Xiphinema plesiopachtaicum, Archidona-Yuste & Navas-Cortés & Cantalapiedra-Navarrete & Palomares-Rius & Castillo, 2016

Archidona-Yuste, Antonio, Navas-Cortés, Juan A., Cantalapiedra-Navarrete, Carolina, Palomares-Rius, Juan E. & Castillo, Pablo, 2016, Cryptic diversity and species delimitation in the Xiphinema americanum-group complex (Nematoda: Longidoridae) as inferred from morphometrics and molecular markers, Zoological Journal of the Linnean Society 176 (2), pp. 231-265 : 237-238

XIPHINEMA PLESIOPACHTAICUM SP. NOV.

( FIGS 1–3 , TABLE 2)

Holotype: Female extracted from soil samples collect- ed from the rhizosphere of wild olive ( Olea europaea ssp. sylvestris ) in Coto Ríos, Jaén province, southern Spain (38°02′11.14″N, 2°54′11.27″E), by J. Martín Barbarroja and G. León Ropero, mounted in pure glycerine and deposited in the nematode collection at the Institute for Sustainable Agriculture ( IAS) of Spanish National Research Council ( CSIC), Córdoba, Spain (collection number AR63-05).

Paratypes: Female and juvenile paratypes extracted from soil samples collected from the rhizosphere of wild olive at Coto Ríos, Jaén province , southern Spain, were deposited in the following nematode collections: IAS- CSIC (collection numbers AR63-01–AR63-02, AR63- 04–AR63-12); two female paratypes at the Royal Belgian Institute of Natural Sciences , Brussels, Belgium ( RIT831 ), and two female paratypes at the USDA Nematode Collection, Beltsville, MD, USA (collection number T-6285p) .

Etymology: The species epithet refers to a compound name from the Greek word plesios = near, and pachtaicum , the closest species of the genus Xiphinema . Description of female: Body medium-sized, forming a close C-shaped to open spiral when killed by heat. Body tapering very gradually towards the extremities. Cuticle smooth, finely striated transversely, 2.0 ± 0.2 (1.5– 2.5) μm thick along body but thicker at tail tip ( Table 2). Lip region flatly rounded, expanded, separated from rest of body by constriction, 9.5 ± 0.4 (8.5–10.5) μm wide. Amphidial fovea funnel-shaped, with slit-like aperture at constriction level, 6.6 ± 0.2 (6.5–7.0) μm wide. Pharynx consisting of an anterior slender narrow part, 238– 350 μm long, extending to a terminal pharyngeal basal bulb well demarcated anteriorly, cylindrical, 73.4 ± 5.1 (63–84) μm long, 14.1 ± 1.1 (11.5–15.5) μm wide, occupying about one fifth to one third of the total pharyngeal length. Glandularium 65.0 ± 5.1 (56–78) μm long. Dorsal pharyngeal nucleus (DN) in anterior part of the bulb 12.4 ± 2.0 (10.4–16.0) % of basal bulb length, and subventrolateral nuclei (SVN) located around midbulb 53.3 ± 4.4 (49.5–61.7) % of basal bulb length (location of gland nuclei according to Loof & Coomans, 1972; Fig. 2 ). Reproductive system amphidelphic, both branches equally developed; ovaries reflexed with symbiontic bacteria; uteri rather short (c. 138 μm long) without any differentiation. Vulva postequatorial, transverse slit-like; vagina 11.3 ± 1.8 (9.0–15.0) μm long with short distal part and well developed proximally ( Fig. 2 ). Prerectum 449.0 ± 53.7 (411.0–487.0) μm long. Rectum 16.7 ± 3.4 (13.5–25.0) μm long. Tail short, but longer than anal body diameter (c′ = 1.3–1.7), dorsally convexconoid, with pointed tip, and often with dorsal and occasionally dorsoventral depression at hyaline region level; two pairs of caudal pores present ( Fig. 2 ). Tail hyaline region 7.6 ± 1.3 (5.5–10.0) μm long.

Male: Not detected.

Description of juveniles: Only one juvenile stage was detected (fourth stage), which was morphologically similar to the female but from which juveniles differ by their size, longer and more tapering tails, and development of reproductive system.

Diagnosis: Xiphinema plesiopachtaicum sp. nov. is a parthenogenetic species characterized by a medium body size (1520–2078 μm); lip region flatly rounded, separated from the rest of the body by constriction; odontostyle and odontophore 83 and 48 μm long, respectively; V = 55–60%; female tail short (23.5– 28.5 μm), dorsally convex-conoid, with pointed tip, and often with dorsal and occasionally dorsoventral depression at hyaline region level; c ratio of 62.5–88.7), c′ ratio of 1.3–1.7; and specific D2-D3 and ITS1- rRNA sequences deposited in GenBank with accession numbers KP268956 – KP268958 , and KP268973 , respectively. Morphologically and morphometrically, X. plesiopachtaicum sp. nov. can be distinguished from

238 A. ARCHIDONA-YUSTE ET AL.

the most similar species by a number of particular characteristics from its specific alphanumeric codes (exceptions are in parentheses): A 3(2), B 3, C 2(3), D 2, E 2, F2, G 2, H 1, I 1(2) sensu Lamberti et al. (2004).

Figures

Figure 1. Line drawings of: A–D, Xiphinema plesiopachtaicum sp. nov.; E–H, Xiphinema vallense sp. nov.; I–L, Xiphinema astaregiense sp. nov. A, E, I, female lip regions. B–D, F, G, J, K, female tail regions. H, L, male tail regions.

Figure 2. Line drawings of pharyngeal bulb and anterior genital branch of: A, B, Xiphinema plesiopachtaicum sp. nov.; C, D, Xiphinema vallense sp. nov.; E, F, Xiphinema astaregiense sp. nov.

Figure 3. Light micrographs of Xiphinema plesiopachtaicum sp. nov. A, entire female. B, female neck region. C, D, female lip region. E, vulval region. F–K, female tail regions from different specimens showing the morphological variability. Abbreviations: a, anus; gr, guiding ring; V, vulva. Scale bars: A = 100 μm; B–K = 20 μm.