{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,5]],"date-time":"2026-10-05T21:56:00Z","timestamp":1791237360644,"version":"4.1.0"},"reference-count":49,"publisher":"American Society of Parasitologists","issue":"2","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Journal of Parasitology"],"published-print":{"date-parts":[[2026,3,20]]},"abstract":"<jats:p>The genus Spiroxys Schneider, 1866 comprises species that commonly parasitize chelonians of the suborder Cryptodira found in the Holarctic and Asian regions. Spiroxys contortus (Rudolphi, 1819) was described as parasitizing a freshwater turtle of the suborder Cryptodira in the Palearctic region and is 1 of the most widely recorded species of the genus worldwide, with records even extending to Brazil. Thus, this study aims to report the first record of S. contortus in Kinosternon scorpioides (Linnaeus, 1766), a cryptodiran freshwater turtle of the family Kinosternidae, from 3 municipalities in the Brazilian Amazon. Nematodes were collected from the turtles' stomachs and identified with light microscopy. We identified several intraspecific variations and provide additional morphological and morphometric data for the species. This is the first record of S. contortus in K. scorpioides and the first record of the species in the Brazilian Amazon. Our findings expand the known host distribution of S. contortus, highlight host-sharing patterns among parasites of freshwater turtles, and contribute to understanding parasite diversity in K. scorpioides.<\/jats:p>","DOI":"10.1645\/25-59","type":"journal-article","created":{"date-parts":[[2026,3,24]],"date-time":"2026-03-24T09:12:32Z","timestamp":1774343552000},"page":"140-149","source":"Crossref","is-referenced-by-count":0,"title":["Host-Sharing Dynamics at Play: First Record of Spiroxys contortus in Kinosternon scorpioides from Brazilian Amazon"],"prefix":"10.1645","volume":"112","author":[{"given":"Leandro Mauricio Oliveira","family":"Silva","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Bianca","family":"Nandyara","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Marlon","family":"Leal","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jeannie Nascimento","family":"Santos","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8935-2923","authenticated-orcid":false,"given":"Francisco Tiago","family":"Vasconcelos Melo","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1220","reference":[{"key":"34","doi-asserted-by":"publisher","unstructured":"E. O. Palumbo, L. Alcalde, M. Bonino, et al.  \"Journal of Helminthology.\"  98, \"Closing the knowledge gap: helminth parasites of freshwater turtles from the Chaco-Pampa Plain, Southern South America.\" e30 (2024)","DOI":"10.1017\/S0022149X24000178"},{"key":"1","unstructured":"C. J. R. Alho,  \"Boletim do Museu Paraense Em\u00edlio Goeldi.\"  58, \"Contribui\u00e7\u00e3o ao conhecimento da fauna helmintol\u00f3gica de quel\u00f4nios do estado do Par\u00e1, Brasil.\" 1 (1965)"},{"key":"2","unstructured":"R. W. \u00c1vila, E. S. Brito, T. H. Barrella, et al.  \"Pan-American Journal of Aquatic Sciences.\"  5, \"Endoparasites new to the neotropical freshwater turtle, Mesoclemmys vanderhaegei (Bour 1973) (Testudines, Chelidae), from central Brazil.\" 478 (2010)"},{"key":"4","doi-asserted-by":"crossref","unstructured":"H. A. Baylis  and C. Lane  \"Proceedings of the Zoological Society of London.\"  90, \"A revision of the nematode family Gnathostomatidae.\" 195 (1920)","DOI":"10.1111\/j.1469-7998.1920.tb07073.x"},{"key":"5","unstructured":"F. F. Bernardon, A. L. Valente, G. M\u00fcller,  \"Pan-American Journal of Aquatic Sciences.\"  8, \"Gastrointestinal helminths of the Argentine side-necked turtle Phrynops hilarii (Dum\u00e9ril & Bibron, 1835) (Testudines, Chelidae), in south Brazil.\" 55 (2013)"},{"key":"6","unstructured":"F. F. Bernardon, A. L. Valente, G. M\u00fcller,  \"Pan-American Journal of Aquatic Sciences.\"  9, \"Gastrointestinal helminths of Trachemys dorbigni Dum\u00e9ril & Bibron, 1835 (Testudines, Emydidae) from artificial urban ponds in southern Brazil.\" 54 (2014)"},{"key":"8","unstructured":"J. F. Berry  and J. B. Iverson  \"Catalogue of American Amphibians and Reptiles.\"  \"Kinosternon scorpioides.\" 725.1 (2001)"},{"key":"9","doi-asserted-by":"crossref","unstructured":"J. F. Berry  and J. B. Iverson  \"Chelonian Research Monographs.\"  5, \"Kinosternon scorpioides (Linnaeus 1766)\u2014Scorpion mud turtle.\" 63.1 (2011)","DOI":"10.3854\/crm.5.063.scorpioides.v1.2011"},{"key":"10","unstructured":"R. R. Brenes  and Bravo-Hollis M.  \"Libro Homenaje al Dr. Eduardo Caballero y Caballero.\"  \"Helmintos de la Republica de Costa Rica IX. Nematoda 3. Algunos nematodos de reptiles, con descripcion de dos nuevas especies: Atractis caballeroi n. sp. y Cyrtosomum longicaudatum n. sp.\" 451 (1960)"},{"key":"11","doi-asserted-by":"publisher","unstructured":"C. R. Bursey  and D. R. Brooks  \"Comparative Parasitology.\"  78, \"Nematode parasites of five species of turtles from the Area de Conservaci\u00f3n Guanacaste, Costa Rica, with description of a new species of Falcaustra.\" 107 (2011)","DOI":"10.1654\/4431.1"},{"key":"14","doi-asserted-by":"publisher","unstructured":"D. F. Conga, Helen Costa J., Bejarano Alegre V., et al.  \"Journal of Helminthology.\"  100, \"Seasonal rainfall drives temporal niche partitioning in the helminth community of scorpion mud turtle (Kinosternon scorpioides) from Maraj\u00f3 Island.\" 1 (2026)","DOI":"10.1017\/S0022149X25101132"},{"key":"15","doi-asserted-by":"crossref","unstructured":"M. Demkowska-Kutrzepa, K. Szczepaniak, M. Roczenkarczmarz, et al.  \"International Journal for Parasitology: Parasites and Wildlife.\"  16, \"The first case of Spiroxys contortus in European pond turtle (Emys orbicularis) in the wild in Poland.\" 26 (2021)","DOI":"10.1016\/j.ijppaw.2021.07.004"},{"key":"16","unstructured":"C. D\u00edaz Ungr\u00eda,  \"Kasmera.\"  6, \"Parasitic helminths of vertebrates in the State of Zulia. Some species new to Venezuela.\" 207 (1978)"},{"key":"17","unstructured":"C. R. Ferrara, C. K. Fagundes, T. Q. Morcatty, et al.  \"Quel\u00f4nios Amaz\u00f4nicos: Guia de Identifica\u00e7\u00e3o e Distribui\u00e7\u00e3o.\"  182 (2017)"},{"key":"18","doi-asserted-by":"publisher","unstructured":"C. F. Fonseca, Rojas N. J. J. T., F. M. Vieira, et al.  \"Veterinary Parasitology: Regional Studies and Reports.\"  26, \"Helminth fauna and histopathology associated with parasites infections Phrynops geoffroanus (Schweigger, 1812) (Testudines, Chelidae) in a Brazilian river subjected to anthropogenic activities.\" 100639 (2021)","DOI":"10.1016\/j.vprsr.2021.100639"},{"key":"19","doi-asserted-by":"publisher","unstructured":"J. F. T. Freitas  and Dobbin J. E.  \"Mem\u00f3rias do Instituto Oswaldo Cruz.\"  69, \"Contribui\u00e7\u00e3o ao conhecimento da fauna helmintol\u00f3gica de quel\u00f4nios no estado de Pernambuco, Brasil.\" 33 (1971)","DOI":"10.1590\/S0074-02761971000100002"},{"key":"20","doi-asserted-by":"crossref","unstructured":"D. Gonz\u00e1lez-Sol\u00eds  and F. Moravec  \"Journal of Parasitology.\"  90, \"Two new nematode species, Orientatractis campechensis n. sp. and Orientatractis chiapasensis n. sp. (Nematoda: Atractidae) from cichlid fishes in southern Mexico and Nicaragua.\" 1443 (2004)","DOI":"10.1645\/GE-3366"},{"key":"22","unstructured":"H., T. Hasegawa, A. Fujisaki, A. Miyata,  \"Comparative Parasitology.\"  67, \"Life history of Spiroxys hanzaki Hasegawa, Miyata et Doi, 1998 (Nematoda: Gnathostomatidae).\" 224 (2000)"},{"key":"23","doi-asserted-by":"crossref","unstructured":"H. Hasegawa, A. Miyata, DoI. T.,  \"Journal of Parasitology.\"  84, \"Spiroxys hanzaki n. sp. (Nematoda: Gnathostomatidae) collected from the giant salamander, Andrias japonicus (Caudata: Cryptobranchidae), in Japan.\" 831 (1998)","DOI":"10.2307\/3284598"},{"key":"24","unstructured":"H. Hasegawa  and M. Otsuru  \"Japanese Journal of Parasitology.\"  27, \"Notes on the life cycle of Spiroxys japonica Morishita, 1926 (Nematoda: Gnathostomatidae).\" 113 (1978)"},{"key":"25","doi-asserted-by":"publisher","unstructured":"L. R. Hedrick,  \"Journal of Parasitology.\"  21, \"Taxonomy of the nematode genus Spiroxys (family Spiruridae).\" 397 (1935a)","DOI":"10.2307\/3271952"},{"key":"26","doi-asserted-by":"publisher","unstructured":"L. R. Hedrick,  \"Transactions of the American Microscopical Society.\"  54, \"The life history and morphology of Spiroxys contortus (Rudolphi); Nematoda: Spiruridae.\" 337 (1935b)","DOI":"10.2307\/3222323"},{"key":"27","doi-asserted-by":"publisher","unstructured":"P. H. Izidro De Brito  and Figueiredo Lacerda A. C.  \"Journal of Helminthology.\"  99, \"Helminth parasites of terrestrial and freshwater chelonians in the Neotropical region: Biogeographic distribution and new record for Phrynops geoffroanus (Schweigger, 1812) (Testudines: Chelidae) in the Brazilian semiarid region.\" 1 (2025)","DOI":"10.1017\/S0022149X25000392"},{"key":"28","doi-asserted-by":"crossref","unstructured":"M. Jaramillo  and Rivera-Parra J. L.  \"Disease Ecology, Social and Ecological Interactions in the Galapagos Islands.\"  \"Host-switching: How it starts.\" 139 (2018)","DOI":"10.1007\/978-3-319-65909-1_6"},{"key":"29","doi-asserted-by":"publisher","unstructured":"C. S. Mascarenhas, B. M. Chaviel, F. F. Bernardon, et al.  \"Parasitology Research.\"  121, \"Gastrointestinal helminths associated with three species of freshwater turtles in the Pampa biome, southern Brazil.\" 225 (2022)","DOI":"10.1007\/s00436-021-07361-y"},{"key":"30","doi-asserted-by":"publisher","unstructured":"C. S. Mascarenhas  and G. M\u00fcller  \"Comparative Parasitology.\"  82, \"Spiroxys contortus (Gnathostomatidae) and Falcaustra affinis (Kathlaniidae) from Trachemys dorbigni (Emydidae) in southern Brazil.\" 129 (2015)","DOI":"10.1654\/4726.1"},{"key":"31","doi-asserted-by":"publisher","unstructured":"C. S. Mascarenhas  and G. M\u00fcller  \"Neotropical Helminthology.\"  15, \"Checklist of helminths associated with continental testudines from South America.\" 97 (2021)","DOI":"10.24039\/rnh20211511047"},{"key":"32","doi-asserted-by":"publisher","unstructured":"C. S. Mascarenhas, J. D. Souza, M. C. A. Coimbra, et al.  \"Parasitology Research.\"  112, \"Nematode parasites of Chelidae (Testudines) from southern Brazil.\" 3365 (2013)","DOI":"10.1007\/s00436-013-3503-3"},{"key":"33","doi-asserted-by":"crossref","unstructured":"F. Moravec  and Vargas-V\u00e1zquez J.  \"Journal of Natural History.\"  32, \"Some endohelminths from the freshwater turtle Trachemys scripta from Yucatan, Mexico.\" 455 (1998)","DOI":"10.1080\/00222939800770241"},{"key":"35","doi-asserted-by":"publisher","unstructured":"E. Palumbo, S. Capasso, M. J. Cassano, et al.  \"Check List.\"  12, \"Spiroxys contortus (Rudolphi, 1819) and Hedruris orestiae (Moniez, 1889) in Argentine turtles.\" 1 (2016)","DOI":"10.15560\/12.6.1993"},{"key":"36","doi-asserted-by":"publisher","unstructured":"A. M. A. Pereira, S. V. Brito, J. A. Filho, et al.  \"Acta Herpetologica.\"  13, \"Diet and helminth parasites of freshwater turtles Mesoclemmys tuberculata, Phrynops geoffroanus (Pleurodira: Chelidae) and Kinosternon scorpioides (Criptodyra: Kinosternidae) in a semiarid region, northeast of Brazil.\" 21 (2018)","DOI":"10.13128\/Acta_Herpetol-20323"},{"key":"37","doi-asserted-by":"crossref","unstructured":"E. Purwaningsih,  \"Journal of Coastal Life Medicine.\"  3, \"Parasitic nematodes from turtles: New species and new record from Indonesia.\" 607 (2015)","DOI":"10.12980\/JCLM.3.2015J5-36"},{"key":"38","unstructured":"E. Rakhshandehroo, A. Gholamhosseini, A. Ahmadi, et al.  \"International Journal of Aquatic Biology.\"  8, \"An investigation on the helminth parasites of Caspian turtle (Mauremys caspica) with a taxonomic note on recovered Falcaustra Lane, 1915 (Nematoda: Kathlaniidae) and Spiroxys Schneider, 1866 species (Nematoda: Gnathostomatidae).\" 246 (2020)"},{"key":"40","doi-asserted-by":"crossref","unstructured":"C. A. Rudolphi,  \"Entozoorum synopsis cui accedunt mantissa duplex et indices locupletissimi.\"  838 (1819)","DOI":"10.5962\/bhl.title.9157"},{"key":"41","doi-asserted-by":"publisher","unstructured":"D. O. Santana, A. M. T. Teixeira, Ara\u00fajo-Filho J. A., et al.  \"Journal of Natural History.\"  57, \"Helminths of freshwater turtles in northeastern Brazil: Parasite\u2013host\u2013environment relationships.\" 503 (2023)","DOI":"10.1080\/00222933.2023.2203334"},{"key":"42","doi-asserted-by":"publisher","unstructured":"L. M. O. Silva, R. F. Jesus, B. Nandyara, et al.  \"Neotropical Helminthology.\"  18, \"Far from home? A new locality record of Falcaustra sanjuanensis Gonz\u00e1lez, Sanabria & Quiroga, 2013 (Nematoda: Kathlaniidae) in a new host from the Brazilian Amazon.\" 117 (2024)","DOI":"10.62429\/rnh20242181781"},{"key":"43","doi-asserted-by":"publisher","unstructured":"L. M. O. Silva, R. F. Jesus, A. N. Santos, et al.  \"International Journal for Parasitology: Parasites and Wildlife.\"  22, \"New species of Serpinema (Nematoda: Camallanidae) from the scorpion mud turtle Kinosternon scorpioides (Testudines: Kinosternidae) from eastern Amazon, Brazil.\" 6 (2023)","DOI":"10.1016\/j.ijppaw.2023.07.006"},{"key":"44","doi-asserted-by":"publisher","unstructured":"A. L. Sousa, A. M. Medeiros, J. B. Almeida, et al.  \"Neotropical Helminthology.\"  18, \"First register of Contracaecum sp. and Eustrongylides sp. (Nematoda) in Kinosternon scorpioides (Linnaeus, 1766) (Testudines: Kinosternidae) from northeastern Brazil.\" 249 (2024)","DOI":"10.62429\/rnh20242181853"},{"key":"45","doi-asserted-by":"crossref","unstructured":"K. S. Todd,  \"Journal of Parasitology.\"  55, \"Spiroxys utahensis n. sp. (Nematoda: Spiruridae) from tiger salamander, Ambystoma tigrinum nebulosum.\" 352 (1969)","DOI":"10.2307\/3277408"},{"key":"46","doi-asserted-by":"publisher","unstructured":"A. G. J. Rhodin, J. B. Iverson, R. Bour, et al.  \"Chelonian Research Monographs.\"  8, \"Turtles of the World: Annotated Checklist and Atlas of Taxonomy, Synonymy, Distribution, and Conservation Status\" 1 (2021)","DOI":"10.3854\/crm.8.checklist.atlas.v9.2021"},{"key":"48","doi-asserted-by":"crossref","unstructured":"A. C. Walton,  \"Journal of Parasitology.\"  17, \"Studies on some nematodes of North American Amphibia. II. Cryptobranchidae.\" 20 (1930)","DOI":"10.2307\/3271645"},{"key":"49","unstructured":"H. S. Yildirimhan  and \u0321sahin R.  \"T\u00fcrkiye Parazitoloji Dergisi.\"  29, \"Bursa ve \u00c7evresinde Yas \u0321ayan Emys orbicularis (Linnaeus, 1758) (Benekli Kaplumba\u011fa)'in Helmint Faunas\u0131.\" 56 (2004)"},{"key":"13","doi-asserted-by":"crossref","unstructured":"M. B. Chitwood,  \"Systematic Zoology.\"  6, \"Intraspecific variation in parasitic nematodes.\" 19 (1957)","DOI":"10.2307\/2411704"},{"key":"21","doi-asserted-by":"crossref","unstructured":"J. A. Haley,  \"Journal of Parasitology.\"  8, \"Role of host relationships in the systematics of helminth parasites.\" 671 (1962)","DOI":"10.2307\/3275256"},{"key":"3","doi-asserted-by":"crossref","unstructured":"H. A. Baylis  and R. Daubney  \"Memoirs of the Indian Museum.\"  7, \"Report on the parasitic nematodes in the collection of the zoological survey of India.\" 264 (1922)","DOI":"10.26515\/rzsi\/v25\/i6\/1923\/162684"},{"key":"12","doi-asserted-by":"publisher","unstructured":"A. O. Bush, K. D. Lafferty, J. M. Lotz, et al.  \"Journal of Parasitology.\"  83, \"Parasitology meets ecology on its own terms: Margolis et al. revisited.\" 575 (1997)","DOI":"10.2307\/3284227"},{"key":"47","doi-asserted-by":"publisher","unstructured":"D. C. Viana, J. F. M. Rodrigues, C. B. Madelaire, et al.  \"Journal of Parasitology.\"  102, \"Nematoda of Kinosternon scorpioides (Testudines: Kinosternidae) from Northeastern Brazil.\" 165 (2016)","DOI":"10.1645\/15-788"},{"key":"7","doi-asserted-by":"crossref","unstructured":"G. N. Berry,  \"Systematic Parasitology.\"  7, \"A new species of the genus Spiroxys (Nematoda; Spiruroidea) from Australian chelonians of the genus Chelodina (Chelidae).\" 59 (1985)","DOI":"10.1007\/BF00010162"},{"key":"39","doi-asserted-by":"publisher","unstructured":"V. Roca  and G. Garc\u00eda  \"Journal of Helminthology.\"  82, \"A new species of the genus Spiroxys (Nematoda: Gnathostomatidae) from Madagascan pleurodiran turtles (Pelomedusidae).\" 301 (2008)","DOI":"10.1017\/S0022149X08996966"}],"container-title":["Journal of Parasitology"],"original-title":[],"deposited":{"date-parts":[[2026,10,5]],"date-time":"2026-10-05T21:10:07Z","timestamp":1791234607000},"score":1,"resource":{"primary":{"URL":"https:\/\/bioone.org\/journals\/journal-of-parasitology\/volume-112\/issue-2\/25-59\/Host-Sharing-Dynamics-at-Play--First-Record-of-Spiroxys\/10.1645\/25-59.full"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,3,20]]},"references-count":49,"journal-issue":{"issue":"2","published-online":{"date-parts":[[2026,3,1]]}},"URL":"https:\/\/doi.org\/10.1645\/25-59","relation":{},"ISSN":["0022-3395","1937-2345"],"issn-type":[{"value":"0022-3395","type":"print"},{"value":"1937-2345","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,3,20]]}}}