Acrolobus longigubernaculum, Amirzadi, Negin, Shokoohi, Ebrahim, Eskandari, Ali & Abolafia, Joaquín, 2012

Amirzadi, Negin, Shokoohi, Ebrahim, Eskandari, Ali & Abolafia, Joaquín, 2012, Description of Acrolobus longigubernaculum sp. n. (Nematoda, Rhabditida, Cephalobidae) from Iran, the second species of the genus, Zootaxa 3407, pp. 61-68 : 62-67

publication ID

https://doi.org/ 10.11646/zootaxa.3407.1.5

DOI

https://doi.org/10.5281/zenodo.5662311

persistent identifier

https://treatment.plazi.org/id/B845A770-5A30-FFF5-FF08-FF1AFA0DFD2F

treatment provided by

Plazi

scientific name

Acrolobus longigubernaculum
status

sp. nov.

Acrolobus longigubernaculum View in CoL sp. n.

( Figs. 1–3 View FIGURE 1 View FIGURE 2 View FIGURE 3 & 4 View FIGURE 4 C, D)

Material examined. Eleven females and five males, in good state of preservation. Measurements. See Table 1 View TABLE 1 .

Description. Adult: Body 0.72–0.98 mm long, almost cylindrical, ventrally curved after fixation. Lateral fields with three incisures, occupying 17–19% of midbody diameter. Lip region set off from the neck. Six rounded, leaflike lips, the lateral ones somewhat smaller and almost transparent in their outer part, being visible under LM only the basal part of lip, this more or less triangular with rounded tip. Labial probolae absent. Amphidial opening circular. Stoma cephaloboid, cheilostom with bar-like rhabdia, gymnostom very short, stegostom long having metastegostom with a small dorsal denticle. Pharynx cephaloboid; corpus cylindrical, 2.7–3.2 times isthmus length, procorpus longer than metacorpus; isthmus narrower than metacorpus; basal bulb ovoid, with median valvular apparatus. Nerve ring surrounding the basal part of pharyngeal corpus, at 52–61% of neck length. Excretory pore located at level of basal part of pharyngeal corpus, 50–56 annuli from lip region or at 66–69% of neck length. Deirids located at level of isthmus, at 59–64 annuli from lip region or 71–75% of neck region. Cardia conoid, surrounded by intestinal tissue.

Female: Reproductive system monodelphic-prodelphic, located on the right-hand side of intestine. Ovary with double flexure in postvulvar region, with single row of oocytes. Oviduct short. Spermatheca well developed, offset, with sperm, 0.8–1.5 times the corresponding body diameter long. Postuterine sac 0.9–1.3 times the corresponding body diameter long, smooth or more or less lobed. Vulva slightly protruding, located posterior to the middle part of body. Rectum 1.0–1.2 times anal body diameter. Tail conical ending in a fine mucro. Phasmids at 48–55% of tail length.

Male: Body curved ventrally after fixation. Reproductive system monorchic, testis reflexed dorsad anteriorly. Tail conical, distally curved ventrad, and ending in a fine mucro. Three pairs of precloacal genital papillae. Five pairs of caudal genital papillae are present along the tail comprising: one ventral pair, one lateral pair, one dorsal pair, and two pairs near tail terminus. Spicules curved ventrally: manubrium almost straight and slightly conoid, calamus with similar width to manubrium, and lamina ventrally curved. Gubernaculum long and well developed, 12–16 mm long or about 50% of the spicule length, slightly curved distally.

Diagnosis. The new species is characterized by its body length of 0.72–0.98 mm in females and 0.73–0.84 mm in males, annulated cuticle, lateral fields with three longitudinal incisures, slightly offset lip region 7–11 μm wide, leaf-like lips, stoma 12–16 µm long, corpus 2.7–3.2 times isthmus length, spermatheca 23–53 µm long, postuterine sac 27–49 µm long or 0.9–1.3 times the corresponding body diameter, vulva located slightly posterior to middle of body (V = 61–65), conical female tail with fine short mucro (47–58 µm, c = 13.9–18.5, c’ = 2.4–3.2), conical male tail bearing a fine mucro (47–50 µm, c = 14.8–17.5, c’ = 2.0–2.3), spicules 26–30 μm long and ventrally curved, and gubernaculum 12–16 µm long (50% of spicule length).

Relationships. The new species is similar to the type species of the genus, Acrolobus emarginatus , but can be distinguished by its longer body (0.72–0.98 vs 0.45–0.62 mm in females and 0.73–0.84 vs 0.43–0.51 mm in males), longer pharynx (154–213 vs 120–150 µm), longer postvulvar sac (27–49 vs 17–25 µm), longer and differently shaped tail (47–58 μm and ventrally straight vs 32–41 µm and with similar dorsal and ventral morphology in females and 47–50 μm and strongly ventrally curved posteriorly vs 30–35 µm and almost straight in males), longer and differently shaped spicules (26–30 µm, strongly bent ventrally vs 17–21 µm, almost straight), and longer gubernaculum (12–16 vs 8–9 µm).

Type habitat and locality. The specimens were collected in association with the rhizosphere of Sonchus arvensis L., in Shahrood (Semnan province), in northeastern Iran.

Type material. Female holotype , eight female and three male paratypes deposited in the nematode collection of the Department of Plant Protection, College of Agriculture, Shahid Bahonar University of Kerman, Iran. Three female paratypes and one male paratype deposited in Departamento de Biología Animal, Biología Vegetal y Ecología, Universidad de Jaén, Spain.

Etymology. The specific epithet refers to the length of the gubernaculum in comparison with the type species.

TABLE 1. Measurements of Acrolobus longigubernaculum sp. n. (all measurements in mm).

Locality Shahrood    
Habitat Sonchus arvensis  
Character Holotype female Paratype females Mean ± S.D. (range) Paratype males Mean ± S.D. (range)
n 1 10 5
Body length 782 804.6 ± 67.6 (721–978) 784.2 ± 45.2 (726–837)
a 23.7 25.3 ± 1.5 (23.3–28.3) 25.5 ± 3.1 (21.4–28.3)
b 3.7 3.9 ± 0.5 (3.5–5.3) 4 ± 0.3 (3.6–4.5)
c 16.3 15.5 ± 1.4 (13.9–18.5) 16.1 ± 1.1 (14.8–17.5)
2.7 2.7 ± 0.3 (2.4–3.2) 2.2 ± 0.1 (2.0–2.3)
V 64 63 ± 1.5 (61–65)
Lip region diam. 8 8.7 ± 1 (8–11) 7.8 ± 0.4 (7–8)
Stoma 16 14.7 ± 1.3 (12–16) 15 ± 1 (14–16)
Pharyngeal corpus length 145 137 ± 15.1 (101–152) 137.4 ± 3.9 (132–142)
Isthmus length 43 42.3 ± 3.4 (37–47) 37.2 ± 6.9 (26–44)
Bulb length 24 22.6 ± 2.3 (19–26) 23.4 ± 2.2 (20–26)
Pharynx length 213 197.8 ± 19.9 (154–209) 198.8 ± 6.1 (188–203)
Nerve ring to ant. end 126 124.5 ± 8.9 (112–135) 124 ± 3.5 (121–128)
Excretory pore to ant. end 128 128 ± 6.9 (118–138) 125 ± 3.2 (121–128)
Deirid to ant. end 142 136.6 ± 5.0 (131–142) 139 ± 4.8 (134–144)
Neck length 229 224.0±19.5 (168–224) 213.8±5.6 (204–218)
Annuli width at midbody 2 1.9 ± 0.3 (1–2) 2.2 ± 0.4 (2–3)
Cuticle thickness 2 2±0.3 (1.7–2.2) 2.2 ± 0.4 (2–3)
Body diameter at: neck base 12 11.6 ± 0.5 (11–12) 11.8 ± 0.4 (11–12)
midbody 33 31.8 ± 2.1 (29–37) 31 ± 2.3 (29–34)
anus 18 19.3 ± 1.4 (17–21) 22.2 ± 0.4 (22–23)
Lateral field width 6 5.4 ± 0.7 (5–7) 5.0 ± 0.0 (5)
Vagina length 10 10.3 ± 0.8 (9–12)
Ovary length 233 248.1 ± 48.7 (184–340)
Anterior genital branch 148 137.8 ± 24.3 (94–176)
Spermatheca length 29 40 ± 11.8 (23–53)
Postuterine sac length 31 36.2 ± 7.8 (27–49)
Rectum length 23 21.8 ± 2.9 (18–27) ?
Tail length 48 52 ± 3.6 (47–58) 48.6 ± 1.5 (47–50)
Vulva to anterior end 498 509 ± 48.9 (453–634)
Spicule length 28 ± 1.6 (26–30)
Gubernaculum length 14.2 ± 1.5 (12–16)

Kingdom

Animalia

Phylum

Nematoda

Class

Chromadorea

Order

Rhabditida

Family

Cephalobidae

Genus

Acrolobus

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