Glaridoglanis verruciloba sp. nov., a new glyptosternine catfish (Siluriformes, Sisoridae) from the Zayul River in southeastern Tibet, China

289 Glaridoglanis verruciloba sp. nov., a new glyptosternine catfish (Siluriformes, Sisoridae) from the Zayul River in southeastern Tibet, China Zheng Gong1, Huanshan Wang2, Yanchao Liu3, Jianchuan Li4 1 College of Life Sciences, Zaozhuang University, Zaozhuang 277160, China 2 Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China 3 Key Lab of Biological Resources and Biosecurity of Xizang Autonomous Region, Institute of Plateau Biology of Xizang Autonomous Region, Lhasa 850030, China 4 Xizang Museum of Natural Science, Lhasa 850011, China Corresponding authors: Yanchao Liu ([email protected]); Jianchuan Li ([email protected]) Copyright: © Zheng Gong et al. This is an open access article distributed under terms of the Creative Commons Attribution License (Attribution 4.0 International – CC BY 4.0). Research Article Abstract Glaridoglanis verruciloba sp. nov. is described from the Zayul River in southeastern Tibet, China. It has long been misidentified as G. andersonii. This new species is diagnosed by the following combination of characters: an enlarged lower lip bearing 4–7 verruciform lobes on the central-posterior margin; an anus situated close to the origin of the anal fin; the ventral surface at the base of maxillary barbels densely covered with striae; 11 branched pectoral-fin rays; 5–6 branched anal-fin rays; and relatively short mandibular barbels. Molecular phylogenetic analyses of mitochondrial cytochrome b sequences further supported the validity of this new species, which is within a well-supported clade with substantial genetic divergence from G. andersonii. Key words: Cytochrome b gene, Glyptosterninae, morphological comparison, phylogenetic analysis, taxonomy Introduction The glyptosternine catfish (Siluriformes, Sisoridae) comprises 13 valid genera, including Barbeuchiloglanis Li, Dao & Zhou, 2022, Chimarrichthys Sauvage, 1874, Creteuchiloglanis Zhou, Li & Thomson, 2011, Exostoma Blyth, 1860, Glaridoglanis Norman, 1925, Glyptosternon McClelland, 1842, Myersglanis Hora & Silas, 1952, Oreoglanis Smith, 1933, Parachiloglanis Wu, He & Chu, 1981, Pareuchiloglanis Pellegrin, 1936, Pseudecheneis Blyth, 1860, Pseudexostoma Chu, 1979, and Tremeuchiloglanis Li, Dao & Zhou, 2022 (Fricke et al. 2025). Species of this group are morphologically distinctive, characterized by the extremely depressed head and body, highly modified mouth structure, and horizontally expanded pectoral and pelvic fins, which enable them to adhere to rocky substrates in fast-flowing mountain streams (Thoni and Gurung 2018). The distribution of glyptosternine catfishes is concentrated in the East Himalayas, Indo-Burman Ranges, Gaoligong Mountains, Shan Hills and Kachin Hills; these catfishes range from Uzbekistan in the west to South China in the east Academic editor: Bakhtiyor Sheraliev Received: 25 September 2025 Accepted: 23 November 2025 Published: 10 December 2025 ZooBank: https://zoobank. org/2351B33E-30D5-4783-8B4DDF1FF15D5D9B Citation: Gong Z, Wang H, Liu Y, Li J (2025) Glaridoglanis verruciloba sp. nov., a new glyptosternine catfish (Siluriformes, Sisoridae) from the Zayul River in southeastern Tibet, China. ZooKeys 1262: 289–301. https://doi.org/10.3897/ zookeys.1262.172819 ZooKeys 1262: 289–301 (2025) DOI: 10.3897/zookeys.1262.172819 290 ZooKeys 1262: 289–301 (2025), DOI: 10.3897/zookeys.1262.172819 Zheng Gong et al.: Glaridoglanis verruciloba sp. nov. from Tibet (Sheraliev and Peng 2021; Chen et al. 2025). Phylogenetic studies based on mitochondrial and nuclear markers suggest that this group diverged from other sisorid catfishes during the late Miocene, a period coinciding with the major phases of Himalayan uplift (Yu and He 2012). The genus Glaridoglanis, which is endemic to the Irrawaddy and the Yarlung Tsangpo–Brahmaputra drainages, currently contains two valid species: G. andersonii (Day, 1870) and G. ramosa Ng & Kottelat, 2022 (Ng and Kottelat 2022). Glaridoglanis species exhibit typical torrent-catfish morphology of the subfamily Glyptosterninae, including the dorsoventrally flattened body, greatly enlarged paired fins with horizontally inserted pinnate first rays, and an inferior mouth with well-developed suctorial lips (Thoni and Gurung 2018). They are further distinguished by the robust, chisel-shaped dentition on both jaws, which is adapted to exploit the primary food resources of these fishes (Chu 1979). Ecologically, these species inhabit cold, oxygen-rich torrents with rocky substrates, where they use their modified pectoral and pelvic fins for adhesion and movement against strong currents (Wu and Wu 1991). Historically, G. andersonii was the only species of Glaridoglanis known from the Zayul (= Chayu) River (Chu and Mo 1999; Ng and Kottelat 2022). It was first described as Exostoma andersonii by Day (1870) from Hotham and Ponsee in Yunnan Province, China. Norman (1925) later established the genus Glaridoglanis and referred Exostoma andersonii to this genus as the type species. For decades thereafter, G. andersonii remained the sole recognized species, recorded from the Irrawaddy and the Yarlung Tsangpo–Brahmaputra drainages (Wu and Wu 1991; Chu and Mo 1999), until G. ramosa was described (Ng and Kottelat 2022). In a recent ichthyological survey, we carefully examined specimens of Glaridoglanis collected from the Zayul River. Comprehensive comparisons with topotypic material of G. andersonii based on both morphology and molecular phylogeny confirmed that these specimens belong to a distinct species. Furthermore, as these specimens could not be assigned to another valid species of this genus (G. ramosa), we describe them here as a new species. Material and methods Specimens of Glaridoglanis verruciloba sp. nov. were collected in April 2025 from mountain streams of the Sangqu River and the Gongrigabu River, two branches of the upper Zayul River. The type-drainage specimens of G. andersonii were collected in July 2025 from the Binglang River, the eastern branch of the Daying River, a tributary of the upper Irrawaddy River in Yunnan Province, which is approximately 100 km north-east of the type locality of the G. andersonii (Fig. 1). Immediately after anesthetizing the fish specimens, a small portion of pectoral-fin tissue was clipped and preserved in ethanol for subsequent DNA extraction, while whole specimens were fixed in 10% formalin and later transferred to 70% ethanol for long-term storage. Morphological measurements were taken from the left side of the preserved specimens whenever possible using digital callipers to the nearest 0.1 mm, by a single operator. Measurements, counts and terminology methods followed Ng and Kottelat (2022). Standard length (SL) was used as the reference for body proportions, and head subunits were expressed as percentages of head length (HL). Meristic data were presented with frequencies in parentheses; 291 ZooKeys 1262: 289–301 (2025), DOI: 10.3897/zookeys.1262.172819 Zheng Gong et al.: Glaridoglanis verruciloba sp. nov. from Tibet Figure 1. The type locality (circle) and paratype locality (triangle) of Glaridoglanis verruciloba sp. nov. in Xizang Autonomous Region, as well as the type locality (diamond) and the locality of type-drainage specimens (star) of G. andersonii in Yunnan Province, China. when multiple values were observed, the holotype condition was marked with an asterisk. All voucher specimens were deposited at the museum of Institute of Plateau Biology of Xizang Autonomous Region (IPBX), Lhasa, China. Genomic DNA was extracted from ethanol-preserved pectoral-fin tissues using a modified salt-extraction protocol (Tang et al. 2009). The mitochondrial cytochrome b (cyt b) gene was amplified by PCR with primers L14724 and H15915 (Xiao et al. 2001). Amplifications were performed in 30 µL reactions following Gong et al. (2023). PCR procedures included an initial denaturation at 94 °C for 3 min, followed by 35 cycles of denaturation at 94 °C for 30 s, annealing at 56 °C for 30 s, and extension at 72 °C for 1 min, with a final extension at 72 °C for 10 min. The amplified products were purified and sequenced bidirectionally by Tianyi Huayu Biotech Co., Ltd (Wuhan, China). Phylogenetic analyses were performed based on 12 newly obtained cyt b sequences of G. verruciloba sp. nov. and G. andersonii, together with 26 sequences retrieved from GenBank representing additional glyptosternine taxa (Table 1). Glyptothorax minimaculatus and G. zanaensis were included as the outgroup taxa. The raw sequences were aligned and edited manually in ClustalX (Thompson et al. 1997). Pairwise genetic distances based on the Kimura-2-parameter (K2P) model were calculated using MEGA 7 (Kumar et al. 2016). Phylogenetic relationships were reconstructed using both Bayesian inference (BI) and maximum-likelihood (ML) methods. The best-fitting nucleotide substitution model was selected with jModelTest 2 (Darriba et al. 2012) under the corrected Akaike information criterion. The BI tree was generated using MrBayes 3 (Huelsenbeck 292 ZooKeys 1262: 289–301 (2025), DOI: 10.3897/zookeys.1262.172819 Zheng Gong et al.: Glaridoglanis verruciloba sp. nov. from Tibet and Ronquist 2001) under GTR + I + G model, with four simultaneous Markov chains run for 1 million generations and trees sampled every 100 generations. After discarding the first 5,000 trees as burn-in, a consensus tree was generated from the remaining 5,001 trees, and posterior probabilities were determined. The ML tree was reconstructed in RAxML 8 (Stamatakis 2014) under the GTR + I + G model, and nodal support was estimated with 1,000 bootstrap replicates. Taxonomy Glaridoglanis verruciloba Gong sp. nov. https://zoobank.org/CBAAE243-78F7-4A14-9ECA-9E2F43AF2A5D Fig. 2, Table 2 Chresonymy. Glaridoglanis andersonii (non Day 1870): Wu et al. 1981 (Zayul River, Zayul County, China); Wu and Wu 1991 (Zayul River, Zayul County, China); Table 1. List of species, distributional drainages, and GenBank accession numbers (cytochrome b) used in the phylogenetic analyses. Species Distributional drainage GenBank accession no. Chimarrichthys kishinouyei Yangtze River AY207478 Chimarrichthys longus Red River DQ192485 Creteuchiloglanis gongshanensis Nujiang–Salween River NC_028516 Creteuchiloglanis kamengensis Yarlung Tsangpo–Brahmaputra River NC_045213 Creteuchiloglanis macropterus Nujiang–Salween River NC_028509 Exostoma gaoligongense Nujiang–Salween River NC_056351 Exostoma tenuicaudatum Yarlung Tsangpo–Brahmaputra River NC_065343 Exostoma tibetanum Yarlung Tsangpo–Brahmaputra River NC_065342 Glaridoglanis andersonii Hap1 Irrawaddy River PX508675 Glaridoglanis verruciloba Hap1 Yarlung Tsangpo–Brahmaputra River PX508676 Glaridoglanis verruciloba Hap2 Yarlung Tsangpo–Brahmaputra River PX508677 Glyptosternon maculatum Yarlung Tsangpo–Brahmaputra River NC_021597 Oreoglanis immaculata Nujiang–Salween River NC_028511 Oreoglanis macroptera Irrawaddy River NC_021607 Parachiloglanis benjii Yarlung Tsangpo–Brahmaputra River MG001360 Parachiloglanis bhutanensis Yarlung Tsangpo–Brahmaputra River MG001359 Parachiloglanis dangmechhuensis Yarlung Tsangpo–Brahmaputra River MG001353 Parachiloglanis drukyulensis Yarlung Tsangpo–Brahmaputra River MG001357 Parachiloglanis immaculata Yarlung Tsangpo–Brahmaputra River OQ437239 Pseudecheneis immaculata Lancang–Mekong River MN082047 Pseudecheneis paviei Red River NC_086847 Pseudecheneis sirenica Yarlung Tsangpo–Brahmaputra River NC_021605 Pseudexostoma brachysoma Nujiang-Salween River KU987338 Pseudexostoma yunnanense Irrawaddy River NC_021604 Tremeuchiloglanis anteanalis Yangtze River NC_028513 Tremeuchiloglanis hupingshanensis Yangtze River KU356571 Tremeuchiloglanis macrotrema Red River OM428185 Tremeuchiloglanis posteranalis Pearl River OM428179 Tremeuchiloglanis rhabdura Red River OM428184 Glyptothorax minimaculatus Irrawaddy River HQ322535 Glyptothorax zanaensis Nujiang-Salween River NC_029709 293 ZooKeys 1262: 289–301 (2025), DOI: 10.3897/zookeys.1262.172819 Zheng Gong et al.: Glaridoglanis verruciloba sp. nov. from Tibet Zhang et al. 1995 (Zayul River, Zayul County, China); Chu and Mo 1999 (partim, Zayul River, Zayul County, China). Type material. Holotype • IPBX F202504001, 147.8 mm SL; China, Xizang Autonomous Region, Zayul County, mountain stream flowing into Sangqu River, eastern branch of upper Zayul River; 28°35'39.31"N, 97°9'20.93"E; 1736 m a.s.l.; Zheng Gong and Yanchao Liu leg.; April 2025. Paratypes • IPBX F202504002, 1, 156.6 mm SL; data as for holotype • IPBX F202504003–F202504006, 4; 106.7–149.8 mm SL; China, Xizang Autonomous Region, Zayul County, mountain stream flowing into Gongrigabu River, western branch of upper Zayul River; 28°54'3.06"N, 96°39'54.58"E; 2016 m a.s.l.; Zheng Gong and Yanchao Liu leg.; April 2025. Diagnosis. Glaridoglanis verruciloba sp. nov. can be distinguished from its two congeneric species by the following combination of characters: enlarged lower lip bearing 4–7 verruciform lobes on the central-posterior margin; anus close to the anal-fin origin; ventral surface at the base of maxillary barbels densely covered with striae; 11 branched pectoral-fin rays; 5–6 branched analfin rays; head relatively short (HL 19.1–21.7% of SL); and mandibular barbels relatively short (inner mandibular barbel length 13.9–17.7% and outer mandibular barbel length 29.1–36.4% of HL). Description. Morphometric data as in Table 2. Head and body greatly depressed. Dorsal profile rising gently and evenly from orbital margin to dorsal-fin origin, then sloping gradually to caudal peduncle; ventral profile nearly flat to the anal-fin base, then slightly ascending to caudal peduncle. Body depth at dorsal-fin origin 11.2–13.4% of SL, at anus 8.4–11.8% of SL. Caudal-peduncle depth 6.9–9.7% of SL. Head moderate in size. Snout rounded and flattened, 49.6–53.9% of HL. Rostral cap with a shallow groove; groove margins papillate. Eye small, located dorsolaterally, subcutaneous. Nostrils paired, located closer to the snout tip than to eye, separated by the nasal barbels. Barbels in four pairs. Nasal barbels moderately long, extending beyond posterior orbital margin. Maxillary barbels slightly flattened, ventral surface at the base densely covered with striae, connected to the lower lip by a skin flap, free only at short distal end; tip pointed, almost reaching the base of first pectoral-fin ray. Inner mandibular barbels short and slightly flattened. Outer mandibular barbels lateral to inner pair, slightly flattened, not reaching the base of first pectoral-fin ray. Mouth inferior, gape width 31.5–36.5% of HL. Lips thick, fleshy, and papillate. Upper lip covered with tiny papillae; lower lip enlarged, with anastomosing rounded plaques, bearing 4–7 irregular verruciform lobes on the central-posterior margin. Postlabial groove interrupted. Mental region with a prominent median depression. Teeth embedded in skin, short, robust and chisel-shaped; similar in form on both jaws, but arranged in a single crescentic band on upper jaw and two well-separated triangular patches on lower jaw. Palate edentulous. Gill opening narrow, extending from the base of the first pectoral-fin ray to a position anterior and dorsal to the last pectoral-fin ray; posterior margin of the branchiostegal membrane forming a distinct boundary between cephalic and thoracic regions. Dorsal fin without spine, with i,5 (1) or i,6 (5*) rays. Adipose fin with long base; anterior extremity at approximately midway between bases of pelvic and anal fins; posterior extremity separate from upper procurrent caudal-fin rays without incision. Pectoral fin enlarged and ovoid when expanded, with i,11 (6) rays; 294 ZooKeys 1262: 289–301 (2025), DOI: 10.3897/zookeys.1262.172819 Zheng Gong et al.: Glaridoglanis verruciloba sp. nov. from Tibet margin slightly concave; the first unbranched ray flattened, ventral surface with closely-arranged striae. Pelvic fin enlarged and ovoid when expanded, with i,5 (6) rays; the first unbranched ray flattened, ventral surface with closely-arranged striae; tip not reaching anus when adpressed. Anal fin with i,5 (1) or i,6 (5*) rays; posterior margin slightly concave; tip reaching approximately midway between anal-fin origin and caudal-fin base. Caudal fin nearly truncate when depressed, with i,14,i (1) or i,15,i (5*) rays. Chest and abdomen densely covered with minute papillae. Anus and urogenital openings located near the anal-fin origin. Colouration. In life, dorsal and lateral surfaces yellow brown; ventral surface pale pink; ventral surface of the first rays of pectoral and pelvic fins faintly pink; all fins with yellowish distal margins. In 70% ethanol, head and dorsum pale gray, ventral region dark yellow; dorsal, anal, and caudal fins yellowish gray; dorsal surfaces of pectoral and pelvic fins yellowish gray, ventral surfaces dark yellow. Distribution and habitat. This species is presently known only from the Zayul River (= upper Lohit River) drainage, a tributary of the Brahmaputra River, Figure 2. Dorsal, lateral, and ventral views of Glaridoglanis verruciloba, holotype, IPBX F202504001, 147.8 mm SL. 295 ZooKeys 1262: 289–301 (2025), DOI: 10.3897/zookeys.1262.172819 Zheng Gong et al.: Glaridoglanis verruciloba sp. nov. from Tibet Table 2. Morphometric data for Glaridoglanis verruciloba sp. nov. and its closest congener, G. andersonii. N = sample size, SD = standard deviation. Glaridoglanis verruciloba sp. nov. (N = 6) G. andersonii (N = 6) Holotype Range Mean ± SD Range Mean ± SD Standard length (mm) 147.8 106.7–156.6 138.4±17.3 114.6–184.8 154.2±23.9 Percent of standard length Body depth at dorsal-fin origin 11.8 11.2–13.4 12.4±0.8 9.8–11.8 10.5±0.7 Body depth at anus 9.0 8.4–11.8 9.7±1.1 8.5–9.9 9.2±0.5 Head length 19.1 19.1–21.7 20.8±0.9 22.2–24.2 22.8±0.4 Head depth 9.7 9.6–10.3 10.0±0.2 7.2–8.5 7.9±0.4 Head width 18.1 17.4–21.1 18.9±1.2 19.2–20.6 19.9±0.5 Predorsal length 29.1 28.8–30.5 29.3±0.6 31.2–32.6 31.9±0.5 Prepectoral length 12.8 12.8–16.7 14.9±1.3 14.9–16.5 15.8±0.5 Prepelvic length 40.4 40.4–42.4 41.3±0.6 42.3–46.5 44.9±1.5 Preanal length 72.0 70.5–74.0 72.1±1.4 72.7–74.4 73.5±0.6 Preadipose length 64.6 62.4–68.1 64.6±1.8 67.1–71.3 69.7±1.5 Dorsal-fin length 12.7 11.3–14.8 13.0±1.1 13.3–16.1 14.0±1.1 Pectoral-fin length 20.8 19.8–23.1 21.3±1.3 19.4–21.6 20.4±0.8 Pelvic-fin length 19.5 17.2–19.8 18.8±1.2 16.3–18.7 17.2±0.8 Anal-fin length 15.4 13.4–15.4 14.3±0.7 14.2–16.8 15.5±0.9 Caudal-fin length 11.8 11.4–15.2 13.4±1.3 10.1–14.6 12.3±1.5 Dorsal-fin base length 6.8 6.3–8.0 7.2±0.6 6.5–7.6 7.2±0.4 Pectoral-fin base length 9.7 8.9–9.9 9.4±0.4 8.6–9.9 9.2±0.5 Pelvic-fin base length 6.6 6.1–7.1 6.5±0.3 5.4–6.1 5.8±0.3 Anal-fin base length 8.1 7.4–8.8 7.9±0.5 7.8–9.3 8.6±0.6 Adipose-fin base length 28.1 24.8–29.5 27.6±1.7 23.3–29.9 26.1±2.4 Dorsal-to-adipose distance 28.1 23.6–30.1 27.6±2.1 26.5–34.3 30.7±2.5 Pectoral–pelvic distance 17.2 15.9–19.5 17.2±1.2 20.0–23.9 21.8±1.5 Pelvic to anal distance 24.0 21.6–25.1 23.4±1.5 21.2–23.7 22.5±0.9 Vent-anal-fin origin distance 2.8 1.7–2.8 2.3±0.3 2.7–4.1 3.2±0.5 Caudal-peduncle length 19.0 16.1–20.9 18.8±1.4 16.4–19.6 17.9±1.1 Caudal-peduncle depth 7.0 6.9–9.7 7.6±0.9 7.4–8.7 7.8±0.5 Percent of head length Snout length 53.9 49.6–53.9 52.1±1.7 43.8–52.1 49.5±3.1 Mouth width 36.5 31.5–36.5 34.5±1.7 31.3–34.2 33.1±1.1 Interorbital distance 28.4 22.3–31.0 26.7±2.8 24.2–26.8 26.0±1.0 Eye diameter 5.3 4.8–7.3 6.0±0.8 4.5–6.0 5.3±0.6 Nasal barbel length 27.3 24.1–37.4 28.5±5.5 32.5–40.5 37.1±3.1 Maxillary barbel length 75.5 71.8–90.1 78.3±6.0 77.9–98.8 87.7±7.6 Inner mandibular barbel length 17.7 13.9–17.7 16.2±1.5 17.2–20.9 19.0±1.5 Outer mandibular barbel length 33.3 29.1–36.4 32.2±2.4 34.2–39.7 37.4±2.3 south-eastern Tibet, China. It occurs mainly in mountain streams and is less frequently found in the river mainstem (Fig. 3). At the type locality during sampling period, the water temperature was 4.1–7.5 °C, the dissolved oxygen was 9.46–12.58 mg/L, and the pH was 7.86–8.32. Sympatric fishes mainly included Creteuchiloglanis kamengensis (Jayaram, 1966) and Schizothorax molesworthi Tsao, 1964. Etymology. The specific epithet is derived from the Latin verruca (= wart) and lobus (= lobe), referring to the verruciform lobes on the central-posterior margin 296 ZooKeys 1262: 289–301 (2025), DOI: 10.3897/zookeys.1262.172819 Zheng Gong et al.: Glaridoglanis verruciloba sp. nov. from Tibet Figure 3. Type locality of Glaridoglanis verruciloba sp. nov.: a mountain stream flowing into the Sangqu River, the eastern branch of the upper Zayul River (upper left); paratype locality: a mountain stream flowing into the Gongrigabu River, the western branch of the upper Zayul River (right); the mainstem of Gongrigabu River (lower left); and a living specimen (approx. 140 mm SL) photographed in an aquarium. of lower lip. As Glaridoglanis is feminine (fide Kottelat 2013), the specific epithet is treated accordingly. The Chinese common name of this species is 疣叶凿齿鮡 (Yóu yè záo chǐ zhào), which literally means “wart-lobed chiseled-tooth catfish”. Molecular phylogenetic analysis. After alignment, 1138 bps of cyt b gene sequences were obtained from 28 species of the subfamily Glyptosterninae and two outgroup taxa for molecular phylogenetic analyses. Among these sites, 492 were variable and 463 were parsimony-informative. Within the genus Glaridoglanis, two haplotypes were detected from six individuals of G. verruciloba sp. nov., and a single haplotype was determined from six individuals of G. andersonii. Phylogenetic tree reconstructed based on the BI and ML methods yielded congruent topologies; therefore, only the ML tree was presented, with posterior probabilities from BI method and bootstrap values from ML method indicated at the nodes (Fig. 4). The resulting topology strongly supported the monophyly of Glaridoglanis, with each of its two species forming well-supported clade. Further, the genus Glaridoglanis, together with Parachiloglanis, was resolved as a relatively basal lineage within the glyptosternine catfishes, although this relationship was weakly supported. Pairwise genetic distance based on the K2P model demonstrated a 3.1% sequence divergence between the two Glaridoglanis species, while divergences between G. verruciloba and other glyptosternine catfishes were summarized in Suppl. material 1. 297 ZooKeys 1262: 289–301 (2025), DOI: 10.3897/zookeys.1262.172819 Zheng Gong et al.: Glaridoglanis verruciloba sp. nov. from Tibet Discussion Until now, only two valid species of Glaridoglanis have been formally recognized, both originally described from the Irrawaddy drainage (Ng and Kottelat 2022). Glaridoglanis andersonii was first recognized by Day (1870) based on the specimens collected from Hotham (= Husa Township, 24°28'09"N, 97°53'54"E) and Ponsee (= Bangxi, approximately 24°28'N, 97°42'E) in Yingjiang County of Yunnan Province, which is within to the upper Irrawaddy drainage (Ng and Kottelat 2022). In the original description of G. andersonii, which had been assigned to Exostoma, the diagnosis is rather brief and lacks several crucial morphological characters now regarded as diagnostic within Glaridoglanis. As a result, for a long time, specimens from adjacent river drainages, including the Zayul River, were referred to G. andersonii due to the absence of comprehensive comparative material across localities (see Chresonymy above). Our results clearly demonstrate that G. verruciloba can be distinguished from G. andersonii by the following morphological characters: presence of verruPseudexostoma yunnanense NC_021604 Pseudexostoma brachysoma KU987338 Oreoglanis immaculata NC_028511 Oreoglanis macroptera NC_021607 Creteuchiloglanis macropterus NC_028509 Creteuchiloglanis gongshanensis NC_028516 Creteuchiloglanis kamengensis NC_045213 Tremeuchiloglanis rhabdura OM428184 Tremeuchiloglanis posteranalis OM428179 Tremeuchiloglanis macrotrema OM428185 Tremeuchiloglanis anteanalis NC_028513 Tremeuchiloglanis hupingshanensis KU356571 Chimarrichthys kishinouyei AY207478 Chimarrichthys longus DQ192485 Exostoma gaoligongense NC_056351 Exostoma tibetanum NC_065342 Exostoma tenuicaudatum NC_065343 Glyptosternon maculatum NC_021597 Parachiloglanis drukyulensis MG001357 Parachiloglanis bhutanensis MG001359 Parachiloglanis benjii MG001360 Parachiloglanis dangmechhuensis MG001353 Parachiloglanis immaculata OQ437239 Glaridoglanis verruciloba sp. nov. PX508676 Glaridoglanis verruciloba sp. nov. PX508677 Glaridoglanis andersonii PX508675 Pseudecheneis immaculata MN082047 Pseudecheneis paviei NC_086847 Pseudecheneis sirenica NC_021605 Glyptothorax zanaensis NC_029709 Glyptothorax minimaculatus HQ322535 0.1 Outgroup taxa 1/100 1/100 0.66/40 1/100 1/99 0.78/57 0.99/83 0.50/64 1/100 1/91 1/100 1/100 1/100 0.99/84 1/99 0.84/61 0.80/43 0.99/100 1/100 1/100 1/100 1/97 1/100 0.60/42 0.84/68 1/100 1/89 1/100 1/100 Figure 4. Phylogenetic tree of 28 glyptosternine catfishes inferred from mitochondrial cytochrome b gene sequences. Numbers on nodes before and after slash (/) represent posterior probabilities of Bayesian inference method and bootstrap values of maximum-likelihood method, respectively.