Longidorus iliturgiensis, 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 : 18-19

Longidorus iliturgiensis sp. nov.

http://zoobank.org/ urn:lsid:zoobank.org:act:253C46DF-D3F4-42BB-B675-6E8EC0A7EF7A

( figs. 5 , 6 and 7 , table 2)

Material examined. Holotype Adult female, collected from the rhizosphere of black alder ( Alnus glutinosa L.) by J. Martin Barbarroja, March 9, 2014; 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 ALAN-09).

Paratypes. Female , male and juvenile paratypes extracted from soil samples were 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 ALAN-01-ALAN-15); two females at Istituto per la Protezione Sostenibile delle Piante ( IPSP), Consiglio Nazionale delle Ricerche ( CNR), Bari, Italy (ALAN-16); and two females and one male at USDA Nematode Collection, Beltsville, MD, USA (T-6984p); collected by J. Martin Barbarroja, March 9, 2014 .

Type locality. Andújar , Jaen province, Spain: 38° 9'7.45"N, 4°0'54.35"W; 267 m above sea level (a.s.l.).

Etymology. The species name is derived from “ iliturgi ” the Roman name of Andújar, where the type specimens were found.

Diagnosis. Longidorus iliturgiensis sp. nov. is an amphimictic species characterised by a moderately long body (4.1–6.1 mm), assuming an open C-shaped body when heat relaxed; lip region expanded distinctly set off from body contour, 8.5–10.5 μm wide and 4.0–5.0 μm high; guiding-ring located 21.5–24.5 μm from anterior end; relatively short odontostyle 57.0–69.0 μm; amphidial fovea slightly asymmetrically bilobed; vulva almost equatorial; female tail long, dorsally convex-conoid, and bearing three pairs of caudal pores; c’ ratio (1.8–2.6); males frequent (2:3 ratio), with short spicules (30.5–37.0 μm) and 7–11 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), new species has the following code (codes in parentheses are exceptions): A2(1)-B1-C2-D4-E2-F23-G3-H6(5)-I21- J1–K6. Specific D2–D3 region, ITS1 rRNA, partial 18S rRNA and CoxI mtDNA gene sequences (GenBank accession numbers MH430012-MH430013, MH429987-MH429988, MH430002-MH430003, and MH454065, respectively)

Description. Female. Body relatively long and thin, slightly tapering towards both ends. When heat relaxed, body ventrally curved in open C-shape.

Cuticle thin appearing smooth under low magnifications, 1.7 ± 0.3 (1.5–2.0) μm thick at mid-body but thicker (9.0 ± 1.0 (7.0–10.0) μm) and marked by very fine superficial transverse striate mainly in tail region. Lateral chord approximately 9.0 μm

wide at mid-body or approximately 29% of corresponding body diameter. Lip region expanded distinctly set off from body contour, anteriorly flattened, 9.6 ± 0.5 (8.5–10.0) μm wide and 4.4 ± 0.3 (4.0–5.0) μm high. Amphidial fovea slightly asymmetrically bilobed with lobes occupying approximately 1/2 of the distance between oral aperture and guiding-ring. Guiding-ring single, located

2.4 ± 0.2 (2.1–2.7) times lip region diameter from anterior end. Odontostyle 1.7 ± 0.2 (1.2–2.2) times as long as odontophore, straight or slightly arcuate; odontophore Downloaded weakly developed from Brill.com, with08/rather 29/2023weak 05:44:51PM via free access basal swellings. Nerve ring surrounding odontophore base at 94.3 ± 6.8 (89.0–102.0) μm from anterior end. Anterior slender part of pharynx usually coiled in its posterior region. Basal bulb short and cylindrical, 82.3 ± 6.6 (68.5–92.0) μm long and 13.5± 1.7 (11.5–16.5)μm in diam.Glandularium 72.4 ± 7.6 (59.0–85.5) μm long. Dorsal pharyngeal gland nucleus (DN) and ventrosublateral nuclei (SVN) located at 23.9% ± 3.8 (18.1–28.4%) and 56.4% ± 3.5 (48.9–59.3%) of distance from anterior end of pharyngeal bulb, respectively. Nucleolus of DN larger than nucleoli of two SVN (3.5–4.0 vs 2.5–3.0 μm). Cardia conoid-rounded, 7.3 ± 1.2 (6.0–8.0) μm long. Prerectum very variable in length, 598.3 ± 163.7 (347.0–783.0) μm long, and rectum 21.7 ± 3.2 (16.5–26.0) μm long ending in anus as a small roundedslit.Reproductivesystemwithbothgenital branches almost equally developed, each branch 236–578 μm long, with reflexed ovaries. Vulva in form of a transverse slit, located almost equatorial, vagina perpendicular to body axis, 13.9 ± 1.8 (11.0– 17.5) μm long or 37–57% of corresponding body width, surrounded by well-developed muscles. Genital branches equally developed, (G1) 7.2 ± 1.4 (5.0–10.0), (G2) 6.9% ± 1.2 (4.9–8.7%) of body length, respectively. Uteri with sperm cells in all female specimens examined; sphincter well-developed, between uterus and oviduct. Eggs measuring205.0 ± 13.1 (191.0–217.0)μ m long and 30.7 ± 1.6 (29.5–32.5) μm wide. Anterior and posterior oviduct of similar size. Tail moderately long, dorsally convex-conoid, with rounded terminus, bearingthreepairsofcaudalpores.

Male. Almost as frequent as female. Morphologically similar to female except for genital system and posterior region slightly curved ventrally. Male genital tract diorchic with testes opposed, containing multiple rows of spermatogonia in the germinal zone. Tail conoid, dorsally conoid and ventrally concave with acute terminus and thickened outer cuticular layer. Spicules very short, moderately developed and slightly curved ventrally, approximately 0.7–0.9 times shorter than tail length; lateral guiding pieces straight with curved proximal end. Moderate number of supplements, one pair of adanal and from 6 to 10 mid-ventral supplements.

Juveniles. All four juvenile stages (first-, second-, third- and fourth-stage) were identified using morphological characters such as body length, length of replacement and functional odontostyle (Robbins et al., 1996). Juveniles were similar to adults apart from developed reproductive system, shorter body length, tail shape and presence of replacement odontostyle ( figs. 5 , 6–7 ). Tail becomes progressively shorter and stouter in each moult ( figs. 5 , 6–7 and table 2). As for other longidorids, first-juvenile stage was characterised by the replacement odontostyle tip close to base of functional odontostyle and located at level of odontophore. In J2–J4, replacement odontostyle located at some distance from odontophore base. J1s were characterised by a bluntly rounded to cylindrical tail with a c’ ratio>3.0 ( figs. 5–6 and table 2).

Remarks. 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 was A2(1)-B1-C2-D4-E2-F23-G3-H6(5)- I21-J1–K6. Based on sorting of matrix codes A (odontostyle length), B (lip region width), C (distance of guiding-ring from anterior body end),

D (lip region shape), and E (shape of amphidial fovea), L. iliturgiensis sp. nov. is closely related to several species described from Spain: L. indalus Archidona-Yuste, Navas-Cortés, Cantalapiedra-Navarrete, Palomares-Rius & and Castillo (2016a), L. carpetanensis and L. unedoi Arias, Andrés & Navas (1986) , from which it can be differentiated by a combination of the characters discussed below. Longidorus iliturgiensis sp. nov. differs from L. indalus by a longer odontostyle (av. 61.9 (57.0– 69.0) vs av. 56.7 (54.0–59.5) μm long), and males (frequent vs very rare) (Archidona-Yuste et al., 2016a). From L. carpetanensis , it differs by a longer body length (4.1–6.1 vs 3.5–4.4 mm), higher a ratio (138.6 Downloaded –179.4 vs 96.0 from – Brill 118.0.com), and higher 08/29/2023 c and c´ 05:44:51PM via free access ratio (87.4–139.6 vs 77.0–96.0 and 1.8–2.6 vs 1.6–2.2, respectively), males presence (extremely rare vs frequent) (Arias, Andrés & Navas, 1986). From L. unedoi , it differs in that it has lower c and V ratio (87.4–139.6 vs 122.0–156.0 and 46.0–52.0 vs 52.0–58.0; respectively) (Arias et al., 1986). Finally, L. iliturgiensis sp. nov. can be related to L. alvegus Roca, Pereira & Lamberti, 1989 from which it can be differentiated by a shorter body length (4.1–6.1 vs 6.3–7.8 mm), a shorter odontostyle (57.0–69.0 vs 82.5–92.5 μm long), and shorter distance from anterior end to guiding-ring (21.5–24.5 vs 25.6–33.1 μm) (Roca et al., 1989). Nevertheless, it can be clearly separated by specific 28S rRNA, ITS1 rRNA and CoxI sequences.

Figures

FIGURE 5 Line drawings of Longidorus iliturgiensis, sp. nov. paratypes. (A) Female neck region.(B) and (C) Female lip regions.(D) and (E) Female tails. (F) Male tail. (G) First-stage juvenile tail

FIGURE 6 Light micrographs of Longidorus iliturgiensis, sp. nov.(A)–(D) Anterior regions. (E) Vulval region. (F)–(I) Female tails. (J)–(M) First-, second-, third-, and fourth-stage juvenile (J1–J4) tails, respectively.(N)–(O) Male tail. Abbreviations:a = anus; af = amphidial fovea; spl = ventromedian supplements; v = vulva.Scale bars (A)–(C), (E)–(O) = 20 μm; (D) = 10 μm

FIGURE 7 Relationship of body length to length of functional and replacement odontostyle (Ost and rOst, respectively) length in all developmental stages from first-stage juveniles (J1) to mature females of. (A) Longidorus iliturgiensis sp.nov. (B) Longidorus pacensis, sp. nov.