Ektaphelenchoides fuchsi, Esmaeili, Mehrab, Heydari, Ramin, Pourjam, Ebrahim & Atighi, Mohammad Reza, 2014

Esmaeili, Mehrab, Heydari, Ramin, Pourjam, Ebrahim & Atighi, Mohammad Reza, 2014, Description of Ektaphelenchoides fuchsi n. sp. (Nematoda: Ektaphelenchinae) from western Iran, Zootaxa 3846 (3), pp. 430-438 : 431-436

Ektaphelenchoides fuchsi n. sp.

Figs 1& 2

Measurements. See Table 1.

Material examined. Holotype, female, from soil samples associated with the rhizosphere of Cucurbita maxima D. in Gilangharb region, Kermanshah province, Western Iran. Collected by Mehrab Esmaili in August 2013. It has been deposited in the Nematode Collection of the Faculty of Agriculture, Tarbiat Modares University, Tehran, Iran (Slide no. Ektaphelenchoides fuschi n. sp., Holotype 1).

Paratypes, one male and one female deposited at Nematode Collection of the Faculty of Agriculture, Tarbiat Modares University, Tehran, Iran. Three female and two male paratypes (Slides AEF001, AEF002) deposited in nematode collection of the Department of Plant Protection, College of Agriculture and Natural Resources, University of Tehran, Karaj, Iran. Three female paratypes deposited at each of the following collections: CABI Europe– UK, Egham, Surrey, UK; USDA Nematode Collection, Beltsville, MD, USA and Department of Nematology, WANECO collection, Wageningen (http://www.waneco.eu/).

1 Length of conus as percentage of total stylet length.

2 Distance between anterior end of body and centre of median pharyngeal bulb as percentage of pharyngeal length. 3 Distance from pharyngo–intestinal junction to tip of dorsal gland.

Description. Female. Body cylindrical, slightly ventrally curved when heat–killed. Cuticle mostly less than 1 Μm thick, finely annulated. Lateral fields with three incisures. Lip region slightly set–off, separated from body contour with a weak constriction, 3–4 µm high, 7–8 µm wide. Stylet 14–18 Μm long, with basal knobs, conus occupying ca 34–41% of its total length. Procorpus cylindrical, ending in an elongate rectangular metacarpus with anterior granular part, occupying 35–40% of its total length. Pharyngeal glands well-developed, overlapping intestine dorsally, 4–7 times as long as body diameter at level of median bulb. Excretory pore 8–22 Μm posterior to the base of metacorpus, hemizonid 13–20 Μm posterior to the excretory pore and 70–84 Μm from anterior end. Reproductive tract prodelphic, gonad outstretched, occupying 40–48% of the body length, oocytes mostly in two rows, spermatheca irregular, filled with rounded sperm, vagina not sclerotised, straight, without flap, post-uterine sac short, less than half body diameter at vulva region. Intestine apparently ending in a blind sac at about one third to half distance from vulva to posterior end, no rectum or functional anus. Posterior end (tail) filiform.

Male. Rare. Body slender, arcuate to J-shaped after heat relaxation, posterior end more ventrally curved. Anterior region similar to that of female. Testis single, expanded anteriorly, not reflexed. Spicules arcuate, separate, ca 3.2–4.0 times longer than capitulum width, lamina/calomus smoothly and symmetrically curved, rostrum sharply pointed, condylus well-developed and more developed than rostrum. Cucullus and bursa absent. Five papillae present with their arrangement as follows: a single mid-ventral pre-cloacal papilla (P1) about 7 µm anterior to the cloacal opening, one pair of sub-ventral papillae (P2) at level of or just posterior to the cloacal opening, and one sub-ventral pair of post-cloacal papillae (P3) at 16–17 µm posterior to the cloacal opening. Tail conoid with sharply pointed filiform terminus.

FIGURE 1. Ektaphelenchoides fuchsi n. sp. A: Female entire body; B: Male entire body; C: Female anterior region; D: Female posterior body; E: Female anterior end; F: Position of excretory pore and Hemizonid. G: Male posterior body showing caudal papillae; H: Female stylet; I: Spicule in detail; J: Cross section of female.

FIGURE 2. Ektaphelenchoides fuchsi n. sp. A, B: Female anterior body; C: Female stylet; D: Cross section of female showing lateral field; E, F: Female genital tract; G: Blind end of the intestine; H–J: Male posterior body showing spicules and papillae arrangement.

FIGURE 3. Bayesian 50% majority rule consensus tree inferred from 51 sequences of D2/D3 expansion segments of 28S rRNA gene under the GTR + I + G model. Posterior probabilities and Maximum Likelihood bootstrap values are given on appropriate clades in the form Bayesian posterior probabilities /Maximum Likelihood bootstrap. The new and previously described species from Iran are in bold.

Type locality and habitat. Collected from rhizosphere of C. maxima in Gilangharb region, Kermanshah province, Western Iran (GPS coordinates: N 33˚ 59', E 46˚ 12', 1248 meters above sea level).

Diagnosis and relationships. Ektaphelenchoides fuchsi n. sp. is characterized by its body length (529–712 Μm long in females), stylet 14–18 Μm long with distinct basal knobs, lateral fields with three incisures, position of excretory pore at level of posterior part of the metacorpus, 70–84 Μm from anterior end, hemizonid 87–96 Μm from anterior end, post-uterine sac short, less than half body diameter at vulva region (6–9 µm) and posterior body end (tail) filiform in females, spicules with sharply pointed rostrum and rounded condylus, and conoid tail with a sharply pointed terminus in males. The male genital papillae comprise a single precloacal papilla and an adcloacal and a post-cloacal pair.

The new species is close to E. attenuata ( Massey, 1974) Baujard, 1984 , E. musae Baujard, 1984 and E. kelardashtensis in morphology and morphometrics. It differs from the closest species, E. kelardashtensis , by its longer stylet (14–18 vs 13–16 Μm) with basal knobs vs none, longer post-uterine sac (6–9 vs 3–6 Μm), more posterior location of the excretory pore and hemizonid (70–84 vs 55–66 and 87–96 vs 67–78 µm posterior to anterior end, respectively), and longer spicules (12–13 vs 8–10 Μm). It differs from E. attenuata by its smaller body length (529–712 vs 959 Μm), lower a ratio (33–42 vs 42), shorter post-uterine sac (6–9 vs 23–28 µm), slightly vs clearly offset lip region, stylet with basal knobs vs not, shape of the tail (conical with slight transition to filiform shape vs conical with sharp transition to filiform shape). Compared with E. musae , the new species has a shorter stylet (14–18 vs 18.5–22.0 Μm) with basal knobs vs not, more posterior location of the excretory pore and hemizonid (70–84 vs 60–74 and 87–96 vs 78–89 Μm from the anterior end, respectively), shorter post-uterine sac (6–9 vs 9–19 Μm) and more posterior location of vulva (V=64.2–87.5 vs 64–69).

Etymology. Named in honor of Gilbert Fuchs, a pioneer in the taxonomy of aphelenchid nematodes.

Molecular phylogenetic relationships. For molecular analyses, the 631bp ribosomal DNA large subunit (LSU) D2/D3 (accession number: KJ 190832 ) of the new species was sequenced. A BlastN search of these sequences revealed the highest match was to aphelenchids, but with nothing identical. The species with the highest identity matches were included in the phylogenetic analyses. The dataset was composed of 837 total characters from which 619 characters were variable and 534 characters were parsimonious informative after manual editing. The average nucleotide composition was as follows: 22.7 % A, 19.2 % C, 30.9 % G and 27.2 % T. Figure 3 presents a phylogenetic tree based on the LSU D2/D3 of various aphelenchids and one outgroup taxon.

Using Poikiliolaimus piniperdae (DQ059060) as an outgroup, Ektaphelenchoides fuchsi n. sp. formed a monophyletic clade with high posterior probability (1.00) with species of Ektaphelenchoides and Devibursaphelenchus Kakuliya, 1967 . The new species is unique and different from four (characterized by molecular data) other described species from Iran with its partial sequence of 28S rDNA D2/D3.