Abstract
During a nematological survey in the Bale Mountains National Park (Ethiopia), an undescribed species belonging to the genus Mesodorylaimus was found. M. aethiopicus sp. nov. is characterised by having a medium-sized body 1483–1858 μm long, the lip region weakly angular and offset by a slight depression, a medium-sized odontostyle (14–17 μm long), a longitudinal vulva slit positioned at mid-body, absence of pars refringens vaginae, a well-developed pars dilatata oviductus, a relatively long female tail (133.5–162.5 μm), male spicules 56.0–63.5 μm long and regularly spaced 12–14 ventromedian supplements. The new species was morphologically compared to eight species of the genus Mesodorylaimus and two species of the genus Calcaridorylaimus with similar body length and tail length values. In molecular phylogenetic studies, using the sequences of 18S rDNA and 28S rDNA, close relationships of M. aethiopicus with representatives of the genera Mesodorylaimus and Calcaridorylaimus were shown. However, the sequences of species with a similarity above 99% for the 18S rRNA gene and above 98% for the 28S rRNA gene were absent in GenBank.
References
- Ahmad, W. & Shaheen, A. (2004) Five new and two known species of the family Dorylaimidae (Nematoda: Dorylaimida) from Costa Rica. Nematology, 6 (4), 567–584. https://doi.org/10.1163/1568541042665232
- Andrássy, I. (1958) Erd- und Süsswassernematoden aus Bulgarien. Acta Zoologica Academiae Scientiarum Hungaricae, 4, 1–88.
- Andrássy, I. (1959) Taxonomische Übersicht der Dorylaimen (Nematoda), I. Acta Zoologica Academiae Scientiarum Hungaricae, 5 (3–4), 191–240.
- Andrássy, I. (1961) Wissenschaftliche Ergebnisse der ersten ungarischen zoologischen Expedition in Ostafrika. 2. Nematoda. Annales Histoirico-Naturalis Musei Nationalis Hungarici, 53, 281–297.
- Andrássy, I. (1965) Erd- und Süsswasser-Nematoden aus Ghana. Klasse Adenophorea (Aphasmidia). Opuscula Zoologica Budapestinensis, 5 (2), 127–151.
- Andrássy, I. (1986) The genus Mesodorylaimus Andrássy, 1959 and its relatives (Nematoda: Dorylaimidae). Acta Zoologica Hungarica, 32 (3–4), 207–261.
- Baermann, G. (1917) Eine einfache Methode zur Auffindung von Ankylostomum (nematoden) Larven in Erdproben. Geneeskundig Tijdschrift voor Nederlandsch-Indie, 57, 131–137.
- Basson, J.B.E. & Heyns, J. (1974) The genus Mesodorylaimus in South Africa (Nematoda: Dorylaimoidea). Phytophylactica, 6, 261–288.
- De Ley, P., Félix, M.A., Frisse, L.M., Nadler, S.A., Sternberg, P.W. & Thomas, W.K. (1999) Molecular and morphological characterisation of two reproductively isolated species with mirror-image anatomy (Nematoda: Cephalobidae). Nematology, 1 (6), 591–612. https://doi.org/10.1163/156854199508559
- De Man, J.G. (1876) Onderzoekingen over vrij in de aarde levende Nematoden. Tijdschrift der Nederlandsche Dierkundige Vereeniging, 2, 78–196.
- Dujardin, F. (1845) Histoire naturelle des helminthes ou vers intestinaux. Librairie encyclopedique de Roret, Paris, 654 pp. https://doi.org/10.5962/bhl.title.10123
- Goodey, T. (1963) Soil and freshwater nematodes. Second edition, rewritten by J. B. Goodey. Methuen & Co Ltd., London and John Wiley & Sons, Inc., New York, 544 pp.
- Kreis, H.A. (1930) Freilebende terrestrische Nematoden aus der Umgebung von Peking (China). II. Zoologischer Anzeiger, 87, 67–87.
- Kumar, S., Stecher, G. & Tamura, K. (2016) MEGA7: Molecular evolutionary genetics analysis version 7.0 for bigger datasets. Molecular Biology and Evolution, 33 (7), 1870–1874. https://doi.org/10.1093/molbev/msw054
- Loof, P.A.A. (1969) Taxonomy of some species of the genus Mesodorylaimus Andrássy, 1959 (Dorylaimoidea). Nematologica, 15 (2), 253–274. https://doi.org/10.1163/187529269X00687
- Loof, P.A.A. & Coomans, A. (1970) On the development and location of the oesophageal gland nuclei in the Dorylaimina. Proceedings IX International Nematology Symposium (Warsaw 1967) Zeszyty Problemowe Postępów Nauk Rolniczych, 92, 79–161.
- Loof, P.A.A. (1975) Dorylaimoidea of some subantarctic islands. Nematologica, 21 (2), 219–255. https://doi.org/10.1163/187529275X00581
- Mwamula, A.O., Lee, S.M, Jung, Y.H, Kim, Y.S. & Lee, D.W. (2024) Description and molecular characterization of a new dorylaimid nematode, Mesodorylaimus pini n. sp. (Nematoda: Dorylaimidae) from Korea. Journal of Nematology, 56 (e2024-1), 1–12, https://doi.org/10.2478/jofnem-2024-0028
- Naumova, T.V. & Gagarin, V.G. (2021) Mesodorylaimus ushkaniensis sp. n. and Allodorylaimus baikalensis sp. n. (Nematoda, Dorylaimida) from Lake Baikal, Russia. Zootaxa, 4985 (2), 285–293. https://doi.org/10.11646/zootaxa.4985.2.12
- Olson, M., Harris, T., Higgins, R., Mullin, P., Powers, K., Olson, S. & Powers, T.O. (2017) Species delimitation and description of Mesocriconema nebraskense n. sp. (Nematoda: Criconematidae), a morphologically cryptic, parthenogenetic species from North American grasslands. Journal of Nematology, 49, 42–66. https://doi.org/10.21307/jofnem-2017-045
- Peña-Santiago, R. (2022) Dorylaimida Mundi (Nematoda): checklist of genera and species, with their records. Universidad de Jaén, Jaén, 962 pp.
- Seinhorst, J.W. (1959) A rapid method for the transfer of nematodes from fixative to anhydrous glycerine. Nematologica, 4 (1), 67–69. https://doi.org/10.1163/187529259X00381
- Siddiqi, M.R. (1969) Mumtazium mumtazae n. gen., n. sp. (Nematoda: Tylencholaimidae) with the proposal of Laimydorus n. gen. (Thornenematidae). Nematologica, 15 (2), 234–240. https://doi.org/10.1163/187529269X00669
- Tsalolikhin, S. (1995) Review of the fauna of free living nematodes from inland waters of Ethiopia. Zoosystematica Rossica, 4 (2), 205–218.
- Uzma Tauheed & Ahmad, W. (2010) Four new species of the genus Mesodorylaimus Andrássy, 1961 (Nematoda: Dorylaimida) from India. Zootaxa, 2642 (1), 19–35. https://doi.org/10.11646/zootaxa.2642.1.2
- Uzma Tauheed & Ahmad, W. (2015) A monographic study of the genus Mesodorylaimus Andrássy, 1959 (Nematoda: Dorylaimida). Zoological Survey of India, Kolkata (Calcutta),148 pp.
- Zullini, A. (1988) A new genus and five species of nematodes from Ethiopian lakes. Revue de Nématologie, 11 (3), 279–288.