On the identity of Eucephalobus oxyuroides (de Man, 1876) Steiner, 1936 (Rhabditida, Cephalobidae), with an updated taxonomy of the genus and notes about its phylogeny

Abolafia, Joaquín; Peña-Santiago, Reyes

On the identity of Eucephalobus oxyuroides (de Man, 1876) Steiner, 1936 (Rhabditida, Cephalobidae), with an updated taxonomy of the genus and notes about its phylogeny

Journal of Nematology

Volume 52 (2020): Issue 1 (January 2020)

By:

Joaquín Abolafia and Reyes Peña-Santiago

Open Access

|Jul 2020

Figures & Tables

Facsimile reproduction of the original drawings of Cephalobus oxyuroides (A, H from de Man (1881) and B-G from de Man (1984)). (A) Neck; (B) Stoma; (C) Entire female; (D) Excretory pore; (E) Female posterior end; (F-H) Male posterior end.

Eucephalobus oxyuroides (de Man, 1876) Steiner, 1936a (line drawing). (A) Neck; (B) Lip region; (C) Female posterior end; (D) Female reproductive system; (E) Stoma; (F) Entire female; (G) Entire male; (H) Male posterior end; (I) Lateral field.

Eucephalobus oxyuroides (de Man, 1876) Steiner, 1936a (light microscopy). (A) Neck (black arrow pointing to the excretory pore, white arrow pointing to the deirid); (B) Lip region; (C) Stoma; (D) Lateral field; (E) Female reproductive system; (F) Uterine egg; (G) Female posterior end (arrow pointing the phasmid); (H) Male posterior end (arrows pointing genital papillae).

Eucephalobus oxyuroides (de Man, 1876) Steiner, 1936a (scanning electron microscopy). (A, B) Lip region in lateral and frontal view, respectively; (C) Female phasmid (arrow); (D) Neck (arrow pointing the excretory pore); (E) Excretory pore (arrow); (F, G) Female posterior end in lateral and ventral view, respectively (arrow pointing the phasmid); (H) Lateral field; (I) Anus.

Lip region, post-vulval uterine sac, male and female tails of the species of the genus Eucephalobus Steiner, 1936a including species inquirendae. Based on original descriptions except E (male tail) cf. Amirzadi et al. (2013); G (lip region), M (lip region, tails) cf. Andrássy (1967); H (post-vulval sac), M (post-vulval sac) cf. Boström (1984); H (female tail) cf. de Man (1984). Not to scale.

Bayesian inference tree showing the phylogenetic position of Eucephalobus and related taxa based on sequences of the 18S rDNA region. Bayesian posterior probabilities (%) are given for each clade. Scale bar shows the number of substitutions per site.

Bayesian Inference tree showing the phylogenetic position of Eucephalobus and related taxa based on sequences of the 28S rDNA region. Bayesian posterior probabilities (%) are given for each clade. Scale bar shows the number of substitutions per site.

Morphometrics of Eucephalobus oxyuroides (de Man, 1876) Steiner, 1936a from Spain_

Province	Navarra		Jaén
Habitat	Oak forest		Whine forest
Sex	Female	Male	Female
n	11	9	2
Body length	610 ± 44.7 (554-695)	567 ± 35.7 (513-629)	493, 602
a	28.7 ± 1.9 (26.6-32.4)	29.1 ± 2.9 (25.1-32.9)	21.4, 26.2
b	4.2 ± 0.3 (3.9-4.7)	4.0 ± 0.2 (3.8-4.3)	3.5, 4.3
c	8.8 ± 0.6 (8.0-10.0)	12.7 ± 1.0 (10.9-14.3)	7.1, 8.4
c'	5.3 ± 0.3 (5.0-5.8)	2.9 ± 0.3 (2.4-3.4)	4.9, 5.5
V	60.3 ± 1.1 (58-64)	–	58, 60
Lip region width	6.0 ± 0.0 (6)	6.0 ± 0.0 (6)	6, 7
Stoma length	13.5 ± 0.5 (13-14)	13.2 ± 0.8 (12-14)	14, 14
Pharyngeal corpus length	86.2 ± 3.4 (82–91)	84.9 ± 5.6 (77-97)	88, 86
Isthmus length	28.2 ± 3.0 (23-31)	27.2 ± 2.9 (22-32)	21, 25
Bulbus length	17.0 ± 1.2 (14-18)	16.4 ± 0.9 (15-18)	17, 15
Pharynx length	131 ± 5.4 (123–140)	128.6 ± 8.0 (119-145)	126, 126
Nerve ring – anterior end	95.1 ± 4.0 (89–103)	93.0 ± 5.3 (84-101)	100, 102
Excretory pore – anterior end	98.3 ± 43.8 (94-107)	95.4 ± 5.2 (86-102)	103, 101
Deirid – anterior end	114 ± 3.5 (106-117)	110.4 ± 6.5 (97-119)	119, 117
Neck length (stoma + pharynx)	145 ± 5.4 (137-153)	141.8 ± 8.3 (132-158)	140, 140
Body diameter at midbody	21.4 ± 2.1 (19-25)	19.7 ± 2.2 (17-23)	23, 23
Lateral field width	3.5 ± 0.6 (3-4)	3.4 ± 0.5 (3-4)	4, 4
Anterior ovary/testis length	135 ± 17.4 (116-160)	115.6 ± 14.9 (99-144)	118, 110
Spermatheca length	33.4 ± 7.9 (23-47)	–	44, 55
Post-vulval uterine sac length	47.1 ± 4.0 (40-54)	–	48, 57
Vulva – anterior end	368 ± 25.3 (328-405)	–	285, 363
Rectum length	18.9 ± 1.4 (16-20)	5.0 ± 0.7 (4-6)	20, 20
Anal body diameter	13.1 ± 0.8 (12-14)	15.7 ± 1.1 (14-18)	14, 13
Tail length	69.5 ± 5.1 (60-79)	44.9 ± 4.2 (36-49)	69, 72
Spicules length	–	21.4 ± 0.5 (21-22)	–
Gubernaculum length	–	13.7 ± 1.9 (12-16)	–

Compendium of Eucephalobus oxyuroides (de Man, 1876) Steiner, 1936a populations_

Reference	Country	n	Body length	a	b	c	c ^'	V	Stoma	Pharynx length	Neck length	Nerve ring − ant. end (%)	Excretory pore − ant. end (%)	Body width at midbody	Sper-matheca length	Post-vulval uterine sac / body diameter	Vulva-ant. end	Rectum length (female)	Anal body width	Tail length	Tail mucro	Spicules length	Gubernaculum length
1	Spain	13 females	493-695	21.4-32.4	3.5-4.7	7.1-10.0	4.9-5.8	58-64	13-14	123-140	137-153	61-69	65-72	19-25	23-47	2.0-2.5	285-405	16-20	12-14	60-79	Conoid elongate	–	–
		9 males	513-629	21.1-32.9	3.8-4.3	10.9-14.3	2.4-3.4	–	12-14	119-145	132-158	64-68	64-71	17-23	–	–	–	–	14-18	36-49	Conoid elongate	21-22	12-16
2	The Netherlands	5 males	447-514**	20.0-21.8**	3.1-3.2**	10.4-11.9**	2.5-2.7**	–	12**	125-149**	145-161**	?	59**	22-24**	–	–	–	–	16-17**	33-45**	Conoid elongate	22**	12*
3	The Netherlands	? females	700	20.0-25.0	4.0	8.0-9.0	5.1*	61*	?	?	?	66*	65*	?	?	2.5*	?	?	?	?	Conoid elongate	–	–
		? males	640	20.0-25.0	4.0	12.0-13.0	2.4*	–	?	?	?	?	?	?	–	–	–	–	?	?	Conoid elongate	?	?
4	Hungary	1 female	620	23.8**	3.9**	8.9**	?	56**	?	?	160	?	?	26	?	?	350**	?	?	70	?	?	?
		2 males	450-500	20.8-21.4**	3.6-3.8**	11.1-11.3**	?	–	?	?	125-132	?	?	21-24	–	–	–	–	?	40-45	Conoid elongate	–	–
5	Australia	1 female	640	17.8**	4.5*	7.1**	5.3**	51	10**	?	143**	?	69**	36**	?	?	?	?	17**	90	?	–	–
6	Switzerland	1 male	342	19.0	2.8	6.0	?	–	11	112**	122**	?	?	16**	–	–	–	–	?	57**	?	?	?
7	Austria	1 female	459	22.0	3.1	8.1	?	61	8**	141**	149**	57**	?	21**	?	?	?	?	10**	57**	?	–	–
8	Rumania	5 females	500-565	19.4-21.8	3.7-4.1	6.8-7.8	?	56-59	?	?	?	?	?	?	?	?	?	?	?	?	?	–	–
		1 male	527	19.0	3.0	17.8	?	–	?	?	176**	?	?	28**	?	?	?	?	?	30**	?	?	?
9	Austria	19 females	450-610	18.6-29.0	3.0-4.9	6.8-18.0	5.0*	58-72	?	?	?	?	?	?	?	?	?	?	?	?	Short conoid	–	–
		11 males	410-520	17.7-24.0	3.5-5.9	9.6-12.8	?	–	?	?	?	?	?	?	–	–	–	–	?	?	?	?	?
10	Brazil	1 female	1926	21.4	4.2-5.0	12.4	?	60	?	?	?	?	?	?	?	?	?	?	?	?	?	–	–
		1 male	1485	29.0	4.9	16.5	?	–	?	?	?	?	?	?	–	–	–	–	?	?	?	45	?
11	UK	1 female	650	19.0	3.9	8.3	5.2*	60	?	?	167**	?	?	34**	?	?	390**	?	?	78**	Conoid elongate	–	–
		1 male	550	21.0	3.5	11.6	2.7*	-	?	?	?	?	?	29**	–	–	–	–	?	47**	Conoid elongate	?	?
12	D. R. Congo	1 female	356	22.2	3.4	8.0	?	?	?	?	104**	?	?	16**	?	?	?	?	?	45**	?	–	–
13	Sweden	1 female	787	28.4	4.8	16.0	?	65	?	?	164**	?	?	28**	?	?	512**	?	?	49**	?	–	–
14	Norway	1 female	800	38.1	3.8	12.3	?	?	?	?	213	?	?	21	?	?	?	?	?	65	?	–	–
		1 male	787	35.7	4.2	15.7	?	?	?	?	213	?	?	22	?	?	?	?	?	50	?	?	?
15	Italy	? females	467-683	16.8-22.4	3.3-4.3	7.7-9.0	?	59-65	?	?	?	?	?	?	?	?	?	?	?	?	?	–	–
16	South Africa	? females	410-460	20.0-22.0	3.8-3.9	8.7-13.1	?	63	?	?	?	?	?	?	?	?	?	?	?	?	?	–	–
17	Mongolia	1 female	540	20.0	3.4	10.7	3.6	60	?	?	158**	?	?	27**	?	1.4	326**	?	?	50**	Short conoid	?	?
		1 male	490	20.0	2.6	13.5	2.2	–	?	?	188**	?	?	25**	–	–	–	–	?	36**	Short conoid	–	–
18	Hungary	? females	450-500	20.0-23.0	4.0-4.2	8.5-9.5	5.0-6.0	60-62	12	?	?	?	74-77	?	?	0.8*	?	?	?	?	Conoid elongate	–	–
19	Tadjikistan	? females	460	20.0-22.0	3.4-3.8	8.0	4.3*	60	?	?	?	?	?	?	?	?	276**	?	?	58**	?	–	–
20	Uzbekistan	1 female	450	22.2	39.4¹	9.1	?	62	?	?	?	?	?	20**	?	?	279**	?	?	49**	?	–	–
21	Russia, Turkmenistan, Moldavia	? females	750-900	22.0-24.0	3.8-4.4	7.0-9.6	?	58-62	?	?	?	?	?	?	?	?	?	?	?	?	?	–	–
		? males	700-800	24.0-25.2	5.0-5.6	7.0-10.7	?	–	?	?	?	?	?	?	–	–	–	?	?	?	?	?	?
22	Russia	1 female	353	17.6	4.0	5.7	?	50	?	?	88**	?	?	20**	?	?	?	?	?	62**	?	–	–
		2 males	480-488	16.0-20.0	3.0-3.5	10.0	2.9*	-	13	131*	144	65*	66*	30-	–	–	–	–	18*	48-49**	Conoid elongate	20	12
23	Spain	42 females	450-700	17.0-23.0	3.0-5.0	6.5-9.0	6.0*	56-72	?	?	?	?	?	?	?	?	?	?	?	?	Conoid elongate	–	–
		3 males	450-650	19.0-28.0	3.0-5.0	7.0-11.0	2.3*	–	?	?	?	?	?	?	–	–	–	–	?	?	Absent	?	?
24	Sweden	? females	?	?	?	?	?	?	?	?	?	?	?	?	?	1.0-3.0	?	?	?	59-73	Conoid elongate	–	–
25	Brazil	74 females	370-650	18.0-32.0	3.3-5.0	5.0-8.5	7.3*	55-63	10-14	140*	108-170	61*	65*	19-23*	16-32*	1.1-1.3*	?	20-24	13*	57-105	Short conoid	–	–
		28 males	390-600	21.0-35.0	3.2-4.2	14.6-19.8	2.5*	–	10-14	?	117-144	?	?	21*	–	–	–	–	14*	24-37	Seta-like or wart-like	14-20	9-12
26	Austria	6 females	510-560	19.0-22.0	3.4-3.7	7.1-8.0	4.0-5.0	60–62													?	–	–
		1 male	520	20.0	3.4	9.5	?	–								1.0-1.5					?	23	12
27	Turkey	1 female	609	23.0	4.0	8.7	4.4	63	12	154	166**	61	63	27	34	1.2	?	19	16**	70	Short conoid	–	–
		1 male	525	28.0	3.9	16.4	1.9	–	11	133	144**	63	65	19	–	–	–	–	?	32	Short conoid	17	10
28	Spain	4 females	524-535	21.4-27.6	3.5-3.7	8.4-8.9	4.2-5.3	60-64	9-14	143-150	156-161**	54-64	54-67	19-25	26-36	0.7-1.7	317-338	18-20	12-15	60-64	Short conoid	–	–
29	Bulgaria	5 females	588-729	19.0-26.0	3.8-4.3	5.9-7.4	5.0-6.8	57-61	?	127-136	?	?	66-74	17-22	?	0.5	?	13-20	?	32-36	?	–	–
		3 males	436-556	25.0-30.0	3.2-3.8	10.9-15.7	1.9-2.3	–	?	124-139	?	?	64-69	16-17	?	?	?	–	?	30-36	?	14-21	8-10
30	Hungary	? females	380-740	18.0-28.0	3.3-5.0	6.0-10.0	4.2-5.8	56-66	10-14	120-150	?	?	74-78	?	?	< 1.0	?	?	?	70-90	?	–	–
		? males	300-620	20.0-28.0	3.2-4.2	14.0-18.0	?	–	10-14	120-150	?	?	74-78		–	–	–	–	?	?	?	14-20	9-11

DOI: https://doi.org/10.21307/jofnem-2020-061 | Journal eISSN: 2640-396X | Journal ISSN: 0022-300X

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Language: English

Page range: 1 - 20

Submitted on: Feb 1, 2020

Published on: Jul 28, 2020

Published by: Society of Nematologists, Inc.

In partnership with: Paradigm Publishing Services

Publication frequency: 1 issue per year

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© 2020 Joaquín Abolafia, Reyes Peña-Santiago, published by Society of Nematologists, Inc.
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On the identity of Eucephalobus oxyuroides (de Man, 1876) Steiner, 1936 (Rhabditida, Cephalobidae), with an updated taxonomy of the genus and notes about its phylogeny

Figures & Tables

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Figure 2:

Figure 3:

Figure 4:

Figure 5:

Figure 6:

Figure 7:

Morphometrics of Eucephalobus oxyuroides (de Man, 1876) Steiner, 1936a from Spain_

Compendium of Eucephalobus oxyuroides (de Man, 1876) Steiner, 1936a populations_

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