Xiphinema barooghii, Vazifeh & Niknam & Jabbari & Naghavi, 2019

Vazifeh, Nasir, Niknam, Gholamreza, Jabbari, Habibeh & Naghavi, Arezoo, 2019, Description of a new dagger nematode, Xiphinema barooghii n. sp. (Nematoda: Longidoridae) and additional data on the three known species of the genus from northwest of Iran, Journal of Nematology 51 (1), pp. 1-17 : 3-4

Xiphinema barooghii n. sp.

( Figs. 1–3 ; Tables 1–3).

Description

Female

It is characterized by having a cylindrical body, gradually tapered towards both ends, ventrally curved, open C to G-shape upon fixation. It has a two-layered cuticle and very fine transverse striations are visible more in tail region, 3.0–4.0 μm wide at mid-body and 11–16 μm at the tail tip. Lateral pores are present along the body, with four dorsal and five ventral located between anterior end and guiding ring. Lateral chords of 14–17 μm or those occupying one-fifth of the mid-body diameter are present. The lip region is flat and the cephalic region is rounded, separated from body contour by a shallow depression, 1.7–2.5 times as broad as high and one-fourth to one-fifth (21–28%) of body diameter at neck base. Amphidial fovea is cup shaped, with aperture occupying 52–59% of the corresponding lip region diameter, located slightly anterior to depression of head, remainder of body and pouches typical of the genus. Odontostyle is long and slender, furcates at junction with odontophore, 8.8–9.4 times lip region diameter or 1.5–1.8 times odontophore length. Odontophore with well-developed basal flanges, 14–18 μm wide, exists. A double guiding ring and a guiding sheath of 3–30μm length, depending on the degree of protraction/retraction of stylet, is present. Esophagus is slen- der with a weak muscular narrow part extending to a cylindrical terminal esophageal bulb with three nuclei. The esophageal basal bulb is 128–153 μm long, occupying about 24–29% of total esophagus length and 24–31 μm width. The nucleus of dorsal esophageal gland ( DN) is located at the beginning of basal bulb (8–11%), 3.7–5.1 μm in diameter, dorsal gland esophageal orifice ( DGEO), 4.7–6.5 μm from anterior end, and two smaller ventrosublateral nuclei ( SVN) located at 52–57% of the terminal bulb length. The esophageal intestinal valve is rounded conoid with 12–14 μm length. The tip of reserve odontostyle (vestigium) is observed in isthmus in some specimens. The nerve ring is positioned at 55 68% length from anterior end and intestine is simple. The female reproductive system is didelphic–amphidelphic with equally developed genital branches (428–575) μm and (387–512) μm long, respectively. Each branch is composed of a 64–117 μm long reflexed ovary, not reaching the oviduct–uterus junction; oocytes are arranged first in several rows and then in a single row; oviduct is 70–160 μm long with developed pars dilatata oviductus near the sphincter, joining the ovary terminally; oviduct-uterus junction is marked by a poorly developed sphincter and a 256–297 μm long bipartite uterus composed of pars dilatata uteri close to sphincter and a tubular part containing spines 2–5 μm long, spindle-shaped and scattered between the enlarged distal portion and the ovejector, with a lack of sperm in the genital tract. Ovejector is well developed (71- 84×15- 28 μm); vagina is perpendicular to body axis, 31–37 μm long or 42–52% of corresponding body diameter in lateral view and surrounded by robust muscles. Vulva, a transverse slit, pre-equatorial in position, is present. Pre-rectum variable is 503–700 μm in length and the rectum length is 0.7–1.1 times anal body diameter. A short tail, conoid and dorsally convex, ventrally directed with a small terminal peg, 4.5–7.5 μm long, and a distinct terminal blind canal, exists. Three to four caudal pores are present on each side.

Male

Not found.

Figures

Figure 1: Xiphinema barooghii n. sp. (A) Amphidial pouch; (B) Entire body; (C) Neck region; (D) Female tail; (E) Anterior end; (F) Posterior genital branch; (G–J) Tail of juveniles from J1–J4, respectively.

Figure 2: Xiphinema barooghii n. sp. Female (A, B) anterior end; (C, G) uterine differentiation spines; (D) entire body; (E) reproductive system; (F) vagina; (H) tail; (I) caudal pores in lateral optical view; (J) amphidial pouch; (K) pharyngeal expansion. (Scale bars: A–K=10μm, D=70μm).

Figure 3: Juvenile stages of Xiphinema barooghii n. sp. Anterior region and tail shape of (A, B) first; (C, D) second; (E, F) third and (G, H) fourth juvenile stages, respectively (Scale bars =10μm).