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Diseases caused by Vibrio harveyi in shrimps have gradually become one group of the most serious threats to shrimp production, while related molecular mechanisms of infections with Vibrio harveyi are still not known well in shrimps. Here, we performed proteomic sequencing of hepatopancreas in whiteleg shrimps (Litopenaeus vannamei) infected with exogenous Vibrio harveyi, and subsequent functional annotation and calculation of differentially expressed proteins (DEPs) in this study. A total of 145 DEPs were obtained, among them 36 were up-regulated and 109 were down-regulated after the infection. Meanwhile, our results showed that after the infection of Vibrio harveyi, expression levels of a variety of C-type lectins (CTLs) were changed significantly. In-depth functional domain analysis and spatial structure prediction of these CTLs revealed that amino acid sequences and spatial structures of the C-type lectin domain (CTLD) shared by the CTL-S and IML proteins were variant, suggesting differential functions between the two CTLs. In summary, various members of the CTL family have different epidemic responses to Vibrio harveyi infection, which provides a theoretical guidance for deep-going investigations on practical immunity reactions and pathogen infections in shrimps.

The genus Schizothorax is one of the most diverse groups of schizothoracine fish. Many species within this genus possess highly similar morphological characters and are very difficult to be identified accurately only based on morphology. The present study aims to test the effectiveness of mitochondrial cytochrome c oxidase subunit I (COI) gene and cytochrome b (Cytb) gene for discriminating the Schizothorax fish. A total of 185 individuals of 11 species for COI gene and 264 individuals of 23 species for Cytb gene were used for analyzing, respectively. According to the genetic distances, only one species based on COI gene and five species based on Cytb gene had "barcoding gaps," respectively. The tree-based analysis displayed that four species based on COI gene and six species based on Cytb gene clustered monophyletic group with strong support, respectively. The optimal threshold value of Schizothorax is 0.005 based on COI gene and 0.008 based on Cytb gene. The results of genetic similarity tests performed through online BLAST showed that 108 of 185 similarity searches succeeded in identifying conspecific sequences based on COI gene and 199 of 264 succeeded in identifying conspecific sequences based on Cytb gene. Considering greater interspecific genetic distance in Kimura 2-parameter (K2P) analysis and many clades with higher supporting values in tree-based analysis, we suggest that Cytb gene has better resolution in discrimination of Schizothorax species than COI gene. However, there are still many confused clustering relationships based on molecular data currently available. Incomplete lineage sorting, the existence of possible cryptic species and problematic morphological identification, etc. might have greatly weakened the resolution of Cytb gene in discrimination of Schizothorax species.

The family Bagridae is a collection of species widely distributed in Africa and Asia with a high diversity of morphology. The species identification and phylogenetic relationship in this family have been confused and controversial. In order to explore the effectiveness of DNA barcoding in species identification of Bagridae, sequences of mitochondrial cytochrome c oxidase I (COI) gene of 20 species in four genera of Bagridae were used to analyse barcoding gap and to reconstruct phylogenetic relationship. Both the barcoding gap and the phylogenetic tree analysis showed that the COI gene-based DNA barcoding is an effective molecular technique for most species recognition of Chinese Bagridae. However, the rapid speciation and incomplete lineage sorting may affect the accuracy of DNA barcoding in species identification in certain species, and adding additional genes, such as nuclear gene, may help to achieve accurate identification of these species. The phylogenetic tree showed that the monophyly of genera Pelteobagrus, Leiocassis and Pseudobagrus did not exist, which supports that the species of genera Pelteobagrus, Pseudobagrus and Leiocassis distributed in China should be revised into one genus.

Swimming performance (aerobic and anaerobic) is often used to predict the ability of fish to adapt and survive. Fish raised in captivity are typically poor swimmers and have lower survival rates than wild conspecifics when released into the natural environment. We investigated the potential for exercise training to enhance the swimming performance of Schizothorax wangchiachii held in captivity. Juvenile fish (mean body mass 1.40 ± 0.13 g, mean body length 4.36 ± 0.24 cm) were trained under five different regimes [3 cm·s-1 control group (C), 10 cm·s-1 for 6 (L6) and 12 h (L12) per day and 20 cm·s-1 for 6 (H6) and 12 h (H12) per day] for 30 days and then detrained for 20 days (i.e. no training). Aerobic (i.e. critical swimming speed, Ucrit), anaerobic swimming performance (i.e. endurance time at 1.2 or 1.5 Ucrit), and morphological parameters were measured at the beginning (T0), after 30 days of exercise training (T30) and after 20 days of detraining (DT20). Aerobic exercise training significantly improved the Ucrit, endurance time at 1.2 and 1.5 Ucrit of juvenile S. wangchiachii (P < .05). After 20 days of detraining, both the aerobic and anaerobic swimming performance of the H6 and H12 groups declined and no longer differed from the control group indicating a failure to maintain improved swimming performance, whereas improved swimming performance was maintained in L6 and L12 groups. No significant difference in swimming performance was found between 6 and 12 hours training at 10 cm·s-1. Thus, exercise at close to 10 cm·s-1 for 6 h per day for 30 days or a longer time periods prior to release appears to be a suitable regime for swimming performance enhancement, potentially increasing survivability of released S. wangchiachii in wild.

The tectonic events and Quaternary climatic oscillations in the Shaluli Mountains (the margin of the southeastern Tibetan Plateau) had an extensive effect on the genetic structure and distribution patterns of this region's terrestrial fauna and flora. It is not yet clear whether similar mechanisms influence this region's fish fauna. Schizopygopsis malacanthus is limited to high-elevation rivers and lakes, and exhibits distinct adaptations to the mountains of, and near to, the Qinghai-Tibet Plateau (QTP). Therefore, this species is a good candidate for investigating patterns of genetic variation resulting from palaeoenvironmental fluctuations in the Shaluli Mountains (China). Here, we used microsatellite and mitochondrial DNA control region sequences to analyze six populations of S. malacanthus collected from the Jinsha and Yalong River drainages. Genealogical analyses identified four maternal lineages and perhaps even four putative species, of which the Ouqu River lineage played a pivotal role during the course of the species' evolution. Two lineages from the Yalong River drainage did not cluster together, whereas those from different drainages grouped together, suggesting tectonic event impacts that possibly altered regional river drainages have been highly influential in population connectivity and gene flow. Population genetic analysis indicated that the geographic barriers and this species preference for higher elevations both played key roles in the divergence of S. malacanthus populations. Demographic tests suggested large-scale spatial synchrony in population fluctuations of S. malacanthus, accompanying dramatic Pleistocene climatic oscillations. It appears that palaeoenvironmental changes in the Shaluli Mountains influenced the distribution and evolution of studied S. malacanthus populations, which provide important information about the factors that influenced the phylogeographic history of this region's fish fauna. Additionally, our study also has implications for ongoing conservation of this vulnerable fish.

Raptors are carnivorous birds including accipitrids (Accipitridae, Accipitriformes) and owls (Strigiformes), which are diurnal and nocturnal, respectively. To examine the evolutionary basis of adaptations to different light cycles and hunting behavior between accipitrids and owls, we de novo assembled besra (Accipiter virgatus, Accipitridae, Accipitriformes) and oriental scops owl (Otus sunia, Strigidae, Strigiformes) draft genomes. Comparative genomics demonstrated four PSGs (positively selected genes) (XRCC5, PRIMPOL, MDM2, and SIRT1) related to the response to ultraviolet (UV) radiation in accipitrids, and one PSG (ALCAM) associated with retina development in owls, which was consistent with their respective diurnal/nocturnal predatory lifestyles. We identified five accipitrid-specific and two owl-specific missense mutations and most of which were predicted to affect the protein function by PolyPhen-2. Genome comparison showed the diversification of raptor olfactory receptor repertoires, which may reflect an important role of olfaction in their predatory lifestyle. Comparison of TAS2R gene (i.e. linked to tasting bitterness) number in birds with different dietary lifestyles suggested that dietary toxins were a major selective force shaping the diversity of TAS2R repertoires. Fewer TAS2R genes in raptors reflected their carnivorous diet, since animal tissues are less likely to contain toxins than plant material. Our data and findings provide valuable genomic resources for studying the genetic mechanisms of raptors’ environmental adaptation, particularly olfaction, nocturnality and response to UV radiation.

Species of the genus Gynandropaa within the family Dicroglossidae are typical spiny frogs whose taxonomic status has long been in doubt. We used integrative methods, involving morphological and molecular analyses, to elucidate the phylogenetic relationships, and to determine identities and the geographic distribution of each valid species. We obtained DNA sequence data of 5 species of Gynandropaa (complete sequences of the mitochondrial NADH dehydrogenase subunit 2 [ND2] gene, and 890 bp of 12S rRNA and 16S rRNA partial sequences) from 37 localities (including the topotypes of 5 described species) and constructed Bayesian and maximum-likelihood trees to examine the patterns of phylogeography. A total of 28 morphological variables were taken on 624 specimens. Three clades with clear geographic patterns were recognized: clade C (from south-western Sichuan Province and central Yunnan Province), clade E (western Guizhou Province and eastern to central Yunnan Province) and clade W (western to southern Yunnan Province). Integrating morphological characteristics and distribution information, the clades W, E and C represent Gynandropaa yunnanensis, G. phrynoides and G. sichuanensis, respectively. We draw the following conclusions: (i) the taxon G. phrynoides, formerly evaluated as a junior synonym of G. yunnanensis, is revalidated herein at the rank of species; (ii) G. liui is a junior synonym of G. sichuanensis; and (iii) G. yunnanensis is a valid species while G. bourreti is probably a subspecies of G. yunnanensis, with the distribution range from Vietnam to southern Yunnan Province. This study clears up the taxonomic status of Gynandropaa and provides important information for understanding the evolution and conservation of these spiny frogs.

Length–weight relationships (LWRs) are presented for 11 species [Acrossocheilus monticola (Gunther, 1888), Squalidus wolterstorffi (Regan, 1908), Sinibrama taeniatus (Nichols, 1941), Gnathopogon herzensteini (Gunther, 1896), Rhynchocypris oxycephalus (Sauvage & Dabry de Thiersant, 1874), Rhodeus lighti (Wu, 1931), Platysmacheilus nudiventris Luo, Le & Chen, 1977, Hemibagrus macropterus Bleeker, 1870, Glyptothorax fokiensis (Rendahl, 1925), Liobagrus marginatoides (Wu, 1930), Sinogastromyzon szechuanensis Fang, 1930] from the Nuoshuihe Precious Water Animal National Nature Reserve in southwestern China. Samples were collected bimonthly with trap‐nets (mesh size: 5 × 5 mm; height 0.3 m; width 0.4 m; length 7 m) from 2015 to 2016.

The viviparous Tartar sand boa, Eryx tataricus, is a widespread species in arid Central Asia. A complete mitochondrial genome of one individual from Junggar Basin in Northwest China was determined by next-generation sequencing. The mitogenome is 17,537 bp in size, comprising 2 ribosomal RNA genes, 13 protein-coding genes (PCGs), 22 transfer RNA genes (tRNAs), and 2 control regions. The order and structure of the genes are similar to those of other Henophidia snakes. Phylogenetic analysis based on 13 concatenated PCGs recovered the monophyly of Boidae and indicated that E. tataricus is closely related to Boa constrictor plus Eunectes notaeus.

The complete mitochondrial genome of the Hainan Glass Lizard (Dopasia hainanensis) from its type locality (Diaoluo Mountain in Hainan Island, China) was determined using next-generation sequencing....

Triplophysa fishes are the primary component of the fish fauna on the Tibetan Plateau and are well adapted to the high-altitude environment. Despite the importance of Triplophysa fishes on the plateau, the genetic mechanisms of the adaptations of these fishes to this high-altitude environment remain poorly understood. In this study, we generated the transcriptome sequences for three Triplophysa fishes, that is, Triplophysa siluroides, Triplophysa scleroptera, and Triplophysa dalaica, and used these and the previously available transcriptome and genome sequences from fishes living at low altitudes to identify potential genetic mechanisms for the high-altitude adaptations in Triplophysa fishes. An analysis of 2,269 orthologous genes among cave fish (Astyanax mexicanus), zebrafish (Danio rerio), large-scale loach (Paramisgurnus dabryanus), and Triplophysa fishes revealed that each of the terminal branches of the Triplophysa fishes had a significantly higher ratio of nonsynonymous to synonymous substitutions than that of the branches of the fishes from low altitudes, which provided consistent evidence for genome-wide rapid evolution in the Triplophysa genus. Many of the GO (Gene Ontology) categories associated with energy metabolism and hypoxia response exhibited accelerated evolution in the Triplophysa fishes compared with the large-scale loach. The genes that exhibited signs of positive selection and rapid evolution in the Triplophysa fishes were also significantly enriched in energy metabolism and hypoxia response categories. Our analysis identified widespread Triplophysa-specific nonsynonymous mutations in the fast evolving genes and positively selected genes. Moreover, we detected significant evidence of positive selection in the HIF (hypoxia-inducible factor)-1A and HIF-2B genes in Triplophysa fishes and found that the Triplophysa-specific nonsynonymous mutations in the HIF-1A and HIF-2B genes were associated with functional changes. Overall, our study provides new insights into the adaptations and evolution of fishes in the high-altitude environment of the Tibetan Plateau and complements previous findings on the adaptations of mammals and birds to high altitudes.

Two novel mitogenomes of Eozapus setchuanus (KJ648495) and Sicista concolor (KJ648496) were reported and their total lengths were 16,630 bp and 16,493 bp, respectively. Both mitogenomes which were analogous to other rodent mitogenomes, contained 13 protein-coding genes, 22 tRNAs, 2 rRNAs, and a control region. Specifically, the ND2 gene of S. concolor has three amino acids lesser than that of two other Dipodidae species (E. setchuanus and Jaculus jaculus) due to a premature termination codon in the 3′ end. We detected a tandem repeat cluster of 221 bp and 274 bp in the control region of S. concolor and E. setchuanus, respectively. Along with phylogenetic relationship analysis, we speculated that the tandem repeats in control regions might be common in Dipodinae species. Our phylogenetic analysis using concatenated mitochondrial gene datasets suggested five suborder and 16 family monophyletic groups in 54 rodent taxa sampled and strongly supported a basal position of the squirrel-related clade (PP = 1; BP = 100). Dipodidae had a sister-group relationship with Muroidea, and Sicistinae was in the base of Dipodidae clade. The complete mitochondrial genomes showed high resolution in deep-level phylogenetic relationship reconstructions of Rodentia.

Both Dabry’s sturgeon (Acipenser dabryanus) and Chinese sturgeon (A. sinensis) are rare fish and listed as first class protected animals in China. Nowadays, an artificial release program has been established as a main way to maintain and restore their wild populations. Unintentional interspecific hybridization of these two sturgeons might occur because of their close relationship. To ensure the purity of germplasm, Dabry’s sturgeon and Chinese sturgeon must be identified before releasing. Owing to their highly similar morphological characteristics, it is difficult to discriminate the two sturgeon species based on morphology in their larval and juvenile stages. Moreover, it is almost impossible to discriminate their hybrids based on morphology. Therefore, we established a new molecular approach to discriminate Dabry’s sturgeon and Chinese sturgeon based on mitochondrial DNA barcode and six nuclear markers (three nuclear genes (TYR, GHR, and RAG2) and three SNP markers (SNP21564, SNP28822, and SNP12974) in this study. These two sturgeons were explicitly distinguished from other sturgeon species using the DNA barcode and three nuclear genes. Further, the two species were accurately discriminated using the three SNP markers. We concluded through blind laboratory trials involving 95 individuals that our method is 100% reliable in distinguishing between the two species.

Through the RT-PCR and rapid amplification of cDNA ends, two complementary deoxyribonucleic acid (cDNA) clones encoding heat-shock cognate 70 (HSC70, designated Sp-HSC70) and inducible heat-shock protein 70 (HSP70, designated Sp-HSP70) were isolated from the liver of Prenant's schizothoracin (Schizothorax prenanti). The cDNAs were 2344- and 2292-bp in length and contained 1950- and 1932-bp open reading frames, encoded proteins of 649 and 643 amino acids, respectively. Amino acid sequence analysis indicated that both Sp-HSC70 and Sp-HSP70 contained three signature sequences of HSP70 family, two partial overlapping bipartite nuclear localization signal sequences (an ATP-binding site motif, a bipartite nuclear targeting signal), and a cytoplasmic characteristic motif EEVD. Homology analysis revealed that Sp-HSC70 and Sp-HSP70 shared 77.5% identity and Sp-HSC70 shared more than 81.1% identity with the known HSC70s of other vertebrates, while Sp-HSP70 shared more than 77.5 % identity with the known HSP70s of other vertebrates. Fluorescent real-time quantitative RT-PCR showed that Sp-HSC70 and Sp-HSP70 mRNAs were found in all tested tissues, including blood, brain, heart, liver, spleen, head kidney, white muscle, skin, gonad, hypophysis, red muscle, and gill. The Sp-HSC70 and Sp-HSP70 mRNA expression level in blood and head kidney displayed a significant increase in vibrio-challenged group with the bacterium Aeromonas hydrophila at 24 h post-infection compared to a control group. Temporally, there was a clear time-dependent expression pattern of Sp-HSC70 or Sp-HSP70 gene after bacterial challenge, and the expression of Sp-HSC70 and Sp-HSP70 mRNAs reached a maximum level at 12 and 6 h post-challenge, respectively. Both returned to control level after 7 × 24 h. The results suggest that Sp-HSC70 and Sp-HSP70 genes may play important roles in mediating the immune responses of A. hydrophila-related diseases in the Prenant's schizothoracin.

The occurrence of cannibalism in teleosts is well documented, yet the role and extent of genotype in determining this behavior have not been determined clearly. We investigated sibling cannibalism among juvenile hybrids of southern catfish (Silurus meridionalis) ♀ × Chinese catfish (Silurus asotus) ♂ and within the two parental species, under varying levels of (i) food availability (satiated with 200% body mass versus restricted feeding with 10% body mass) and (ii) size distribution (homogeneity in experiment 1 versus heterogeneity in experiment 2). Two types of cannibalism were documented during the experiments: type I (incomplete predation), and type II (complete swallow). For the hybrids, cannibalism rates in the satiated and restricted feeding treatments were 5.6 ± 4.2% and 15.6 ± 6.3%, respectively. Both measures were intermediate between those for the pure progenitors (0% and 13.4 ± 4.7% in S. meridionalis; 58.9 ± 12.3% and 72.5 ± 3.7% in S. asotus) in trials with uniformly-sized conspecifics (experiment 1). In contrast, cannibalism rates of hybrids with heterogeneous size distributions (experiment 2) in the satiated and restricted feeding treatments were 12.2 ± 11.9% and 86.7 ± 8.2% respectively, both of which were significantly higher than those in the two pure species (p

Dabry’s sturgeon (Acipenser dabryanus) is an endemic freshwater species in China mainly distributed in the mainstream of the upper Yangtze River and its tributaries. Due to river fragmentation, sand/gravel extraction, over-fishing, and water pollution, the wild population of Dabry’s sturgeon suffered a dramatic decline. In the present study, 26 novel single nucleotide polymorphism (SNP) markers were developed based on high-throughput sequencing. Genetic diversity analysis revealed that the values of observed heterozygosity (Ho) and expected heterozygosity (He) varied from 0.1000 to 0.9000 and from 0.0974 to 0.5115, respectively, and the minor allele frequency ranged from 0.0500 to 0.4750. Only three loci showed significant deviation from Hardy–Weinberg equilibrium after Bonferroni correction. The SNP markers will serve as a valuable tool for further population genetics, genetic breeding, and resource conservation in this species.

The releasing program of Chinese sucker (Myxocyprinusasiaticus) has been conducted for years in China. To prevent loss of genetic variation in wild populations, it is important to assess and monitor genetic diversity of broodstocks before release of offspring. Three broodstocks (Pixian Base of Sichuan Fisheries Research Institute, China (PBS), Yibin Base of Sichuan Fisheries Research Institute, China (YBS) and Yibin Rare Aquatic Animal Research Institute, China (YRA)) were investigated using mitochondrial control region and 12 microsatellites. The relatively low genetic diversities of these broodstocks were detected (PBS, haplotype diversity (h) = 0.877, observed heterozygosity (Ho) = 0.416; YBS, h = 0.812, Ho = 0.392; YRA, h = 0.818, Ho = 0.365). PBS showed higher Ho than YBS and YRA (P <0.05). Genetic divergence (FST) based on microsatellites between PBS and YRA was significant (FST= 0.1270,P< 0.05), the same situation happened between YBS and YRA (FST= 0.1319,P< 0.05). However, divergence between PBS and YBS was not significant (FST= 0.0029,P> 0.05). Structure analysis revealed that YRA were distinct from PBS and YBS. Based on these results, it is important to propose some suggestions of genetic management for artificial propagation of Chinese sucker, such as broodstock exchange among hatcheries and broodstock supplement from wild.

Schizothorax wangchiachii is a key fish species in the stock enhancement program of the Yalong River hydropower project, China. Alizarin red S (ARS) was used to mark large numbers of juvenile S. wangchiachii in the Jinping Hatchery and later used to evaluate stock enhancement in the Jinping area of the Yalong River. In a small-scale pilot study, 7,000 juveniles of the 2014 cohort were successfully marked by immersion in ARS solution, and no mortality was recorded during the marking process. The ARS mark in the fish otoliths remained visible 20 months later. In the large-scale marking study, approximately 600,000 juveniles of the 2015 cohort were successfully marked. Mortalities of both marked and unmarked juveniles were very low and did not differ significantly. Total length, wet mass and condition factor did not differ significantly between unmarked and marked individuals after three months. On 24 July 2015, about 840,000 Jinping Hatchery-produced young S. wangchiachii, including 400,000 marked individuals, were released at two sites in the Jinping area. Recapture surveys showed that (1) marked and unmarked S. wangchiachii did not differ significantly in total length, wet mass and condition factor; (2) stocked individuals became an important part of recruitment of the 2015 cohort; (3) instantaneous growth rate of marked individuals tended to slightly increase; and (4) most stocked individuals were distributed along a 10–15 km stretch near the release sites. These results suggest that the ARS method is a cost-efficient way to mass mark juvenile S. wangchiachii and that releasing juveniles is an effective means of stock recruitment.

Quaternary climatic oscillations and geography are of primary importance in shaping intraspecific genetic diversity. We examined the diversification patterns and inferred processes for the green odorous frog (Odorrana margaretae) of western China. Species distribution modelling showed that the species has a continuous circular distribution around the Sichuan Basin while the basin itself is largely uninhabitable. Population genetic and phylogenetic analyses revealed that the species has a ring-shaped divergent pattern. While the chain of populations around the Basin maintains a mostly gradual and continuous genetic variation, populations between the north and west showed little gene exchange. Two processes, glacial refugial history and geography, likely contributed to the observed patterns. Our genetic clustering analysis revealed two clusters, suggesting two refugial groups among the populations, one from the west and the other from the east. Postglacial expansion may have created two contact zones. One at the south had extensive population admixture and produced a gradual transition between the western and eastern populations. Consequently, this region has the highest genetic diversity and represents an evolutionary "melting pot." In contrast, the second contact zone at the northwestern side of the Basin has limited admixture, suggesting partial reproductive isolation between the northern and western populations. Furthermore, an isolation-by-distance analysis revealed a strong correlation (Mantel r = 0.745) between the genetic and geographic distances, when we assumed that populations were connected following the circular distribution without gene flow across the NW contact zone. We also explored alternative explanations, such as a one-refugium scenario. With its micro-ring, the green odorous frog is poised to make an excellent model system for understanding the process of speciation.

Rock carp (Procypris rabaudi (Tchang)) is an endemic species in the upper Yangtze River drainage. The genetic variability and population structure of eight populations (Mudong (MD), Hejiang (HJ), Wanzhou (WZ), Xishui (XS), Nantan (NT), Cangxi (CX), Tongjiang (TJ) and Wulong (WL)) were investigated based on mitochondrial DNA control region. According to the river dimensions, MD, HJ, WZ, WL and CX were defined as large river populations, while TJ, XS and NT were defined as small. The total genetic diversity level of rock carp was moderate (h = 0.858, π = 0.0079). Genetic differentiations among populations in small rivers were greater than those among populations in large rivers, and small rivers showed significant differentiation from large rivers. Analysis from the coalescent-based method showed that there were asymmetric gene flows among four large river populations (CX, HJ, MD and WZ). Demographic analyses suggested that the species as a whole and the WZ population experienced population expansion, while the HJ, NT, and MD populations experienced bottlenecks. The analysis of genetic diversity and population structure suggested that the WL, TJ, CX, NT and XS populations should be protected and managed separately, and that the HJ, MD and WZ populations should be considered as a genetic management unit.

The Zhougong River is one of the most important tributaries of the Qingyi River in upper Yangtze River drainage, Sichuan Province, southwest China. The river has been dammed in several places by hydroelectric stations and thus, we aimed to characterize the longitudinal and seasonal patterns of fish assemblage structure in it and whether anthropogenic perturbations have impacted fish assemblages. An extensive survey of fish was conducted in spring (April), summer (August) and autumn (November) of 2015, and winter (February) of 2016 at a total of 18 sampling locations across the river’s watershed. It was found that fish abundance, richness and Shannon-Wiener diversity all increased from upstream to downstream. Fish assemblage showed significant spatial differences between the upstream, midstream and downstream, while there were no differences between seasons as was expected. The spatial variation in the abundance of Rhodeus sinensis, Schizothorax prenanti, Pseudorasbora parva, Zacco platypus and Abbottina obtusirostris were considered to contribute most to the spatial pattern in fish assemblage. The canonical correspondence analysis (CCA) results revealed that spatial variations of fish community in the Zhougonng River were significantly correlated with water velocity, total phosphorus and water depth. Our findings indicate that spatial differences and no seasonal change in fish assemblage were partially attributed to the physicochemical changes caused by cascade hydroelectric dams (e.g., channel blocking, hydrological alterations) and water pollution (e.g., phosphorus) and it is also likely that overfishing has exacerbated impacts. We recommend that pollution prevention, dam removal, modifying dam ecological operations and fishery control may effectively lessen the impacts on fish biodiversity in the Zhougong River.

Prenant’s schizothoracin, Schizothorax prenanti (Tchang) is an important polyploidy fish in upper reaches of the Yangtze River. Given the extreme anthropogenic environmental alteration in the region, S. prenanti represents an excellent model organism to study historical and contemporary environmental changes. We developed twenty tetranucleotide microsatellite DNA markers from a tetranucleotide microsatellite enriched library. These highly polymorphic markers (2–23 alleles) will facilitate the population genetic analyses of this species.

Schizopygopsis chengi, which belongs to the subfamily Schizothoracinae, comprises two subspecies, Schizopygopsis chengi chengi and Schizopygopsis chengi baoxingensis. S. c. chengi inhabits streams and lakes in upper reaches of the Dadu River. S. c. baoxingensis occurs as a single population endemic to the Baoxing River in China. In order to provide the reliable molecular markers for genetic investigation of S. chengi, eleven tetranucleotide microsatellite loci were developed from GATA-enriched library. The polymorphism of the loci was tested in 25 S. c. chengi individuals and the results showed that the loci were highly polymorphic. Eight loci were successfully amplified in S. c. baoxingensis. Sixty-seven different alleles were observed in the 82 S. c. baoxingensis individuals, and AI, HO, and PIC were 2.258, 0.549 and 0.572, respectively. The level of genetic diversity based on microsatellite loci was different from the previous studies based on mitochondrial DNA for S. c. baoxingensis, suggesting combined analysis of nuclear and mitochondrial DNA was required.

The genus Triplophysa is the largest and most difficult to identity morphologically fish group of superfamily Cobitoidea with 140 currently valid species, and is mainly distributed in the Qinghai-Tibetan Plateau (QTP) and adjacent regions. Most species within this genus possess highly similar morphological characteristics for adaption to the highland environment and are very difficult to be identified only based on morphology. The traditional species identification, mainly based on external morphological diagnostic characters, leads to inconsistent results in many cases. Herein, we provided a molecular method based on mitochondrial cytochrome c subunit I (COI) for the identification of Triplophysa fishes. Thirty-three Triplophysa species, 244 individuals, were used to determine whether barcoding was effective in discriminating species for this genus. The mean intraspecific and interspecific K2P distances ranged from 0 to 14.9% (mean, 2.9%) and 0 to 23.4% (mean, 9.7%), respectively. The tree-based analysis displayed most of species formed discrete clusters with strong bootstrap support values (>90%). The results showed that most of Triplophysa species could be identified by DNA barcode and indicated DNA barcode could be used as a molecular marker for these species.

Tibetan loaches are the largest group of Tibetan fishes and are well adapted to the Tibetan Plateau. To investigate the origin of Tibetan loaches and their adaptations to the Tibetan Plateau, we determined 32 complete mitochondrial genomes that included 29 Tibetan loach species, two Barbatula species and Schistura longus. By combining these newly determined sequences with other previously published mitochondrial genomes, we assembled a large mitogenomic data set (11,433 bp) of 96 species in the superfamily Cobitoidea, to investigate the phylogenetic status of the genus Triplophysa. The resulting phylogeny strongly supported that the genus Triplophysa forms a monophyletic group within Nemacheilidae. Our molecular dating time suggests that the lineage leading to the Tibetan loaches and other loaches diverged approximately 23.5 Ma, which falls within the period of recent major uplifts of the Tibetan Plateau in the Early Miocene. Selection analyses revealed that the mitochondrial protein-coding genes of Tibetan loaches have larger ratios of nonsynonymous to synonymous substitutions than do those of non-Tibetan loaches, indicating that Tibetan loaches accumulated more nonsynonymous mutations than non-Tibetan loaches and exhibited rapid evolution. Two positively selected sites were identified in the ATP8 and ND1 genes.

To understand genetic variation and population dispersal in the Yangtze vole Microtus fortis calamorum distributed in the Dongting Lake region, 144 individuals were collected from six habitat patches. The mitochondrial DNA control region was sequenced and 17 haplotypes were observed. Of the six investigated populations, haplotype and nucleotide diversities of those from larger patches were higher than those from smaller patches. Nonparametric correlation analysis showed that patch size had a positive correlation with haplotype diversity (r = 0.943, P < 0.01). A neighbour-joining tree of the 17 haplotypes showed no geographic genetic structure among the six populations. Analysis of isolation by distance showed that genetic differentiation among the six populations was not positively related to geographic distance. Analysis of mismatch distribution indicated that the voles had passed through a population expansion. The pattern of haplotype distribution in the Changsha population suggests that the population was established by a founder effect [Current Zoology 58 (2): 211–220, 2012].

In Trinidad, guppies (Poecilia reticulata) in high-predation localities show more cohesive shoaling behaviour than those living with less dangerous predators in low-predation sites. We evaluated the relative contributions of population origin (i.e. genetic and/or maternal effects) and social environment on the expression of shoaling by assessing the behaviour of juveniles reared in a range of social conditions. Focal individuals, offspring of guppies from populations from high- or low-predation localities, were reared in a multifactorial experiment; we created four different social conditions by manipulating the source and demography of the conspecific residents with whom focal individuals interacted. We found that high-predation fish displayed a stronger propensity to shoal than low-predation ones. Our results also suggest a role for interactions between the source of the focal individuals, the demography of the group in which they were reared and the origin of the guppies with whom they were reared. Depending on their origin (high- vs. low- predation) and rearing density, our focal fish were more likely to shoal if they were reared with high-predation residents. Learning from high-predation residents, aggressive interactions with low-predation residents and/or phenotype matching could have played a role in driving this effect of social environment. This effect of the phenotype of conspecifics on shoaling development would enhance heritable differences in shoaling propensity such that both could contribute to the well-documented difference in shoaling behaviour of high- and low-predation guppies in natural populations.

Prenant’s schizothoracin (Schizothorax prenanti) was found naturally distributed in a plateau lake (Lake Wuxu) in upper reaches of the River Jiulong. The genetic diversities of the populations from L. Wuxu and R. Jiulong were investigated according to analysis of mtDNA control region and compared against three other reported river populations. The L. Wuxu population showed lower haplotype (h = 0.74) and nucleotide (π = 0.001) diversities compared to the R. Jiulong population (h = 0.87; π = 0.012); the lake population had suffered from a bottleneck, which might contribute to its low genetic diversity; the lake population significantly differentiated from the river populations, and significant gene flow was hardly found between river populations and L. Wuxu population, suggesting that there is a strong population structure between the lake and river populations. The L. Wuxu population was ecologically isolated from the R. Jiulong population, while the relatively low genetic variability had not affected its viability.

The whole mitochondrial genome of Hucho taimen was firstly sequenced and characterized. The genome is 16,833bp in length and contains 13 protein-coding genes, 2 ribosomal RNAs, 22 transfer RNAs, and a noncoding control region. Twelve protein-coding genes on the heavy strand showed that the content of A þTwas higher than that of G þ C, whereas the nd6 protein-coding gene on the light strand displayed an opposite pattern. We described the secondary structure of the origin of light strand (oriL) replication and found that the conserved 5 0 -GCCGG-3 0 sequence motif is variable in H. taimen and some other salmonids. We conclude that the control region is variable in length and represents the high A þT content, compared with other mitochondrial control regions available in Salmonidae and other non-salmonids. Additionally, another interesting feature of H. taimen mitogenome is that a T-type mononucleotide microsatellite and an 82bp tandem repeat were identified in the control region.

Ten tetranucleotide microsatellite loci were isolated from GATA-enriched library of rock carp (Procypris rabaudi). The loci were tested in 25 individuals from four populations. The number of alleles per locus ranged from 3 to 6. Polymorphism information content (PIC) ranged from 0.460 to 0.788. Observed and expected heterozygosities ranged from 0.375 to 0.739 and from 0.531 to 0.833, respectively. These microsatellites will facilitate the study of population genetics of rock carp.

Otolith thermal marking was conducted in larval Chinese sucker, Myxocyprinus asiaticus, by exposing the larvae to water with different temperature regimes ranging from heated water (28°C) to chilled water (16°C) at different time intervals. The results showed that increment patterns differed among groups; the control of duration in the heated water could produce some increments much narrower or wider than those deposited in the natural diel water temperature fluctuation; there was a significantly positive relation between increment width and the duration reared in heated water in each cycle of water temperature fluctuation. These increments with abnormal widths were thermal marks in otoliths, and would be used as bar codes to track the released individuals, and discriminate them from the wild populations in the future. The thermal marking is suitable to mass-mark the Chinese sucker larvae.

Wild populations of Prenant’s schizothoracin, Schizothorax prenanti, were collected from the Qingyi, Dadu, and Muli rivers in upper reaches of the Yangtze River. Genetic variation and population structure were examined based on analysis of the mitochondrial DNA control region. Nucleotide sequence analysis defined 30 haplotypes in 41 individuals. The nucleotide and haplotype diversities were very high, and genetic distances between the Dadu and Qingyi populations were much smaller than between either of them and the Muli population. The analysis of molecular variance demonstrated that most variation occurred within samples, and the differentiation between Muli and Dadu or Qingyi was significant. Estimates of gene flow indicated reproductive isolation between Muli and the other populations, and this divergence might be related to geographical location. The results are mostly consistent with the findings from AFLP analysis and also suggested considerable genetic diversity of the populations in the Muli, Dadu, and Qingyi rivers.

Phylogenetic relationships of three subspecies of Schizopygopsis malacanthus, S. m. malacanthus, S. m. chengi, and S. m. baoxingensis, were investigated based on the mitochondrial DNA control region and the cytochrome b gene. Phylogenetic analysis indicated that the three subspecies did not cluster as one monophyletic group; S. m. malacanthus clustered into one clade, while S. m. chengi and S. m. baoxingensis clustered into another. Genetic distances between S. m. malacanthus and the other two subspecies were either very close to or larger than those between S. m. malacanthus and some other species of Schizopygopsis. There was very small genetic distance between S. m. chengi and S. m. baoxingensis. The results suggested S. m. chengi should be split from S. malacanthus into a separate species, Schizopygopsis chengi (Fang); S. m. baoxingensis should be regarded as a subspecies, S. c. baoxingensis (Fu, Ding et Ye), of Schizopygopsis chengi.

Prenantȁ9s schizothoracin, Schizothorax prenanti, an endemic fish to China, has undergone a dramatic decline in numbers due to human impacts. We studied its genetic diversity in three tributaries of the Yangtze River: the Qingyi River, which has many hydropower dams, and the Dadu River and Muli River where many hydropower dams are being proposed. Using amplified fragment length polymorphism (AFLP), 621 loci were amplified with seven AFLP primer combinations in 45 individuals. The loci were highly polymorphic and heterozygous (87% polymorphism, 30% heterozygosity). The genetic distances within populations were large. The analysis of molecular variance demonstrated that most variation occurred within populations. The estimated fixation index (Φst) value averaged over all polymorphic loci across the three rivers was 0.0837, indicating a moderate genetic differentiation. The differentiations between populations were significant, and population structure was strong. The results suggested that China had wild populations of Prenantȁ9s schizothoracin with considerable genetic diversity in the Muli, Dadu and Qingyi rivers. The proposals to dam these rivers should take into account the importance of conserving their genetic quality.

Anthropogenic factors have contributed to a severe decline of Leptobotia elongata. Conservation information of L. elongata will be required. Here, 14 tetranucleotide microsatellite DNA markers were developed from L. elongata through high-throughput (454) sequencing data. Twenty-four individuals of the species were genotyped using these markers. All of the loci displayed a high level of polymorphism with the number of alleles per locus ranged from 7 to 23, polymorphism information content ranged from 0.650 to 0.943. Observed and expected heterozygosities ranged from 0.609 to 1.000 and from 0.699 to 0.967, respectively. These markers provide an excellent toolkit to study population genetic structure and would benefit the conservation of this species.

Ten dinucleotide microsatellite DNA markers were developed for a polyploidy fish, Schizothorax prenanti. Twenty-four individuals from two populations of this species were genotyped using these markers. All ten loci displayed a high level of polymorphism with the number of alleles per locus ranged from 9 to 19. Additionally, Nei’s genetic diversity ranged from 0.81 to 0.92. These markers provide an excellent toolkit to study population genetic structure and other biological characteristics of this commercially important species.

The complete mitochondrial genome of the stone loach Triplophysa stoliczkae is 16,571 bp in size, consisting of 13 protein-coding genes, 22 transfer RNA (tRNA) genes, two ribosomal RNA (rRNA) genes, and a noncoding control region. As in other vertebrates, most mitochondrial genes are encoded on the heavy strand, except for nd6 and eight tRNA genes which are encoded on the light strand. The overall base composition of the heavy strand of the T. stoliczkae mitochondrial genome is A: 28.1%, T: 29.0%, C: 25.0%, and G: 17.9%. The alignment of the Triplophysa species control regions exhibited high genetic variability and rich A+T content.

The complete mitochondrial genome of the stone loach Triplophysa bleekeri collected from the Anning River, a tributary of the Yalong River, in Sichuan Province was sequenced. The genome is 16,573 bp in length, consisting of 13 protein-coding genes, 22 transfer RNA (tRNA) genes, two ribosomal RNA (rRNA) genes, and a noncoding control region. Most of the genes are encoded on the heavy strand, except for ND6 and eight tRNAs. The overall base composition of T. bleekeri is 28.1% for A, 28.4% for T, 25.5% for C, 18.0% for G, with a slight A+T bias of 56.5%. The complete mitochondrial genetic variability is high among different Triplophysa species and between the two T. bleekeri individuals from different rivers.

Triplophysa dalaica, endemic species of Qinghai-Tibetan Plateau, is informative for understanding the genetic basis of adaptation to hypoxic conditions of high altitude habitats. Here, a comprehensive gene repertoire for this plateau fish was generated using the Illumina deep paired-end high-throughput sequencing technology. De novo assembly yielded 145,256 unigenes with an average length of 1632 bp. Blast searches against GenBank non-redundant database annotated 74,594(51.4%) unigenes encoding for 30,047 gene descriptions in T. dalaica. Functional annotation and classification of assembled sequences were performed using Gene Ontology (GO), clusters of euKaryotic Orthologous Groups (KOG) and Kyoto Encyclopedia of Genes and Genomes (ICEGG) analysis. After comparison with other fish transcriptomes, including silver carp (Hypophthalmichthys molitrix) and mud loach (Misgurnus anguillicaudatus), 2621 high-quality orthologous gene alignments were constructed among these species. 61 (2.3%) of the genes were identified as having undergone positive selection in the T. dalaica lineage. Within the positively selected genes, 13 genes were involved in hypoxia response, of which 11 were listed in HypoxiaDB. Furthermore, duplicated hif-alpha (hif-1 alpha A/B and hif-2 alpha A/B), EGLN1 and PPARA candidate genes involved in adaptation to hypoxia were identified in T. dalaica transcriptome. Branch-site model in PAML validated that hif-1 alpha B and hif-2 alpha A genes have undergone positive selection in T.dalaica. Finally, 37,501 simple sequence repeats (SSRs) and 19,497 high-quality single nucleotide polymorphisms (SNPs) were identified in T. dalaica. The identified SSR and SNP markers will facilitate the genetic structure, population geography and ecological studies of Triplophysa fishes. (C) 2015 Elsevier B.V. All rights reserved.

To restore the natural populations of Chinese sucker (Myxocyprinus asiaticus), a hatchery release program has been underway for nearly 10 years. Using DNA sequences of the mitochondrial control region, we assessed the genetic diversity and genetic structure among samples collected from three sites of the wild population as well as from three hatcheries. The haplotype diversity of the wild samples (h = 0.899–0.975) was significantly higher than that of the hatchery ones (h = 0.296–0.666), but the nucleotide diversity was almost identical between them (π = 0.0170–0.0280). Relatively high gene flow was detected between the hatchery and wild samples. Analysis of effective population size indicated that M. asiaticus living in the Yangtze River has been expanding following a bottleneck in the recent past. Our results suggest the hatchery release programs for M. asiaticus have not reduced the genetic diversity, but have influenced the genetic structure of the species in the upper Yangtze River.

The complete mitochondrial DNA genome of Gymnodiptychus pachycheilus was sequenced and characterized. The genome is 16,586 bp in length. As with most teleosts, the mitogenome of G. pachycheilus is structurally conserved, containing two ribosomal RNA (rRNA) genes, 13 protein-coding genes, 22 transfer RNA (tRNA) genes and one displacement loop (D-loop) region. The 12 heavy-strand protein-coding genes of G. pachycheilus and other 15 Schizothoracinae species were used for phylogenetic analysis by Bayesian inference and maximum likelihood methods. The topology demonstrated that G. pachycheilus is relatively close to species in genera of Gymnocypris, Schizopygopsis and Oxygymnocypris but differentiated earlier in Schizothoracinae than them.

Transcriptome profiles provide a practical and inexpensive alternative to explore genomic data in non-model organisms, particularly in amphibians where the genomes are very large and complex. The odorous frog Odorrana margaretae (Anura: Ranidae) is a dominant species in the mountain stream ecosystem of western China. Limited knowledge of its genetic background has hindered research on this species, despite its importance in the ecosystem and as biological resources. Here we report the transcriptome of O . margaretae in order to establish the foundation for genetic research. Using an Illumina sequencing platform, 62,321,166 raw reads were acquired. After a de novo assembly, 37,906 transcripts were obtained, and 18,933 transcripts were annotated to 14,628 genes. We functionally classified these transcripts by Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG). A total of 11,457 unique transcripts were assigned to 52 GO terms, and 1,438 transcripts were assigned to 128 KEGG pathways. Furthermore, we identified 27 potential antimicrobial peptides (AMPs), 50,351 single nucleotide polymorphism (SNP) sites, and 2,574 microsatellite DNA loci. The transcriptome profile of this species will shed more light on its genetic background and provide useful tools for future studies of this species, as well as other species in the genus Odorrana. It will also contribute to the accumulation of amphibian genomic data.

The circular mitochondrial genomes of Brachymystax lenok and B. lenok tsinlingensis are 16,832 and 16,669 bp in length, respectively. The mitogenomes of two lenoks shared common features with those of other teleosts in terms of gene arrangement, base composition, and transfer RNA structures. The two genomes have an overall nucleotide sequence identity of 98.3%. Through the comparisons between the two lenoks, we found their gene arrangement, composition, and sizes are the same, and the A+T content is identical. As with other freshwater salmonids, a T-type mononucleotide microsatellite and various tandem repeats were identified in the control regions of the lenoks. The low pairwise distance (2.1%) inferred from 12 mitochondrial protein-coding genes on heavy strand showed close proximity of B. lenok and B. lenok tsinlingensis.

The Chevrier's field mouse (Apodemus chevrieri) is an endemic species to China and is an important pest in agriculture and human diseases. In this study, the complete mitochondrial genome of this species was sequenced and its size was 16,298 bases (accession no.: HQ896683). The mitogenome structure was similar compared with other reported rodent mitochondrial genomes and includes 13 protein-coding genes, 2 rRNA genes (12S rRNA and 16S rRNA), 22 tRNA genes, and 1 control region. This was the first complete mitogenome sequenced in genus Apodemus. The phylogenetic analyses based on the sequences of 12 heavy-strand protein-coding genes demonstrated that A. chevrieri clustered together with genus Mus. Additionally, extremely high haplotype and nucleotide diversities (h=0.978, π=2.6%) were observed based on 44 mitochondrial cytochrome b (cyt b) gene sequences. This suggests adaptive divergence of this species to a variety of living habitats and potential refuges in the eastern margin of the Hengduan Mountains during the Quaternary ice ages. No population expansions or genetic bottlenecks were observed in demographic analyses. The phylogenetic analysis of cyt b sequences and haplotypes revealed a genetic differentiation between north and south populations. The divergence between north clade and south clade occurred probably in the middle Pleistocene 1.1815 million years ago (Mya) (95% highest posterior density 2.3189-0.2737 Mya), which was congruent with the periods of the most tense uplift events in the Tibetan Plateau.

AIM. The complete mitochondrial genome sequence of a newly discovered vole, Proedromys liangshanensis (Rodentia: Cricetidae: Arvicolinae), was determined. RESULTS. The mitogenome of P. liangshanensis is 16,296 bp in length. As with most other mammals, it contains the same gene order and an identical number of genes or regions, including 13 protein-coding genes, two ribosomal RNA genes, 22 transfer RNA genes, and one putative control region. The A+T content of the control region is 58.2%, the lowest proportion detected so far in Myomorpha. To confirm the phylogenetic position of P. liangshanensis, we carried out phylogenetic analyses based on complete mitochondrial genomic data using Bayesian, maximum parsimony, and maximum likelihood methods. CONCLUSION. All results revealed that P. liangshanenis is sister to Microtus. Although the results do not bear light on the validity of the genus Proedromys, based on the morphological characters, we suggest that Proedromys is an independent genus of equal rank to the genus Microtus.

Nine highly polymorphic microsatellite loci were isolated from AC- and GATA-repeat microsatellite enrichment DNA libraries in the rock carp, Procypris rabaudi (Tchang). The number of alleles for these loci ranged from eight to 18 in tested individuals. Polymorphism information content ranged from 0.712 to 0.908 with an average of 0.837. Average observed and expected heterozygosities were 0.719 and 0.870, respectively. These molecular markers will be useful for the assessment of genetic diversity and analysis of population structure in wild rock carp.

The complete mitochondrial DNA genome of the Sichuan taimen (Hucho bleekeri) was determined by the long and accurate polymerase chain reaction (LA-PCR) and primer walking sequence method. The entire mitochondrial genome of this species is 16,997bp in length, making it the longest among the completely sequenced Salmonidae mitochondrial genomes. It consists of two ribosomal RNA (rRNA) genes, 13 protein-coding genes, 22 transfer RNA (tRNA) genes, and one control region (CR). The gene arrangement, nucleotide composition, and codon usage pattern of the mitochondrial genome are similar to those of other teleosts. A T-type mononucleotide microsatellite and an 82bp tandem repeat were identified in the control region, which were almost identical among the three H. bleekeri individuals examined. Both phylogenetic analyses based on 12 concatenated protein-coding genes of the heavy strand and on just the control region show that H. bleekeri is a basal species in Salmoninae. In addition, Salmo, Salvelinus and Oncorhynchus all represent monophyletic groups, respectively. All freshwater species occupied basal phylogenetic positions, and also possessed various tandem repeats in their mitochondrial control regions. These results support established phylogenetic relationships among genera in Salmonidae based on morphological and molecular analyses, and are consistent with the hypothesis that Salmonidae evolved from freshwater species.

The complete mitochondrial genome of the Triplophysa robusta has been determined in this study. It is 16,572 bp in size and consists of 13 protein-coding genes, 22 tRNA genes, two rRNA genes, and one non-coding control region (D-loop). The overall base composition of the heavy strand of the T. robusta mitochondrial genome was A: 28.20%, T: 28.27%, C: 25.37%, and G: 18.16%. The total length of the 13 protein-coding genes was 11,428 bp. Analysis of the genes indicated the high genetic variability among Triplophysa species.

The complete mitochondrial DNA genome of Ptychobarbus kaznakovi was sequenced and characterized. The genome is 16,842 bp in length. Similar with most teleosts, it has two ribosomal RNA (rRNA) genes, 13 protein-coding genes, 22 transfer RNA (tRNA) genes, and one displacement loop (D-loop) region. Conserved sequence blocks, including ETAS, CSB-B, D, E, F, and CSB1-3, were identified in the D-loop, which is similar to other species in Cypriniformes. Nevertheless, a 55 bp tandem repeat array was also identified at 3′ end of the D-loop, which is the first finding in Schizothoracinae. Phylogenetic analysis showed that the species of Ptychobarbus (P. dipogon and P. kaznakovi) formed a monophyletic group and represented close relationship to the species without scales in Schizothoracinae.