Nominal Taxa of Freshwater Mollusca from Southeast Asia Described by Dr

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Ecologica Montenegrina 41: 73-83 (2021) This journal is available online at: www.biotaxa.org/em http://dx.doi.org/10.37828/em.2021.41.11

https://zoobank.org/urn:lsid:zoobank.org:pub:2ED2B90D-4BF2-4384-ABE2-630F76A1AC54

Nominal taxa of freshwater Mollusca from Southeast Asia described by Dr. Nguyen N. Thach: A brief overview with new synonyms and fixation of a publication date

IVAN N. BOLOTOV1,2, EKATERINA S. KONOPLEVA1,2,*, ILYA V. VIKHREV1,2, MIKHAIL Y. GOFAROV1,2, MANUEL LOPES-LIMA3,4,5, ARTHUR E. BOGAN6, ZAU LUNN7, NYEIN CHAN7, THAN WIN8, OLGA V. AKSENOVA1,2, ALENA A. TOMILOVA1, KITTI TANMUANGPAK9, SAKBOWORN TUMPEESUWAN10 & ALEXANDER V. KONDAKOV1,2

1N. Laverov Federal Center for Integrated Arctic Research of the Ural Branch of the Russian Academy of Sciences, Northern Dvina Emb. 23, 163000 Arkhangelsk, Russia. 2Northern Arctic Federal University, Northern Dvina Emb. 17, 163002 Arkhangelsk, Russia. 3CIBIO/InBIO – Research Center in Biodiversity and Genetic Resources, University of Porto, Campus Agrário de Vairão, Rua Padre Armando Quintas 7, 4485-661 Vairão, Portugal. 4CIIMAR/CIMAR – Interdisciplinary Centre of Marine and Environmental Research, University of Porto, Terminal de Cruzeiros do Porto de Leixões, Avenida General Norton de Matos, S/N, 4450-208 Matosinhos, Portugal. 5SSC/IUCN – Mollusc Specialist Group, Species Survival Commission, International Union for Conservation of Nature, c/o The David Attenborough Building, Pembroke Street, CB2 3QZ Cambridge, United Kingdom. 6North Carolina Museum of Natural Sciences, 11 West Jones St., Raleigh, NC 27601, United States of America 7Fauna & Flora International – Myanmar Programme, Yangon, Myanmar. 8 Department of Zoology, Dawei University, Dawei, Tanintharyi Region, Myanmar. 9Department of Science, Faculty of Science and Technology, Loei Rajabhat University, Loei, Thailand. 10Department of Biology, Faculty of Science, Mahasarakham University, Maha Sarakham, Thailand. *Corresponding author: [email protected]

Received: 27 February 2021│ Accepted by V. Pešić: 21 April 2021 │ Published online: 26 April 2021.

In this correspondence, we present a summary of taxonomic names of freshwater Mollusca introduced by Dr. Nguyen N. Thach, an enthusiastic and productive malacologist from Vietnam. We show that this researcher described one new genus and 12 new nominal species of freshwater molluscs from Southeast Asia. Two of these nominal species, Sinanodonta hunganhi Thach, 2016 and Lanceolaria bogani Thach, 2016 (Bivalvia: Unionidae), were already considered junior synonyms of S. jourdyi (Morlet, 1886) and L. fruhstorferi (Dautzenberg, 1900), respectively (Do et al. 2018; Đặng and Hố 2019). Here, we propose one more synonym for the invasive Golden Apple Snail as follows: Pomacea canaliculata (Lamarck, 1822) [=Pomacea thachi Huber in Thach, 2020 syn. nov.] (Gastropoda: Ampullariidae). Furthermore, we establish the formal synonymy for the following taxa: Taia Annandale, 1918 [=Boganmargarya Thach, 2018 syn. nov.]; Taia shanensis (Kobelt, 1909) [=Boganmargarya huberi Thach, 2018 syn. nov.] (Gastropoda: Viviparidae); Brotia henriettae (Gray in Griffith & Pidgeon, 1833) [=Brotia frankhuberi Thach, 2020 syn. nov.; Brotia bogani Thach & Huber in Thach, 2020 syn. nov.] (Gastropoda: Pachychilidae); Pila pesmei (Morlet, 1889)

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[=Pila huberi Thach, 2020 syn. nov.] (Gastropoda: Ampullariidae); and Paludomus andersoniana Nevill, 1877 [=Paludomus huberi Thach, 2020 syn. nov.] (Gastropoda: Paludomidae). Additionally, four nominal species are treated here as taxa inquirenda: Melanoides thachi Huber in Thach, 2020 (Gastropoda: Thiaridae), Trochoita frankohleri Thach & Huber in Thach, 2020 (Gastropoda: Viviparidae), Paracrostoma huberi Thach, 2018 (Gastropoda: Pachychilidae), and Pseudodon artbogani Thach & Huber in Thach, 2020 (Bivalvia: Unionidae). We also show that the publication date written on the title page of the book “New Shells of South Asia. Volume 2” (Thach, 2020a) is a bit misleading and that this book appeared in the printed form on 23 June 2020. The latter date is fixed here as the date of availability of taxonomic names introduced in this work. Finally, we present an annotated checklist of freshwater Mollusca described by N. N. Thach with approximate coordinates of the type localities and reference to corresponding river drainage basins. Nguyen N. Thach is a productive amateur malacologist, who initially published several faunal reviews and guides on Mollusca from Vietnam (Thach 2005, 2007, 2012). These works were considered an important source of taxonomic and distributional information on the regional malacofauna, at least for freshwater taxa (Do et al. 2018). Later, this author described multiple new taxa of marine, terrestrial, and freshwater molluscs from Southeast Asia in a series of papers and books (e.g., Thach 2016a, 2016b, 2017, 2018, 2020a). In summary, these works contain descriptions of one new genus and 12 new nominal species of freshwater Mollusca (Appendix). The new species-group names were attributed to three bivalves and nine gastropods. Several of these species were co-authored/authored by Franz Huber, who is an amateur shell collector from Austria (Thach 2020a). All the Mollusca taxa under discussion conform to the requirements of the International Code of Zoological Nomenclature and must be considered taxonomically available names (see Appendix). The holotypes of these nominal species were deposited in the following museums:  North Carolina Museum of Natural Sciences [NCSM], Raleigh, North Carolina, United States of America (8 species);  Muséum National d’Histoire Naturelle [MNHN], Paris, France (2 species);  British Museum of Natural History [NHMUK], London, United Kingdom (1 species);  Royal Belgian Institute of Natural Sciences [IRSNB], Brussels, Belgium (1 species). The protologues contain color images of the type series of each new taxon (Thach 2016b, 2016c, 2018, 2020a). It is nice to see that four names are dedicated to Dr. Arthur Bogan, a prominent American malacologist, who is working in the NCSM (Thach 2016c, 2018, 2020a; see Appendix for detail). These names are as follows: Pseudodon artbogani Thach & Huber in Thach, 2020 and Lanceolaria bogani Thach, 2016 [=L. fruhstorferi (Dautzenberg, 1900)] (Bivalvia: Unionidae), Brotia bogani Thach & Huber in Thach, 2020 (Gastropoda: Pachychilidae), and the genus Boganmargarya Thach, 2018 (Gastropoda: Viviparidae). Although a complete reappraisal of N. N. Thach’s freshwater Mollusca will be published elsewhere, here we would discuss and revise a few remarkable nomenclatural cases which appeared in this work. These examples mostly arose because the author overlooked several historical works on the target taxa. In particular, one genus and five nominal species were described from Lake Inle in Myanmar as follows: Boganmargarya Thach, 2018; Boganmargarya huberi Thach, 2018; Brotia frankhuberi Thach, 2020; B. bogani Thach & Huber in Thach, 2020; Melanoides thachi Huber in Thach, 2020; and Paludomus huberi Thach, 2020 (see Appendix). This lake and surrounding water bodies were a focus of comprehensive surveys, the results of which were published in a special volume of “Records of the Indian Museum” (Vol. 14, 1918) edited by the Director of the Zoological Survey of India Dr. Nelson Annandale. This 214-page volume contains 13 chapters characterizing the geography, geology, natural history, and fauna of this lake in detail (Annandale 1918a). Three chapters comprise the results of taxonomic and morphological research on freshwater malacofauna from the lake (Annandale 1918b, 1918c; Prashad 1918), including the comprehensive “Aquatic Molluscs of the Inle Lake and connected waters” with numerous shell images of gastropods and bivalves (Annandale 1918b). Regrettable, however, N. N. Thach overlooked those historical works, presenting a thorough taxonomic revision of freshwater molluscs from Lake Inle with descriptions of taxa from several families such as Viviparidae, Pachychilidae, Thiaridae, Paludomidae, and others. Hence, a genus and five nominal species described by N. N. Thach from this lake could represent junior synonyms of some already known taxa, and certainly need a revision. The genus Boganmargarya was introduced on the basis of conchological features alone. In the diagnosis, it was compared with Tchangmargarya He, 2013 and Margarya Nevill, 1877 (Thach, 2018). Unfortunately, the author was not aware of the genus Taia Annandale, 1918 that was described from

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Myanmar. This genus was established for a group of peculiar viviparids from the Salween and Irrawaddy river basins, reaching the maximum species diversity in Lake Inle (Annandale 1918b). In the original description, Annandale (1918b: 124) wrote that “The shells of these remarkable species exhibit affinities both with Vivipara (s.s.) and with Margarya, Nevill; they also have some resemblance to those of Tulotoma, Haldeman”. Furthermore, Annandale (1918b: 124) developed a key for identification of the 11 fossil and recent Taia species from the Shan State of Myanmar based on conchological features. Using this key, we found that the holotype of Boganmargarya huberi undoubtedly belongs to Taia shanensis (Kobelt, 1909). The formal synonymy is proposed here as follows: Taia shanensis (Kobelt, 1909) [=Boganmargarya huberi Thach, 2018 syn. nov.]; and Taia Annandale, 1918 [=Boganmargarya Thach, 2018 syn. nov.] (Gastropoda: Viviparidae). The status of Brotia frankhuberi and B. bogani, two other nominal species described from Lake Inle, could also be accessed based on the work of Annandale (1918b). This researcher illustrated shells of Melania baccata elongata Annandale, 1918 (see Annandale 1918b: 115, pl. 12, figs 3–7) that are conchologically identical to the type series of Brotia frankhuberi. The first nominal taxon was considered a junior synonym of Brotia henriettae (Gray in Griffith & Pidgeon, 1833) (Köhler and Glaubrecht 2002), and hence Brotia frankhuberi became a synonym of the latter species. In its turn, Brotia bogani shares the same shell sculpture as does Brotia frankhuberi (compare pl. 5, figs 57–58 and pl. 4, figs 50–56 in Thach 2020a) but differs from the latter taxon by the lack of dark periostracum. It became clear that the type series of Brotia bogani was cleaned from the periostracal layer artificially or naturally. Hence, the formal synonymy is proposed here as follows: Brotia henriettae (Gray in Griffith & Pidgeon, 1833) [=Brotia frankhuberi Thach, 2020 syn. nov.; Brotia bogani Thach & Huber in Thach, 2020 syn. nov.] (Gastropoda: Pachychilidae). A new Paludomus species was also described from Lake Inle, i.e. Paludomus huberi. In the original diagnosis, this nominal taxon was compared with Paludomus siamensis Blanford, 1903. Unfortunately, the author did not notice several Paludomus taxa described from Myanmar (e.g., Benson 1856; Nevill 1877). Annandale (1918b) identified two shells from Lake Inle as Paludomus ornatus Benson, 1856. However, Paludomus huberi is more similar to P. andersoniana Nevill, 1877 from northern Myanmar (“Upper Burma”). The latter taxon was described as follows: “Large and globose; spire produced and pointed; of a very striking greenish yellow colour, with four intense black bands on the last whorl, the one at the suture and the two near the base about the width of the broadest band on P. ornata; the second band from the suture twice this width, this latter, in all but very old specimens, is very distinctly visible within the aperture; whorls seven, the first two or three generally decollated, transversely superficially ridged, ridges more or less obsolete towards the centre of the upper whorls, one of them below the suture more prominent that the rest; columella pure white” (Nevill 1877: 35). It is clear that Paludomus huberi and P. andersoniana are conspecific based on the identical shell shape, similar size, and the same coloration patterns. The formal synonymy is proposed here as follows: Paludomus andersoniana Nevill, 1877 [=Paludomus huberi Thach, 2020 syn. nov.] (Gastropoda: Paludomidae). The nominal taxon Pomacea thachi described from Laos is a striking example of incorrect identification of an alien and economically important species. Recent phylogenetic and phylogeographic surveys have shown that only two Pomacea species were introduced to Asia (Hayes et al. 2015; Yang et al. 2018). It is clear that Pomacea thachi is conspecific with P. canaliculata (Lamarck, 1822), the invasive Golden Apple Snail, native to South America (Joshi et al. 2017). Currently, this introduced species is common and widespread throughout Laos and other Southeast Asian countries, where it inhabits a variety of stagnant waters such as paddy fields, swamps, canals, ponds, and lakes (Halwart 1994; Carlsson and Lacoursiere 2005; Ng et al. 2020). It is unclear why the author (F. Huber in this case) compared the type series of Pomacea thachi with P. maculata Perry, 1810 only (see Thach 2020a: 21), while the presence of another alien species, P. canaliculata, in Laos was omitted completely in the differential diagnosis. Indeed, it is itself an unfortunate failure but this taxonomic novelty may strongly affect the management of invasive pest species in the region. Therefore, we propose the formal synonymy here: Pomacea canaliculata (Lamarck, 1822) = Pomacea thachi Huber in Thach, 2020 syn. nov. (Gastropoda: Ampullariidae). Pila huberi Thach, 2020 is another example of a new nominal species, the diagnosis of which was developed on the basis of incomplete taxonomic analyses. This taxon was compared with Pila ampullacea (Linnaeus, 1758), P. gracilis (Lea, 1856), P. scutata (Mousson, 1848), and P. polita (Deshayes, 1830) [currently P. virescens (Deshayes, 1824)] (Thach 2020a). Unfortunately, the author did not include reference to Pila pesmei (Morlet, 1889), a conchologically variable species, which often shares a flattened spire and somewhat triangular shell shape (e.g., Brandt 1974; Ng et al. 2020). The deep black periostracum of the type

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FRESHWATER MOLLUSCA DESCRIBED BY DR. NGUYEN N. THACH shells of Pila huberi almost certainly resulted from an exposition in organic-rich anaerobic sediments of a highly eutrophic water body such as paddy fields mentioned in the original description (Thach 2020a). Samples of gastropod and bivalve shells from such tropical water bodies often share similar glossy-black coloration (Bolotov, pers. observ., 2012–2020). Anyway, the periostracum color cannot be used as a diagnostic character for freshwater molluscs (both gastropods and bivalves) due to its high environment- induced variability. The formal synonymy is proposed here as follows: Pila pesmei (Morlet, 1889) [=Pila huberi Thach, 2020 syn. nov.] (Gastropoda: Ampullariidae). Other nominal species such as Melanoides thachi, Trochoita frankohleri Thach & Huber in Thach, 2020, Paracrostoma huberi Thach, 2018, and Pseudodon artbogani Thach & Huber in Thach, 2020 belong to taxonomically complicated and conchologically variable groups of Mollusca (see comments in Appendix). Indeed, species-level taxa within such groups can be delineated by means of a molecular approach only. A description of a new species in such a group using a few shells from a single locality in the absence of available molecular data looks exactly like playing Russian roulette with taxa. Therefore, we prefer to assess the status of these nominal species in the future based on a more scientifically valid ground despite the fact that they were introduced using conchological features alone. However, the taxonomic status of these taxa cannot be justified on the basis of original diagnoses, and we would treat the four nominal species, listed above, as taxa inquirenda until the validity of their species-level status is confirmed. The publication date of a taxonomic work is essential to estimate the priority of described taxa, especially when such a work introduces a large number of new names. Regrettably, however, the publication date of the book “New Shells of South Asia. Volume 2” (Thach 2020a) indicated on the title page (“First published in April 8th, 2020”) is a bit misleading, most likely due to a typo. This book could not have been published on 8 April 2020, as on 24 April 2020 its author requested permission to use a shell photo from Bolotov et al.’s (2017b) work (Bolotov, pers. comm., 2020) that appeared in the printed book later on (Thach 2020a: 189, fig. 992). On 23 June 2020, Thach sent an e-mail to several malacologists worldwide (Bolotov and Bogan, pers. comm., 2020). This e-mail contained three attachments, i.e. front and back cover images of the book, and a letter addressed personally to a given scientist and dated 23 June 2020. In the letter, Thach (2020b) stated that: “With this email, I would like to present my new shell book (written in English) with one New Genus and 140 new Species and Subspecies that has been published”. Based on the author’s statement and the date posted on the letter, we conclude that this self-published book has appeared in a printed form on 23 June 2020. Hence, this date is fixed here as the book’s publication date, being available for further taxonomic revisions of the corresponding genus and species-group names. This recent issue with a misleading printing date of the book partly resembles that with Isaac Lea’s dates of publication before 1850. Bogan and Bogan (2002) described that historical example in detail. It was because Lea used the date the paper was read before a meeting, instead of the date when the paper was actually published. The time elapsed between the manuscript presentation and the actual date of its publication may have been as much as three years (Bogan and Bogan 2002). Conrad (1853) published a paper correcting the dates of publication and making many of Lea’s names junior synonyms. Finally, one genus and six nominal species of freshwater Mollusca described by N. N. Thach are considered here to be junior synonyms of older available names. Unfortunately, this researcher was not aware of several important taxonomic works on freshwater Mollusca of Southeast Asia that led him to the description of a few taxa that were already named by other (mostly historical) scholars. Moreover, the identity of four nominal species belonging to conchologically variable and poorly known groups cannot be justified for now because they were defined incompletely. Here, we consider these four nominal species as taxa inquirenda until their validity is confirmed. Some inconsistencies in the land snails descriptions authored by this malacologist were also noticed recently (Páll-Gergely et al. 2020; Thach 2021). However, we would conclude that N. N. Thach made an interesting contribution to the knowledge of freshwater Mollusca in Southeast Asia. The fully illustrated faunal books published by this scholar are of use to tropical zoologists and malacologists, and found a place on the shelves of malacological libraries worldwide.

Acknowledgements This study was partly supported by the Ministry of Science and Higher Education of the Russian Federation (projects 0409-2019-0042 to O.V.A. and 0793-2020-0005 to I.N.B.). Morphological research on freshwater Mollusca was supported by the Russian Science Foundation (project No. 21-17-00126 to I.N.B., I.V.V. and E.S.K).

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References

Annandale, N. (1918a) (Ed.) The fauna of the Inle Lake. Records of the Indian Museum, 14, 1–214. Annandale, N. (1918b) Aquatic Molluscs of the Inle Lake and connected waters. Records of the Indian Museum, 14, 103–182. Annandale, N. (1918c) The fauna of the Inle Lake. Summary of results with a description of a new species of Taia from the Chindwin Valley, Upper Burma. Records of the Indian Museum, 14, 195–214. Benson, W. H. (1856) Descriptions of three new species of Paludomus from Burmah, and of some forms of Stenothyra (Nematura) from Penang, Mergui, etc. Annals and Magazine of Natural History, Series 2, 17(102), 494–504. Bespalaya, Y. V., Bolotov, I. N., Aksenova, O. V., Gofarov, M. Y., Kondakov, A. V., Vikhrev, I. V. & Vinarski, M. V. (2018) DNA barcoding reveals invasion of two cryptic Sinanodonta mussel species (Bivalvia: Unionidae) into the largest Siberian river. Limnologica, 69, 94–102. https://doi.org/10.1016/j.limno.2017.11.009 Bogan, A. E. & Bogan, C. M. (2002) The development and evolution of Isaac Lea’s publications on the Unionoida. In: Falkner M, Groh K, Speight MCD (Eds), Collectanea Malacologica: Festschrift für Gerhard Falkner. ConchBooks and Verlag der Friedrich-Held-Gesellschaft, Germany, pp. 363–375. Bolotov, I. N., Bespalaya, Y. V., Gofarov, M. Y., Kondakov, A. V., Konopleva, E. S. & Vikhrev, I. V. (2016) Spreading of the Chinese pond mussel, Sinanodonta woodiana, across Wallacea: One or more lineages invade tropical islands and Europe. Biochemical Systematics and Ecology, 67, 58–64. https://doi.org/10.1016/j.bse.2016.05.018 Bolotov, I. N., Kondakov, A. V., Vikhrev, I. V., Aksenova, O. V., Bespalaya, Y. V. Gofarov, M. Y., Kolosova, Y. S., Konopleva, E. S., Spitsyn, V. M., Tanmuangpak, K. & Tumpeesuwan, S. (2017a) Ancient river inference explains exceptional Oriental freshwater mussel radiations. Scientific Reports, 7, 2135. https://doi.org/10.1038/s41598-017-02312-z Bolotov, I. N., Vikhrev, I. V., Kondakov, A. V., Konopleva, E. S., Gofarov, M. Y., Aksenova, O. V. & Tumpeesuwan, S. (2017b) New taxa of freshwater mussels (Unionidae) from a species-rich but overlooked evolutionary hotspot in Southeast Asia. Scientific Reports, 7, 11573. https://doi.org/10.1038/s41598-017-11957-9 Bolotov, I. N., Konopleva, E. S., Vikhrev, I. V., Gofarov, M. Y., Lopes-Lima, M., Bogan, A. E., Zau Lunn, Nyein Chan, Than Win, Aksenova, O. V., Tomilova, A. A., Tanmuangpak, K., Tumpeesuwan, S. & Kondakov, A. V. (2020) New freshwater mussel taxa discoveries clarify biogeographic division of Southeast Asia. Scientific Reports, 10, 6616. https://doi.org/10.1038/s41598-020-63612-5 Brandt, R. A. M. (1974) The non-marine aquatic Mollusca of Thailand. Archiv für Molluskenkunde, 105, 1– 423. Carlsson, N. O. & Lacoursiere, J. O. (2005) Herbivory on aquatic vascular plants by the introduced golden apple snail (Pomacea canaliculata) in Lao PDR. Biological Invasions, 7(2), 233–241. https://doi.org/10.1007/s10530-004-0741-4 Chiu, Y. W., Gan, Y. C., Kuo, P. H., Hsu, K. C., Tan, M. S., Ju, Y. M. & Lin, H. D. (2019) Mitochondrial genetic diversity of the freshwater snail Melanoides tuberculata. Biochemical Genetics, 57(2), 323– 337. https://doi.org/10.1007/s10528-018-9892-3 Conrad, T. A. (1853) A synopsis of the family of Naïades of North America, with notes, and a table of some of the genera and sub-genera of the family, according to their geographical distribution, and descriptions of genera and sub-genera. Proceedings of the Academy of Natural Sciences of Philadelphia, 6, 243–269. Đặng, N. T. & Hố, T. H. (2019) Inland Freshwater Molluscs (Mollusca: Gastropoda, Bivalvia) of Vietnam. Fauna of Vietnam, 29, 1–360 [in Vietnamese, English abstract]. Dautzenberg, P. (1900) Diagnose d’une nouvelle espèce d’Unio provenant de L’Indo-Chine. Journal de Conchyliologie, 48, 429. Do, V. T., Tuan, L. Q. & Bogan, A. E. (2018) Freshwater mussels (Bivalvia: Unionida) of Vietnam: Diversity, distribution, and conservation status. Freshwater Mollusk Biology and Conservation, 21, 1–18. Facon, B., Pointier, J. P., Glaubrecht, M., Poux, C., Jarne, P. & David, P. (2003) A molecular phylogeography approach to biological invasions of the New World by parthenogenetic Thiarid snails. Molecular Ecology, 12(11), 3027–3039. https://doi.org/10.1046/j.1365-294X.2003.01972.x

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Graf, D. L. & Cummings, K. S. (2021) A ‘big data’ approach to global freshwater mussel diversity (Bivalvia: Unionoida), with an updated checklist of genera and species. Journal of Molluscan Studies, 2021, eyaa034. https://doi.org/10.1093/mollus/eyaa034 Halwart, M. (1994) The golden apple snail Pomacea canaliculata in Asian rice farming systems: present impact and future threat. International Journal of Pest Management, 40(2), 199–206. https://doi.org/10.1080/09670879409371882 Hayes, K. A., Burks, R. L., Castro-Vazquez, A., Darby, P. C., Heras, H., Martín, P. R., Qiu, J.-W., Thiengo, S. C., Vega, I. A., Wada, T., Yusa, Y., Burela, S., Cadierno, M. P., Cueto, J. A., Dellagnola, F. A., Dreon, M. S., Frassa, M. V., Giraud-Billoud, M., Godoy, M. S., Ituarte, S., Koch, E., Matsukura, K., Pasquevich, M. Y., Rodriguez, C., Saveanu, L., Seuffert, M. E., Strong, E. E., Sun, J., Tamburi, N. E., Tiecher, M. J., Turner, R. L., Valentine-Darby, P. L. & Cowie, R. H. (2015) Insights from an integrated view of the biology of apple snails (Caenogastropoda: Ampullariidae). Malacologia, 58(1–2), 245–302. https://doi.org/10.4002/040.058.0209 Joshi, R. C., Cowie, R. H. & Sebastian, L. S. (2017) Biology and Management of Invasive Apple Snails. Philippine Rice Research Institute, Nueva Ecija, 406 pp. Khay, S., Joshi, R. C. & Sastroutomo, S. S. (2018) Invasive apple snails: integrated management in lowland ricefields of Cambodia and probing their utilization in aquaculture. Fish for the People, 16(3), 34– 37. Kobelt, W. (1909) 261. Vivipara shanensis Theobald. Die Gattung Paludina Lam. (Vivipara Montfort). Neue Folge. Systematisches Conchylien-Cabinet von Martini und Chemnitz, Ersten Bandes, einundzwanzigste Abtheilung (A), 21a(540), 411. Köhler, F. & Glaubrecht, M. (2002) Annotated catalogue of the nominal taxa of Southeast Asian freshwater gastropods, family Pachychilidae Troschel, 1857 (Mollusca, Caenogastropoda, Cerithioidea), with an evaluation of the types. Zoosystematics and Evolution, 78(1), 121–156. https://doi.org/10.1002/mmnz.20020780107 Köhler, F. & Glaubrecht, M. (2007) Out of Asia and into India: on the molecular phylogeny and biogeography of the endemic freshwater gastropod Paracrostoma Cossmann, 1900 (Caenogastropoda: Pachychilidae). Biological Journal of the Linnean Society, 91(4), 627– 651. https://doi.org/10.1111/j.1095-8312.2007.00866.x Kondakov, A. V., Bespalaya, Y. V., Vikhrev, I. V., Konopleva, E. S., Gofarov, M. Y., Tomilova, A. A., Vinarski, M. V. & Bolotov, I. N. (2020) The Asian pond mussels rapidly colonize Russia: successful invasions of two cryptic species to the Volga and Ob rivers. BioInvasions Records, 9(3), 504–518. https://doi.org/10.3391/bir.2020.9.3.07 Kondakov, A. V., Palatov, D. M., Rajabov, Z. P., Gofarov, M. Y., Konopleva, E. S., Tomilova, A. A., Vikhrev, I.V. & Bolotov, I. N. (2018) DNA analysis of a non-native lineage of Sinanodonta woodiana species complex (Bivalvia: Unionidae) from Middle Asia supports the Chinese origin of the European invaders. Zootaxa, 4462(4), 511–522. https://doi.org/10.11646/zootaxa.4462.4.4 Lamarck, [J.-B. M.] de (1822) Histoire naturelle des animaux sans vertèbres. Tome sixième, 2me partie. Published by the Author, Paris, France, 232 pp. Li-Na, D., Jun-Xing, Y. & Xiao-Yong, C. (2011) A new species of Trochotaia (Caenogastropoda: Viviparidae) from Yunnan, China. Molluscan Research, 31(2), 85–89. Maldonado, M. A. & Martín, P. R. (2019) Dealing with a hyper-successful neighbor: effects of the invasive apple snail Pomacea canaliculata on exotic and native snails in South America. Current Zoology, 65(3), 225–235. https://doi.org/10.1093/cz/zoy060 Morlet, L. (1886) Diagnoses Molluscorum novorum Tonkini. Journal de Conchyliologie, 34, 75–78. Nevill, G. (1877) List of the Mollusca brought back to Mr. Anderson from Yunnan and upper Burma, with descriptions of new species. Journal of the Asiatic Society of Bengal, 46, 14–41. Ng, T. H., Jeratthitikul, E., Sutcharit, C., Chhuoy, S., Pin, K., Pholyotha, A., Siriwut, W., Srisonchai, R., Hogan, Z. S. & Ngor, P. B. (2020) Annotated checklist of freshwater molluscs from the largest freshwater lake in Southeast Asia. ZooKeys, 958, 107–141. https://doi.org/10.3897/zookeys.958.53865 Páll-Gergely, B., Hunyadi, A. & Auffenberg, K. (2020) Taxonomic vandalism in malacology: comments on molluscan taxa recently described by NN Thach and colleagues (2014–2019). Folia Malacologica, 28(1), 35 –76. https://doi.org/10.12657/folmal.028.002

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Pfeiffer, J. M., Graf, D. L., Cummings, K. S. & Page, L. M. (2021) Taxonomic revision of a radiation of Southeast Asian freshwater mussels (Unionidae: Gonideinae: Contradentini+Rectidentini). Invertebrate Systematics. https://www.publish.csiro.au/IS/justaccepted/IS20044 Prashad, B. (1918) Studies on the Anatomy of Indian Mollusca: I. The Marsupium of Glochidium of the genus Physunio. Records of the Indian Museum, 14, 183–186. Thach, N. N. (2005) Shells of Vietnam: An Illustrated Guide to the Molluscs of the Chinese Sea & Eastern Indo-china. ConchBooks, Hackenheim, Germany, 338 pp. Thach, N. N. (2007) Recently collected shells of Vietnam. L’Informatore Piceno and N.N.T, Ancona, Italy, 384 pp. Thach, N. N. (2012) New records of Molluscs from Vietnam. 48HrBooks Company, Akron, Ohio, 276 pp. Thach, N. N. (2016a) Papuina abbasi, a new species (Gastropoda: Pupinidae) from Indonesia. Malacologia Mostra Mondiale, 93, 23–25. Thach, N. N. (2016b) Vietnamese new mollusks, seashells, land snails, cephalopods with 59 new species. 48HrBooks Company, Akron, 205 pp. Thach, N. N. (2016c) Lanceolaria bogani (Bivalvia: Unionidae), a new species from Vietnam. Novapex, 17(1), 9–11. Thach, N. N. (2017) New Shells of Southeast Asia. Sea Shells & Land Snails with 2 new genera and 85 new species. 48HrBooks Company, Akron, 128 pp. Thach, N. N. (2018) New Shells of South Asia. Seashells – Freshwater & Land Snails: 3 New Genera, 132 New Species & Subspecies. 48HRBooks Company, Akron, 173 pp. Thach, N. N. (2020a) New Shells of South Asia. Volume 2. Sea Shells, Freshwater & Land Snails. With one new genus and 140 new species and subspecies, reply to comments made in error. 48HrBooks Company, Akron, 190 pp. Thach, N. N. (2020b) My new shell book PUBLISHED. Nha Trang, June 23, 2020. Information Letter. Received on 23 June 2020 (available from the corresponding author upon request). Thach, N. N. (2021) Rejected Synonyms in MolluscaBase. The Festivus, 53(1), 63–66. Van Bocxlaer, B., Clewing, C., Etimosundja, J. P. M., Kankonda, A., Ndeo, O. W. & Albrecht, C. (2015) Recurrent camouflaged invasions and dispersal of an Asian freshwater gastropod in tropical Africa. BMC Evolutionary Biology, 15, 33. https://doi.org/10.1186/s12862-015-0296-2 Yang, Q. Q., Liu, S. W., He, C. & Yu, X. P. (2018) Distribution and the origin of invasive apple snails, Pomacea canaliculata and P. maculata (Gastropoda: Ampullariidae) in China. Scientific Reports, 8, 1185. https://doi.org/10.1038/s41598-017-19000-7.

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Appendix List of nominal taxa of freshwater Mollusca described by N. N. Thach with new synonyms

Class Bivalvia Linnaeus, 1758 Family Unionidae Rafinesque, 1820

Lanceolaria bogani Thach, 2016 =Unio fruhstorferi Dautzenberg (1900): 429. =Lanceolaria bogani Thach (2016c): 9; fig. 1A–I.

Holotype: IRSNB IG.33095/MT.3235 (Royal Belgian Institute of Natural Sciences, Brussels, Belgium). Type locality: Huế city, Thừa Thiên Huế Province, Vietnam [approx. 16.47°N, 107.58°E, Perfume River basin]. Comments: This nominal species was considered a junior synonym of Lanceolaria fruhstorferi (Dautzenberg, 1900) (Do et al. 2018; Đặng and Hố 2019). We agree with this decision.

Pseudodon artbogani Thach & Huber in Thach, 2020 [taxon inquirendum] =Pseudodon artbogani Thach (2020a): 94; pl. 86, figs 986–989.

Holotype: NCSM 113635 (North Carolina Museum of Natural Sciences, Raleigh, North Carolina, United States of America). Type locality: “Las Freci River, near Thakhek, Laos” [approx. 17.4352°N, 104.8359°E, Mekong River basin]. Comments: This nominal species may belong to the genus Nyeinchanconcha Bolotov et al., 2020, which is endemic to the Mekong Basin in Laos (Bolotov et al. 2020). It needs further research because the tribe Pseudodontini contains multiple species and genera, most of which can be distinguished by means of a molecular approach only (Bolotov et al. 2017a, 2017b, 2020). At this stage, we would prefer to consider it as taxon inquirendum until a more convincing proof of its validity and taxonomic placement is presented.

Sinanodonta hunganhi Thach, 2016 =Anodonta jourdyi Morlet (1886): 76. =Sinanodonta hunganhi Thach (2016b): 7, fig. 23; 80; pl. 38, figs 472, 473; pl. 39, figs 475, 478. =Sinanodonta jourdyi Do et al. (2018): 12.

Holotype: NHMUK 20160308 (British Museum of Natural History, London, United Kingdom). Type locality: Around Vinh City, Nghệ An Province (North Vietnam) [approx. 18.67°N, 105.67°E, Cả River basin]. Comments: This taxon was considered a junior synonym of Sinanodonta jourdyi (Morlet, 1886) (Do et al. 2018; Kondakov et al. 2018; Graf and Cummings 2021). We agree with this decision. The genus Sinanodonta contains several cryptic species that can be delineated on the basis of a molecular approach exclusively (Bolotov et al. 2016; Bespalaya et al. 2018; Kondakov et al. 2020; Graf and Cummings 2021).

Class Gastropoda Cuvier, 1795 Family Ampullariidae Gray, 1824

Pila huberi Thach, 2020 syn. nov. =Ampullaria pesmei Morlet (1899): 185; pl. 8, fig. 2. =Pila pesmei Brandt (1974): 51; pl. 5, figs 70, 71. =Pila pesmei Ng et al. (2020): 123; fig. 5B. =Pila huberi Thach (2020a): 21; pl. 3, figs 29–38.

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Holotype: NCSM 113628 (North Carolina Museum of Natural Sciences, Raleigh, North Carolina, United States of America). Type locality: Battambang, Cambodia [approx. 13.1°N, 103.2°E, Tonlé Sap Lake – Mekong River basin]. Comments: This nominal species is a conchological form of Pila pesmei (Morlet, 1889) that was described from Cambodia (Morlet 1899; Brandt 1974; Ng et al. 2020). Regrettably, the latter species was overlooked in the protologue (Thach 2020a). The deep black periostracum of the type shells should reflect an exposition in organic-rich anaerobic sediments of a highly eutrophic water body, i.e. rice fields, where the type series was collected (Thach 2020a).

Pomacea thachi Huber in Thach, 2020 syn. nov. =Ampullaria canaliculata Lamarck (1822): 178. =Pomacea thachi Thach (2020a): 21; pl. 2, figs 17–24.

Holotype: NCSM 113634 (North Carolina Museum of Natural Sciences, Raleigh, North Carolina, United States of America). Type locality: South of Attapeu Province, Laos [approx. 14.51°N, 106.84°E, Mekong River basin]. Comments: This nominal species represents a junior synonym of Pomacea canaliculata (Lamarck, 1822), the invasive Golden Apple snail, native to South America (Joshi et al. 2017; Ng et al. 2020). This species is a pest of rice and other aquatic plants (Halwart 1994; Carlsson and Lacoursiere 2005; Khay et al. 2018; Ng et al. 2020), and it could negatively affect native snail assemblages (Maldonado and Martín 2019). We establish the synonymy here because we want to avoid confusion among regional researchers, pest control managers, conservation biologists, and stakeholders in Laos and other Southeast Asian countries.

Family Viviparidae Gray, 1847

Boganmargarya Thach, 2018 syn. nov. =Taia Annandale (1918b): 123–125 [type species: Paludina naticoides Theobald, 1865; by original designation]. =Boganmargarya Thach (2018): 23 [type species: Boganmargarya huberi Thach, 2018; by original designation].

Comments: This name is a junior synonym of the genus Taia Annandale, 1918. Unfortunately, Thach (2018) was not aware of the latter genus and did not include reference to it in the protologue.

Boganmargarya huberi Thach, 2018 syn. nov. =Vivipara shanensis Kobelt (1909): 411; pl. 77, figs 4, 5. =Taia shanensis Annandale (1918b): 129–130; pl. 15, figs 14, 15; pl. 16, fig. 10; pl. 18, figs 4–6. =Boganmargarya huberi Thach (2018): 23; pl. 14, figs 156–163.

Holotype: MNHN-IM-2000-34037 (Muséum National d’Histoire Naturelle, Paris, France). Type locality: Inle Lake, Nyaungshwe Township of Taunggyi, District of Shan State, Myanmar [approx. 20.6606°N, 96.9250°E, Salween River basin]. Comments: This nominal taxon is a junior synonym of Taia shanensis (Kobelt, 1909) based on conchological features (see Annandale 1918b: 125, 129–130). Unfortunately, Thach (2018) completely overlooked the work of Annandale (1918b) with a revision of Taia spp. from Lake Inle and other water bodies of the Shan State of Myanmar.

Trochoita frankohleri Thach & Huber in Thach, 2020 [taxon inquirendum] =Trochoita frankohleri Thach (2020a): 22; pl. 4, figs 45–48.

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Holotype: NCSM 113632 (North Carolina Museum of Natural Sciences, Raleigh, North Carolina, United States of America). Type locality: Huahin District, Prachuap Khiri Khan Province, 200 km south of Bangkok, Thailand [approx. 12.57°N, 99.96°E, Pran Buri River basin]. Comments: This nominal taxon seems to be a conchological variety of Trochotaia trochoides (Martens, 1860). The latter species shares a vague type locality (Siam = Thailand) and could hardly be distinguished from Thach’s taxon by conchological features (Brandt 1974; Li-Na et al. 2011). Small rivers draining into the Gulf of Thailand were connected with Mekong and Chao Phraya basins via continuous paleo-river systems during the Pleistocene (Bolotov et al. 2017a; Pfeiffer et al. 2021). However, the morphological delineation of taxa in this genus is next to impossible, and hence we would treat Trochoita frankohleri as taxon inquirendum until its status is confirmed based on a more convincing set of morphological and molecular evidences.

Family Pachychilidae Fischer & Crosse, 1892

Brotia bogani Thach & Huber in Thach, 2020 syn. nov. =Melania baccata elongata Annandale (1918b): 115; pl. 12, figs 3–7. =Brotia henriettae Köhler & Glaubrecht (2002): 137. =Brotia bogani Thach (2020a): 23; pl. 5, figs 57–58.

Holotype: NCSM 113629 (North Carolina Museum of Natural Sciences, Raleigh, North Carolina, United States of America). Type locality: Inle Lake, Myanmar [approx. 20.55°N, 96.92°E, Salween River basin]. Comments: It is unfortunate that Thach (2020a) did not notice the work of Annandale (1918b) on the malacofauna of Lake Inle and surrounding waters. The shell appearance and sculpture of Brotia bogani are identical to those of B. frankhuberi Thach, 2020 but the type series of the first taxon lacks the dark periostracum due to artificial or natural cleaning. In its turn, Brotia frankhuberi is conspecific with Melania baccata elongata Annandale, 1918 that was considered a synonym of Brotia henriettae (Gray in Griffith & Pidgeon, 1833) [=B. baccata (Gould, 1847)] (see below for detail and references).

Brotia frankhuberi Thach, 2020 syn. nov. =Melania baccata elongata Annandale (1918b): 115; pl. 12, figs 3–7. =Brotia henriettae Köhler & Glaubrecht (2002): 137. =Brotia frankhuberi Thach (2020a): 22; pl. 4, figs 50–56.

Holotype: NCSM 113630 (North Carolina Museum of Natural Sciences, Raleigh, North Carolina, United States of America). Type locality: Inle Lake, Myanmar [approx. 20.55°N, 96.92°E, Salween River basin]. Comments: Regrettably, Thach (2020a) overlooked the work of Annandale (1918b) on the malacofauna of Lake Inle and surrounding waters. This nominal species is a junior synonym of Melania baccata elongata Annandale, 1918 from Lake Inle on the basis of identical shell shape, sculpture, and size (see Annandale 1918b: 115, pl. 12, figs 3–7). The latter taxon was considered a synonym of Brotia henriettae (Gray in Griffith & Pidgeon, 1833) [=B. baccata (Gould, 1847)] (Köhler & Glaubrecht 2002).

Paracrostoma huberi Thach, 2018 [taxon inquirendum] =Paracrostoma huberi Thach (2018): 23–24; pl. 15, figs 168–172.

Holotype: MNHN-IM-2000-34038 (Muséum National d’Histoire Naturelle, Paris, France). Type locality: “300 km north of Rangon [=Yangon], Myanmar” [it might be somewhere around Naypyidaw (the capital of the country), approx. 19.75°N, 96.11°E, Sittaung River basin]. Comments: The type locality of this nominal species is uncertain. It was also the case of some land snail taxa introduced by N. N. Thach (see Páll-Gergely et al. 2020). The genus Paracrostoma is rather poorly

BOLOTOV ET AL. known (Köhler and Glaubrecht 2007). This nominal species seems to be a synonym of Paracrostoma huegelii (Philippi, 1843), because the diagnostic features mentioned in the original description are within the range of conchological variability of the latter species. However, taxa in this genus are almost indistinguishable conchologically (Köhler and Glaubrecht 2007), and we prefer to consider Paracrostoma huberi as taxon inquirendum until the separate species-level status of this taxon is confirmed on the basis of more convincing morphological and molecular evidences.

Family Thiaridae Gill, 1871 (1823)

Melanoides thachi Huber in Thach, 2020 [taxon inquirendum] =Melanoides thachi Thach (2020a): 23; pl. 5, figs 61–66.

Holotype: NCSM 113631 (North Carolina Museum of Natural Sciences, Raleigh, North Carolina, United States of America). Type locality: Inle Lake, Myanmar [approx. 20.55°N, 96.92°E, Salween River basin]. Comments: It seems to be a junior synonym of the widespread and variable species Melanoides tuberculata (O. F. Müller, 1774) (see Annandale 1918b: 114, pl. 12, figs 1–2). It was shown that Melanoides tuberculata sensu lato represents a complex of distant phylogenetic lineages that cannot be separated by means of a morphological approach alone (Facon et al. 2003; Van Bocxlaer et al. 2015; Chiu et al. 2019). The validity of Melanoides thachi cannot be justified based on the original diagnosis, and hence we would consider it as taxon inquirendum until its full species status is reaffirmed using a body of more convincing evidences.

Family Paludomidae Stoliczka, 1868

Paludomus huberi Thach, 2020 syn. nov. =Paludomus andersoniana Nevill (1877): 35. =Paludomus huberi Thach (2020a): 23; pl. 5, figs 67–68; pl. 6, 69–74.

Holotype: NCSM 113633 (North Carolina Museum of Natural Sciences, Raleigh, North Carolina, United States of America). Type locality: Inle Lake, Myanmar [approx. 20.55°N, 96.92°E, Salween River basin]. Comments: In the original diagnosis, this nominal taxon was compared with Paludomus siamensis Blanford, 1903. Regrettably, however, the author overlooked several Paludomus taxa described from Myanmar (Benson 1856; Nevill 1877; Annandale 1918b). Paludomus huberi is conspecific with P. andersoniana Nevill, 1877 based on the identical shell shape, similar size, and the same coloration patterns (Nevill 1877).

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