

× 100)

Odontostyle length 62.0

Replacement odontostyle length –

Odontophore length 37.0

18 12 2 5

4.9 ± 0.59 4.6 ± 0.37 (1.18, 1.21) 1.7 ± 0.27 (4.1–6.1) (4.0–5.1) (1.28–1.95) 156.3 ± 12.9 159.0 ± 18.3 (56.3, 58.9) 81.5 ± 4.7 (138.6–179.4) (133.0–186.3) (77.2–88.8) 16.2 ± 2.0 15.7 ± 1.5 (6.8, 7.5) 9.1 ± 1.5 (13.5–19.9) (13.1–18.8) (7.8–11.2) 106.8 ± 16.4 103.6 ± 10.5 (27.7, 29.9) 38.1 ± 5.4 (87.4–139.6) (87.5–117.6) (29.5–42.5) 2.2 ± 0.3 2.0 ± 0.1 (3.2, 3.5) 3.2 ± 0.1 (1.8–2.6) (1.8–2.3) (3.0–3.3) 48.7 ± 1.7 29.2 ± 7.0 – – (46.0–52.0) (16.0–41.2)

61.7 ± 2.9 62.8 ± 2.4 (42.0, 42.5) 44.5 ± 1.1 (57.0–69.0) (59.0–66.5) (43.0–46.0) – – (45.0, 46.5) 49.5 ± 0.9

(48.5–51.0) 38.0 ± 4.8 34.2 ± 4.5 (24.5, 25.0) 26.5 ± 02.8 (29.5–47.5) (27.0–41.0) (24.0–30.5)

2.7 ± 0.19 (2.46–2.98) 112.3 ± 11.5 (97.5–128.1) 11.3 ± 0.8 (10.0–12.2) 58.8 ± 4.5 (53.6–66.2) 2.7 ± 0.2 (2.5–3.0)

–

52.0 ± 2.3 (49.5–54.5) 56.8 ± 2.2 (53.0–59.0) 27.3 ± 2.8 (24.0–31.5) 4

3.4 ± 0.29 (3.02–3.64) 145.4 ± 7.0 (137.3–151.5) 12.3 ± 2.4 (8.8–14.3) 74.7 ± 7.6 (69.4–85.6) 2.6 ± 0.2 (2.4–2.9)

–

53.4 ± 2.1 (51.0–56.0) 60.9 ± 2.0 (58.0–62.5) 33.6 ± 3.2 (29.0–36.0) Total stylet length 99.0 99.7 ± 5.6 97.0 ± 5.5 – – – – (92.0–110.0) (87.0–107.5)

Lip region width 8.5 9.6 ± 0.5 9.3 ± 0.5 (7.0, 7.5) 7.8 ± 0.6 8.5 ± 0.5 8.4 ± 0.8 (8.5–10.5) (8.5–10.0) (7.0–8.5) (8.0–9.5) (8.0–9.5)

Oral aperture guiding-ring 23.0 23.2 ± 1.0 23.0 ± 1.3 (15.0, 15.5) 17.3 ± 1.4 19.3 ± 1.1 21.3 ± 0.9 (21.5–24.5) (21.0–25.0) (16.0–19.0) (18.0–21.0) (20.5–22.0)

Tail length 42.5 45.7 ± 5.4 44.2 ± 2.7 (40.5, 42.5) 45.0 ± 1.6 45.4 ± 2.0 45.8 ± 3.2 (36.0–55.0) (40.0–49.0) (43.0–46.5) (43.5–49.0) (42.5–48.5)

Spicules – – 33.5 ± 1.9 – – – –

(30.5–37.0)

Lateral accessory piece – – 9.9 ± 1.2 – – – –

(8.0–12.0)

J (hyaline tail region length) 10.0 9.0 ± 1.0 9.4 ± 1.4 (4.0, 4.5) 6.3 ± 0.3 7.5 ± 1.7 7.1 ± 0.9 (7.0–10.0) (7.5–11.5) (6.0–6.5) (6.5–10.0) (6.0–8.0)

n 1 13 6 4 3

L 6.9 7.3 ± 0.51 7.2 ± 0.39 2.2 ± 0.86 3.2 ± 0.54 (6.7–8.3) (6.6–7.7) (2.09–2.27) (2.67–3.74) a (body length/maximum body 104.1 102.4 ± 5.7 107.7 ± 11.6 101.4 ± 9.2 102.3 ± 6.1 width) (91.8–112.8) (85.6–116.2) (88.7–109.7) (96.9–108.9) b (body length/pharyngeal length) 12.1 15.2 ± 1.9 15.2 ± 1.9 9.3 ± 1.4 10.7 ± 3.5 (12.1–18.1) (12.7–16.7) (7.3–10.6) (8.1–14.6)

c (body length/tail length) 170.2 184.1 ± 16.3 178.0 ± 11.6 53.2 ± 2.5 79.5 ± 17.7 (155.9–212.9) (164.8–195.2) (50.2–55.9) (63.5–98.5) c´ (tail length/body width at anus) 0.9 0.8 ± 0.1 1.0 ± 0.1 2.5 ± 0.1 1.6 ± 0.2 (0.7–0.9) (0.9–1.1) (2.4–2.6) (1.3–1.7)

V or T ((distance from anterior end 50 49.5 ± 0.7 54.7 ± 6.5 – –

to vulva or male gonad length/body (48.0–50.0) (47.6–63.2)

length) × 100)

Odontostyle length 123.0 122.4 ± 4.0 119.4 ± 4.9 72.3 ± 0.5 83.7 ± 3.2 (115.0–129.0) (114.0–125.0) (72.0–73.0) (80.0–86.0) Replacement odontostyle length – – – 80.9 ± 3.3 92.3 ± 6.1 (77.0–85.0) (87.0–99.0) Odontophore length 64.0 64.3 ± 3.4 55.4 ± 9.6 36.1 ± 1.4 42.8 ± 3.6 (57.0–68.0) (48.0–69.0) (34.0–37.0) (40.5–47.0) Total stylet length 187.0 186.7 ± 6.7 174.8 ± 14.1 – – (175.0–197.0) (163.0–193.0)

4.4 ± 0.18 (4.20–4.61) 92.6 ± 14.8 (74.4–106.5) 9.5 ± 1.7 (7.8–11.9) 95.3 ± 14.9 (79.3–115.3) 1.2 ± 0.1 (1.1–1.3)

–

95.4 ± 2.1 (93.0–98.0) 113.0 ± 1.6 (111.0–115.0) 47.4 ± 1.4 (46.0–49.0)

–

6.0 ± 0.45 (5.48–6.51) 99.3 ± 1.6 (82.5–109.9) 12.3 ± 1.3 (10.8–13.7) 141.4 ± 14.0 (123.2–154.9) 1.0 ± 0.1 (0.9–1.1)

–

107.1 ± 3.6 (101.0–110.0) 122.8 ± 2.2 (121.0–126.0) 55.3 ± 1.6 (54.0–58.0)

–

Lip region width 12.0 11.7 ± 0.7 11.7 ± 0.8 5.9 ± 0.8 7.5 ± 0.5 9.0 ± 0.7 10.4 ± 0.9

(11.0–12.5) (10.5–12.5) (5.0–6.5) (7.0–8.0) (8.5–10.0) (9.5–11.5) Oral aperture guiding-ring 36.5 38.2 ± 1.5 38.3 ± 1.8 23.5 ± 0.6 26.7 ± 1.3 30.5 ± 1.9 36.1 ± 0.5

(36.5–40.5) (36.0–40.5) (23.0–24.0) (25.5–28.0) (28.0–32.0) (35.5–36.5) Tail length 41.0 40.1 ± 4.6 40.4 ± 2.2 41.0 ± 2.0 40.2 ± 2.0 47.3 ± 5.4 42.4 ± 1.4

(32.5–50.0) (36.5–43.0) (39.0–43.5) (38.0–42.0) (40.0–53.0) (41.0–44.5) Spicules – – 70.8 ± 7.4 – – – –

(62.0–79.0)

Lateral accessory piece – – 12.8 ± 1.5 – – – –

(10.0–14.0)

J (hyaline tail region length) 20.5 19.3 ± 2.4 19.2 ± 2.9 10.8 ± 0.6 14.2 ± 2.5 15.2 ± 2.3 16.7 ± 1.6

(16.5–24.0) (14.5–22.0) (10.0–11.5) (12.5–17.0) (12.5–16.5) (14.5–18.0)

shorter body length, tail shape and presence of replacement odontostyle ( fig. 7b View FIGURE 7 ). Tail becoming progressively shorter and stouter in each moult ( fig. 9 View FIGURE 9 and table 4). J1s characterised by a bluntly rounded to cylindrical tail with a c’ ratio 2.4–2.6 ( table 3). J2–J4 tails dorsally convex conoid and terminus bluntly rounded compared to that of female in shape ( fig. 9 View FIGURE 9 and table 4). Remarks. Morphologically and according to the updated polytomous key by Chen et al. (1997) and the supplement by Loof & Chen (1999), the specific matrix code for this species is A4(5)-B1-C3-D1-E3-F4-G1-H1-I2- J1–K1. Based on sorting of matrix codes A (length of odontostyle), C (distance of guiding-ring from anterior body end), D (lip region shape), F (body length), and H (tail shape) ( fig. 9 View FIGURE 9 , table 3), L. pacensis sp. nov. is closely related to L. baeticus , and L. fasciatus , from which it can be differentiated by a combination of several characters discussed below. From L. baeticus , it can be mainly differentiated by a higher c’ ratio in females (0.7–0.9 vs.05–0.7), a higher c’ ratio in J1 (2.4–2.6 vs 1.7–2.0), a slightly higher a ratio (av. 103.3 (91.8–112.8) vs av. 94.8 (73.4–106.3)), a slightly longer female tail (av. 40.1 (32.5–50.0) vs av. 37.1 (30.0–43.0 μm)), slightly lower c ratio (av. 184.1 (155.9–212.9) vs av. 207.5 (180.0–286.2)) and shorter spicules (62.0–79.0 vs 80.0–95.0 μm) (Gutiérrez-Gutiérrez et al., 2013). From a morphological and morphometrical point of view, this new species is almost indistinguishable from L.fasciatus and, therefore, should be considered a cryptic species, since all morphometric characters are within the range of the original description and those from Gutiérrez-Gutiérrez et al. (2013). Nevertheless, it can be clearly separated by specific 28S rRNA, ITS1 rRNA and CoxI sequences. Morphologically L. pacensis sp. nov. is also close to L. andalusicus Gutiérrez-Gutiérrez, Cantalapiedra-Navarrete, Montes-Borrego, Palomares-Rius and Castillo, 2013 , but the new species can be clearly differentiated by a longer body (6.7–8.3 vs 3.7–5.1 mm), and longer odontostyle (115.0–129.0 vs 78.0– 86.0 μm) (Gutiérrez-Gutiérrez et al., 2013). In addition, L. pacensis sp. nov. is molecularly related to L. macrodorus Archidona-Yuste, Navas-Cortés, Cantalapiedra-Navarrete, Palomares-Rius and Castillo, 2016a , but it can be differentiated by important characters, such as the shorter body and odontostyle length (6.3–8.3 vs. 8.3–10.1 mm, 115.0– 129.0 vs. 183.0–210.0 μm, respectively) (Archidona-Yuste et al., 2016a).

Morphology and Morphometry of other

Longidorus Species

Remarks. Morphological and morphometric data as well as DNA sequences were provided for L. africanus , L. carpetanensis , L. nevesi , L. cf. olegi , and L. pini . For these species, below brief descriptions and comparisons with previous records are provided.