Enchodelus repis, Brzeski, 1992

Brzeski, Michal W., 1992, Enchodelus repis sp. n. and comments on E. laevis Thorne, 1939 and E. microdoroides Baqri & Jairajpuri, 1974 (Nematoda: Dorylaimoidea) from Korea, Fundam. appl. Nematol. 15 (4), pp. 319-326 : 319-325

Enchodelus repis * sp. n.

(Figs l, 2, 4 A)

MEASUREMENTS

Females (paratypes: n = 25): L = 0.81 - 1.12 (1.00 ± 0.08) mm; a = 20-29 (25 ± 1.8); b = 4.0-5.1 (4.6 ± 0.3); c = 20.3-26.8 (24.1 ± 1.7); c' = 1.5-2.2 (1.8 ± 0.2); V = 50-57 (53.7 ± 1.7); body width at vulva = 35-42 (39.6 ± 2.6) Ilm; body width at anus = 21 -27 (23.4 ± 2.0) Ilm; odontostyle 7-9 (7.9 ± 0.5) Ilm, odontophore = 14- 19 (16.8 ± 1.4) Ilm, total stylet = 23-27 (25.1 ± 1.1); oesophagus = 196-236 (215 ± 10.3); tail = 31 -51 (41.5 ± 4.7 Ilm; DO = 69-73 (71.2 ± 0.9); DN = 75-78 (76.8 ± 1.0); SIO 83-86 (84.0 ± 1.0); SIN = 84-87 (85.0 ± 0.9); SzO = 91 -96 (93.0 ± 1.5); SzN = 90-95 (92.0 ± 1.8).

Males (paratypes: n = 15): L = 0.85- 1.07 (0.96 ± 0.06) mm; a = 24-29 (27 ± 1.5); b = 4.2-4.9 (4.5 ± 0.2); c = 19.1 -25.2 (22.3 ± 1.6); c' = 1.5- 1.7 (1.6 ± 0.1); maximum body width = 31 -40 (36 ± 2.6) Ilm; body width at cloacal opening = 25-29 (27 ± 1.2) Ilm; odontostyle = 7-9 (8.1 ± 0.5) Ilm; odontophore = 14- 19 (17.1 ± 1.5) Ilm; total stylet = 23-27 (25.5 ± 1.2) llm;oesophagus = 197-229 (213 ± 9.1) Ilm; tail = 38-46 (42.3 ± 2.4) Ilm; spicule along arc = 37-41 (39.8 ± 2.0) Ilm.

Holotype (female):L = 0.99 mm; a = 22; b = 4.7; c = 24.0; c' = 1.7; V = 54; body width at vulva 44 = 1lJl1; body width at anus = 25 Ilm; odontostyle = 8 Ilm, odontophore = 17 1lJl1; oesophagus = 210 Ilm; tail = 411lm; DO = 72; DN = 79; SIO = 86; SIN = 85; SzO = 93; SzN = 92.

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Allolype(male): L = 0.99 mm; a = 27; b = 4.7; c = 22.3; c' = 1.7; maximum body width = 36 lJll1; body width at c10acal opening = 27 llm; odomostyle = 81lm; odomophore = 16)lm; oesophagus = 212 Ilm; tail = 44 lJll1; spicule = 41 Ilm; ventromedian supplements = 4; DO = 73; DN = 80; SIO = 83; SIN = 84; S20 = 92; S2N = 92.

DESCRIPTION

AdullS: Body curved ventrad, the posterior part bent more strongly. Cuticle about 1.5 Ilm thick, smooth when viewed under light microscope. Subcuticular layer delicately striated. Lip region offset and narrower than adjacent body (sometimes less so). Lip region width 10- 11 Ilm. Lips amalgamated, rounded. Lip papillae large, dome shaped, cephalic papillae not distinct. Amphidial aperture about 6-7 Ilm. Guiding ring single, 6 Ilm from anterior end. Odontostyle Thin, 0.7-0.9 of head width long, with aperture of about 0.2-0.25 of its length. Odomophore devoid of sclerotized flanges, 1.6 (1.4- 1.8) of head width 10ng.Oesophagus starts ta widen at 63 (60-65) % and attains its full width at 74 (69-78) % of its length. Intestine filled, at least partly, with green structureless substance. Cylindroid crystals of various thickness seen in intestine of most specimens regardless of sex or age. Sometimes these crystals fill emire intestine width indicating they were formed within gut. Tail conical, bent ventrad to various degree, tip rounded to finely rounded almost pointed. Single caudal pore, very indistinct, could be detected in most specimens on each subdorsal tail sectar. Cuticle thickness at the tail end 7 (3-13) Ilm, depending on the elongation of the terminal part of tail.

Female: Vulva surrounded by cuticular flaps, cuticle between flaps usually wrinkled, occasionally flaps with 1 -2 wrinkles. Genital branches paired, recurved; out of 27 females 12 have both branches on the left side of body, lion the right side, and four had anterior branch on the right and posterior on the left side. Vagina 17-20 Ilm long, it is 41 -49 % of body width. Cuticular sclerotization near vagina not refractive. Uterus composed of twO parts: near vagina it is a spacious sac built of more or less rounded to haxagonal cells, then it forms a narrow tube probably surrounded by muscles. More distally uterus expands into a chamber in which a rigid tube, also termed sphincter, is observed. Intra-uterine eggs (n = 8) measure 67 (61 -70) x 30 (27-33) Ilm. Most egg bearing females have one egg, but one female with three eggs and another one with four eggs were seen. An aberrant bivulval female was observed CV = 53 and 56). Each vulva leads to a vagina and then to the common uterus. This female was functional as an egg was observed in uterine sac. Prereetum length 65 (50-82) Ilm or 2.8 (2.2-3.9) and rectum 19-24 Ilm or 0.8-0.9 of anal body width.

Male: Testes two, opposed, join in a non-muscular vas deferens. Four ejaculatory glands seen on each body side. Rectal glands poorly visible, located dorsally from spicules. Spicules rather plump, strongly curved, 1.5 (1.3-1.6) of anal body width long. Distance between cloaca (C) and first vemromedian supplement (SI)' and then between subsequent supplements in males with various supplement number is shown in Table 1 . Prerectum 64 (41-81) Ilm long.

TYPE HABITAT AND LOCALITY

Unidentified moss in a deciduous forest near Kaesong , Kores .

TYPE SPECIMENS

Holotype female, allotype male and paratypes (26 females, 14 males and 4 juveniles) deposited at the nematode collection of the Instytut Zoologii PAN, Warszawa, Poland. Two females and one male paratypes in each of the following centers: Nematology Department, Agricultural University, Wageningen, the Netherlands, and Institute of Zoology, University of Gem , Belgium. Seven females and four males paratypes in author's collection.

DIAGNOSIS AND RELATIONSHIPS

Small species with strongly arcuate body when relaxed. Odontostyle 7-9 Ilm, odontophore 14- 19 Ilm. Vulva with distinct cuticular flaps, cuticle mostly wrinkled near vulva, sometimes smooth. Tail conical and bent ventrad, Male with two to six, mostly four or five, ventromedian supplements.

Having conical arcuate tail and wrinkled cuticle near vulva E. repis should be compared with E. microdorus Schiemer, 1965 , E. iuventUlis (Andnlssy, 1971) Laof, 1989, E. VulvoslrialUs (Stefanski, 1924) Loof, 1989 and E. ebsaryi Loof, 1989 ,

Two males of E. microdorus from Austria served as a basis for description of this species ( Schiemer, 1965) and these can be differentiated from E. repis males by having double guiding ring. Male and females of this species were redescribed by Vinciguerra and de Francisci (1973) using specimens from Toscana, Italy. Accepting the Italian specimens are conspecific with the Austrian ones, the differences are noted in the advulval structure: the cuticle is wrinkled in E. microdorus but the advulval flaps are lacking, while these are distinct in E. repis ; the sclerotized plates near vulva are very refractive in E. microdorus and very indistinct in E. repis . These differences were observed in E. microdorus specimens kindly made available for comparison by Prof. M. T. Vinciguerra.

E. iuvenlUlis is longer, has shorter tail, more anterior vulva and longer spicules. In E. iuvenlUlis L = 1.42- 1.65 mm, c = 43-55, c· about l, V = 47-51, spicule = 50-54. Beside that E. iuventulis lack advulval f1aps and sclerotizations near vulva are more distinct.

E. vulvostriatus, as redescribed by Andrassy (1971), is larger J has longer odontophore and total odontostylet, and longer spicules. In E. VulvoslrialUs L 1.25- 1.98 mm, odontophore = 21 -23 Ilm, total stylet length = 30-31 1J.ffi. Other characters of E. Vulvoslrialus that differentiate this species from E. repis are: lip region continuous with body contour, cuticle 3-4 Ilm thick, cuticular sclerotizations near vulva strongly refractive.

E. ebsaryi has longer body, odontostyle, rectum and spicules: L = 1.4-2.2 mm, odontostyle = 8-12 Ilm; rectum = 38-45 Ilm or 1.2- 1.5 of anal body width long; spicule = 50-58 1J.ffi. E. ebsaryi has distinct triangular and sclerotized vulval plates and 8-12 supplements, these characters further differentiate the compared species.

The species with wrinkled cuticle near vulva were placed in the genus Rhyssocolpus Andrassy, 1971 . Loof (1989) discussed and synonymised Rhyssocolpus with Enchodelus Thome, 1939 , although this action has not been accepted by Eliava and Eliashvili (1990). Presence of E. repis females with or without cuticular wrinkles near vulva supports Loors (1989) conclusion.

Tables

Table 1. Distance between ventromedian supplements in Enchode/us repis sp. n. males.

Number of ventromedian		Distance between supplements (~)					Cloacal opening ta anteriormost
supplements							supplement
	C-SI	SI-S2	S2-S)	SrS4	S4-SS	SS-S6
2 (n. 1) 4 (n. 8) 5 (n. 6) 6 (n. 2)	41 48 (45-56) 45 (41 -50) 44,48	23 12 (10- 15) 10 (8- 12) 7, Il	14 (1 I-20) li (10- 13) 9, 12	16 (9-21) 12 (9- 14) Il, 12	13 (11 - 15) 12, 15	10, 12	64 91 (82-98) 91 (80-96) 99, 104