Systematic revision of the limestone karst-restricted land snail genus Aenigmatoconcha (Eupulmonata: Helicarionidae), with description of a new species

Keywords: Endemic, Indochina, limestones, COI gene, DNA barcoding


Thai limestone karsts are known to contain a rich biodiversity of animals, especially terrestrial snails, but still require further intensive exploration to evaluate their biodiversity. To date, only a few studies on the limestone karst-inhabiting land snail genera have been published. The present work focuses on the species diversity and phylogenetic relationships of the limestone karst-restricted land snail genus Aenigmatoconcha from Thailand, based on comparative morphology and molecular evidence. The results yielded three known species (A. clivicola Tumpeesuwan & Tumpeesuwan, 2017, A. sumonthai Tumpeesuwan & Tumpeesuwan, 2018, and A. mitis (Pfeiffer, 1863) comb. nov.), plus a new species (A. eunetis Pholyotha & Panha sp. nov). The phylogenetic analyses of partial fragments of the mitochondrial cytochrome oxidase c subunit I (COI) gene confirmed the monophyly of all recognized species and congruence with the traditional morphology-based species designations. Average uncorrected p-distances of COI sequences between species were 9.7–12.0% and within species were 0.2–4.2%. This study also provides the re-description of penial sculpture, penial sheath, flagellum, penial caecum, and mantle lobe morphology that were neglected from the type species description. The present discovery of a new species increases the known diversity of Thai land snails and will support the conservation planning to protect karst biodiversity.


American Veterinary Medical Association. 2020. AVMA Guidelines for the Euthanasia of Animals: 2020 Edition. Available from [accessed 12 Feb 2020]

Ashburton J. 1864. Paper read at the Royal Geographical Society 10th March, 1862. In: Mouhot H. (ed.) Travels in the Central Parts of Indo-China (Siam), Cambodia, and Laos, During the Years 1858, 1859, and 1860: 296–300. Murray, London.

Baur B. 2010. Stylommatophoran Gastropods. In: Leonard J.L. & Córdoba-Aguilar A. (eds) The Evolution of Primary Sexual Characters in Animals: 197–217. Oxford University Press, USA.

Blanford W.T. & Godwin Austen H.H. 1908. Mollusca: Testacellidae and Zonitidae. In: Bingham C.T. (ed.) The Fauna of British India including Ceylon and Burma. Taylor and Francis, London.

Clements R., Sodhi N.S., Schilthuizen M. & Ng P.K. 2006. Limestone karsts of Southeast Asia: Imperiled arks of biodiversity. Bioscience 56 (9): 733–742.

Dumrongrojwattana P. & Tanmuangpak K. 2020. The terrestrial microsnail genus Aulacospira Möllendorff, 1890 (Eupulmonata, Stylommatophora, Hypselostomatidae) in Thailand with key to Thai species. ZooKeys 980: 23–42.

Felsenstein J. 2004. Inferring Phylogenies. Massachusetts: Sinauer Associates, Sunderland.

Fischer H. & Dautzenberg P. 1904. Catalogue des Mollusques terrestres et fluviatiles de ľIndo-Chine orientale cités jusqu’ à ce jour. Mission Pavie, Études diverses 3: 390–450. [accessed 22 July 2021]

Fischer P. 1891. Catalogue et distribution géographique des Mollusques terrestres, fluviatiles & marins ďune partie de ľIndo-Chine (Siam, Laos, Cambodge, Cochinchine, Annam, Tonkin). Imprimerie Dejussieu Père et Fils, Autun.

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.

Foon J.K., Clements G.R. & Liew T.-S. 2017. Diversity and biogeography of land snails (Mollusca, Gastropoda) in the limestone hills of Perak, Peninsular Malaysia. ZooKeys 682: 1–94.

Gardner S., Sidisunthorn P. & Chayamarit K. 2015. Forest Trees of Southern Thailand Volume 1 (Acanthaceae to Escalloniaceae). Kobfai Publishing Project, Bangkok.

Grismer L.L., Wood P.L., Le M.D., Quah E.S.H. & Grismer J.L. 2020. Evolution of habitat preference in 243 species of Bent-toed geckos (Genus Cyrtodactylus Gray, 1827) with a discussion of karst habitat conservation. Ecology and Evolution 10: 13717–13730.

Hausdorf B. 1998. Phylogeny of the Limacoidea sensu lato (Gastropoda: Stylommatophora). Journal of Molluscan Studies 64: 35–66.

Hillis D.M. & Bull J.J. 1993. An empirical test of bootstrapping as a method for assessing confidence in phylogenetic analysis. Systematic Biology 42: 182–192.

Hirano T., Kameda Y., Kimura K. & Chiba S. 2014. Substantial incongruence among the morphology, taxonomy, and molecular phylogeny of the land snails Aegista, Landouria, Trishoplita, and Pseudobuliminus (Pulmonata: Bradybaenidae) occurring in East Asia. Molecular Phylogenetics and Evolution 70: 171–181.

Hirano T., Wada S., Mori H., Uchida S., Saito T. & Chiba S. 2018. Genetic and morphometric rediscovery of an extinct land snail on oceanic islands. Journal of Molluscan Studies 84: 148–156.

Huelsenbeck J.P. & Rannala B. 2004. Frequentist properties of Bayesian posterior probabilities of phylogenetic trees under simple and complex substitution models. Systematic Biology 53: 904–913.

Hyman I.T. & Köhler F. 2018 Reconciling comparative anatomy and mitochondrial phylogenetics in revising species limits in the Australian semislug Helicarion Férussac, 1821 (Gastropoda: Stylommatophora). Zoological Journal of the Linnean Society 184: 933–968.

Hyman I.T. & Köhler F. 2019. Phylogeny and systematic revision of the helicarionid semislugs of eastern Queensland (Stylommatophora, Helicarionidae). Contributions to Zoology 88 (4): 351–451.

Hyman I.T. & Ponder W.F. 2010. A morphological phylogenetic analysis and generic revision of Australian Helicarionidae (Gastropoda: Pulmonata: Stylommatophora), and an assessment of the relationships of the family. Zootaxa 2462: 1–148.

Inkhavilay K., Sutcharit C., Bantaowong U., Chanabun R., Siriwut W., Srisonchai R., Pholyotha A., Jirapatrasilp P. & Panha S. 2019. Annotated checklist of the terrestrial molluscs from Laos (Mollusca, Gastropoda). ZooKeys 834: 1–166.

Köhler F. & Criscione F. 2015. A molecular phylogeny of camaenid land snails from northwestern Australia unravels widespread homoplasy in morphological characters (Gastropoda, Helicoidea). Molecular Phylogenetics and Evolution 83: 44–55.

Köhler F., Criscione F. & Shea M. 2020. A mitochondrial phylogeny uncovers taxonomic ambiguity and complex phylogeographic patterns in the eastern Australian land snail Austrochloritis (Stylommatophora, Camaenidae). Journal of Zoological Systematics and Evolutionary Research 58: 1005–1020.

Kumar S., Stecher G. & Tamura K. 2016. MEGA7: molecular evolutionary genetics analysis version 7.0 for bigger datasets. Molecular Biology and Evolution 33: 1870–1874.

Latinne A., Waengsothorn S., Rojanadilok P., Eiamampai K., Sribuarod K. & Michaux J.R. 2013. Diversity and endemism of Murinae rodents in Thai limestone karsts. Systematics and Biodiversity 11: 323–344.

Liew T.S., Schilthuizen M. & Vermeulen J.J. 2009. Systematic revision of the genus Everettia Godwin-Austen, 1891 (Mollusca: Gastropoda: Dyakiidae) in Sabah, northern Borneo. Zoological Journal of the Linnean Society 157: 515–550.

Likhitrakarn N., Golovatch S.I., Jeratthitikul E., Srisonchai R., Sutcharit C. & Panha S. 2020. A remarkable new species of the millipede genus Trachyjulus Peters, 1864 (Diplopoda, Spirostreptida, Cambalopsidae) from Thailand, based both on morphological and molecular evidence. ZooKeys 925: 55–72.

Mauro D.S. & Agorreta A. 2010. Molecular systematics: a synthesis of the common methods and the state of knowledge. Cellular & Molecular Biology Letters 15: 311–341.

Miller M.A., Pfeiffer W. & Schwartz T. 2010. Creating the CIPRES science gateway for inference of large phylogenetic trees. Proceedings of the Gateway Computing Environments Workshop (GCE), IEEE, New Orleans, Louisiana.

Mouhot H. 1864. Travels in the Central Parts of Indo-China (Siam), Cambodia, and Laos, During the Years 1858, 1859, and 1860. Murray, London.

Myers N., Mittermeier R.A., Mittermeier C.G., da Fonseca G.A.B. & Kent J. 2000. Biodiversity hotspots for conservation priorities. Nature 403: 853–858.

Naggs F., Panha S. & Raheem D. 2006. Developing land snail expertise in South and Southeast Asia, a new Darwin Initiative Project. The Natural History Journal of Chulalongkorn University 6: 43–46.

Páll-Gergely B., Fehér Z., Otani J. U. & Asami T. 2016. An integrative taxonomic approach to infer the systematic position of Chalepotaxis Ancey, 1887 (Gastropoda: Stylommatophora: Helicarionidae). Molluscan Research 37: 113–119.

Pauwels O.S.G., Sumontha M., Panitvong N. & Varaguttanonda V. 2014. Cyrtodactylus khelangensis, a new cave-dwelling Bent-toed Gecko (Squamata: Gekkonidae) from Lampang Province, northern Thailand. Zootaxa 3755 (6): 584–594.

Pfeiffer L. 1863. Descriptions of thirty-six new land shells from the collection of H. Cuming, Esq. Proceedings of the Zoological Society of London 30: 268–278. [Published in parts, dates follow Duncan (1937)].

Pfeiffer L. 1868. Monographia heliceorum viventium supplementum tertium: sistens descriptiones systematicas et criticas omnium hujus familiae generum et specierum hodie cognitarum, volume quintum. F.A. Brockhaus, Lipsiae.

Pholyotha A., Sutcharit C. & Panha S. 2018. The land snail genus Macrochlamys Gray, 1847 from Thailand, with descriptions of five new species (Pulmonata: Ariophantidae). Raffles Bulletin of Zoology 66: 763–781.

Pholyotha A., Sutcharit C., Thach P., Chhuoy S., Ngor P.B. & Panha S. 2020a. Land snail genus Sarika Godwin-Austen, 1907 (Eupulmonata: Ariophantidae) from Cambodia, with description of three new species. European Journal of Taxonomy 674: 1–21.

Pholyotha A., Sutcharit C., Tongkerd P. & Panha S. 2020b. Integrative taxonomic revision of the land snail genus Sarika Godwin-Austen, 1907 in Thailand, with descriptions of nine new species (Eupulmonata, Ariophantidae). ZooKeys 976: 1–100.

Pholyotha A., Sutcharit C., Tongkerd P., Jeratthitikul E. & Panha S. 2021. Integrative systematics reveals the new land-snail genus Taphrenalla (Eupulmonata: Ariophantidae) with a description of nine new species from Thailand. Contributions to Zoology 90(1): 21–69.

Rambaut A., Suchard M.A., Xie D. & Drummond A.J. 2014. Tracer v1.6.

Ridd M.F., Barber A.J. & Crow M.J. 2011. Introduction to the geology of Thailand. In: Ridd M.F., Barber A.J. & Crow M.J. (eds) The Geology of Thailand: 1–18. Geological Society, London.

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.

Sedgwick W.C. & Schwendinger P.J. 1990. On a new cave-dwelling Liphistius from Thailand (Araneae: Liphistiidae). Bulletin of the British Arachnological Society 8:109–112.

Siriboon T., Sutcharit C., Naggs F., Rowson B. & Panha S. 2014. Revision of the carnivorous snail genus Discartemon Pfeiffer, 1856, with description of twelve new species (Pulmonata, Streptaxidae). ZooKeys 401: 45–107.

Siriboon T., Naggs F., Wade C.M., Jeratthitikul E., Tongkerd P., Jirapatrasilp P., Panha S. & Sutcharit C. 2020. Phylogenetic relationships of the carnivorous terrestrial snail family Streptaxidae (Stylommatophora: Achatinina) in Thailand and surrounding areas of Southeast Asia. Systematics and Biodiversity 18: 720–738.

Solem A. 1966. Some non-marine mollusks from Thailand, with notes on classification of the Helicarionidae. Spolia Zoologica Musei Hauniensis 24: 1–110.

Srisonchai R., Enghoff H., Likhitrakarn N. & Panha S. 2018. A revision of dragon millipedes I: genus Desmoxytes Chamberlin, 1923, with the description of eight new species (Diplopoda, Polydesmida, Paradoxosomatidae). ZooKeys 761: 1–177.

Stamatakis A. 2014. RAxML Version 8: A tool for phylogenetic analysis and post-analysis of large phylogenies. Bioinformatics 30: 1312–1313.

Sumontha M., Chomngam N., Phanamphon E., Pawangkhanant P., Viriyapanon C., Thanaprayotsak W. & Pauwels O.S.G. 2017. A new limestone-dwelling leaf-toed gecko (Gekkonidae: Dixonius) from Khao Sam Roi Yot massif, peninsular Thailand. Zootaxa 4247 (5): 556–568.

Sutcharit C., Jeratthitikul E., Pholyotha A., Lin A. & Panha S. 2020a. Molecular phylogeny reveals high diversity and endemism in the limestone karst-restricted land snail genus Sophina Benson, 1859 from Myanmar (Eupulmonata: Helicarionidae), with description of four new species. Journal of Zoological Systematics and Evolutionary Research 58: 957–981.

Sutcharit C., Jeratthitikul E., Tongkerd P. & Panha S. 2020b. Reassessment and systematic position of the sinistral snails of genus Hemiplecta from Thailand (Eupulmonata: Ariophantidae), with description of two new species. Contributions to Zoology: 1–33.

Sutcharit C., Thach P., Chhuoy S., Ngor P.B., Jeratthitikul E., Siriwut W., Srisonchai R., Ng T.H., Pholyotha A., Jirapatrasilp P. & Panha S. 2020c. Annotated checklist of the land snail fauna from southern Cambodia (Mollusca, Gastropoda). ZooKeys 948: 1–46.

Tanabe A.S. 2011. Kakusan4 and Aminosan: two programs for comparing nonpartitioned, proportional and separate models for combined molecular phylogenetic analyses of multilocus sequence data. Molecular Ecology Resources 11: 914–921.

Tompa A.S. 1984. Land snails (Stylommatophora). In: Tompa A.S. & Verdonk N.H. (eds) The Mollusca, Vol. 7: Reproduction: 47–140. Academic Press, London.

Tongkerd P., Lee T., Panha S., Burch J.B. & O’Foighil D. 2004. Molecular phylogeny of certain Thai gastrocoptine micro land snails (Stylommatophora: Pupillidae) inferred from mitochondrial and nuclear ribosomal DNA sequences. Journal of Molluscan Studies 70: 139–147.

Tryon Jr. G.W. 1886. Manual of Conchology; Structural and Systematic. With illustrations of the species. Second Series: Pulmonata. Volume II. Zonitidae. Academy of Natural Sciences, Philadelphia.

Tumpeesuwan C. & Tumpeesuwan S. 2017. Discovery of an overlooked helicarionid land snail (Helicarionidae: Durgellinae) from northeastern Thailand, with description of a new genus and new species, and a note on radula morphology and genital system. Raffles Bulletin of Zoology 65: 174–181.

Tumpeesuwan C. & Tumpeesuwan S. 2018. Aenigmatoconcha sumonthai, a new helicarionid land snail from Chumphon Province, Southern Thailand (Helicarionidae: Durgellinae). Raffles Bulletin of Zoology 66: 170–176.

Vermeulen J.J., Luu H.T., Theary K. & Anker K. 2019. New species of land snails (Mollusca: Gastropoda: Caenogastropoda and Pulmonata) of the Mekong Delta Limestone Hills (Cambodia, Vietnam). Folia Malacologica 27: 7–41.

Zhang L.-J., Zhu Y.-J. & Lyu Z.-T. 2020. A new sinistral species of the land-snail genus Satsuma (Pulmonata: Camaenidae) from China. Molluscan Research 40 (1): 93–100.

How to Cite
Pholyotha, A., Sutcharit, C. ., Tongkerd, P. ., & Panha, S. . (2021). Systematic revision of the limestone karst-restricted land snail genus Aenigmatoconcha (Eupulmonata: Helicarionidae), with description of a new species. European Journal of Taxonomy, 767(1), 55-82.
Research article