Zoosyst. Evol. 100 (4) 2024, 1259-1267 | DOI 10.3897/zse.100.125866 > PENSUFT. eee BERLIN Description of a new species of the genus Oreonectes (Teleostei, Cypriniformes, Nemacheilidae) from Guangxi, China Jia-Hong Zhong', Jian Yang', Hao-Lin Mo!, Wei-Cai Chen? 1 Key Laboratory of Wildlife Evolution and Conservation in Mountain Ecosystem of Guangxi, Nanning Normal University, Nanning 530001, Guangxi, China 2 Key Laboratory of Environment Change and Resources Use in Beibu Gulf Ministry of Education, Nanning Normal University, Nanning 530001, Guangxi, China https://zoobank. org/29F 191C5-30BF-491B-8B59-5EC344BD2584 Corresponding authors: Jian Yang (yj1981yj@163.com); Wei-Cai Chen (chenweicai2003@126.com) Academic editor: Nicolas Hubert # Received 21 April 2024 # Accepted 15 August 2024 Published 10 September 2024 Abstract A new loach species, Oreonectes zhangi sp. nov., was identified from Xingye County, Yulin City, Guangxi, China. The species can be distinguished from all other congeners by a combination of the following characters: six branched pelvic-fin rays; a reduced posterior chamber of air-bladder; vertebrae 4 + 32; the tip of the male pelvic fin does not reach the anus. Molecular analyses using the Cyt b gene showed that the new species forms a monophyletic group and is closely related to O. damingshanensis. Key Words Morphology, new species, phylogeny, stream fish, taxonomy Introduction The genus Oreonectes Gunther, 1868, comprises a group of loaches predominantly distributed in southern China (Guangxi, Guangdong, and Hong Kong) and northern Vietnam (Zheng 1981; Zhu and Cao 1987; Zhu 1989; Lan et al. 1995; Kottelat 2001). The genus is charac- terized by several distinctive features, including closely spaced anterior and posterior nostrils, anterior nostrils with a barbel-like elongation that extends beyond the depth of the nostril tube, a flat head that is wider than it 1s tall, an incomplete lateral line, and a dorsal fin with six or seven branched rays (Du et al. 2023). Historically, the identification of species within the genus Oreonectes has been complicated by their morphological similarities, which have often led to misidentifications. For instance, Oreonectes platycephalus, the type species of the genus Oreonectes described by Gunther in 1868, was previ- ously considered to be widespread throughout the Pearl River Basin and Hong Kong. However, recent studies suggest that O. platycephalus may represent a complex of multiple cryptic species (Huang et al. 2020; Yu et al. 2023). Ito (2024) redescribed this species and proved the effectiveness of O. polystigmus and O. damingshanensis. Advances in molecular biology and phylogenetics have enabled the effective analysis of genetic materials and genetic differences between species, facilitating a clearer understanding of their evolutionary history and taxonomic status. Luo et al. (2023) recently employed multiple genes to elucidate the phylogeny of cave fish within the Nemacheilidae family, resulting in the de- scription of a new genus, Karstsinnectes. Currently, the genus Oreonectes comprises seven species: O. andon- gensis Luo, Yang, Du & Luo, 2024; O. damingshanen- sis Yu, Luo, Zhou, Deng & Zhou, 2023; O. guananensis Yang, Wei, Lan & Yang, 2011b; O. guilinensis Huang, Yang, Wu & Zhao, 2020; O. luochengensis Yang, Wu, Wei & Yang, 2011a; O. platycephalus Gunther, 1868; and O. polystigmus Du, Chen & Yang, 2008. In 2023, 15 specimens were collected from a mountain stream in Yulin City, Guangxi, China (Fig. 1). Analysis of these specimens, including both morphological Copyright Zhong, J.-H. et al. This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. 1260 110°E 112°E «0. platycephalus Bi O. polystigmus AO. guananensis 4 O. luochengensis @ O. guilinensis 0. damingshanensis @ O. andongensis @ O. zhangi sp. nov. Figure 1. Distributions of Oreonectes species. examination and molecular data from the cytochrome b gene (Cyt 5), revealed significant variations compared to their congeners. Based on these findings, the speci- mens were identified as a new species within the genus Oreonectes, which is described herein. Materials and methods Morphological comparisons In this study, 15 newly collected Oreonectes specimens were examined. All measurements and counts follow Kottelat (1990). The specimens were measured point-to- point with a caliper, accurate to 0.1 mm. All measure- ments were taken on the left side of the specimens. The last two rays of the dorsal and anal fins were counted as one ray, each pair associated with a single pterygiophore. The internal anatomy of the specimens followed the method of Liu and Zheng (2010). Vertebral counts, including the Weberian apparatus and the last half-centrum, were examined by X-ray im- ages. The caudal skeleton of the new species was stud- ied based on X-ray images, cutting epidermis, and mus- cle removal. Osteological terminology followed that of Sawada (1982). Morphological data were analyzed using Microsoft Excel, and statistical analyses were carried out using SPSS v22.0 (SPSS, Inc., Chicago, IL, USA). Principal component analysis (PCA) was utilized to explore mor- phometric differences between the new species and the similar species. Before analysis, the raw morphometric data were normalized by a logarithmic transformation to minimize the impact of allometry. Abbreviations used in the study include: SL, standard length; TL, total length; HL, lateral head length; and NNNU, Nanning Normal University. zse.pensoft.net Zhong, J.-H. et al.: Description a new species of the genus Oreonectes 114°E 116°E ZS 118°E DNA extraction, polymerase chain reaction (PCR), and sequencing Genomic DNA was extracted from alcohol-preserved pectoral fin tips using a DNA extraction kit from Genen- ode Biotech (Hubei) Co. Ltd. (China). The mitochon- drial Cyt b gene was sequenced from three individuals. The forward and reverse primers used were F14724 (5’°-GACTTGAAAAACCACCGTTG-3’) and R15915 (5’°-CTCCGATCTCCGGATTACAAGAC-3’), —_ respec- tively (Xiao et al. 2001). PCR amplifications were carried out in a 25 wL reaction volume with the following cycling conditions: an initial denaturing step at 95 °C for 5 min, 35 cycles of denaturing at 95 °C for 40 s, annealing at 45 °C for 40 s, and extending at 72 °C for 1 min, followed by a final extension at 72 °C for 10 min. The fragments were sequenced using an ABI Prism 3730 automated DNA sequencer (Applied Biosystems, USA), and the newly obtained sequences were submitted to GenBank. Phylogenetic analyses A total of 35 Cyt 6 sequences were used for phylogenetic analysis. In addition to the three new sequences and one O. damingshanensis sequence, all the other sequences were obtained from GenBank. Botia udomritthiruji Ng 2007 and Botia lohachata Chaudhuri 1912 were chosen as outgroups for phylogenetic tree construction. The Cyt b sequences were aligned in MEGA v7.0 (Kumar et al. 2016) using the MUSCLE (Edgar 2004) algorithm with default parameters. Both maximum likelihood (ML) and Bayesian inference (BI) methods were used to reconstruct the phylogenetic re- lationship. ML analysis was run in IQ-TREE 1.6.8 (Nguyen et al. 2015), with the selected F81+F+I+G4 model and 1,000 non-parametric bootstrap replicates. BI was constructed in PhyloSuite v1.2.3. (Xiang et al. 2023), with two independent Zoosyst. Evol. 100 (4) 2024, 1259-1267 runs of 2 x 10’ generations and sampling every 1 000 gen- erations. The initial 25% of samples were discarded as burn- in, resulting in a potential scale reduction factor of < 0.01. The best-fit model for BI analyses was determined using the Bayesian information criterion (BIC) in PartitionFinder v2.1.1. (Lanfear et al. 2017), resulting in the selection of the K80 + I + G model. Tree nodes were considered strongly supported with Bayesian posterior probabilities (BPP) > 0.95 and Maximum Likelihood ultrafast bootstrap support (UFB) > 95%. Uncorrected p-distances (1 000 replicates) based on the Cyt 5 gene were calculated in MEGA v7.0. Results Morphometric analysis Based on the results of PCA, two principal components of the morphological characters of Oreonectes zhangi sp. nov. and O. damingshanensis were extracted (Table 1). The first principal component (PC1), which accounted for 67.6% of the variance, was influenced by total length, standard length, prepelvic length, preanus length, lateral head length, and predorsal length; the second principal component (PC2), which accounted for 11.4% of the vari- ance, was influenced by body width at dorsal-fin origin, head depth at nape, and body depth at dorsal-fin origin. The principal component scatter plot of 30 measurements of O. damingshanensis and O. zhangi sp. nov. constructed showed that the phenotypic traits of O. damingshanensis and O. zhangi sp. nov. formed a cluster with fewer overlapping areas (Fig. 2). The samples of the same group are relative- ly close in the figure, while the samples of different groups are far apart, indicating that the morphological indexes of the same group are similar, while the morphological index- es of different groups have distinct differences. Thus, Ore- onectes zhangi sp. nov. could be clearly distinguished from O. damingshanensis based on morphological characters. 4 * 0. damingshanensis O. zhangi sp. nov. PC2 (9.5%) -2 1261 Table 1. Results and percentage of variance explained by prin- cipal component analysis. Morphometric characters PC1 PC2 Total length 0.22 -0.09 Standard length 0.22 -0.07 Body depth at dorsalfin origin 0.16 0.31 Body width at dorsalfin origin 0.12 0.39 Lateral head length 0.21 -0.05 Predorsal length 0.21 0.13 Dorsal fin length 0.19 0.22 Dorsal fin base length 0.15 -0.19 Prepelvic length 0.22 -0.08 Pelvic fin length 0.20 -0.01 Pelvic fin base length 0.13 0.29 Preanus length 0.22 -0.05 Preanal length 0.19 -0.20 Anal fin length 0.19 -0.20 Anal fin base length 0.16 -0.14 Prepectoral length 0.19 -0.14 Pectoral fin length 0.20 0.12 Pectoral fin base length 0.14 0.29 Caudal peduncle length 0.18 -0.18 Caudal peduncle depth 0.18 0.23 Head depth at nape 0.17 0.32 Maximum head width 0.20 0.09 Snout length 0.19 0.04 Outer rostral barber length Osty. 0.13 Maxillary barber length 0.17 0.04 Inner barber length 0.16 -0.05 Eye diameter 0.08 0.25 Interorbital width 0.14 0.03 Distance between anterior nostrils 0.19 0.18 Distance between posterior nostril 0.19 0.15 Eigenvalue 20.29 3.42 Contribution ratio (%) 67.6 11.4 Cumulative contribution ratio (%) 67.6 79 Phylogenetic analyses and genetic divergence BI and ML methods resulted in similar phylogenetic to- pologies based on the Cyt b sequence, consistent with Du et al. (2023). In addition to the outgroups, seven known genera were included in the phylogenetic trees. PCI (66.3%) Figure 2. PCA plots of Oreonectes zhangi sp. nov. and similar species O. damingshanensis based on morphological characters. zse.pensoft.net 1262 The newly collected specimens formed a distinct and well-supported clade with O. damingshanensis (BPP = 1; UFB = 95%) (Fig. 3). Uncorrected p-distances be- tween the new specimens and other species in Oreonectes ranged from 4.6% (for O. damingshanensis) to 9.2% (for O. guananensis) (Table 2). Table 2. Uncorrected p-distances (%) between six species of Oreonectes based on the mitochondrial Cyt b gene. ID Species 1 Oreonectes zhangi sp. nov. 2 0. andongensis 7.0% 3 O.damingshanensis 4.6% 6.5% 4 0. luochengensis 7.5% 6.5% 8.0% 5 0. guilinensis 74% 7.0% 7.6% 8.2% 6 O. guananensis 9.2% 7.6% 8.9% 5.0% 8.8% 7 O. platycephalus 7.2% 6.7% 7.1% 8.1% 6.7% 8.8% 8 0. polystigmus 6.5% 6.0% 6.3% 7.6% 7.5% 8.6% 6.5% Taxonomic account Oreonectes zhangi Zhong, Yang & Chen, sp. nov. https://zoobank. org/73962B24-DB58-4 1 FF-8DBE-0332CAD9635C Figs 4-10, Tables 3, 4 Materials. Holotype. * NNNU2023100203 (Fig. 4); 71.1 mm TL, 63.1 mm SL; collected by Jia-Hong Zhong on 2 October 2023; in Mt. Hanshan, Xinye County, Yulin City, Guangxi, China; (22.7364°N, 110.0605°E; elevation 199 m; Fig. 1). Paratypes. + 14 specimens; NNU2023100201- 202, 2023 100204—215; were collected by Jia-Hong Zhong from the same locality and at the same time as the holotype. 0.98/97 0.96/38 1/99 1/83 1/94 V8 L100 0.51/83 1/99 1/100 ATA 1/100 aR /oo 1/100) Batia ndomritthirafi NCO3 1601 Botia lohackata NCOZ7A9S 0.72/69 1/100 Traccatichthys puicher NCO73140 Traccatichthys zispi NCOT3141 Zhong, J.-H. et al.: Description a new species of the genus Oreonectes Etymology. The species was named in honor of the three Zhang brothers, who assisted local residents in lo- cating water during an ancient drought. Following their passing, they were revered as rain deities by the commu- nity (Li 2014). We suggest the common Chinese name “Te PGI HH” (Zhang Shi Ling Qiu). Comments. Oreonectes zhangi sp. nov. is classified within the genus Oreonectes based on molecular phy- logenetic analyses and genus-specific characteristics, including narrowly separated anterior and posterior nos- trils, elongated barbel-like anterior nostrils longer than the depth of the nostril tube (Fig. 5), having an epural in the caudal skeleton (Fig. 7), and a rounded caudal fin with 7 branched dorsal-fin rays. (Du et al. 2023; Ito 2024) Diagnosis. Comparative data between Oreonectes zhangi sp. nov. and all seven known species within the genus Oreonectes are provided in Table 3. Oreonectes zhangi sp. nov. can be distinguished from O. guilinen- sis, O. luochengensis, O. guananensis, O. andongensis, and O. polystimus by the reduced posterior chamber of air-bladder (vs. developed), from O. platycephalus by six branched plevic-fin rays (vs. 7), seven branched dorsal-fin rays (vs. 6), from O. damingshanensis by six branched pelvic-fin rays (vs. 7), the tip of the male pelvic fin not reaching the anus (vs. exceeding) (Fig. 8), vertebrae 4 + 32 (vs. 4 + 34), head depth at nape (59.6—68.1% HL vs. 46.7-54.6%), body depth at dorsal-fin origin (14.0- 16.1% SL vs. 11.1-13.3%). Description. Morphometric data are given in Tables 3, 4. Body elongated and cylindrical, with insignificant depth decreasing from dorsal-fin origin to caudal-fin base. Head short, head length 18.6—20.2% of standard length, slight- ly depressed and flattened, width greater than depth (head 0.78/07 pr fregloneerfes denglanensis NCOTI132 Troglonectes duanensis NCO73135 1/100 Troglonectes iransincens NCO?3136 Troglenectes fiarangensix NCOT3145 Trogtonectes dagikongensis NCO73146 froglanectes retradarsalis NCOT3137 Troglonectes shndongernsis WCO73144 Parancmachitus changzuo NCUS8284 Paranemachilus chenghaoshani NCO73147 TA Paranemachilus pingeuoensis NCO64S527 Troglonectes 0.89/§ Paranemachilus 1/79 Paranemachilus jinxiensis NCO393 8 Paranemachilus genilepis ON116497 1/983 lunnanilus plenrotaenia NCOG3 105 g Fannanilas analis NCO64370 Yennanilus jiuchiensis NCUS82Z82 Yrananiius nicer NC063106 1/90, Greorectes zhangi sp. noy. PPS90242 Oreanectes zhangi sp. nov. PP6O1247 1/98} W100 L Oreonectes zhangi sp. nov. PP601248 1/99, Oreonectes damingshanensis PPO46058 Oreanectes damingshanensis OO754116 Oreconecies polystigmus NCOGSISO Oreenectes guiltnensis MN239094 Oreonectes platycephatus ON116328 OGreonectes anfongensis OR188128 Oreonecies laochengensis NCOT3128 Oreconectes guananensis NCO7T3134 Gainemachilus bailiarensis NCOG1O31 Guinemachilus fongibarbatus NCOGB149 Micronemacheilus cractatns 6WC033960 Micronemacheitus puicherrimas NCOOTAL Furnnanilus 0.79/73 Los Oreonectes 1/96 L100 Guinemachilus | Micronemecheilus Traccatichthys Tree scale: 0.1 —————— Figure 3. The phylogenetic tree of Oreonectes based on the Cyt b gene was constructed by Bayesian inference (BI) and maximum likelihood (ML). Node values showed posterior probabilities/bootstrap supports. zse.pensoft.net Zoosyst. Evol. 100 (4) 2024, 1259-1267 1263 Figure 4. Dorsal, lateral, ventral, and living views of Oreonectes zhangi sp. nov. NNNU2023100203, holotype, 71.1 mm TL, 63.1 mm SL. width/head depth = 1.1—1.5), head depth 59.6—68.1% of head length. Snout round, oblique, and flat, length 38.2—48 8% of head length (HL). Mouth inferior, curved, upper, and lower lips have shallow wrinkles and small spinous processes; lower lip with V-shaped median notch (Fig. 6). Three pairs of barbels, long: inner rostral bar- bel 35.4-44.1% of HL, extending backward, not reaching anterior margin of eye; outer rostral barbel 49.0-67.6% of HL, extending backward beyond posterior margin of eye. Maxillary barbel 38.4—52.2% of HL, tip not reaching posterior margin of gill cover. Anterior and posterior nos- trils are separated by a short distance, 16.8%-36.8% of eye diameter. Anterior nostril tube short, with elongated, short barbel-like tip. Eyes normal, diameter 11.9-17.1% of HL. Gill opening small; gill rakers not developed; nine inner gill rakers on first gill arch (n = 2). Dorsal-fin rays 111, 7, pectoral-fin rays 1, 8-9, pelvic-fin rays 1, 6, anal-fin rays 11, 5, branched caudal fin rays 15-16. Dorsal fin short, length 16.7%—21.1% of SL, dis- tal margin round, origin posterior to pelvic-fin insertion, situated slightly posterior to two-thirds distance between snout tip and caudal-fin base. Pectoral fin short, length 15.9%-18.9% of SL. Pelvic fin length 16.1-17.7% of SL; tips of pelvic fin not reaching anus; distance between tips zse.pensoft.net 1264 Zhong, J.-H. et al.: Description a new species of the genus Oreonectes Figure 5. Oreonectes zhangi sp. nov., dorsal view of head., NNNU2023100203, holotype, 63.1 mm SL. of pelvic fin and anus 0.7 times eye diameter. Anal fin short, length 15.1%-19.5%, origin short distance from anus. Caudal fin rounded, length 13.3%-19.9% of SL, length greater than depth (caudal peduncle length/caudal peduncle depth = 1.1—1.7). vertebrae 4 + 32 (n = 4), hav- ing an epural in the caudal skeleton (Fig. 7). Body completely covered by scales, except head; lat- eral line incomplete, with 7-13 pores, last one not reach- ing above tip of pectoral fin; cephalic lateral-line system, with 8 supraorbital pores, 4+9—10 infraorbital pores, three supratemporal canal pores, and 5—8 preoperculo-mandib- ular canal pores. U-shaped stomach with straight intestines (Fig. 9). Anterior chamber covered by dumbbell-shaped bony cap- sule, and posterior chamber reduced, reaching the vertical of the pectoral-fin base (Fig. 10). Coloration. The body is mainly light yellowish brown in color, with dark brown extending from the front of the eyes to the outer rostral barbel. The base of the caudal fin is black, with each fin showing a light yellow hue. When preserved in 10% formalin, the body color fades to a dark brown shade (Fig. 4B). Sexual dimorphism. Males have an oval genital papil- la located immediately posterior to the anus (Fig. 8B), which is unclear in females (Fig. 4C). Figure 6. Oreonectes zhangi sp. nov., NNNU2023100203, holotype, 71.1 mm TL, 63.1 mm SL. The ventral view of the mouth (A) and close-ups of the upper (B) and lower (C) lips are shown; the black arrow indicates the position of the small spinous processes. Figure 7. The caudal fin skeleton of Oreonectes zhangi sp. nov., NNNU2023100202, paratype, 64.2 mm SL, pcl, first preural centrum; pc2, second preural centrum; h, hypural; hs, haemal spine and arch; ph, parhypural; pls, pleurostylar. Table 3. Oreonectes species and comparison of identifying characteristics between the new species and its congeners. Body Dorsal-fin rays Pectoral-fin pigmentation rays Oreonectes zhangi sp. nov. Present il, 7 i, 8-9 O. damingshanensis Present iil, 7 i, 9 O. platycephalus Present iii, 6 i, 9-11 O. guilinensis Present ii, 7 i, 10-11 O. luochengensis Absent iil, 7 i, 11-12 O. guananensis Present iil, 7 i, 10-11 O. andongensis Present lil, 7 i, 9-10 O. polystigmus Present iil, 6-7 i, 9 zse.pensoft.net Pelvic-fin rays Anal-fin rays Caudal-fin rays Posterior chamber of air-bladder i, 6 iii, 5 15-16 Reduced i, 7 iii, 5 14-15 Reduced i, 7 iii, 5 13-15 Reduced i, 6 il, 5 13-14 Developed i, 7 ii, D 14-16 Developed i, 7-8 il, 5 13-17 Developed i, 6 il, 5 13-14 Developed i, 6 il, D 14-15 Developed Zoosyst. Evol. 100 (4) 2024, 1259-1267 Figure 8. Gonadal structure of O. damingshanensis (A), NNNU2024052007, 56 mm SL, and O. zhangi sp. nov. (B), NNNU2023100215, paratype, 43.2 mm SL; the black arrow re- fers to the position of the anus. Figure 9. Oreonectes zhangi sp. nov., NNNU2023100202, paratype, 64.18 mm SL; digestive tract. Distribution, habitat, and populations. Based on field investigations, the species is abundant and com- monly found in the streams of Mt. Hanshan in Xingye County, Yulin City, and Guangxi, China (Fig. 11). During the day, the species typically seeks shelter in stone crev- ices and substrates, emerging at night to feed. Exposure to intense light can cause their body color to change from light yellow to dark brown or black. Their diet consists of sediment and tadpoles, including those of Quasipaa spi- nosa. Interestingly, many pregnant females were collect- ed, even in December. The stream habitats also harbored other species, such as Schistura fasciolatus, Liniparhom- aloptera disparis, and Rhinogobius similis. 1265 Figure 10. Air-bladder of Oreonectes zhangi sp. nov.: a, anteri- or chamber; b, tube connecting anterior and posterior chambers of the air-bladder; c, posterior chamber. Discussion Morphological distinctions between Oreonectes zhangi sp. nov. and O. damingshanensis included variations in head depth, body depth, number of branched fins, and the shape of genital papillae. Molecular analyses re- vealed that Oreonectes zhangi sp. nov. formed a distinct lineage with O. damingshanensis, with an uncorrected p-distance of 4.6%. All morphological characters and molecular evidence supported the validity of the new species. Oreonectes zhangi sp. nov. is the fourth benthic fish to be identified in surface water systems, similar to O. damingshanensis, O. platycephalus, and O. guilinen- sis. These fish, inhabiting surface rivers and mountain streams, exhibit sleeker bodies, longer fins and fin bases, and narrower, flatter heads with shorter barbels compared to those species living in underground cave water systems (Yu et al. 2023). Furthermore, except for O. guilinensis, the mountain stream-residing species typically possess a reduced air-bladder posterior chamber (Fig. 10, Table 3). Given the shallow water depths usually found in moun- tain streams, these fish seldom require vertical move- ment, instead favoring lateral shifts from one location to another (Zhu 1989). Phylogenetic analysis suggested that the Oreonectes group could be divided into two sister groups, with O. /u- ochengensis and O. guananensis forming one group and Oreonectes zhangi sp. nov., O. polystigmus, O. daming- shanensis, O. guilinensis, O. andongensis, and O. platy- cephalus forming the other. Comparative material examined Oreonectes damingshanensis, NNNU2024052001-10, 10 ex, 69.8-85.9 mm, Leping Village, Guling Town, Mashan County, Guangxi, China. Oreonectes guilinensis, ASIZB208001, holotype, 73.5 mm SL, ASIZB208002-—007, paratypes, 6 ex., 52.0- 68.3 mm, Shigumen Village, Xingping Town, Yangshuo County, Guilin City, Guangx1. zse.pensoft.net 1266 Table 4. Comparison of measurable traits between Oreonectes zhangi sp. nov. and similar species, O. damingshanensis. The numbers in parentheses are the mean + standard deviation (SD). Number of specimens TL (mm) SL (mm) Percentage of SL (%) Body depth at dorsalfin origin Body width at dorsalfin origin Lateral head length Predorsal length Dorsal fin length Dorsal fin base length Prepelvic length Pelvic fin length Pelvic fin base length Preanus length Preanal length Anal fin length Anal fin base length Prepectoral length Pectoral fin length Pectoral fin base length Caudal peduncle length Caudal peduncle depth Percentage of HL (%) Head depth at nape Maximum head width Snout length Outer rostral barber length Maxillary barber length Inner barber length Eye diameter Interorbital width Distance between anterior nostrils Distance between posterior nostril Oreonectes zhangi O. damingshanensis sp. nov. 15 10 59.8-81.8 (71.0 + 8.3) 69.8-85.7 (78.9 + 4.5) 49.8-67.6 (58.8 + 7.1) 56-70.6 (65.4 + 4.6) 14.0-16.1 (14.7 + 0.7) 11.1-13.3 (12.2 + 0.7) Goal Ot See LT cer On Ao aleeoO } 18,6-20:2-019;3:'0. 71835-22019: 711) 56.2-59.4 (58.0 + 1.2) 56.8-60.5 (58.3 +1.1) lo7=2) Ls = TAs 16.9=207:(18,9-+41..3) Fie GINOF = 0:8) ~ B,25)1.249;5.27 1.0) 48.1-50.8 (49.1 + 1.0) 48.7-52.6 (50.7 + 1.1) 16.1-17.7 (16.7 + 0.7) 14.4-18.3 (15.8 + 1.2) 3.9-4.9 (4.3 + 0.3) 2.8-4.4 (3.5 + 0.5) 67.4-72.1 (69.3 + 1.5) 67.0-70.8 (69.2 + 1.0) 67.7-78.7 (73.8 + 0.4) 73.8-78.3 (76.0 + 1.8) 15.1-19.5 (16.7 + 1.5) 14.8-20.9 (17.4 + 1.6) 6.6-9.0 (7.4 + 0.8) 69-9, 5 (7.5:+ 018) V6.3421 21197 Lil) VG=2 77421-6426) LOH TSO (7 Si 0.9) 1S 6s Or ile 4.4-5.3 (4.8 + 0.3) 3.3-4.6 (3.9 + 0.4) 133-19 O16 To 43-18: S650) TUS=12.9(1 1:9 +.0:3) 92-108 (10.4 £10.38) 59.6-68.1 (63.2 + 2.9) 46.7-54.6 (51.2 + 2.6) 70.4-89.3 (82.2 + 5.3) 71.9-83.2 (76.3 + 3.7) 38.2-48.8 (41.8 + 3.1) 37.0-44.7 (39.5 + 2.6) 49.0-67.6 (57.9 + 5.2) 50.0-68.2 (56.3 + 5.6) 38.4-52.2 (46.3 + 4.7) 37.1-46.4 (41.9 + 3.6) 35.4-44.1 (38.8 + 2.8) 37.1-46.4 (41.9 + 3.1) 11.9-17.1 (14.6 + 1.8) 10.2-17.7 (14.5 + 2.4) 29.2-52.5 (44.2 + 6.7) 39.9-47.5 (43.5 + 2.2) 25.4-34.4 (31.9 + 2.8) 25.5-30.6 (28.6 + 1.8) 29.6-41.9 (37.2 + 3.8) 30.5-34.6 (33.3 + 1.4) Figure 11. Habitat of Oreonectes zhangi sp. nov. Oreonectes guananensis, K1Z2010003068—072, para- types, 5 ex., 51.0—-71.9 mm SL, Guan’an Village, Chang- mei Town, Huanjiang County, Guangx1. zse.pensoft.net Zhong, J.-H. et al.: Description a new species of the genus Oreonectes Oreonectes luochengensis, K1Z2010003073, holo- type, 71.2 mm SL, NNNU2023080201-2, 2ex, 56.6—70.1 mm, Tianhe Town, Luocheng County, Guangxi, China. Oreonectes polystigmus, NNNU2024042201-02, 2ex, 47.1-69.8mm, Dabu Village, Guilin City, Guangxi, China. Acknowledgments This research was supported by the Project of Finan- cial Funds of the Ministry of Agriculture and Rural Af- fairs: Investigation of Fishery Resources and Habitat in the Pearl River Basin and the National Natural Science Foundation of China (Grant No. 32360128). We sincerely thank Dr. Lina Du of Guangxi Normal University and Dr. Chaofang Zhong of Nanning Normal University for their help in this study. 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