Abstract
The taxonomic ambiguity of North African Rhabdias Stiles & Hassall, 1905 requires a deep revision and re-evaluation to define the genuine taxa. Based on newly gathered specimens, the African/Saharo-Arabian Rhabdias aegyptiaca El-Garhy & Garo, 2006 is redescribed for specimens collected from the lungs of the common African toad, Sclerophrys regularis (Reuss) (Anura: Bufonidae) from Egypt, northeast Africa. The species characterization is investigated through detailed morphology using light and scanning electron microscopy, as well as in-depth morphological and morphometric comparisons against closely related Rhabdias spp. The problematic morphological/taxonomic status of the original description of R. aegyptiaca is elucidated, discussed, and treated. Additionally, species identification is confirmed by genetic divergence, phylogenetic, and species delimitation analyses using the mitochondrial gene (cox1 mtDNA) and ribosomal genetic markers (28S rDNA + ITS rDNA). Rhabdias aegyptiaca differs from other African congeners in the combination of the following characteristics: truncate anterior end, buccal capsule 11–17 (15 ± 0.4) µm wide, four submedian circumoral lips with two lateral pseudolabia, esophagus with dilatation at end of first third and tail wholly covered with inflated cuticle except for its end tip. Present investigations on the validity of the Saharo-Arabian record of R. africanus sensu Abdel-Hakeem, Fadladdin, El-Sagheer & Adel, 2022 regard it as another record of R. aegyptiaca. The confusing status of the Saharo-Arabian record of Rhabdias bufonis sensu Morsy, Mohamed, Abdel-Ghaffar, Fayoumi & Abdel-Haleem, 2018 is discussed and assigned as belonging to another genus, Thubunaea Seurat, 1914. Rhabdias bufonis sensu Moravec, Baruš & Ryšavý, 1987 is considered a highly likely stand-alone Saharo-Arabian species, distinguished from the complex of Rhabdias bufonis (Schrank, 1788) Stiles & Hassall, 1905 by its pre-equatorial vulva, and largely sized buccal capsule and eggs. However, their specimens still need futural re-investigation for an appropriate description and designating type specimens.
References
- Abdel-Hakeem, S.S., Fadladdin, Y.A., El-Sagheer, A.M. & Adel, A. (2022) New host record, Sclerophrys regularis (Bufonidae), for Rhabdias africanus (Rhabdiasidae, Kuzmin, 2001) based on molecular and morphological evidence. Saudi Journal of Biological Sciences, 29, 103366. https://doi.org/10.1016/j.sjbs.2022.103366
- Abun-Nasr, J.M., Warmington, B.H. & Brett, M. (2024) North Africa. Encyclopedia Britannica. Available from: https://www.britannica.com/place/North-Africa (accessed 21 March 2024)
- Amphibiansoftheworld (2025) Amphibian Species of the World 6.1, an Online Reference. Available from: https://amphibiansoftheworld.amnh.org (accessed 13 February 2025)
- AmphibiaWeb (2025) Amphibia Web. University of California, Berkeley, CA, USA. Available from: https://amphibiaweb.org (accessed 4 August 2025)
- Anderson, R.C. & Bain, O. (2009) Rhaditida. In: Anderson, R.C., Chabaud, A.G. & Willmott, S. (Eds.), Keys to the Nematode Parasites of Vertebrates. Archival Volume. CAB International, Wallingford, pp. 30–43. https://doi.org/10.1079/9781845935726.0030
- Anderson, R.C., Chabaud, A.G. & Willmott, S. (2009) Keys to the Nematode Parasites of Vertebrates. Archival Volume. CAB International, Wallingford, 463 pp. https://doi.org/10.1079/9781845935726.0000
- Baker, M.R. (1978) Morphology and taxonomy of Rhabdias spp. (Nematoda: Rhabdiasidae) from reptiles and amphibians of southern Ontario. Canadian Journal of Zoology, 2127–2141. https://doi.org/10.1139/z78-289
- Baker, M.R. (1980) Revision of Entomelas Travassos, 1930 (Nematoda: Rhabdiasidae) with a review of genera in the family. Systematic Parasitology, 1, 83–90. https://doi.org/10.1007/bf00009853
- Baker, M.R. (1982) Systematics and zoogeography of three new nematode parasites of the frog Breviceps sylvestris sylvestris FitzSimons from South Africa. Canadian Journal of Zoology, 60, 3134–3142. https://doi.org/10.1139/z82-398
- Baker, M.R. (1987) Rhabdias collaris n. sp. (Nematoda: Rhabdiasidae) from frogs of Tanzania. Systematic Parasitology, 9, 199–201. https://doi.org/10.1007/bf00010854
- Bouckaert, R., Heled, J., Kühnert, D., Vaughan, T., Wu, C-H., Xie, D., Suchard, M.A., Rambaut, A. & Drummond, A.J. (2014) BEAST 2: A Software Platform for Bayesian Evolutionary Analysis. PLoS computational biology, 10, e1003537. https://doi.org/10.1371/journal.pcbi.1003537
- Bursey, C.R., Goldberg, S.R. & Vitt, L.J. (2007) New species of Rhabdias (Nematoda: Rhabdiasidae) and other helminths from Norops capito (Sauria: Polychrotidae) from Nicaragua. Journal of Parasitology, 93, 129–131. https://doi.org/10.1645/ge-887r.1
- Bush, A.O., Lafferty, K.D., Lotz, J.M. & Shostak, A.W. (1997) Parasitology meets ecology on its own terms: Margolis et al. revisited. Journal of Parasitology, 83, 575–583. https://doi.org/10.2307/3284227
- Chabaud, A.G. (2009) Spirurida. In: Anderson, R.C., Chabaud, A.G. & Willmott, S. (Eds.), Keys to the Nematode Parasites of Vertebrates. Archival Volume. CAB International, Wallingford, pp. 334–360. https://doi.org/10.1079/9781845935726.0334
- Chitwood, B.G. & McIntosh, A. (1934) A new variety of Alloionema (Nematoda: Diplogasteridae), with a note on the genus. Proceedings of the Helminthological Society of Washington, 1, 37–38
- Cipriani, P., Mattiucci, S., Paoletti, M., Santoro, M. & Nascetti, G. (2012) Rhabdias esculentarum n. sp. (Nematoda: Rhabdiasidae) from green frogs of the Rana esculenta species complex in Italy: molecular evidence, morphological description and genetic differentiation from its congeners in frogs and toads. Systematic Parasitology, 82, 131–146. https://doi.org/10.1007/s11230-012-9355-x
- Cole, R.A. & Roderick, C.L. (2021) Direct Submission. Journal Submitted (26 November 2021). National Wildlife Health Center, Madison, Wisconsin. Available from: https://www.usgs.gov/centers/nwhc (accessed 26 November 2021)
- Costa-Silva, G.J., Rodriguez, M.S., Roxo, F.F., Foresti, F. & Oliveira, C. (2015) Using different methods to access the difficult task of delimiting species in a complex Neotropical hyperdiverse group. PLoS One, 10, e0135075. https://doi.org/10.1371/journal.pone.0135075
- Darriba, D., Taboada, G.L., Doallo, R. & Posada, D. (2012) jModelTest 2: more models, new heuristics and parallel computing. Nature Methods, 9, 772. https://doi.org/10.1038/nmeth.2109
- de Oca, E.U.G.M., López-Caballero, J.D. & Mata-López, R. (2017) New records of helminths of Sceloporus pyrocephalus Cope (Squamata, Phrynosomatidae) from Guerrero and Michoacán, Mexico, with the description of a new species of Thubunaea Seurat, 1914 (Nematoda, Physalopteridae). ZooKeys, 716, 43–62. https://doi.org/10.3897/zookeys.716.13724
- Drummond, A.J. & Rambaut, A. (2007) BEAST: Bayesian evolutionary analysis by sampling trees. BMC Evolutionary Biology, 7, 214. https://doi.org/10.1186/1471-2148-7-214
- Dubey, S. & Shine, R. (2008) Origin of the parasites of an invading species, the Australian cane toad (Bufo marinus): are the lungworms Australian or American?. Molecular Ecology, 17, 4418–4424. https://doi.org/10.1111/j.1365-294x.2008.03922.x
- Duvaud, S., Gabella, C., Lisacek, F., Stockinger, H., Ioannidis, V. & Durinx, C. (2021) Expasy, the Swiss Bioinformatics Resource Portal, as designed by its users. Nucleic Acids Research, 49, W216–W227. https://doi.org/10.1093/nar/gkab225
- Edgar, R.C. (2004) MUSCLE: multiple sequence alignment with high accuracy and high throughput. Nucleic Acids Research, 32, 1792–1797. https://doi.org/10.1093/nar/gkh340
- Edler, D., Klein, J., Antonelli, A. & Silvestro, D. (2021) raxmlGUI 2.0: a graphical interface and toolkit for phylogenetic analyses using RAxML. Methods in Ecology and Evolution, 12, 373–377. https://doi.org/10.1111/2041-210X.13512
- El-Garhy, M. & Garo, K. (2006) Rhabdias aegyptiaca sp. n. (Nematoda: Rhabdiasidae) from the lungs of Bufo regularis (Amphibia: Bufonidae) in Egypt: light and scanning electron microscopic study. Journal of Union Arab Biology, Cairo, Series A, Zoology, 26, 127–137.
- Folmer, O., Black, M., Hoeh, W., Lutz, R. & Vrijenhoek, R. (1994) DNA primers for amplification of mitochondrial cytochrome c oxidase subunit I from diverse metazoan invertebrates. Molecular Marine Biology and Biotechnology, 3, 294–299
- Goodey, T. (1924) The anatomy and life-history of the nematode Rhabdias fuscovenosa (Railliet) from the grass snake Tropidonotus natrix. Journal of Helminthology, 2, 51–64. https://doi.org/10.1017/s0022149x00003023
- Gutierrez, R.O. (1945) Contribución al conocimiento de los nematodes parásitos de anfibios argentinos. Tesis, Universidad Nacional de La Plata, La Plata, 148 pp. https://doi.org/10.35537/10915/4530
- Harras, S. & Elmahy, R. (2019) New record of Thubunaea pudica Seurat, 1914 (Spirurida: Physalopteridae) in lizard Trapelus mutabilis from Egypt. Parasitologists United Journal, 12, 1231–129. https://doi.org/10.21608/puj.2019.13643.1046
- Hartwich, G. (1972) Über Rhabdias bufonis (Schrank, 1788) und die Abtrennung von Rhabdias dossei nov. spec. (Nematoda, Rhabdiasidae). Mitteilungen aus dem Museum für Naturkunde in Berlin. Zoologisches Museum und Institut für Spezielle Zoologie, Berlin, 48, 401–414. https://doi.org/10.1002/mmnz.19720480206
- Hartwich, G. (1975) Schlauchwurmer, Nemathelminthes Rundoder Fadenwurmer, Nematoda Parasitische Rundwurmer von Wirbeltieren. I. Rhabditida und Ascaridida. Die Tierwelt Deutschlands. Vol. 62. Gustav Fischer Verlag, Jena, 256 pp. https://doi.org/10.2307/3279060
- Hasegawa, H. (1989) Neoentomelas asatoi gen. et sp. n. (Nematoda: Rhabdiasidae) from skinks of the Ryukyu Archipelago, Japan. Proceedings of the Helminthological Society of Washington, 56, 145–150
- Holt, B.G., Lessard, J.-P., Borregaard, M.K., Fritz, S.A., Araújo, M.B., Dimitrov, D., Fabre, P.-H., Graham, C.H., Graves, G.R., Jønsson, K.A., Nogués-Bravo, D., Wang, Z., Whittaker, R.J., Fjeldså, J. & Rahbek, C. (2013) An Update of Wallace’s Zoogeographic Regions of the World. Science, 339, 74–78. https://doi.org/10.1126/science.1228282
- Ibrahim, A.A. (2013) Amphibians of Egypt: a troubled resource. Basic and Applied Herpetology, 27, 107–117. https://doi.org/10.11160/bah.13007
- Ingles, L.G. (1935) Worm parasites of California Amphibia. Transactions of American Microbiological Society, 55, 73–92. https://doi.org/10.2307/3223012
- Irving, E. (2005) The role of latitude in mobilism debates. PNAS, 102, 1821–1828 https://doi.org/10.1073/pnas.0408162101
- Johnston, T.H. (1916) A census; of the endoparasites recorded as occurring in Queensland, arranged under their hosts. Proceeding of Royal Society of Queensland, 28, 31–79. https://doi.org/10.5962/p.272115
- Junker, K., Lhermitte-Vallarino, N., Barbuto, M., Ineich, I., Wanji, S. & Bain, O. (2010) New species of Rhabdias (Nematoda: Rhabdiasidae) from Afrotropical anurans, including molecular evidence and notes on biology. Folia Parasitologica, 57, 47–61. https://doi.org/10.14411/fp.2010.007
- Kumar, S., Stecher, G., Li, M., Knyaz, C. & Tamura, K. (2018) MEGA X: molecular evolutionary genetics analysis across computing platforms. Molecular biology and evolution, 35, 1547–1549. https://doi.org/10.1093/molbev/msy096
- Kuzmin, Y.I. (2001) Rhabdias africanus sp. nov. (Nematoda, Rhabdiasidae), a new nematode species from the South African toads (Amphibia, Bufonidae). Acta Parasitologica, 46, 148–150
- Kuzmin, Y.I. (2013) Review of Rhabdiasidae (Nematoda) from the Holarctic. Zootaxa, 3639 (1), 1–76. https://doi.org/10.11646/zootaxa.3639.1.1
- Kuzmin, Y.I. & Tkach, V.V. (2025) Family Rhabdiasidae Railliet, 1915. List of Species. Available from: http://izan.kiev.ua/ppages/rhabdias/list.htm (accessed 4 August 2025)
- Kuzmin, Y.I., Du Preez, L.H. & Junker, K. (2015) Some nematodes of the genus Rhabdias Stiles et Hassall, 1905 (Nematoda: Rhabdiasidae) parasitising amphibians in French Guiana. Folia Parasitologica, 62, 031. https://doi.org/10.14411/fp.2015.031
- Kuzmin, Y.I., Du Preez, L.H., Nel, T. & Svitin, R. (2022) Three new species of Rhabdias Stiles et Hassall, 1905 (Nematoda: Rhabdiasidae) parasitic in Ptychadena spp. (Amphibia: Anura: Ptychadenidae) and an identification key to Rhabdias spp. from Afrotropical anurans. Parasitology International, 91, 102649. https://doi.org/10.1016/j.parint.2022.102649
- Kuzmin, Y.I., Giese, E.G., Melo, F.T. de V., da Costa, P.A.F.B., Maschio, G.F. & dos Santos, J.N. (2016) Description of Serpentirhabdias atroxi n. sp. (Nematoda: Rhabdiasidae), a parasite of Bothrops atrox (Linnaeus) (Reptilia: Serpentes: Viperidae) in Brazilian Amazonia. Systematic Parasitology, 93, 37–45. https://doi.org/10.1007/s11230-015-9603-y
- Kuzmin, Y.I., Halajian, A., Tavakol, S., Luus-Powell, W.J. & Tkach, V.V. (2017) Description and phylogenetic position of a new species of Rhabdias Stiles et Hassall, 1905 (Nematoda: Rhabdiasidae) from the banded rubber frog, Phrynomantis bifasciatus (Smith) (Amphibia: Microhylidae), in South Africa. Folia Parasitologica, 64, 1–8. https://doi.org/10.14411/fp.2017.035
- Kuzmin, Y.I., Svitin, R., Harnoster, F. & Du Preez, L. (2020) Description and molecular characterisation of a new nematode species parasitic in the lungs of Strongylopus grayii (Smith) (Anura: Pyxicephalidae) in South Africa. Systematic Parasitology, 97, 369–378. https://doi.org/10.1007/s11230-020-09917-5
- Kuzmin, Y.I., Svitin, R., McAllister, C.T., Guderyahn, L. & Tkach, V.V. (2024) Descriptions and Phylogenetic Affinities of Two New Species of Rhabdias Stiles and Hassall, 1905 (Nematoda: Rhabdiasidae) from North American Frogs: Are We Still Only Scratching the Surface? Journal of Parasitology, 110, 339–350. https://doi.org/10.1645/24-10
- Kuzmin, Y.I., Tkach, V.V. & Brooks, D.R. (2007) Two new species of Rhabdias (Nematoda: Rhabdiasidae) from the marine toad, Bufo marinus (L.) (Lissamphibia: Anura: Bufonidae), in Central America. Journal of Parasitology, 93, 159–165. https://doi.org/10.1645/ge-858r.1
- Kuzmin, Y.I., Tkach, V.V. & Melo, F.T.V. (2019) Description, molecular characterization and life cycle of Serpentirhabdias mussuranae n. sp. (Nematoda: Rhabdiasidae) from Clelia clelia (Reptilia: Colubroidea) in Brazil. Journal of Helminthology, 94, e55. https://doi.org/10.1017/s0022149x19000348
- Kuzmin, Y.I., Tkach, V.V. & Snyder, S.D. (2001) Rhabdias ambystomae sp. n. (Nematoda: Rhabdiasidae) fröm the North American spotted salamander Ambystoma maculatum (Amphibia: Ambystomatidae). Comparative Parasitology, 68, 228–235
- Kuzmin, Y.I., Tkach, V.V. & Vaughan, J.A. (2005) Rhabdias kongmongthaensis sp. n. (Nematoda: Rhabdiasidae) from Polypedates leucomystax (Amphibia: Anura: Rhacophoridae) in Thailand. Folia Parasitologica, 52, 339–342. https://doi.org/10.14411/fp.2005.046
- Langford, G.J. & Janovy Jr., J. (2009) Comparative life cycles and life histories of North American Rhabdias spp. (Nematoda: Rhabdiasidae): lungworms from snakes and anurans. Journal of Parasitology, 95, 1145–1155. https://doi.org/10.1645/ge-2044.1
- Langford, G.J. & Janovy Jr., J. (2013) Host Specificity of North American Rhabdiasspp. (Nematoda: Rhabdiasidae): Combining Field Data and Experimental Infections with a Molecular Phylogeny. Journal of Parasitology, 99, 277–286. https://doi.org/10.1645/ge-3217.1
- Lewis, P.O., Holder, M.T. & Holsinger, K.E. (2005) Polytomies and Bayesian phylogenetic inference. Systematic biology, 54, 241–253. https://doi.org/10.1080/10635150590924208
- Lhermitte-Vallarino, N., Bain, O., Deharo, E., Bertani, S., Voza, T., Attout, T. & Gaucher, P. (2005) A New Rhabdiasid Nematode, Chabirenia cayennensis n. g., n. sp., Parasitic in the Glands of the Buccal Mucosa of a South American Saurian. Journal of Parasitology, 62, 151–160. https://doi.org/10.1007/s11230-005-5494-7
- Lhermitte-Vallarino, N., Barbuto, M., Ineich, I., Wanji, S., Lebreton, M., Chirio, L. & Bain, O. (2008) First report of Rhabdias (Nematoda: Rhabdiasoidea) from lungs of montane chameleons in Cameroon: description of two new species and notes on biology. Parasite, 15, 553–564. https://doi.org/10.1051/parasite/2008154553
- Machado, S.A., Kuzmin, Y., Tkach, V.V., dos Santos, J.N., Gonçalves, E.C. & Melo, F.T.V. (2018) Description, biology and molecular characterisation of Serpentirhabdias moi n. sp. (Nematoda: Rhabdiasidae) from Chironius exoletus (Serpentes: Colubridae) in Brazil. Parasitology International, 67, 829–837. https://doi.org/10.1016/j.parint.2018.05.004
- Maupas, É. (1916) Nouveaux Rhabditis d’Algérie. Comptes Rendus de la Société Biologique, Paris, 79, 607–613
- Michonneau, F. (2016) Using GMYC for species delineation. Zenodo. Available from: https://zenodo.org/records/838260 (accessed 3 June 2025) https://doi.org/10.5281/zenodo.838260
- Moravec, F., Baruš, V. & Ryšavy´, B. (1987) Some parasitic nematodes, excluding Heterakidae and Pharyngodonidae, from amphibians and reptiles in Egypt. Folia Parasitologica, 34, 255–267
- Morsy, K., Mohamed, S.A., Abdel-Ghaffar, F., El-Fayoumi, H. & Abdel-Haleem, H. (2018) Rhabdias bufonis (Rhabdiasidae) from the lung of the African common toad, Amietophrynus regularis (Bufonidae) in Egypt: new data on the basis of light and scanning electron microscopic study. PeerJ, 6, e5328. https://doi.org/10.7717/peerj.5328
- Müller, M.I., Morais, D.H., Costa-Silva, G.J., Aguiar, A., Ávila, R.W. & da Silva, R.J. (2018) Diversity in the genus Rhabdias (Nematoda, Rhabdiasidae): Evidence for cryptic speciation. Zoologica Scripta, 47, 595–607. https://doi.org/10.1111/zsc.12304
- Müller, M.I., Morais, D.H., da Costa, L.F.S.T., de Vasconcelos Melo, F.T., Giese, E.G., Ávila, R.W. & da Silva, R.J. (2023) Revisiting the taxonomy of Rhabdias fuelleborni Travassos, 1928 (Nematoda, Rhabdiasidae) with approaches to delimitation of species and notes on molecular phylogeny. Parasitology International, 92, 102692. https://doi.org/10.1016/j.parint.2022.102692
- Nascimento, L.C.S., Gonçalves, E.C., Melo, F.T.V., Giese, E.G., Furtado, A.P. & dos Santos, J.N. (2013) Description of Rhabdias breviensis n. sp. (Rhabdotoidea: Rhabdiasidae) in two Neotropical frog species. Systematic Parasitology, 86, 69–75. https://doi.org/10.1007/s11230-013-9432-9
- Nylander, J.A.A. (2004) MrModeltest. Version 2. Program distributed by the author, Evolutionary Biology Centre, Uppsala University, Uppsala.
- Olson, D.M. & Dinerstein, E. (1998) The Global 200: A representation approach to conserving the Earth’s most biologically valuable ecoregions. Conservation Biology, 12, 502–515. [archived 7 October 2016 at the Wayback Machine] https://doi.org/10.1046/j.1523-1739.1998.012003502.x
- Olson, D.M. & Dinerstein, E. (2002) The Global 200: Priority Ecoregions for Global Conservation. Annals of the Missouri Botanical Garden, 89, 199. https://doi.org/10.2307/3298564
- Pramuk, J.B., Robertson, T., Sites Jr., J.W. & Noonan, B.P. (2008) Around the world in 10 million years: biogeography of the nearly cosmopolitan true toads (Anura: Bufonidae). Global Ecology and Biogeography, 17, 72–83. https://doi.org/10.1111/j.1466-8238.2007.00348.x
- Prosser, S.W., Velarde‐Aguilar, M.G., León‐Règagnon, V. & Hebert, P.D. (2013) Advancing nematode barcoding: a primer cocktail for the cytochrome c oxidase subunit I gene from vertebrate parasitic nematodes. Molecular Ecology Resources, 13, 1108–1115. https://doi.org/10.1111/1755-0998.12082
- Railliet, A. (1893) Traite´ de zoologie me´dicale et agricole. Fasc. I. Asselin & Houzeau, Paris, 1303 pp.
- Railliet, A. (1915) L’Emploi des Medicaments dans le Traitement des Maladies causees par des Nematodes. Tenth International Veterinary Congress. London, 1915, 733–749
- Ramallo, G., Goldberg, S., Bursey, C., Castillo, G. & Acosta, J.C. (2016) Thubunaea eleodori sp. nov. (Nematoda: Physalopteridae) from Liolaemus eleodori (Sauria: Liolaemidae) from Argentina. Parasitology Research, 116, 293–297. https://doi.org/10.1007/s00436-016-5290-0
- Rambaut, A., Drummond, A.J., Xie, D., Baele, G. & Suchard, M.A. (2018) Posterior Summarization in Bayesian Phylogenetics Using Tracer 1.7. Systematic Biology, 67, 901–904. https://doi.org/10.1093/sysbio/syy032
- Rambaut, A. (2018) FigTree v.1.4.4. Available from: http://tree.bio.ed.ac.uk/software/figtree/ (accessed 13 February 2025)
- Rasband, W.S. (2014) ImageJ. In: U.S. National Institutes of Health, Bethesda, Maryland, USA. [http://rsb.info.nih.gov/ij/]
- Rausch, R.L., Rausch, V.R. & Atrashkevich, G.I. (1984) Rhabdias bermani sp. nov. (Nematoda, Rhabdiasidae) from the Siberian salamander (Hynobius keyserlingi) from the north-east of Asia. Zoologičeskij žurnal, 63, 1297–1303
- Ronquist, F., Teslenko, M., van der Mark, P., Ayres, D.L., Darling, A., Höhna, S., Larget, B., Liu, L., Suchard, M.A. & Huelsenbeck, J.P. (2012) MrBayes 3.2: Efficient Bayesian Phylogenetic Inference and Model Choice Across a Large Model Space. Systematic Biology, 61, 539–542. https://doi.org/10.1093/sysbio/sys029
- Saad, A.I., Khalifa, R. & Mostafa, N. (2009) A lungworm nematode from amphibian hosts at Aswan Governorate, Egypt. World Journal of Zoology, 4, 37–41
- Sarkar, M.D. & Manna, B. (2004) On a new species of the genus Rhabdias Stiles and Hassall, 1905 (Nematoda: Rhabditida) from Bufo melanostictus Schneider, 1799 from Belur and Habra, West Bengal, India, with a host-parasite list. Philippine Journal of Science, 133, 55–69
- Sata, N., Takeuchi, H. & Nakano, T. (2020) Description of a New Species of Rhabdias (Nematoda: Rhabditida: Rhabdiasidae) from Ishigakijima Island, Okinawa, Japan. Species Diversity, 25, 17c175. https://doi.org/10.12782/specdiv.25.171
- Schneider, A. (1866) Monografie der Nematoden. Druck und Verlag von Georg Veimer, Berlin, 357 pp. https://doi.org/10.5962/bhl.title.1938
- Schrank, F.von P. (1788) Verzeichniß der bisher hinlänglich bekannten Eingeweidewürmer, nebst einer Abhandlung über ihre Anverwandtschaften. Johann Baptist Strobl, München, 1–12, 1–116
- Semenov, V.D. (1929) Eine neue Nematodenart - Rhabdias microoris n. sp. - aus den Lungen von Amphibien. Zentralblatt für Bakteriologie 1 Abt Originale, 114, 533–539
- Seurat, L.G. (1914) Sur un nouveau parasite de la perdrix rouge. Comptes rendus des séances de la Société de biologie et de ses filiales, 76, 390–393
- Sharpilo, V.P. (1976) Parasitic Worms of Reptilians of the Fauna of the USSR. Naukova Dumka, Kiev
- Sharpilo, V.P. & Vakker, V.G. (1972) A new species of the genus Entomelas (Nematoda, Rhabdiasidae), a lung parasite of Ophisaurus apodus. Vestnik Zoologii, 6, 86–88
- Stiles, Ch.W. & Hassall, A. (1905) The determination of generic types, and a list of roundworm genera, with their original and type species. Bureau of Animal Industry, U.S. Department of Agriculture Bulletin No 79. Government Printing Office, Washington, D.C., 150 pp. https://doi.org/10.5962/bhl.title.31560
- Svitin, R., Kuzmin, Y.I. & Preez, L. du (2018) Molecular and morphological characterisation of Rhabdias picardiae Junker, Lhermitte-Vallarino et Bain, 2010 (Nematoda: Rhabdiasidae) from Delaland’s River Frog, Amietia delalandii (Duméril et Bibron, 1841) (Amphibia: Pyxicephalidae) in South Africa. Acta Parasitologica, 63, 55–64. https://doi.org/10.1515/ap-2018-0007
- Szczerbak, N.N. & Sharpilo, V.P. (1969) Materials on systematics, ecology and parasite fauna of the reptiles of Kuril Islands. Communication 1. Vestnik Zoologii, 4, 18–25
- Swofford, D.L. (2002) PAUP: phylogenetic analysis using parsimony (and other methods). Version 4.0b10. Sunderland, MA: Sinauer Associates
- Tkach, V.V., Halajian, A. & Kuzmin, Y.I. (2014b) Phylogenetic affinities and systematic position of Entomelas sylvestris Baker, 1982 (Nematoda: Rhabdiasidae), a parasite of Breviceps sylvestris FitzSimons (Amphibia: Brevicipitidae) in South Africa. Systematic Parasitology, 87, 293–298. https://doi.org/10.1007/s11230-014-9469-4
- Tkach, V.V., Kuzmin, Y.I. & Pulis, E.E. (2006) A new species of Rhabdias from lungs of the wood frog, Rana sylvatica, in North America: the last sibling of Rhabdias ranae?. Journal of Parasitology, 92, 631–636. https://doi.org/10.1645/ge-625r.1
- Tkach, V.V., Kuzmin, Y.I. & Snyder, S.D. (2014a) Molecular insight into systematics, host associations, life cycles and geographic distribution of the nematode family Rhabdiasidae. International Journal for Parasitology, 44, 273–284. https://doi.org/10.1016/j.ijpara.2013.12.005
- Travassos, L. (1930) Pesquizas helminthologicas realisadas em Hamburgo: VII. notas sobre os Rhabdiasoidea Railliet, 1916: (Nematoda). Memorias do Instituto Oswaldo Cruz, 24, 161–181. https://doi.org/10.1590/s0074-02761930000800003
- Uetz, P., Freed, P. & Hošek, J. (Eds.) (2025) The Reptile Database. Available from: http://www.reptile-database.org (accessed 13 February 2025)
- Walton, A.C. (1929) Studies on Some Nematodes of North American Frogs. I. Journal of Parasitology, 15, 227–240. https://doi.org/10.2307/3271977
- Willkens, Y., Rebêlo, G.L., dos Santos, J.N., Furtado, A.P., Vilela, R.V., Tkach, V.V., Kuzmin, Y.I. & Melo, F.T.V. (2019) Rhabdias glaurungi sp. nov. (Nematoda: Rhabdiasidae), parasite of Scinax gr. ruber (Laurenti, 1768) (Anura: Hylidae), from the Brazilian Amazon. Journal of Helminthology, 94, e54. https://doi.org/10.1017/s0022149x19000476
- Willmott, S. & Chabaud, A.G. (2009) Glossary and Keys to Subclasses. In: Anderson, R.C., Chabaud, A.G. & Willmott, S. (Eds.), Keys to the Nematode Parasites of Vertebrates. Archival Volum. CAB International, Wallingford, pp. 1–17. https://doi.org/10.1079/9781845935726.0001
- Yamaguti, S. (1961) Systema Helminthum. Vol. III. The Nematodes of Vertebrates. Interscience Publishers, Inc., New York, 1261 pp.
- Zeng, J.L., Chen, H.X., Ni, X.F., Kang, J.Y. & Li, L. (2024) Molecular phylogeny of the family Rhabdiasidae (Nematoda: Rhabditida), with morphology, genetic characterization and mitochondrial genomes of Rhabdias kafunata and R. bufonis. Parasites & Vectors, 17, 1–19. https://doi.org/10.1186/s13071-024-06201-z
- Zhang, J. (2025) Species delimitation server. bPTP server: a Bayesian implementation of the PTP model for species delimitation. Available from: https://species.h-its.org/ptp/ (accessed 13 February 2025)
- Zhang, J., Kapli, P., Pavlidis, P. & Stamatakis, A. (2013) A general species delimitation method with applications to phylogenetic placements. Bioinformatics, 29, 2869–2876. https://doi.org/10.1093/bioinformatics/btt499