Skip to main content Skip to main navigation menu Skip to site footer
Responsive image
Issue: Vol. 5785 No. 3: 31 Mar. 2026
Type: Article
Published: 2026-03-31
DOI: 10.11646/zootaxa.5785.3.5
Page range: 508-526
Abstract views: 28
PDF downloaded: 0

A new Opisthotropis Günther, 1872 (Colubridae: Natricinae) from northern Laos allied to the enigmatic Opisthotropis maculosa Stuart & Chuaynkern, 2007

North Carolina Museum of Natural Sciences; 11 West Jones Street; Raleigh; North Carolina 27601; USA
Department of Biology; Faculty of Natural Sciences; National University of Laos; Dongdok Campus; P.O. Box 7322; Vientiane; Laos
Department of Biology; Faculty of Science; Khon Kaen University; Mueang Khon Kaen; Khon Kaen; 40002; Thailand
Herpetological Museum; Chengdu Institute of Biology; Chinese Academy of Sciences; No. 23; Qun Xian South Street; Tianfu New District; Chengdu 610213; Sichuan; China
American Museum of Natural History; 200 Central Park West; New York; New York 10024; USA
Department of Biology; Faculty of Natural Sciences; National University of Laos; Dongdok Campus; P.O. Box 7322; Vientiane; Laos; North Carolina Museum of Natural Sciences; 11 West Jones Street; Raleigh; North Carolina 27601; USA
Reptilia Hydrablabes integrative taxonomy Opisthotropis haihaensis Opisthotropis hungtai Phou katha

Abstract

The natricid snake genus Opisthotropis contains approximately 25 species distributed across tropical Asia. Three specimens of a distinctively patterned Opisthotropis from the Phou Katha Platea in Hom District, Xaysomboun Province, northern Laos, are shown to be molecularly and morphologically distinct from all other members of the genus and are described as a new species. Based on more than 9 kb of multi-locus sequence data from mitochondrial and nuclear genes, Opisthotropis hanseli sp. nov. is phylogenetically recovered to be sister to O. maculosa, a species known only by its holotype specimen from northeastern Thailand. The new species differs from its congeners by having the combination of a dark dorsum with a light spot on each scale, 20 maxillary teeth, the nasal cleft extending to near suture of the first and second supralabial, and the number and arrangement of head and body scales, notably a single internasal. The monophyly of Opisthotropis is resolved by transferring O. typica from Borneo and Palawan to the genus Hydrablabes as H. typicus comb. nov.

 

References

  1. Angel, F. (1929) Liste des Reptiles et Batraciens du Haut-Laos recueillis par M. Delacour. Description d’un genre, de deux espèces et d’une variété d’Ophidens. Bulletin du Muséum national d’Histoire naturelle, Series 2, 1 (1), 75–81.
  2. Angel, F. & Bourret, R. (1933) Sur une petite collection de serpents du Tonkin. Descriptions d’espèces nouvelles. Bulletin de la Société Zoologique de France, 58 (3–4), 129–140.
  3. Arèvalo, E., Davis, S.K. & Sites, J.W. (1994) Mitochondrial DNA sequence divergence and phylogenetic relationships among eight chromosome races of the Sceloporus grammicus complex (Phrynosomatidae) in central Mexico. Systematic Biology, 43 (3), 387–418. https://doi.org/10.1093/sysbio/43.3.387
  4. Bernstein, J.M. & Ruane, S. (2022) Maximizing molecular data from low-quality fluid-preserved specimens in natural history collections. Frontiers in Ecology and Evolution, 10, Article 893088. https://doi.org/10.3389/fevo.2022.893088
  5. Boulenger, G.A. (1888) Description of two new snakes from Hongkong, and note on the dentition of Hydrophis viperina. Annals and Magazine of Natural History, Series 6, 2 (7), 43–44. https://doi.org/10.1080/00222938809460874
  6. Boulenger, G.A. (1899) On a collection of reptiles and batrachians made by Mr. J. D. La Touche in N.W. Fokien, China. Proceedings of the Zoological Society of London, 1899, 159–172. https://doi.org/10.1111/j.1469-7998.1899.tb06855.x
  7. Boulenger G.A. 1903. Descriptions of new snakes in the collection of the British Museum. Annals and Magazine of Natural History, Series 7, 12 (69), 350–354. https://doi.org/10.1080/00222930308678866
  8. Boulenger, G.A. (1904) Description of a new snake. Spolia Zeylanica, 2, 95.
  9. Brakels, P., Maury, N. & Nguyen, T.V. (2021) Opisthotropis durandi (Durand’s Mountain Stream Snake). Herpetological Review, 52 (1), 88.
  10. Burbrink, F.T., Lawson, R. & Slowinski, J.B. (2000) Mitochondrial DNA phylogeography of the polytypic North American rat snake (Elaphe obsoleta): A critique of the subspecies concept. Evolution, 54 (6), 2107–2118. https://doi.org/10.1111/j.0014-3820.2000.tb01253.x
  11. Chuaynkern, C., Khajitmathee, N., Phochayavanich, R., Maiphrom, W., Phetcharat, E., Chaiyes, A., Duengkae, P. & Chuaynkern, Y. (2025a) Present and future habitat suitability of an endemic tree frog, Zhangixalus jarujini, under climate change scenario. Biodiversitas Journal of Biodiversity, 26 (9), 4445–4456. https://doi.org/10.13057/biodiv/d260917
  12. Chuaynkern, C., Khajitmathee, N., Phochayavanich, R., Phommexay, P., Chaiyes, A., Maury, N., Sudavanh, S., Aowphol, A., Rujirawan, A., Pailoblee, S., Suksavate, W., Duengkae, P. & Chuaynkern, Y. (2025b) Present and future habitat suitability of Mantheyus phuwuanensis under climate change scenario. Biodiversitas Journal of Biodiversity, 26 (3), 1075–1084. https://doi.org/10.13057/biodiv/d260306
  13. Chuaynkern, Y., Duengkae, P., Pongcharoen, C., Chuaynkern, C. & Horsin, L. (2014) Opisthotropis spenceri Smith, 1918 (Serpentes: Natricidae): The third and fourth specimens. Journal of Wildlife in Thailand, 21 (1), 1–14.
  14. Cope, E.D. (1871) Ninth contribution to the herpetology of tropical America. Proceedings of the Academy of Natural Sciences of Philadelphia, 23, 200–224.
  15. Cope, E.D. (1895) On a collection of Batrachia and Reptilia from the island of Hainan. Proceedings of the Academy of Natural Sciences of Philadelphia, 46, 423–428. [1894]
  16. David, P., Pham, C.T., Nguyen, T.Q. & Ziegler T. (2011) A new species of the genus Opisthotropis Günther, 1872 (Squamata: Natricidae) from the highlands of Kon Tum Province, Vietnam. Zootaxa, 2758 (1), 43–56. https://doi.org/10.11646/zootaxa.2758.1.3
  17. David, P., Teynié, A. & Vogel, G. (2023) The Snakes of Laos. Edition Chimaira, Frankfurt am Main, 960 pp.
  18. Deepak, V., Cooper, N., Poyarkov, N.A., Kraus, F., Burin, G., Das, A., Narayanan, S., Streicher, J.W., Smith, S.J. & Gower, D.J. (2021a) Multilocus phylogeny, natural history traits and classification of natricine snakes (Serpentes: Natricinae). Zoological Journal of the Linnean Society, 195 (1), 279–298. https://doi.org/10.1093/zoolinnean/zlab099
  19. Deepak, V., Maddock, S.T., Williams, R., Nagy, Z.T., Conradie, W., Rocha, S., Harris, D.J., Perera, A., Gvoždík, V., Doherty-Bone, T.M., Kamei, R.G., Menegon, M., Labisko, J., Morel, C., Cooper, N., Day, J.J. & Gower, D.J. (2021b) Molecular phylogenetics of sub-Saharan African natricine snakes, and the biogeographic origins of the Seychelles endemic Lycognathophis seychellensis. Molecular Phylogenetics and Evolution, 161, 107152. https://doi.org/10.1016/j.ympev.2021.107152
  20. Dowling, H.G. (1951) A proposed standard system of counting ventrals in snakes. British Journal of Herpetology, 1 (5), 97–99.
  21. Edler, D., Klein, J., Antonelli, A. & Silvestro, D. (2021) raxml GUI 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
  22. Figueroa, A., McKelvy, A.D., Grismer, L.L., Bell, C.D. & Lailvaux, S.P. (2016) A species-level phylogeny of extant snakes with description of a new colubrid subfamily and genus. PLoS ONE, 11, e0161070. https://doi.org/10.1371/journal.pone.0161070
  23. Frippiat, C., Kremarik, P., Ropars, A., Dournon, C., Frippiat, J.P. (2001) The recombination-activating gene 1 of Pleurodeles waltl (urodele amphibian) is transcribed in lymphoid tissues and in the central nervous system. Immunogenetics, 52, 264–275. https://doi.org/10.1007/s002510000275
  24. Gao, Z., Zhang, Y., Nguyen, V.D.H., Jiang, K., Nguyen, T.T., Li, J. & Ren, J. (2025) Rediscovery and revision of the diagnostic characters of Opisthotropis daovantieni Orlov, Darevsky, and Murphy, 1998 (Squamata: Natricidae) from southern Vietnam, with notes on its hemipenial morphology and defensive behavior. Asian Herpetological Research, 16 (1), 49–65. https://doi.org/10.3724/ahr.2095-0357.2024.0048
  25. Giri, V.B., Gower, D.J., Das, A., Lalremsanga, H.T., Lalronunga, S., Captain, A. & Deepak, V. 2019. A new genus and species of natricine snake from northeast India. Zootaxa, 4603 (2), 241–264. https://doi.org/10.11646/zootaxa.4603.2.2
  26. Groth, J.G. & Barrowclough, G.F. (1999) Basal divergences in birds and the phylogenetic utility of the nuclear RAG-1 gene. Molecular Phylogenetics and Evolution, 12 (2), 115–123. https://doi.org/10.1006/mpev.1998.0603
  27. Günther, A.C.L.G. (1872a) Seventh account of new species of snakes in the collection of the British Museum. Annals and Magazine of Natural History, Series 4, 9 (1), 13–37. https://doi.org/10.1080/002229372011951771
  28. Günther, A. (1872b) On the amphibians and reptiles of Borneo. Proceedings of the Zoological Society of London, 1872, 596–600.
  29. Guo, P., Liu, Q., Xu, Y., Jiang, K., Hou, M., Ding, L., Pyron, R.A. & Burbrink, F.T. (2012) Out of Asia: Natricine snakes support the Cenozoic Beringian dispersal hypothesis. Molecular Phylogenetics and Evolution, 63 (3), 825–833. https://doi.org/10.1016/j.ympev.2012.02.021
  30. Guo, P., Zhu, F. & Liu, Q. (2019) A new member of the genus Sinonatrix (Serpentes: Colubridae) from western China. Zootaxa, 4623 (3), 533–544. https://doi.org/10.11646/zootaxa.4623.3.5
  31. Guo, P., Zhu, F., Liu, Q., Wang, P., Che, J. & Nguyen, T.Q. (2020) Out of the Hengduan Mountains: Molecular phylogeny and historical biogeography of the Asian water snake genus Trimerodytes (Squamata: Colubridae). Molecular Phylogenetics and Evolution, 152, 106927. https://doi.org/10.1016/j.ympev.2020.106927
  32. Ha, N.V., Ziegler, T., Nguyen, T.Q., Le, M.D. & Luu, V.Q. (2023) First record of Opisthotropis durandi Teynié, Lottier, David, Nguyen & Vogel, 2014 (Squamata: Natricidae) from Vietnam. Academia Journal of Biology, 45 (2), 1–7. https://doi.org/10.15625/2615-9023/17556
  33. Hikida, T. (2015) Book review: A Field Guide to the Reptiles of Thailand. Natural History Bulletin of the Siam Society, 61 (4), 41–51.
  34. Kambayashi, C., Kakehashi, R., Sato, Y., Mizuno, H., Tanabe, H., Rakotoarison, A., Künzel, S., Furuno, N., Ohshima, K., Kumazawa, Y., Nagy, Z.T., Mori, A., Allison, A., Donnellan, S.C., Ota, H., Hoso, M., Yanagida, T., Sato, H., Vences, M. & Kurabayashi, A. (2022) Geography-dependant horizontal gene transfer from vertebrate predators to their prey. Molecular Biology and Evolution, 39 (4), msac052. https://doi.org/10.1093/molbev/msac052
  35. Katoh, K. & Standley, D.M. (2013) MAFFT multiple sequence alignment software version 7: Improvements in performance and stability. Molecular Biology and Evolution, 30, 772–780. https://doi.org/10.1093/molbev/mst010
  36. Kocher, T.D., Thomas, W.K., Meyer, A., Edwards, S.V., Pääbo, S., Villablanca, F.X. & Wilson, A.C. (1989) Dynamics of mitochondrial DNA evolution in animals: amplification and sequencing with conserved primers. Proceedings of the National Academy of Sciences of the United States of America, 86 (16), 6196–6200. https://doi.org/10.1073/pnas.86.16.6196
  37. Köhler, G. (2012) Color Catalogue for Field Biologists. Herpeton, Offenbach, 49 pp.
  38. Lalronunga, S., Lalrinchhana, C., Ramliana, V., Das, A., Gower, D.J. & Deepak, V. (2020) A multilocus molecular perspective on the systematics of the poorly known northeast Indian colubrid snakes Blythia reticulata (Blyth, 1854), B. hmuifang Vogel, Lalremsanga & Vanlalhrima, 2017, and Hebius xenura (Wall, 1907). Zootaxa, 4768 (2), 193–200. https://doi.org/10.11646/zootaxa.4768.2.2
  39. Lanfear, R., Frandsen, P.B., Wright, A.M., Senfeld, T. & Calcott, B. (2017) PartitionFinder 2: New methods for selecting partitioned models of evolution for molecular and morphological phylogenetic analyses. Molecular Biology and Evolution, 34, 772–773. https://doi.org/10.1093/molbev/msw260
  40. Lawson, R., Slowinski, J.B., Crother, B.I. & Burbrink, F.T. (2005) Phylogeny of the Colubroidea (Serpentes): New evidence from mitochondrial and nuclear genes. Molecular Phylogenetics and Evolution, 37 (2), 581–601. https://doi.org/10.1016/j.ympev.2005.07.016
  41. Li, J.-N., Liang, D., Wang, Y.-Y., Guo, P., Huang, S. & Zhang, P. (2020) A large-scale systematic framework of Chinese snakes based on a unified multilocus marker system. Molecular Phylogenetics and Evolution, 148, 106807. https://doi.org/10.1016/j.ympev.2020.106807
  42. Liu, W., Cai, B., Xia, Q.R. & Wu, Y.Q. (2021) The complete mitochondrial genome of the Chinese mountain keelback (Natricidae: Opisthotropis kuatunensis), comparative and phylogenetic analysis. Mitochondrial DNA Part B: Resources, 6 (12), 3350–3351. https://doi.org/10.1080/23802359.2021.1964397
  43. Malkmus, R., Manthey, U., Vogel, G., Hoffman, P. & Kosuch, J. (2002) Amphibians & Reptiles of Mount Kinabalu (North Borneo). A.R.G. Gantner Verlag Kommanditgesellschaft, Rugell, 424 pp.
  44. Manthey, U. & Nabhitabhata, J. (1991) Eine neue Agame, Ptyctolaemus phuwuanensis sp. n. (Sauria: Agamidae), aus Nordost-Thailand. Sauria, 13 (4), 3–6.
  45. Matsui, M. & Panha, S. (2006) A new species of Rhacophorus from eastern Thailand (Anura: Rhacophoridae). Zoological Sciences, 23, 477–481. https://doi.org/10.2108/zsj.23.477
  46. Miller, M.A., Pfeiffer, W. & Schwartz, T. (2010) Creating the CIPRES Science Gateway for Inference of Large Phylogenetic Trees. In: 2010 Gateway Computing Environments Workshop (GCE). IEEE, Piscataway, New Jersey, pp. 1–8. https://doi.org/10.1109/GCE.2010.5676129
  47. Mirza, Z.A., Bhardwaj, V.K., Lalmuanawma, J.C., Choure, G., Lalremsanga, H.T., Vabeiryureilai, M., Captain, A., Zagade, A. & Patel, H. (2024) A new species of Smithophis Giri et al. 2019 from the Indo-Burma region. Diversity, 16, 480. https://doi.org/10.3390/d16080480
  48. Mocquard, F. (1890) Recherches sur la faune herpétologique des îles de Bornéo et de Palawan. Nouvelles Archives du Muséum d’Histoire Naturelle de Paris, 3 (2), 115–168.
  49. Muansanga, L., Purkayastha, J., Hruaia, V., Vabeiryureilai, M., Biakzuala, L., Decemson, H., Lalremsanga, H.T. & Bohra, S.C. (2025) A new species of the genus Smithophis Giri, Gower, Das et al., 2019 (Reptilia: Serpentes: Natricidae) from Mizoram, Northeast India. Taprobanica, 14 (2), 158–165. https://doi.org/10.47605/tapro.v14i2.367
  50. Nagy, Z.T., Sonet, G., Glaw, F. & Vences, M. (2012) First large-scale DNA barcoding assessment of reptiles in the biodiversity hotspot of Madagascar, based on newly designed COI primers. PLoS ONE, 7 (3), e34506. https://doi.org/10.1371/journal.pone.0034506
  51. Noonan, B.P. & Chippindale, P.T. (2006) Dispersal and vicariance: The complex evolutionary history of boid snakes. Molecular Phylogenetics and Evolution, 40, 347–358. https://doi.org/10.1016/j.ympev.2006.03.010
  52. Nguyen, T.V., Nguyen, T.Q., Pham, C.T. & Ziegler, T. (2018) First country record of Opisthotropis maculosa Stuart et Chuaynkern, 2007 from Vietnam. Russian Journal of Herpetology, 25 (1), 74–78. https://doi.org/10.30906/1026-2296-2018-25-1-74-78
  53. Palumbi, S.R. (1996) Nucleic acids II: The polymerase chain reaction. In: Hillis, D.M., Moritz, C. & Mable, B.K. (Eds.), Molecular Systematics. 2nd Edition. Sinauer Associates, Inc., Sunderland, Massachusetts, pp. 205–247.
  54. Purkayastha, J., Asem, B.M., Lalremsanga, H.T., Das, M., Warjri, H., Thongni, G. & Bohra, S.C. (2025) Comments on the systematics and morphology of Smithophis bicolor (Blyth, 1855) (Reptilia: Squamata: Natricidae) based on topotypical specimens from Meghalaya, India. Journal of Threatened Taxa, 17 (4), 26803–26813. https://doi.org/10.11609/jott.9436.17.4.26803-26813
  55. Pyron, R.A., Burbrink, F.T. & Wiens, J.J. (2013) A phylogeny and revised classification of Squamata, including 4161 species of lizards and snakes. BMC Evolutionary Biology, 13, 93. https://doi.org/10.1186/1471-2148-13-93.
  56. Pyron, R.A., Kandambi, H.K.D., Hendry, C.R., Pushpamal, V., Burbrink, F.T. & Somaweera, R. (2013) Genus-level phylogeny of snakes reveals the origins of species richness in Sri Lanka. Molecular Phylogenetics and Evolution, 66 (3), 969–978. https://doi.org/10.1016/j.ympev.2012.12.004
  57. 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 (5), 901–904. https://doi.org/10.1093/sysbio/syy032
  58. Ren, J.L., Wang, K., Guo, P. & Li, J.T. (2017) A new species of the Southeast Asian genus Opisthotropis (Serpentes: Colubridae: Natricinae) from western Hunan, China. Zoological Research, 38 (5), 251–263. https://doi.org/10.24272/j.issn.2095-8137.2017.068
  59. Ren, J.-L., Li, R.-H., Jia, R.-W., Lyu, Z.-T., Yan, C., Jiang, D., Wang, Y.-Y. & Li, J.-T. (2025) Quaternary glaciation accelerates speciation in aquatic snakes through recent bottlenecks. Molecular Ecology, 34 (22), e70071. https://doi.org/10.1111/mec.70071
  60. Ren, J., Wang, K., Guo, P., Wang, Y., Nguyen, T.T. & Li, J. (2019) On the generic taxonomy of Opisthotropis balteata (Cope, 1895) (Squamata: Colubridae: Natricinae): Taxonomic revision of two natricine genera. Asian Herpetological Research, 10 (2), 105–128. https://doi.org/10.16373/j.cnki.ahr.180091
  61. 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 (3), 1–4. https://doi.org/10.1093/sysbio/sys029.
  62. Stuart, B.L. & Chuaynkern, Y. (2007) A new Opisthotropis (Serpentes: Colubridae: Natricinae) from northeastern Thailand. Current Herpetology, 26 (1), 35–40. https://doi.org/10.3105/1345-5834(2007)26[35:ANOSCN]2.0.CO;2
  63. Stuart, B.L., Chuaynkern, Y. Chan-ard, T. & Inger, R.F. (2006) Three new species of frogs and a new tadpole from eastern Thailand. Fieldiana: Zoology, New Series, 111, 1–19. https://doi.org/10.3158/0015-0754(2006)187[1:TNSOFA]2.0.CO;2
  64. Stuebing, R.B. & Inger, R.F. (1999) A Field Guide to the Snakes of Borneo. Natural History Publications (Borneo), Kota Kinabalu, 254 pp. https://doi.org/10.2307/1447418
  65. Stuebing, R.B., Inger, R.F. & Lardner, B. (2014) A Field Guide to the Snakes of Borneo. 2nd Edition. Natural History Publications (Borneo), Kota Kinabalu, 310 pp.
  66. Takeuchi, H., Savitzky, A.H., Ding, L., de Silva, A., Das, I., Nguyen, T.T., Tsai, T.S., Jono, T., Zhu, G.X., Mahaulpatha, D., Tang, Y. & Mori, A. (2018) Evolution of nuchal glands, unusual defensive organs of Asian natricine snakes (Serpentes: Colubridae), inferred from a molecular phylogeny. Ecology and Evolution, 8, 10219–10232. https://doi.org/10.1002/ece3.4497
  67. Teynié, A., Lottier, A., David, P., Nguyen, T.Q. & Vogel, G. (2013) A new species of the genus Opisthotropis Gunther, 1872 from northern Laos (Squamata: Natricidae). Zootaxa, 3774 (2), 165–182. https://doi.org/10.11646/zootaxa.3774.2.4
  68. Thongproh, P., Youjaroen, M., Chuaynkern, Y., Chuaynkern, C., Ratree, P., Duengkae, P., Phetcharat, E., Maiprom, W., Ungprombundith, W. & Wongpaiseart, T. (2018) On the identities of Rhacophorus jarujini Matsui and Panha, 2006 and Rhacophorus orlovi Ziegler and Köhler, 2001 (Amphibia, Anura, Rhacophoridae) from Thailand. Maejo International Journal of Science and Technology, 12 (1), 36–50.
  69. Townsend, T.M., Larson, A., Louis, E. & Macey, J.R. (2004) Molecular phylogenetics of Squamata: The position of snakes, amphisbaenians, and dibamids, and the root of the squamate tree. Systematic Biology, 53(5), 735–757. https://doi.org/10.1080/10635150490522340
  70. Uetz, P., Freed, P., Aguilar, R., Reyes, F., Kudera, J. & Hošek, J. (2025) The Reptile Database. Available from: http://www.reptile-database.org (accessed 21 November 2025)
  71. Vieites, D.R., Min, M.S. & Wake, D.B. (2007) Rapid diversification and dispersal during periods of global warming by plethodontid salamanders. Proceedings of the National Academy of Sciences of the United States of America (PNAS), 104 (5), 19903–19907. https://doi.org/10.1073/pnas.0705056104
  72. Vogel, G., Chen, Z., Deepak, V., Gower, D.J., Shi, J., Ding, L. & Hou, M. (2020) A new species of the genus Smithophis (Squamata: Serpentes: Natricidae) from southwestern China and northeastern Myanmar. Zootaxa, 4803 (1), 51–74. https://doi.org/10.11646/zootaxa.4803.1.3
  73. Wang, J., Lyu, Z.T., Zeng, Z.C., Lin, C.Y., Yang, J.H., Nguyen, T.Q., Le, M.D., Ziegler, T. & Wang, Y.Y. (2020) Re-examination of the Chinese record of Opisthotropis maculosa (Squamata, Natricidae), resulting in the first national record of O. haihaensis and description of a new species. ZooKeys, 913, 141–159. https://doi.org/10.3897/zookeys.913.48622
  74. Wang, Y.Y., Guo, Q., Liu, Z.Y., Lyu, Z.T., Wang, J., Luo, L., Sun, Y.J. & Zhang, Y.W. (2017) Revisions of two poorly known species of Opisthotropis Günther, 1872 (Squamata: Colubridae: Natricinae) with description of a new species from China. Zootaxa, 4247 (4), 391–412. https://doi.org/10.11646/zootaxa.4247.4.3
  75. Wang, Y., Liu, P., Li, H. & Shao, C. (2019) The complete mitochondrial genome of Opisthotropis latouchii (Squamata: Colubridae). Mitochondrial DNA Part B: Resources, 4 (1), 1437–1438. https://doi.org/10.1080/23802359.2019.1598816
  76. Weinell, J.L., Hooper, E., Leviton, A.E. & Brown, R.M. (2019) Illustrated key to the snakes of the Philippines. Proceedings of the California Academy of Sciences, Series 4, 66 (1), 1–49.
  77. Wu, Y.H., Hou, S.B., Yuan, Z.Y., Jiang, K., Huang, R.Y., Wang, K., Liu, Q., Yu, Z.B., Zhao, H.P., Zhang, B.L., Chen, J.M., Wang, L.J., Stuart, B.L., Chambers, E.A., Wang, Y.F., Gao, W., Zou, D.H., Yan, F., Zhao, G.G., Fu, Z.X., Wang, S.N., Jiang, M., Zhang, L., Ren, J.L., Wu, Y.Y., Zhan, L.Y., Yang, D.C., Jin, J.Q., Yin, T.T., Li, J.T., Zhao, W.G., Murphy, R.W., Huang, S., Guo, P., Zhang, Y.P. & Che, J. (2023) DNA barcoding of Chinese snakes reveals hidden diversity and conservation needs. Molecular Ecology Resources, 23, 1124–1141. https://doi.org/10.1111/1755-0998.13784
  78. Yang, J.H., Wang, Y.Y., Zhang, B., Lau, M.W.N. & Chou, W.H. (2011) Revision of the diagnostic characters of Opisthotropis maculosa Stuart and Chuaynkern, 2007 with notes on its distribution and variation, and a key to the genus Opisthotropis (Squamata: Natricidae). Zootaxa, 2785 (1), 61–68. https://doi.org/10.11646/zootaxa.2785.1.4
  79. Zhang, L., Jiang, H., Li, L. & Chen, J. (2019) Complete mitochondrial genome of Opisthotropis andersonii (Serpentes: Colubridae) determined using next-generation sequencing. Mitochondrial DNA Part B: Resources, 4 (1), 1012–1013. https://doi.org/10.1080/23802359.2019.1565927
  80. Zhang, T., Ren, J., Li, M., Xu, Y., Wang, X., Poyarkov, N.A., Nguyen, T.V. & Huang, S. (2025) First description of the male and hemipenial morphology of Opisthotropis haihaensis Ziegler et al., 2019 (Serpentes, Natricidae), with updated diagnosis and distribution. Biodiversity Data Journal, 13, e167521. https://doi.org/10.3897/BDJ.13.e167521
  81. Zhang, J. & Wang, D. (2020) The complete mitochondrial genome of the Opisthotropis guangxiensis (Squamata: Colubridae). Mitochondrial DNA Part B: Resources, 5 (3), 2821–2822. https://doi.org/10.1080/23802359.2020.1789515
  82. Zhao, S. Ou, D., Zhang, L., Cai, B., Ma, S., Liu, S. Guo, K. & Zhou, W. (2026) Expanded description and distribution of Opisthotropis tamdaoensis Ziegler, David & Vu, 2008 (Squamata, Natricidae), first record from Yunnan Province of China. Biodiversity Data Journal, 14, e181301. https://doi.org/10.3897/BDJ.14.e181301
  83. Ziegler, T., David, P. & Vu, T.N. (2008) A new natricine snake of the genus Opisthotropis from Tam Dao, Vinh Phuc Province, northern Vietnam (Squamata, Colubridae). Zoosystematics and Evolution, 84 (2), 197–203. https://doi.org/10.1002/zoos.200800004
  84. Ziegler, T., David, P., Ziegler, T.N., Pham, C.T., Nguyen, T.Q. & Le, M.D. (2018) Morphological and molecular review of Jacob’s Mountain Stream Keelback Opisthotropis jacobi Angel & Bourret, 1933 (Squamata: Natricidae) with description of a sibling species from northern Vietnam. Zootaxa, 4374 (4), 476–496. https://doi.org/10.11646/zootaxa.4374.4.2
  85. Ziegler, T., Pham, C.T., Nguyen, T.V., Nguyen, T.Q., Wang, J., Wang, Y.Y., Stuart, B.L. & Le, M.D. (2019) A new species of Opisthotropis from northern Vietnam previously misidentified as the Yellow-spotted Mountain Stream Keelback O. maculosa Stuart & Chuaynkern, 2007 (Squamata: Natricidae). Zootaxa, 4613 (3), 579–586. https://doi.org/10.11646/zootaxa.4613.3.9
  86. Ziegler, T., Pham, C.T., Nguyen, T.V., Nguyen, T.Q., Wang, J., Wang, Y.Y., Stuart, B.L. & Le, M.D. (2021) Erratum: A new species of Opisthotropis from northern Vietnam previously misidentified as the Yellow-spotted Mountain Stream Keelback O. maculosa Stuart & Chuaynkern, 2007 (Squamata: Natricidae). Zootaxa, 4903 (4), 598. https://doi.org/10.11646/zootaxa.4903.4.8
  87. Ziegler, T., Ziegler, T.N., Peusquens, J., David, P., Vu, T.N., Pham, C.T., Nguyen, T.Q. & Le, M.D. (2017) Expanded morphological definition and molecular phylogenetic position of the Tam Dao Mountain stream keelback Opisthotropis tamdaoensis (Squamata: Natricidae) from Vietnam. Revue suisse de Zoologie, 124 (2), 377–389. https://doi.org/10.5281/zenodo.893551

How to Cite

Stuart, B.L., Seateun, S., Chuaynkern, Y., Ren, J.-L., Bernstein, J.M. & Phimmachak, S. (2026) A new Opisthotropis Günther, 1872 (Colubridae: Natricinae) from northern Laos allied to the enigmatic Opisthotropis maculosa Stuart & Chuaynkern, 2007. Zootaxa, 5785 (3), 508–526. https://doi.org/10.11646/zootaxa.5785.3.5