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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

Joaquín Abolafia

Joaquín Abolafia

Departamento de Biología Animal, Biología Vegetal y Ecología, Universidad de JaénJaén, Spain
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Abolafia, Joaquín
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Reyes Peña-Santiago

Reyes Peña-Santiago

Departamento de Biología Animal, Biología Vegetal y Ecología, Universidad de JaénJaén, Spain
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Peña-Santiago, Reyes
  
Jul 28, 2020
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's Cover Image
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Published Online: Jul 28, 2020
Page range: 1 - 20
Received: Feb 01, 2020
DOI: https://doi.org/10.21307/jofnem-2020-061
Keywords
© 2020 Joaquín Abolafia et al., published by Sciendo.
This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Figure 1:

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.
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.

Figure 2:

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 (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.

Figure 3:

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 (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).

Figure 4:

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.
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.

Figure 5:

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.
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.

Figure 6:

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 18S rDNA region. Bayesian posterior probabilities (%) are given for each clade. Scale bar shows the number of substitutions per site.

Figure 7:

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.
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
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