Skip to main content Skip to main navigation menu Skip to site footer
Responsive image
Issue: Vol. 5757 No. 6: 11 Feb. 2026
Type: Article
Published: 2026-02-11
DOI: 10.11646/zootaxa.5757.6.7
Page range: 583-599
Abstract views: 64
PDF downloaded: 3

Magnischistura khaokrajom, a new genus and species of loach (Cypriniformes: Nemacheilidae) from the Pachi River drainage in Western Thailand

Florida Museum of Natural History; University of Florida; Gainesville; Florida; 32611; USA.
Rabbit in the Moon Foundation; Suanphueng; Ratchaburi 70180; Thailand.
Faculty of Veterinary Medicine; Chiang Mai University; Chiang Mai; 50100; Thailand.
Florida Museum of Natural History; University of Florida; Gainesville; Florida; 32611; USA.
Florida Museum of Natural History; University of Florida; Gainesville; Florida; 32611; USA.
Florida Museum of Natural History; University of Florida; Gainesville; Florida; 32611; USA.
Taxonomy Phylogeny Southeast Asia

Abstract

Magnischistura khaokrajom, new genus and species, is described from a small tributary of the Pachi River in the Suan Phueng region of the Tenasserim Hills in western Thailand. Magnischistura shares with several recently described genera of nemacheilids a globulous suborbital flap with tubercles at its extremity and a highly modified pectoral fin on mature males, but molecular data failed to support a close relationship to any of them. Morphologically, the new genus is distinguished by the presence of a suborbital flap in the female. The highly modified pectoral fin of males is hypothesized to facilitate juxtaposition with a female during spawning.

 

References

  1. Chakrabarty, P., Warren, M., Page, L.M. & Baldwin, C.C. (2013) GenSeq: an updated nomenclature and ranking for genetic sequences from type and non-type sources. Zookeys, 346, 29–41. https://doi.org/10.3897/zookeys.346.5753
  2. Chinglemba, Y., Rameshori, Y. & Vishwanath, W. (2021) A new species of stone loach of the genus Mustura (Teleostei: Nemacheilidae) from Chindwin River drainage, Manipur, north-eastern India. Zootaxa, 5081 (4), 551–565. https://doi.org/10.11646/zootaxa.5081.4.6
  3. Choudhury, H., Das, R., Bharali, R.C., Sarma, K., Tyagi, L.K., Lal, K.K. & Sarma, D. (2021) Description of a new species of Mustura Kottelat (Teleostei: Nemacheilidae) from the Brahmaputra drainage, India. Journal of Fish Biology, 99, 450–461. https://doi.org/10.1111/jfb.14736
  4. 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.
  5. Fowler, H.W. (1934) Zoological results of the third De Schauensee Siamese Expedition, Part I.—Fishes. Proceedings of the Academy of Natural Sciences of Philadelphia, 86, 67–163.
  6. Fowler, H.W. (1936) Zoological results of the third De Schauensee Siamese Expedition, Part VII.—Fishes obtained in 1935. Proceedings of the Academy of Natural Sciences of Philadelphia, 87, 509–513. [for 1935]
  7. Hubbs, C.L., Lagler, K.F. & Smith, G.R. (2004) Fishes of the Great Lakes region. The University of Michigan Press, Ann Arbor, Michigan, 276 pp., 32 pls. https://doi.org/10.3998/mpub.17658
  8. Kottelat, M. (1990) Indochinese nemacheilines. A revision of nemacheiline loaches (Pisces: Cypriniformes) of Thailand, Burma, Laos, Cambodia and southern Viet Nam. Pfeil, München, 262 pp.
  9. Kottelat, M. (2017) Schistura titan, a new species of loach from Dakchung Plateau, southern Laos (Teleostei: Nemacheilidae). Ichthyological Exploration of Freshwaters, 28, 65–73.
  10. Kottelat, M. (2018) Mustura celata, a new genus and species of loaches from northern Myanmar, and an overview of Physoschistura and related taxa (Teleostei:Nemacheilidae). Ichthyological Exploration of Freshwaters, 28, 1–6. https://doi.org/10.23788/IEF-1080
  11. Kottelat, M. (2019) Rhyacoschistura larreci, a new genus and species of loach from Laos and redescription of R. suber (Teleostei: Nemacheilidae). Zootaxa, 4612 (2), 151–170. https://doi.org/10.11646/zootaxa.4612.2.1
  12. Kottelat, M. & Grego, J. (2020) Kayahschistura lokalayensis, a new genus and species of cave fish from Myanmar (Teleostei: Nemacheilidae). Raffles Bulletin of Zoology Supplement, 35, 179–185.
  13. Maurakis, E.G. & Woolcott, W.S. (1992) Spawning in Semotilus corporalis (Fallfish) (Pisces: Cyprinidae). Virginia Journal of Science, 43, 377–380. https://doi.org/10.2307/1446218
  14. Menon, A.G.K. (1987) The fauna of India and the adjacent countries. Pisces. Vol. IV. Teleostei - Cobitoidea. Part 1. Homalopteridae. Zoological Survey of India, Calcutta, x + 259 pp., 16 pls.
  15. Nalbant, T. (1994) Studies on loaches (Pisces: Ostariophysi; Cobitoidea). I. An evaluation of the valid genera of Cobitinae. Travaux du Muséum National d’Histoire Naturelle 'Grigore Antipa', 34, 375–380.
  16. Nguyen, L.-T., Schmidt, H.A., von Haeseler, A. & Minh, B.Q. (2015) IQ-TREE: a fast and effective stochastic algorithm for estimating maximum-likelihood phylogenies. Molecular Biology and Evolution, 32, 268–274. https://doi.org/10.1093/molbev/msu300
  17. Page, L.M. (1983) Handbook of Darters. T.F.H., Inc., Neptune City, New Jersey, 271 pp.
  18. Page, L.M., Pfeiffer, J.M., Suksri, S., Randall, Z.S. & Boyd, D.A. (2020) Variation in the Arrow Loach, Nemacheilus masyae (Cypriniformes: Nemacheilidae), in Mainland Southeast Asia with description of a new species. Copeia, 108, 392–402. https://doi.org/10.1643/CI-19-305
  19. Pellegrin, J. (1936) Poissons nouveaux du haut-Laos et de l'Annam. Bulletin de la Société Zoologique de France, 61, 243–248.
  20. Plongsesthee, R., Beamish, F.W.H. & Page, L.M. (2012) Sexual dimorphism in species of Schistura (Teleostei: Nemacheilidae) from the Mae Khlong basin and peninsular Thailand. Zootaxa, 3586 (1), 353–358. https://doi.org/10.11646/zootaxa.3586.1.33
  21. Qin, T., Kottelat, M., Kyaw, Y.M.M. & Chen, X. (2022) Mustura yangi, a new species of loach (Teleostei: Nemacheilidae) from Putao, Irrawaddy drainage, northern Myanmar. Ichthyological Exploration of Freshwaters, 31, 179–189. https://doi.org/10.23788/IEF-1181
  22. Rameshori, Y., Chinglemba, Y., Darshan, A. & Vishwanath, W. (2022) Mustura daral, a new species of stone loach from Arunachal Pradesh, northeast India (Teleostei: Nemacheilidae). Zootaxa, 5129 (2), 285–294. https://doi.org/10.11646/zootaxa.5129.2.8
  23. Singh, A., Sen, N., Bănărescu, P.M. & Nalbant, T.T. (1982) New noemacheiline loaches from India (Pisces, Cobitidae). Travaux du Muséum d'Histoire Naturelle "Grigore Antipa", 23, 201–212. [for 1981]
  24. Šlechtová, V., Bohlen, J., Freyhof, J. & Ráb, P. (2006) Molecular phylogeny of the Southeast Asian freshwater fish family Botiidae (Teleostei: Cobitoidea) and the origin of polyploidy in their evolution. Molecular Phylogenetics and Evolution, 39, 529–541. https://doi.org/10.1016/j.ympev.2005.09.018
  25. Šlechtová, V., Bohlen, J. & Tan, H.H. (2007) Families of Cobitoidea (Teleostei; Cypriniformes) as revealed from nuclear genetic data and the position of the mysterious genera Barbucca, Psilorhynchus, Serpenticobitis and Vaillantella. Molecular Phylogenetics & Evolution, 44, 1358–1365. https://doi.org/10.1016/j.ympev.2007.02.019
  26. Šlechtová, V., Dvořák, T., Freyhof, J., Kottelat, M., Levin, B., Golubtsov, A., Šlechta, V. & Bohlen, J. (2024) Reconstructing the phylogeny and evolutionary history of freshwater fishes (Nemacheilidae) across Eurasia since early Eocene. eLife, 13, RP101080. https://doi.org/10.7554/eLife.101080.2.sa2
  27. Smith, H.M. (1945) The fresh-water fishes of Siam, or Thailand. Bulletin of the United States National Museum, 188, i–xi + 1–622, pls. 1–9.
  28. Stamatakis, A. (2014) RAxML version 8: a tool for phylogenetic analysis and post-analysis of large phylogenies. Bioinformatics, 30, 1312–1313. https://doi.org/10.1093/bioinformatics/btu033
  29. Ward, R.D., Zemlak, T.S., Innes, B.H., Last, P.R. & Hebert, P.D. (2005) DNA barcoding Australia's fish species. Philosophical Transactions of the Royal Society of London B: Biological Science, 360, 1847–1857. https://doi.org/10.1098/rstb.2005.1716
  30. Yang, L., Mayden, R.L., Sado, T., He, S., Saitoh, K. & Miya, M. (2010) Molecular phylogeny of the fishes traditionally referred to Cyprinini sensu stricto (Teleostei: Cypriniformes). Zoologica Scripta, 39 (6), 527–550. https://doi.org/10.1111/j.1463-6409.2010.00443.x

How to Cite

Page, L.M., Pawangkhant, P., Tangjitjaroen, W., Cagle, D.K., Williams, B.R. & Randall, Z.S. (2026) Magnischistura khaokrajom, a new genus and species of loach (Cypriniformes: Nemacheilidae) from the Pachi River drainage in Western Thailand. Zootaxa, 5757 (6), 583–599. https://doi.org/10.11646/zootaxa.5757.6.7