Revision of the Nemacheilidae (Cypriniformes) Genera of the Burmese Clade, with the Description of Pogonoschistura gen. nov. and Pogonoschistura pawaiensis sp. nov.
Laboratory of Fish Genetics, Institute of Animal Physiology and Genetics, Academy of Sciences of the Czech Republic, Rumburská 89, 277 21 Liběchov, Czech Republic
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Author to whom correspondence should be addressed.
Fishes 2026, 11(2), 78; https://doi.org/10.3390/fishes11020078
Submission received: 31 December 2025
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Revised: 20 January 2026
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Accepted: 24 January 2026
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Published: 27 January 2026
(This article belongs to the Special Issue Freshwater Fishes: Taxonomic Diversity, Conservation Concerns, and Future Directions)
Abstract
A recent phylogenetic reconstruction based on molecular genetic data revealed the presence of six well-supported clades within the freshwater fish family Nemacheilidae (Burmese, Eastern, Indochinese, Northern, Southern and Sundaic Clade). Species with the present generic name Schistura were found in three of the six major clades. Since the type species of Schistura belongs to the Southern Clade, species in other major clades can no longer be considered as members of the genus Schistura. We here review the generic status of ‘Schistura’ species in the Burmese Clade. ‘Schistura’ savona represents an isolated lineage, for which the genus Acoura is available, previously a synonym of Schistura. A second group comprises two species, ‘Schistura’ kohchangensis and the undescribed ‘Schistura’ cf. kohchangensis. We propose Pogonoschistura as a new generic name for these two species and name the undescribed species. Pogonoschistura differs from all other genera within the Burmese Clade by the combination of the following character states: caudal fin slightly emarginate to emarginate; adult males with a suborbital flap and a suborbital groove; dorsal fin with 7½ or 8½ branched rays; lips not covered by papillae; anus closer to anal-fin base than to pelvic-fin base; and lateral line incomplete, but exceeding vertical through pelvic-fin origin. Pogonoschistura pawaiensis, new species, is distinguished from its congener by having 9+8 branched rays in caudal fin, 7½ branched rays in dorsal fin and a distinct head pigmentation pattern.
Key Contribution: The need for a generic revision of the fish species ‘Schistura’ savona, ‘Schistura’ kohchangensis and the undescribed ‘Schistura’ cf. kohchangensis is pointed out on the base of a phylogenetic reconstruction. ‘Schistura’ savona is placed to the genus Acoura, the new genus Pogonoschistura is described for the remaining two species and the undescribed species is named Pogonoschistura pawaiensis.
1. Introduction
With about 840 valid species [1] in 59 genera [2], Nemacheilidae represents one of the biggest families of freshwater fishes on earth. Its large size and wide distribution across nearly all of Eurasia has made comprehensive studies on the whole family a challenge. As a result, the taxonomic understanding of Nemacheilidae was steadily in progress, with species and genera being described regularly. Moreover, several larger genera were known to represent artificial assemblages instead of monophyletic natural units. Recently, the first comprehensive molecular phylogeny of the whole family was published [1], revealing that Nemacheilidae separated into six major clades 39–28.5 mya. The major clades turned out to have distinct distribution, and consequently were named Northern, Eastern, Southern, Indochinese, Sundaic and Burmese Clade (Figure 1).
The vast size of the family Nemacheilidae and its extensive morphological diversity have long hampered biodiversity research on this group. Addressing the family as a whole, without a proper phylogenetic background, was often impractical due to its scale and complexity. Having now identified the major clades within Nemacheilidae therefore represents a major advance, as it provides a practical framework for following studies. Researchers can now focus on single clades rather than the entire family, saving time and effort and enabling studies that would otherwise be unfeasible due to the size of the family.
The study of Šlechtová et al. [1] also identified several para- or polyphyletic genera as well as a number of undescribed species and genera. In particular, the long-known polyphyly of the largest nemacheilid genus, Schistura, was confirmed again, showing that the name Schistura is scattered across three of the major clades: the Southern, Indochinese and Burmese. Since the type species of Schistura, S. rupecula, is a member of the Southern Clade, those species in the other two clades can no longer be considered as species of Schistura, and therefore are in need of a new generic placement. In the present study we reanalyse the Burmese Clade of Šlechtová et al. [1], which in their study included all representatives of the genera Aborichthys, Acanthocobitis, Paracanthocobitis, ‘Schistura’ savona and the sister species ‘Schistura’ kohchangensis and ‘Schistura‘ cf. kohchangensis. We expand the dataset by adding species of the genus Indoreonectes as well as additional specimens of the species pair ‘Schistura’ kohchangensis and ‘Schistura‘ cf. kohchangensis. The aim of the study is to establish new generic names to the species of ‘Schistura’ within the Burmese Clade and to formally describe the previously undescribed species ‘Schistura‘ cf. kohchangensis.
2. Materials and Methods
2.1. Sampling
Specimens and tissue samples were obtained from existing collections listed in the material. Specimens were euthanised by overdose of an approved anaesthetic (MS222 or clove oil) and subsequently fixed either in 4% formaldehyde (later transferred into 70% ethanol for long-term storage) or directly in 96% ethanol. For every DNA sample of the newly analysed specimens a voucher specimen exists (usually under the same collection number) in the listed institutions. The geographical origin of the samples is visualised in Figure 2.
The holotype and nine paratypes of the new species were deposited in the Zoological Reference Collection (ZRC), Lee Kong Chian Natural History Museum, National University of Singapore; four paratypes were deposited in Collection of Maurice Kottelat (CMK), Cornol and two paratypes in the collection of the Laboratory of Fish Genetics, Institute of Animal Physiology and Genetics (IAPG), Liběchov, Czech Republic.
2.2. Morphology and Morphometry
All measurements and counts follow Kottelat [3]. Measurements of 26 morphometric characters were made point-to-point with digital callipers to the nearest 0.1 mm. Genus and species description follow mostly Kottelat [4,5,6,7,8].
All morphometric variables were standardised as percentages of standard length (SL). Principal Component Analysis (PCA) was conducted in R 4.3.3 [9] on a combined dataset of size-corrected morphometric variables (expressed as percentages of SL) and meristic characters using the FactoMineR package 2.13 [10]. Visualisation of individual specimens in biplots was performed using the factoextra package 1.0.7 [11], which relies on ggplot2 [12] for graphical output. The PCA was used to explore overall phenotypic differentiation between the two species of Pogonoschistura.
In addition, we compared the morphological characters of the genera of the Burmese clade to identify diagnostic character states.
This publication has been registered at http://zoobank.org under the number 364361EE-B059-445E-8B48-B04B954B5C1E. The genus name Pogonoschistura and the species name Pogonoschistura pawaiensis have been registered at http://zoobank.org under the numbers 9FBA8E38-D804-4577-AA2B-E962F50449F0 and 6473AA3E-D69F-4626-9A67-76023294BC26, respectably.
2.3. Molecular Phylogeny
DNA was extracted from fin or muscle tissue using the Dneasy Blood & Tissue kit (QIAGEN N.V, Venlo, The Netherlands), NucleoSpin Tissue kit (MACHEREY-NAGEL GmbH & Co. KG., Düren, Germany) or Tissue/Blood DNA Mini Kit (Geneaid Ltd, Taipei, Taiwan). For the present study we used one mitochondrial (mtDNA) gene, cytochrome b gene (cyt b), and four nuclear (nDNA) genes: interphotoreceptor retinoid-binding protein gene 2 (IRBP2), recombination-activating gene 1 (RAG1), rhodopsin 1 gene (RH1) and myosin heavy chain 6 gene (MYH6). For details on primers, polymerase chain reaction (PCR), PCR product purification and sequencing, see Šlechtová et al. [1].
Phylogenetic analyses included 88 specimens: 65 representing the known diversity within the Burmese clade (genera Aborichthys, Acanthocobitis, Acoura, Indoreonectes, Paracanthocobitis) and 13 specimens of Pogonoschistura. An overview of all samples included in the phylogenetic analyses is provided in Table 1. A large portion of the Burmese clade samples was taken from the previous study by Šlechtová et al. [1]. Sequences newly obtained for the present study, mainly those of Pogonoschistura, are indicated in Table 1 with green font. Sequences of all Indoreonectes species and of Paracanthocobitis mooreh were obtained from GenBank. As outgroup, we used published sequences of various Nemacheilidae as well as Cobitis taenia from the closely related loach family Cobitidae [1,13,14,15].
The final concatenated five-gene dataset used for phylogenetic reconstruction comprised 4543 bp. Phylogenetic analyses were performed using both Bayesian inference (BI) and maximum likelihood (ML). BI analysis was conducted in MrBayes 3.2 [16] via the CIPRES Science Gateway [17]. The dataset was partitioned by gene and codon position, with model parameters assigned according to the best-fit models identified previously using PartitionFinder 2 [18]. The BI analysis consisted of two parallel runs of 10 million generations, with four Metropolis-Coupled Markov Chain Monte Carlo (MCMCMC) chains. The relative burnin of 25% was applied, and a 50% majority rule consensus tree was constructed from the post-burnin trees. Partitioned ML analysis was performed using IQ-TREE [19], as implemented in PhyloSuite 1.2.2 [20], with best-fit substitution models estimated automatically using ModelFinder 2 [21]. Node support values were assessed using 5000 ultrafast bootstrap replicates (UFBoot) [22].
3. Results and Discussion
The BI and ML phylogenetic reconstructions revealed highly congruent topologies. The Burmese clade comprises the same lineages found by Šlechtová et al. [1] plus the newly included genus Indoreonectes, all supported by high statistical values (Figure 3).
The species ‘Schistura’ savona represents an isolated lineage within the Burmese Clade. Moreover, as mentioned above, the type species of Schistura (S. rupecula) belongs to the Southern Clade, which justifies the recognition of a distinct genus for ‘Schistura’ savona. Although this species has long been treated under the genus Schistura, it has also been designated—under its synonym Cobites (Acoura) obscura Swainson, 1839—as the type species of the genus Acoura, thereby making Acoura an available name for this lineage. Accordingly, we recognise Acoura here as a valid genus within Nemacheilidae.
The second group of species in the Burmese Clade that has formerly been referred to as Schistura includes the species ‘Schistura’ kohchangensis and ‘Schistura’ cf. kohchangensis. With the same argumentation as for Acoura savona, they are in need of a proper generic name. However, the only genera to which these species have been assigned historically are Nemacheilus [23] and Schistura [3], and the species do not belong to either one of these genera. They are therefore in need of a new generic name, and we provide for them the new genus Pogonoschistura below.
Morphometric and meristic data were used to describe the two species of Pogonoschistura. The PCA based on the complete set of morphometric and meristic characters revealed a structured pattern of phenotypic differentiation between the two taxa, with partial overlap observed along the first two principal components (PC1: 23.1%, PC2: 22.2%; Figure 4). Despite this overlap, the two groups showed distinct centroid positions, indicating non-random separation in multivariate space. A subset of characters showed the highest contributions to the main PCA axes. When the PCA was repeated using the ten most informative characters, the separation between the two taxa became more pronounced, with little to no overlap observed (Figure 5).
The distinctive character states among the genera of the Burmese clade are summarised in Table 2. Additionally, following the approach used for the Schistura cincticauda species group [14], we summarised the genus-specific morphological diagnoses as a morphocode.
Pogonoschistura,new genus
Type species. Nemacheilus kohchangensis Smith, 1933.
Etymology.
From ‘Pogon’ (Greek), meaning ‘beard’, referring to the very long barbels; and ‘Schistura’, the name of a nemacheilid genus. Gender: Feminine.
Diagnosis.
A genus of nemacheilid loach phylogenetically belonging to the Burmese Clade, distinguished from all other genera of this clade by the following combination of characters: caudal fin slightly emarginate; dorsal fin with 7½ or 8½ branched rays; lateral line reaching at least to the vertical through the pelvic-fin origin and at most to the vertical through the anal-fin base; sexual dimorphism present in the form of a suborbital flap plus a suborbital slit in males; anus positioned closer to anal-fin base than to the pelvic-fin base; and lips without papillae (Figure 6).
Pogonoschistura can be identified from all other genera of Nemacheilidae by the combination of the following character states: caudal fin slightly emarginated to emarginated; maxillary barbel reaching two thirds of the distance to the pectoral-fin origin; eyes fully developed; body with pigmentation; no dorsal and no ventral crest on the caudal peduncle; dorsal origin roughly in mid-distance between snout and caudal-fin base; dorsal-fin origin is located roughly at vertical through pectoral-fin origin; nasal tubes do not reach to margin of eye; whole body covered by scales; dorsal fin with 7 ½ or 8 ½ branched rays; males with suborbital flap; males and females have similarly long pectoral fins.
Remarks.
The genus presently includes the type species Pogonoschistura kohchangensis (Smith, 1933) and one species described in the present study, Pogonoschistura pawaiensis. Phylogenetic analyses revealed Pogonoschistura to be the sister lineage to Indoreonectes. Characters shared by both genera include a stout body shape, relatively long barbels, nostrils set close together and not close to the eye, a pigmentation pattern consisting of spotted head and surroundings of the eye and a highly variable pattern of bars on the body. An overview of the morphological characteristics of the genera within the Burmese Clade is provided in Table 2. In addition, diagnostic morphological character states distinguishing genera of the Burmese clade are summarised as a morphocode mapped onto the phylogenetic tree (Figure 7).
However, Pogonoschistura differs from Indoreonectes by having the posterior margin of the caudal fin slightly emarginated to emarginated (vs. convex or truncated); nasal tubes not reaching the anterior margin of eye (vs. reaching margin of eye); a longer lateral line, reaching at least to vertical through pelvic fin origin (vs. reaching at most to the vertical through the tip of the adpressed pectoral fin); a dorsal-fin origin situated slightly anterior to the vertical through pelvic-fin origin (vs. slightly posterior); 12–13 rays in the pectoral fin (vs. 10–11); and the presence of sexual dimorphism, with males having a suborbital flap, a suborbital slit and transformed pectoral-fin rays (vs. sexual dimorphism absent) [24,25,26,27,28,29].
Pogonoschistura differs from Acanthocobitis in having a slightly emarginate to emarginate (vs. pointed) caudal fin; 7½ or 8½ (vs. 17½–19½) branched dorsal-fin rays; anus positioned closer to the anal-fin origin than to the pelvic-fin base (vs. closer to pelvic-fin base); males possessing both a suborbital flap and a suborbital slit (vs. only a suborbital flap); and lips without papillae (vs. papillated lips) [3,30,31,32].
Pogonoschistura differs from Acoura in having an incomplete lateral line (vs. complete); a slightly emarginate to emarginate caudal fin (vs. deeply emarginate); the presence of sexual dimorphism (vs. sexual dimorphism absent); and dark lateral bars reaching the bases of the paired fins on the thorax and extending onto the ventral side of the caudal peduncle (vs. dark pigmentation sharply ending at a straight line extending from the base of the outer rostral barbel along the ventral margin of the eye to the caudal-fin base) [24,25,33].
Pogonoschistura differs from Paracanthocobitis in having 7½ or 8½ (vs. 9½–15½) branched dorsal-fin rays and lips without papillae (vs. papillated lips) [3,31,34,35].
Pogonoschistura differs from Aborichthys in having the anus positioned closer to the anal-fin origin than to the pelvic-fin base (vs. closer to pelvic-fin base); the presence of sexual dimorphism (vs. sexual dimorphism absent); a slightly emarginate to emarginate (vs. convex) caudal fin, and a longer lateral line reaching at least to the vertical through the pelvic-fin origin (vs. reaching at most to the vertical through the tip of the adpressed pectoral fin [33].
- Pogonoschistura pawaiensis, new species
Holotype. ZRC 69209, male, 68.3 mm SL, Thailand: Tak Province: Amphoe Phop Phra; Pa Wai Waterfall (about 16°34′30″ N 98°50′02″ E) draining via Mae Lamao stream into Moei River (Salween basin).
Paratypes. ZRC 69210, 9, 31.3–62.8 mm SL; CMK 29206, 4, 32.7–55.5 mm SL; IAPG A11046; 1, 37.9 mm SL; IAPG A10801, 34.5 mm SL; same data as holotype.
Diagnoses.
Pogonoschistura pawaiensis is distinguished from its only described congener P. kohchangensis by having 9 + 8 (vs. 8 + 8) branched rays in caudal fin and 7½ (vs. 8½) branched rays in dorsal fin, by always having a broad median interruption in the caudal bar, resulting in two isolated blotches (vs. caudal bar usually complete, rarely with small interruption) and by having smaller dark blotches on the head (maximally half eye diameter (vs. same size or wider than eye diameter in P. kohchangensis)).
Description.
See Figure 8 and Figure 9 for general appearance of life and preserved specimens and Table 3 for morphometric data of holotype, and 13 paratypes of Pogonoschistura pawaiensis and 32 specimens of Pogonoschistura kohchangensis. A moderately elongated nemacheilid loach with body depth strongly increasing until the mid-distance between snout and dorsal fin origin, afterwards increasing just slightly until dorsal fin origin; from dorsal fin origin body depth nearly uniform until origin of anal fin; within anal fin base body depth strongly decreasing, than again slightly increasing until base of caudal fin. Head slightly depressed; anterior half of body slightly compressed; posterior half of body compressed strongly. Snout rounded; head width slightly and constantly increasing from level of mouth backwards. Depth of caudal peduncle about 0.75–0.85 in its length. Axillary pelvic lobe present, free, length usually smaller than diameter of pupil. Small adipose crests on dorsal and ventral midline from vertical through posterior end of anal-fin base to base of caudal-fin; its height increasing towards base of caudal-fin. Largest known size 68.3 mm SL (male, holotype).
Dorsal fin with 4 simple and 7½ branched rays; distal margin slightly convex. Anal fin with 3 simple and 5½ branched rays; length of adpressed fin exceeding half distance to caudal-fin base, but never reaching caudal-fin base. Caudal fin with 9+8 branched rays; slightly emarginated and lobes rounded. Pelvic fin with 8 rays; origin slightly before or directly under origin of dorsal fin; reaching slightly behind mid-distance between its origin and origin of anal fin; not reaching anus, which is located about 1–1.5 times the eye diameter in front of the anal-fin origin. Pectoral fin usually with 12 rays, rarely with 13 rays; reaching slightly behind mid-distance to origin of pelvic fin.
Body completely covered with scales, except for the area between the pelvic fins. Lateral line incomplete, reaching at least to the vertical through pelvic fin origin and at most to the vertical through the anus; with 31–82 pores. Cephalic lateral line system with 7 supraorbital pores, 4 + 10 infraorbital pores; 8 preoperculo-mandibular pores and 3 supratemporal pores. Lips and barbels covered with unculi.
Anterior nostril opening on the anterior of a flap-like tube, with a low anterior rim. Mouth approximately twice as wide as long (Figure 10). Upper lip moderately thick, with a small median incision and more than 30 small furrows along its entire length. Lower lip thick, with a well-marked median interruption and 5–6 furrows on each side. Lips not papillated. Barbels long: inner rostral barbel reaching vertical through the anterior margin of the eye, outer rostral barbel exceeding the vertical through the posterior margin of the eye, maxillary barbel exceeding two-thirds of the distance to the pectoral-fin origin.
- Sexual Dimorphism
Only adult males possess a very small suborbital flap located anterior to the vertical through the anterior margin of the eye (Figure 11). From the base of the suborbital flap, a slit extends approximately halfway to the base of the outer rostral barbel. Males also have the last unbranched and the first two branched pectoral-fin rays slightly broader than females, with the first four branched rays and the intervening skin covered with small tubercles. The tubercles do not reach the fin margin but extend beyond the bifurcation point. On branched rays 5–7, single tubercles are present, not forming a dense covering.
Colouration.
Ground colour after fixation dark yellow to light brown, lighter in smaller specimens and darker in larger ones. Dorsal half of head with small, irregular, dark brown spots, their size ranging from approximately one-quarter to about one-half of the eye diameter. In smaller specimens, the body bears 10–15 dark brown bars, split medially but mostly still connected dorsally. With increasing size, the number of bars increases, although the pattern of split bars connected at their dorsal ends generally persists.
The dorsum anterior to the dorsal-fin origin bears blotches or short transverse bars; only occasionally are lateral bars connected with their counterparts on the opposite side by a narrow band. Posterior to the dorsal-fin base, lateral bars regularly connect with their counterparts on the opposite side; these transverse connections alternate with short transverse bars that usually do not reach the lateral midline.
A black bar is present at the caudal-fin base, with a broad median interruption; the dorsal portion forms a small round to triangular black blotch, whereas the ventral portion forms a short, thin bar at the base of the lower caudal-fin lobe. The dorsal fin has a black spot at the base of the last unbranched ray and another black spot at the base of the second to fourth branched rays. Dorsal and caudal fins bear irregular bands of dark blotches on the fin rays but not on the interradial membranes. An indistinct dark bar, sometimes irregular, originates in the midlateral area behind the opercle and extends ventrally to the base of the pectoral fin. The first 4–6 rays of the pectoral fin are covered with dark longitudinal marks. Anal and pelvic fins are hyaline.
Distribution.
Currently known only from the type locality, Pa Wai Waterfall, Tak Province, Thailand.
Etymology.
pawaiensis: for Pa Wai waterfall, the type locality.
Remarks.
The holotype is the largest known specimen and the only individual in which male characteristics are well developed. In two other specimens, a very short suborbital slit and few tubercles on the pectoral fin are visible, but to a much lesser extent than in the holotype. We consider these two smaller specimens to be males that have only just reached sexual maturity. However, even in the large holotype (68.3 mm SL), the suborbital flap and suborbital slit are much less developed than in considerably smaller males of P. kohchangensis. In combination with the low proportion of externally identifiable males (3 of 16 examined specimens), this observation raises the question whether males are fully mature within the size range analysed here, or whether sexual dimorphism develops at a larger body size than represented in the present material.
4. Conclusions
The first comprehensive molecular phylogenetic reconstruction of the freshwater fish family Nemacheilidae identified six major clades and highlighted several unresolved taxonomic issues. In this study, we focused on one of these clades, the Burmese Clade, and provide a revised taxonomic assessment. Our results indicate that the species ‘Schistura’ savona should be reclassified as Acoura savona. Additionally, we establish the new genus Pogonoschistura for ‘Schistura’ kohchangensis and describe the new species Pogonoschistura pawaiensis. These taxonomic revisions contribute to a more accurate understanding of species diversity within Nemacheilidae and provide a framework for future phylogenetic and biodiversity studies of the family.
- Material Examined
- Pogonoschistura
Pogonoschistura kohchangensis: IAPG A1818-1820, 3, 34.9–63.2 mm SL: Thailand: Trat: Koh Chang Island: waterfall Khiri Phet:; IAPG A916-919, 4, 29.4–33.6 mm SL, IAPG A1822-1826, 5, 44.3–50.1 mm SL, IAPG A1832,1, 39.8 mm SL, IAPG A1834-1838, 5, 39.1–49.5 mm SL, IAPG A7559-7565, 7, 37.3–52.8 mm SL; Thailand: Chanthaburi: Mekong drainage: Pong Nam Ron. IAPG A10783-10788, 11554–11555, 10, 42.1–65.8 mm SL; Thailand: Chanthaburi: Nakhon Nayok drainage: Ta Lang. IAPG A2689, 1, 38.4 mm SL; Thailand: Chanthaburi: Chanthaburi drainage: Phlio.
Pogonoschistura pawaiensis: ZRC 69209, ZRC 69210, CMK 29206, IAPG A11046, IAPG A10801, 16, 32.2–68.3 mm SL.; Thailand: Tak: Salween drainage: waterfall Pa Wei.
- Burmese Clade
Aborichthys kempi: CMK25538_1, CMK25538_2, 2, Myanmar: Kachin: Irrawaddy drinage. Aborichthys sp.: IAPG A3972-3973, 2, India: West Bengal: Brahmaputra drainage. Acanthocobitis pavonacea: IAPG A1863-1865, 3, ornamental fish trade. Acoura savona: IAPG A2444, 2599, 3962–3971, 7523–7532, 22, ornamental fish trade. IAPG A3440, 1, Nepal: Koshi: Ganges drainage. Paracanthocobitis epimekes: IAPG A2460, Thailand: Phang Nga: Takua Pa drainage. CMK 24940, 1,, Myanmar: Tanintharyi: Tenasserim drainage. Paracanthocobitis linypha: IAPG A2562-2563, Myanmar: ornamental fish trade. Paracanthocobitis linypha: IAPG A82-83, A3437, 3: ornamental fish trade. Paracanthocobitis mandalayensis: IAPG A11558, 1: Thailand: Tak: Salween drainage. Paracanthocobitis phuketensis: CMK 28791, 1: Myanmar: Tanintharyi: Tenasserim drainage. IAPG A5190, 1: Thailand: Phatthalung: Phaniat drainage. IAPG A5175, 1: Thailand: Trag: Palian drainage. IAPG 9713, 1: Thailand: Phang Nga: Tam Nang drainage. IAPG A2466,1: Thailand: Phang Nga: Takua Pa drainage. Paracanthocobitis pictilis: IAPG A6940-6941, 10938, 3: ornamental fish trade. Paracanthocobitis pictilis: IAPG A5774, 6621, 2: Myanmar: Magway: Irrawaddy drainage. Paracanthocobitis sp. Rakhine: IAPG A5331-5332, 2: Myanmar: Rakhine: no details. Paracanthocobitis sp. Sittaung: IAPG A4102, 1: Myanmar: Mon: Sittaung drainage. Paracanthocobitis zonalternans: IAPG 4942, 1: Thailand: Tak: Salween.
- Other Genera of Nemacheilidae
See material list in Šlechtová et al. [1].
Author Contributions
Conceptualization, J.B., V.Š.; methodology, J.B., V.Š.; software, J.B., T.D., V.Š.; validation, J.B., T.D., V.Š.; formal analysis, V.Š., T.D.; investigation, J.B., T.D.; resources, J.B.; data curation, J.B., T.D., V.Š.; writing—original draft preparation, J.B., T.D.; writing—review and editing, J.B., V.Š.; visualisation, J.B., V.Š.; supervision, J.B.; project administration, J.B.; funding acquisition, J.B., V.Š. All authors have read and agreed to the published version of the manuscript.
Funding
The study was supported by grants 206/08/0637 and 19-18453S of the Czech Science Foundation.
Institutional Review Board Statement
This work was approved by the Ethical Committee for the Welfare of Experimental Animals (Approval Code: 403/2023. Approval Date: 3 February 2023).
Data Availability Statement
The original contributions presented in the study are included in the article; further inquiries can be directed to the corresponding author.
Acknowledgments
We wish to thank Z. Hang, R. Hoyer, M. Kottelat, J. Kuehne, H.H. Ng, F. Schäfer, I. Seidel, H.-H. Tan, T.K. Toe, K. Udomritthiruji and T. Win for help with the specimens.
Conflicts of Interest
The authors declare no conflicts of interest. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript or in the decision to publish the results.
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Figure 1.
Cladogram showing the six major clades within the family Nemacheilidae and their phylogenetic relationships, as recovered by Šlechtová et al. (adapted from [1]).
Figure 1.
Cladogram showing the six major clades within the family Nemacheilidae and their phylogenetic relationships, as recovered by Šlechtová et al. (adapted from [1]).
Figure 2.
Map of a part of Indochina showing the geographical origin of the samples of Pogonoschistura. Major river systems and political boundaries are shown to provide geographic context; the locality on Koh Chang Island is shown by an offset symbol connected to the island.
Figure 2.
Map of a part of Indochina showing the geographical origin of the samples of Pogonoschistura. Major river systems and political boundaries are shown to provide geographic context; the locality on Koh Chang Island is shown by an offset symbol connected to the island.
Figure 3.
Maximum-likelihood (ML) tree showing the placement of the genus Pogonoschistura within the phylogeny of the family Nemacheilidae. The inset cladogram in the upper left corner illustrates relationships among the major clades; colours representing major clades are consistent between the inset and the phylogram. ML bootstrap support values and Bayesian inference (BI) posterior probabilities are indicated at the corresponding nodes. Support values are omitted for nodes that were not statistically supported by either analysis, as well as for intraspecific relationships.
Figure 3.
Maximum-likelihood (ML) tree showing the placement of the genus Pogonoschistura within the phylogeny of the family Nemacheilidae. The inset cladogram in the upper left corner illustrates relationships among the major clades; colours representing major clades are consistent between the inset and the phylogram. ML bootstrap support values and Bayesian inference (BI) posterior probabilities are indicated at the corresponding nodes. Support values are omitted for nodes that were not statistically supported by either analysis, as well as for intraspecific relationships.
Figure 4.
Result of PCA on all morphometric and meristic characters, showing partial overlap between the two species of Pogonoschistura: P. kohchangensis and P. pawaiensis. Abbreviations: relTL—total length, relDHL—dorsal head length, relLHL—lateral head length, relPDL—pre-dorsal length, relPPL—pre-pelvic length, relPAL—pre-anus length, relPalL—pre-anal length, relHDE—head depth at eye, relHDN—head depth at nape, relBD—body depth, relCPD—depth of caudal peduncle, relCPL—length of caudal peduncle, relSL—snout length, relHWN—head width at nares, relBWDO—body width at dorsal origin, relBWAO—body width at anal origin, relED—eye diameter, relIOW—interorbital width, relHDF—height of dorsal fin, relupCLL—length of upper caudal lobe, relloCLL—length of lower caudal lobe, relmedCLR—length of medium caudal rays, relAFD—depth of anal fin, relPlFL—length of pelvic fin, relPcFL—length of pectoral fin, DF—dorsal fin ray count, Cfup—caudal fin rays—upper lobe, Pre_mand—preoperculo-mandibular pore counts.
Figure 4.
Result of PCA on all morphometric and meristic characters, showing partial overlap between the two species of Pogonoschistura: P. kohchangensis and P. pawaiensis. Abbreviations: relTL—total length, relDHL—dorsal head length, relLHL—lateral head length, relPDL—pre-dorsal length, relPPL—pre-pelvic length, relPAL—pre-anus length, relPalL—pre-anal length, relHDE—head depth at eye, relHDN—head depth at nape, relBD—body depth, relCPD—depth of caudal peduncle, relCPL—length of caudal peduncle, relSL—snout length, relHWN—head width at nares, relBWDO—body width at dorsal origin, relBWAO—body width at anal origin, relED—eye diameter, relIOW—interorbital width, relHDF—height of dorsal fin, relupCLL—length of upper caudal lobe, relloCLL—length of lower caudal lobe, relmedCLR—length of medium caudal rays, relAFD—depth of anal fin, relPlFL—length of pelvic fin, relPcFL—length of pectoral fin, DF—dorsal fin ray count, Cfup—caudal fin rays—upper lobe, Pre_mand—preoperculo-mandibular pore counts.
Figure 5.
Result of PCA based on the ten characters with the highest contributions to the main PCA axes, illustrating the characters most responsible for interspecific differentiation. Abbreviations: relDHL—dorsal head length, relBD—body depth, relBWDO—body width at dorsal origin, relupCLL—length of upper caudal lobe, relloCLL—length of lower caudal lobe, relPlFL—length of pelvic fin, DF—dorsal fin ray count, CFup—caudal fin rays—upper lobe, Pre_mand—preoperculo-mandibular pore counts.
Figure 5.
Result of PCA based on the ten characters with the highest contributions to the main PCA axes, illustrating the characters most responsible for interspecific differentiation. Abbreviations: relDHL—dorsal head length, relBD—body depth, relBWDO—body width at dorsal origin, relupCLL—length of upper caudal lobe, relloCLL—length of lower caudal lobe, relPlFL—length of pelvic fin, DF—dorsal fin ray count, CFup—caudal fin rays—upper lobe, Pre_mand—preoperculo-mandibular pore counts.
Figure 6.
Pogonoschistura kohchangensis; (a): females, 48.7 mm SL (top), 48.5 mm SL (middle), 51.3 mm SL (bottom); (b): male, 46.1 mm SL, suborbital slit and suborbital flap present as characters of sexual dimorphism, slit and flap missing in females and juveniles; (c): male, 46.1 mm SL, mouth in ventral view.
Figure 6.
Pogonoschistura kohchangensis; (a): females, 48.7 mm SL (top), 48.5 mm SL (middle), 51.3 mm SL (bottom); (b): male, 46.1 mm SL, suborbital slit and suborbital flap present as characters of sexual dimorphism, slit and flap missing in females and juveniles; (c): male, 46.1 mm SL, mouth in ventral view.
Figure 7.
A cladogram of the genera of the Burmese Clade with an associated morphocode that visualises the distinctive character states of each genus within the clade. In Paracanthocobitis, both the extent and completeness of the lateral line vary among species. The number of branched dorsal-fin rays and lateral line length were coded as discrete character states based on predefined ranges (branched dorsal-fin rays) and on extent categories and completeness of the lateral line. For details on all character states, see Table 2.
Figure 7.
A cladogram of the genera of the Burmese Clade with an associated morphocode that visualises the distinctive character states of each genus within the clade. In Paracanthocobitis, both the extent and completeness of the lateral line vary among species. The number of branched dorsal-fin rays and lateral line length were coded as discrete character states based on predefined ranges (branched dorsal-fin rays) and on extent categories and completeness of the lateral line. For details on all character states, see Table 2.
Figure 8.
Pogonoschistura pawaiensis, life specimen, not preserved. (Photo by Jens Kühne.).
Figure 9.
Pogonoschistura pawaiensis, (a–c) holotype, male 68.3 mm SL; (d) paratype 55.3 mm SL; (e) paratype 47.2 mm SL; (f) paratype 37.5 mm SL.
Figure 9.
Pogonoschistura pawaiensis, (a–c) holotype, male 68.3 mm SL; (d) paratype 55.3 mm SL; (e) paratype 47.2 mm SL; (f) paratype 37.5 mm SL.
Figure 10.
Pogonoschistura pawaiensis, holotype, male 68.3 mm SL, mouth in ventral view.
Figure 11.
Pogonoschistura pawaiensis, sexual dimorphism. (a) Male, holotype, 68.3 mm SL, with suborbital flap and slit (indicated by arrows); (b) female, paratype, 62.7 mm SL, without suborbital flap and slit.
Figure 11.
Pogonoschistura pawaiensis, sexual dimorphism. (a) Male, holotype, 68.3 mm SL, with suborbital flap and slit (indicated by arrows); (b) female, paratype, 62.7 mm SL, without suborbital flap and slit.
Table 1.
Overview of all samples included in the phylogenetic analyses. Collection abbreviations: BNHS, Bombay Natural History Society; Mumbay, India; CMK, Collection of Maurice Kottelat, Delémont, Switzerland; IAPG, Collection of the Institute of Animal Physiology and Genetics, Liběchov, Czech Republic; NHMOU, Natural History Museum, Osmania University, Hyderabad, India; WILD, Wildlife Information Liaison Development Society, Coimbatore, India; ZRC, Zoological Reference Collection, Lee Kong Chian Natural History Museum, National University of Singapore, Singapore. The sequences newly obtained in the present study are indicated by green font.
Table 1.
Overview of all samples included in the phylogenetic analyses. Collection abbreviations: BNHS, Bombay Natural History Society; Mumbay, India; CMK, Collection of Maurice Kottelat, Delémont, Switzerland; IAPG, Collection of the Institute of Animal Physiology and Genetics, Liběchov, Czech Republic; NHMOU, Natural History Museum, Osmania University, Hyderabad, India; WILD, Wildlife Information Liaison Development Society, Coimbatore, India; ZRC, Zoological Reference Collection, Lee Kong Chian Natural History Museum, National University of Singapore, Singapore. The sequences newly obtained in the present study are indicated by green font.
| Species Name | Country; Province | River Basin | Voucher | GenBank Accession Numbers | |||||
|---|---|---|---|---|---|---|---|---|---|
| Cyt b | RAG 1 | IRBP2 | MYH6 | RH 1 | |||||
| BURMESE CLADE | |||||||||
| Aborichthys kempi | Myanmar; Kachin | Irrawaddy | CMK25538_1 CMK25538_2 | PP280061 PP280062 | PP315697 PP315698 | - - | PP280275 PP280276 | PP259732 PP259733 | |
| Aborichthys sp. | India; West Bengal | Brahmaputra | A3972 A3973 | PP279977 PP279978 | PP315814 PP315815 | PP280177 PP280178 | PP280407 PP280408 | PP259857 - | |
| Acanthocobitis cf. pavonacea | Ornamental fish trade | A1863 A1864 | MK608119 MK608120 | EF056379 MK608146 | MK608242 MK608243 | PP280338 PP280339 | PP259794 PP259795 | ||
| Acoura savona | India; West Bengal Brahmaputra Ornamental fish trade | A3962 A0441 A7530 A7532 | PX729489 PX729478 KP738598 KP738599 | PX729477 PX729467 KP738558 KP738559 | - PX729456 KP738518 KP738519 | - - PP280482 OL191354 | - - PP259939 PP259940 | ||
| Indoreonectes evezardi | India; Maharashtra | Mutha | BNHS FWF 299 BNHS FWF 300 BNHS FWF 322 | KY497108 KY497109 KY497107 | KY497180 KY497181 KY497179 | - - - | - - - | - KY944751 KY944750 | |
| Indoreonectes keralensis | India; Kerala India; Tamil Nadu | Erattayar Vaigai | WILD-17-PIS-342 WILD-17-PIS-343 WILD-17-PIS-344 | MG208866 MG018981 MG208867 | MG208869 MG208868 MG208870 | - - - | - - - | - - - | |
| Indoreonectes neeleshi | India; Maharashtra | Godavari | BNHS FWF 317 | KY497100 | KY497173 | - | - | KY944749 | |
| Indoreonectes rajeevi | India; Maharashtra | Hiranyakeshi | BNHS FWF 316 | KY497093 | KY497166 | - | - | KY944746 | |
| Indoreonectes telanganaensis | India; Telangana | Godavari | NHMOU.F.18 NHMOU.F.19 | MT569389 MT569390 | - - | - - | - - | - - | |
| Paracanthocobitis epimekes | Thailand; Phang Nga Myanmar; Tanintharyi | Takua Pa Tenasserim | A2460 CMK 24940_1 CMK 24922_2 | MK608038 MK608104 MK608111 | MK608151 MK608213 MK608220 | MK608248 MK608307 MK608314 | PP280357 PP280247 - | PP259811 PP259730 - | |
| Paracanthocobitis linypha | Myanmar; no details Myanmar; Kachin | Irrawaddy | A2562 A2563 CMK25619 | MK608044 MK608045 MK608103 | MK608157 MK608158 MK608212 | MK608254 MK608255 MK608306 | PP280365 PP280366 - | PP259821 - - | |
| Paracanthocobitis mackenziei | Ornamental fish trade | A0082 A0083 | EF508598 MK608121 | EF056383 MK608127 | MK608221 MK608222 | PP280495 PP280496 | PX729453 - | ||
| Paracanthocobitis cf. mandalayensis | Thailand; Tak | Chao Phraya | A11558 | PP279890 | PP315726 | - | PP280304 | PP259759 | |
| Paracanthocobitis mooreh | India; Maharashtra India; Maharashtra | Mutha Nira | BNHS-FWF-49 WILD-15-PIS-180 | KT005607 KT005611 | - KY497220 | - - | - - | - - | |
| Paracanthocobitis nigrolineata | Thailand; Kanchanaburi | Salween | A0902 A0903 A0904 | MK608116 MK608027 MK608028 | MK608135 MK608136 MK608137 | MK608231 MK608232 MK608233 | - - - | - - - | |
| Paracanthocobitis phuketensis | Thailand; Trang Thailand; Phang Nga Thailand; Phang Nga | Palian Tam Nang Takua Pa | A5175 A9713 A2466 | MK608071 MK608099 MK608042 | MK608182 MK608208 MK608155 | MK608277 MK608302 MK608252 | PP280433 PP280526 PP280358 | - - PP259812 | |
| Paracanthocobitis pictilis | Ornamental fish trade | A6940 A6941 A10938 | KP738589 KP738590 PP279882 | KP738549 KP738550 PP315715 | KP738509 KP738510 - | OL191347 PP280471 PP280293 | PP259929 - PP259749 | ||
| Paracanthocobitis sp. Irrawaddy | Myanmar; Magway Myanmar; Ayeyarwady | Irrawaddy Irrawaddy | A5774 A6621 A6573 | MK608078 MK608089 MK608086 | MK608189 MK608198 MK608196 | MK608284 MK608293 MK608291 | PP280456 PP280459 PP280458 | PP259905 - PP259912 | |
| Paracanthocobitis sp. Rakhine | Myanmar; Rakhine Myanmar; Rakhine | no details Irrawaddy | A5331 A5332 A5559 | KP738582 KP738583 MK608077 | KP738542 KP738543 MK608188 | KP738502 KP738503 MK608283 | OL191324 PP280443 - | PP259891 PP259892 - | |
| Paracanthocobitis sp. Sittaung | Myanmar; Mon Myanmar; Bago | Sittaung Sittaung | A4102 A4103 A4025 | MK608051 MK608052 MK608050 | MK608164 MK608165 MK608163 | MK608261 MK608262 MK608260 | PP280411 - - | - - - | |
| Paracanthocobitis zonalternans | Thailand; Tak Thailand; Mae Hong Son Thailand; Tak | Salween Salween Salween | A0812 A1365 A4941 | MK608124 MK608029 MK608065 | MK608132 MK608141 MK608176 | MK608228 MK608237 MK608271 | - - PX729455 | - - - | |
| Pogonoschistura kohchangensis | Thailand; Trat Thailand; Chanthaburi Thailand; Chanthaburi | Koh Chang isl. Mekong Chanthaburi | A1818 A1819 A1820 A0910 A0911 A0912 A1822 A1823 A1832 A1834 A2689 | PX729483 PX729484 PX729485 PX729479 PX729480 PX729481 PP279912 PP279913 PX729486 PX729487 PX729488 | PX729472 PX729473 PX729474 PX729468 PX729469 PX729470 PP315746 PP315747 PX729475 PX729476 - | PX729472 PX729473 PX729474 PX729457 PX729458 PX729459 PP280124 PP280125 PX729464 PX729465 PX729466 | - - - PX729454 - - PP280332 PP280333 - - - | - - - - - - PP259787 PP259788 - - - | |
| Pogonoschistura pawaiensis | Thailand; Tak | Salween | A10800 A11046 | PX729482 PP279884 | PX729471 PP315719 | PX729460 PP280095 | - PP280297 | - PP259753 | |
| OUTGROUP | |||||||||
| EASTERN CLADE | |||||||||
| Lefua costata | Korea; Gangwon | Cheon Jin | A6942 | KP738591 | KP738551 | KP738511 | OL191348 | - | |
| NORTHERN CLADE | |||||||||
| Barbatula barbatula | Czechia; Středočeský | Elbe | A8393 | KP738604 | KP738564 | KP738524 | PP280499 | PP259955 | |
| INDOCHINESE CLADE | |||||||||
| Schistura bolavenensis | Laos; Champasak | Mekong | A4618 | KP738575 | KP738535 | KP738495 | OL191315 | PP259869 | |
| Schistura fasciolata | China; Guangxi | Pearl | A5300 | KP738579 | KP738539 | KP738499 | PP280441 | PP259888 | |
| SUNDAIC CLADE | |||||||||
| Nemacheilus binotatus | Thailand; Chiang Mai | Chao Phraya | A6926 | KP738586 | KP738546 | KP738506 | OL191346 | PP259926 | |
| Nemacheilus masyae | Thailand; Surat Thani | Tapi | A1422 | MW512998 | MW513121 | PP280110 | PP280317 | PP259772 | |
| Nemacheilus ornatus | Thailand; Surat Thani | Tapi | A1403 | MW513024 | MW513146 | PP280108 | PP280315 | PP259770 | |
| Nemacheilus selangoricus | Thailand; Nakhon Si Thammarat | Pak Paying | A1437 | MW513062 | MW513186 | PP280111 | PP280318 | - | |
| SOUTHERN CLADE | |||||||||
| Mesonoemacheilus guentheri | India; Ornamental fish trade | A6935 | KP738588 | KP738548 | KP738508 | PP280470 | PP259928 | ||
| Nemachilichthys ruppelli | India; Ornamental fish trade | A4341 | KP738573 | KP738533 | KP738493 | OL191311 | PP259864 | ||
| Petruichthys brevis | Myanmar; Shan | Salween | A4184 | KP738571 | KP738531 | KP738491 | OL191307 | PP259859 | |
| Physoschistura sp. | Myanmar; Shan | Salween | A7545 | KP738600 | KP738560 | KP738520 | OL191355 | PP259943 | |
| Pteronemacheilus lucidorsum | Myanmar; Shan | Irrawaddy | A8465 | KP738606 | KP738566 | KP738526 | OL191360 | PP259958 | |
| Schistura balteata | Myanmar; Ornamental fish trade | A2554 | MK886971 | OL191502 | MK886880 | OL191384 | PP259819 | ||
| Schistura corica | India; Ornamental fish trade | A6945 | KP738592 | KP738552 | KP738512 | PP280472 | PP259930 | ||
| Schistura devdevi | India; Ornamental fish trade | A7541 | KP738608 | KP738568 | KP738528 | PP280483 | PP259941 | ||
| Schistura hypsiura | Myanmar; Ornamental fish trade | A6922 | KP738584 | KP738544 | KP738504 | PP280467 | PP259924 | ||
| Schistura notostigma | Sri Lanka; Ornamental fish trade | A7519 | KP738595 | KP738555 | KP738515 | PP280479 | PP259936 | ||
| Schistura poculi | Thailand; Tak | Mae Klong | A4202 | OL191193 | OL191442 | OL345511 | OL191309 | - | |
| Schistura pridii | Thailand; Ornamental fish trade | A7548 | KP738602 | KP738562 | KP738522 | OL191357 | PP259945 | ||
| Schistura robertsi | Thailand; Phang Nga | Tam Nang | A2424 | MK886959 | OL191501 | MK886869 | OL191383 | PP259810 | |
| Seminemacheilus ispartensis | Turkey; Isparta | Egirdir | A4833 | KP738577 | KP738537 | KP738497 | PP280423 | PP259872 | |
| COBITIDAE | |||||||||
| Cobitis taenia | Germany; Lower Saxonia | Weser | A1860 | EF508508 | EF056334 | MK608315 | OL191279 | PP259793 | |
Table 2.
Overview about the diagnostic morphological characters of the genera included in the Burmese Clade of Nemacheilidae.
Table 2.
Overview about the diagnostic morphological characters of the genera included in the Burmese Clade of Nemacheilidae.
| Genus Character | Aborichthys | Acoura | Acanthocobitis | Indoreonectes | Paracanthocobitis | Pogonoschistura | |
|---|---|---|---|---|---|---|---|
| 1 | Caudal fin shape | Convex | Deeply emarginate | Pointed | Convex | Slightly emarginate | Slightly emarginate |
| 2 | Branched dorsal-fin ray nos. *1 | 71/2 | 81/2 | 171/2–191/2 | 71/2 | 91/2–151/2 | 71/2–81/2 |
| 3 | Lateral line completeness | Incomplete | Incomplete | Complete | Incomplete | Variable | Incomplete |
| 4 | Lateral line length | Ends between pectoral and pelvic fin level | Exceeding anal-fin origin | Complete | Not reaching tip of adpressed pectoral fin | Variable, from not reaching pelvic-fin level to complete | Ends between pelvic and anal fin bases |
| 5 | Suborbital flap (♂) | No | No | Yes | No | Yes *2 | Yes |
| 6 | Suborbital slit (♂) | No | No | No | No | Yes | Yes |
| 7 | Tubercles on pectoral fins (♂) | No | No | No | No | Yes | Yes |
| 8 | Lip papillation | No | No | Yes | No | Yes | No |
| 9 | Anus position | Closer to pelvic fin | Closer to anal fin | Closer to pelvic fin | Closer to anal fin | Closer to anal fin | Closer to anal fin |
| 10 | Caudal marks | Dark spot | Dark bar | Dark spot | Dark spot + bar | Dark spot + bar | Dark spot + bar |
| 11 | Axillary pelvic lobe | Present | Present | Present | Absent | Present | Present |
| 12 | Maxillary barbel length | reaching anterior margin of eye | reaching anterior margin of eye | exceeding posterior margin of eye | exceeding posterior margin of eye | exceeding posterior margin of eye | exceeding posterior margin of eye |
| 13 | Dorsal- vs. pelvic-fin (V) origin | D origin behind V origin | D origin before V origin | D origin before V origin | D origin behind V origin | D origin before V origin | Above or slightly behind |
| 14 | Nasal tube length | Not reaching anterior margin of eye | Not reaching anterior margin of eye | Not reaching anterior margin of eye | Reaching anterior margin of eye | Not reaching anterior margin of eye | Not reaching anterior margin of eye |
Notes: *1—The last, smallest branched fin ray is counted as ½ in fish taxonomy; *2—not in all species.
Table 3.
Morphometric data of Pogonoschistura pawaiensis (holotype and 13 paratypes; range and mean include holotype) and Pogonoschistura kohchangensis (N = 32).
Table 3.
Morphometric data of Pogonoschistura pawaiensis (holotype and 13 paratypes; range and mean include holotype) and Pogonoschistura kohchangensis (N = 32).
| Pogonoschistura pawaiensis | Pogonoschistura kohchangensis | ||||
|---|---|---|---|---|---|
| Holotype | Range | Mean | Range | Mean | |
| In mm | |||||
| Standard length (mm) | 68.3 | 30.7–68.3 | 44.5 | 29.4–65.8 | 45.1 |
| Total length (mm) | 82.7 | 37.4–82.7 | 54.4 | 36.8–82.5 | 56.3 |
| In % of standard length | |||||
| Dorsal head length | 19.3 | 18.9–22.7 | 20.6 | 17.5–22.3 | 19.3 |
| Lateral head length | 23.6 | 22.5–25.2 | 23.6 | 20.6–25.4 | 22.9 |
| Pre-dorsal length | 50.5 | 50.5–53.4 | 52.3 | 49.5–55.0 | 51.7 |
| Pre-pelvic length | 50.7 | 49.7–52.4 | 51.1 | 49.4–54.0 | 51.3 |
| Pre-anus length | 74.5 | 73.4–76.2 | 74.9 | 70.6–76.2 | 73.9 |
| Pre-anal length | 78.3 | 75.6–80.5 | 78.4 | 74.6–81.1 | 78.2 |
| Head depth at eye | 11.6 | 10.0–11.6 | 10.7 | 9.1–11.8 | 10.3 |
| Head depth at nape | 15.7 | 12.7–15.7 | 13.8 | 11.5–16.1 | 13.7 |
| Body depth | 18.4 | 15.2–18.4 | 16.6 | 14.3–19.2 | 16.9 |
| Depth of caudal peduncle | 13.9 | 11.8–13.9 | 12.7 | 11.9–15.4 | 13.4 |
| Length of caudal peduncle | 15.7 | 14.3–17.1 | 15.7 | 14.4–17.9 | 16.0 |
| Snout length | 9.5 | 8.1–10.0 | 9.1 | 7.5–9.7 | 8.8 |
| Head width at nares | 10.4 | 9.7–11.2 | 10.4 | 9.0–12.5 | 10.4 |
| Maximum head width | 17.3 | 14.2–17.3 | 15.4 | 14.9–17.5 | 16.0 |
| Body width at dorsal origin | 14.2 | 11.2–14.2 | 12.1 | 10.9–17.0 | 13.9 |
| Body width at anal origin | 9.1 | 7.4–9.1 | 8.1 | 6.1–10.8 | 8.4 |
| Eye diameter | 3.5 | 3.5–5.5 | 4.6 | 3.6–5.4 | 4.1 |
| Interorbital width | 7.9 | 7.9–10.2 | 9.1 | 7.7–9.5 | 8.5 |
| Height of dorsal fin | 14.3 | 14.0–15.8 | 14.8 | 12.9–16.3 | 14.9 |
| Length upper caudal lobe | 21.8 | 20.2–23.4 | 21.6 | 20.2–26.8 | 22.8 |
| Length lower caudal lobe | 21.4 | 19.9–23.6 | 21.2 | 19.8–26.1 | 22.9 |
| Length medium caudal rays | 20.9 | 18.8–22.7 | 20.3 | 17.7–23.3 | 19.9 |
| Depth of anal fin | 18.0 | 17.0–19.1 | 18.1 | 16.0–21.9 | 18.7 |
| Length of pelvic fin | 17.7 | 17.3–18.9 | 17.9 | 17.2–22.3 | 19.7 |
| Length of pectoral fin | 19.6 | 17.8–22.5 | 20.2 | 19.0–25.7 | 21.4 |
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Bohlen, J.; Dvořák, T.; Šlechtová, V. Revision of the Nemacheilidae (Cypriniformes) Genera of the Burmese Clade, with the Description of Pogonoschistura gen. nov. and Pogonoschistura pawaiensis sp. nov. Fishes 2026, 11, 78. https://doi.org/10.3390/fishes11020078
AMA Style
Bohlen J, Dvořák T, Šlechtová V. Revision of the Nemacheilidae (Cypriniformes) Genera of the Burmese Clade, with the Description of Pogonoschistura gen. nov. and Pogonoschistura pawaiensis sp. nov. Fishes. 2026; 11(2):78. https://doi.org/10.3390/fishes11020078
Chicago/Turabian StyleBohlen, Jörg, Tomáš Dvořák, and Vendula Šlechtová. 2026. "Revision of the Nemacheilidae (Cypriniformes) Genera of the Burmese Clade, with the Description of Pogonoschistura gen. nov. and Pogonoschistura pawaiensis sp. nov." Fishes 11, no. 2: 78. https://doi.org/10.3390/fishes11020078
APA StyleBohlen, J., Dvořák, T., & Šlechtová, V. (2026). Revision of the Nemacheilidae (Cypriniformes) Genera of the Burmese Clade, with the Description of Pogonoschistura gen. nov. and Pogonoschistura pawaiensis sp. nov. Fishes, 11(2), 78. https://doi.org/10.3390/fishes11020078
