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The salt lakes on the Qinghai-Xizang plateau ( China).
Abstract
Some of the saline lakes in this district developed from the Neogene fossil lakes, others in the Quaternary. Most of them are tectonic lakes. Rocks and hot springs are the main sources of the saline lake mineral.-after English summary
... Fishes of the genus Schizothorax Heckel, 1838, possess two pairs of barbels, 3 or 4 rows of pharyngeal teeth and two rows of enlarged scales along the vent (Chen & Cao, 2000;Chu & Chen, 1989;Day, 1878;Tilak, 1987;Wu & Wu, 1991). The taxonomy of Schizothorax is contentious (Chen & Cao, 2000;Wu & Wu, 1992;Tilak, 1987;Day, 1878). ...
... The type locality of S. griseus is Koei-Tchéou (Guizhou Province), China. The species was earlier thought to be widely distributed, having been reported from the Yangtse, the Pearl, the Lancang Jiang (upper Mekong) and the Irrawaddy drainages (Fang, 1936;Cao, 1964;Huang, 1989; Mo in Chu & Chen, 1989;Wu & Wu, 1991;Chen & Cao, 2000). In this study, we examined specimens from Guizhou Province, which are clearly different from those described by Pellegrin (1931) and Fang (1936) in that scales are present on the thorax in adults. ...
... 8,9), indicate that the regression lines are significantly different (p < 0.001 in all cases) between the two. Wu & Wu (1991) allocated the specimens of 'Schizothorax griseus' examined by Cao (1964) from the Lancang Jiang drainage area to S. yunnanensis. According to the descriptions of S. griseus in Cao (1964), we feel certain that the specimens from the Lancang Jiang drainage examined by Cao (1964) were in fact S. nudiventris. ...
The identity of Schizothorax griseus Pellegrin, 1931, is clarified and the species redescribed. Three new species previously identified as S. griseus are described: S. nudiventris, from the Lancang Jiang, China; S. heterophysallidos, from the Nanpan Jiang, China; and S. beipanensis, from the upper Beipan Jiang, China. The group comprising Schizothorax griseus, S. nudiventris, S. heterophysallidos and S. beipanensis can be diagnosed from other members of this genus by the absence of an obvious horny sheath on the lower jaw; lower lip developed with three labial lobes in mature individuals; postlabial groove continuous, with a small labial lobe present in the middle of the lower lip; last unbranched dorsal-fin ray strong, its posterior edge with numerous serrae; and scales absent on ventral surface between pectoral fins in adults (except in S. griseus). Schizothorax griseus differs from S. nudiventris, S. heterophysallidos and S. beipanensis by the presence (vs. absence) of concealed scales in the skin on the ventral surface between the pectoral fins in adults; the presence (vs. absence) of a shallow ethmoidal groove before the nostrils; and having barbels much longer than eye diameter (eye diameter 33.4–93.7 % (vs. 57.2–160.0) of maxillary-barbel length). Schizothorax nudiventris is distinguished from S. heterophysallidos and S. beipanensis in having only the proximal ¾ (vs. entirety) of the last unbranched dorsal-fin ray strong; pelvic-fin origin opposite or posterior (vs. opposite or anterior) to vertical through dorsal-fin origin; and irregular black spots present (vs. absent) on side of body. Schizothorax heterophysallidos is distinguished from S. griseus, S. nudiventris and S. beipanensis in having a larger posterior chamber of the air bladder (vs. posterior chamber as large as, or slightly larger than, anterior one), length of posterior chamber 3–6 (vs. 2) times length of anterior chamber. Schizothorax beipanensis is distinguished from S. griseus by the absence (vs. presence) of scales on the thorax in mature individuals; absence (vs. presence) of black spots on side of body; and having the maxillary barbel 58.5–120.1 % SL (vs. 33.4–93.7 % SL).
... Recent studies reported that miRNAs as vital regulators involved into a variety of pivotal biological processes in fish[3][4][5][6][7]. Schizothoracinae fishes are the predominant fish fauna in the Tibetan Plateau (TP), which have more than 60 species widely distributed throughout TP altitudes[8,9]. These fish species have evolved specific genetic and phenotypic characteristics to adapt to extremely harsh aquatic environments, such as chronic cold, hypoxia, saline and alkaline aquatic environments[8,10,11]. ...
... Schizothoracinae fishes are the predominant fish fauna in the Tibetan Plateau (TP), which have more than 60 species widely distributed throughout TP altitudes[8,9]. These fish species have evolved specific genetic and phenotypic characteristics to adapt to extremely harsh aquatic environments, such as chronic cold, hypoxia, saline and alkaline aquatic environments[8,10,11]. Tibetan naked carp, Gymnocypris przewalskii (Teleostei: Cyprinidae) is one of the best-studied Schizothoracinae fish species in TP, making it an ideal model to study evolutionary biology. ...
... Unlike other Schizothoracinae fishes, G. przewalskii survives in both its natural habitant Lake Qinghai (high saline up to 13‰, high alkaline up to pH 9.4) and connective rivers of freshwater environment in the spawning migration. Besides high PH aquatic environment, G. przewalskii had evolved to surmount chronic cold and hypoxia environment in Lake Qinghai[8,17,18]. With unique characteristics, G. przewalskii is considered as an exceptional model to investigate the genetic mechanisms of aquatic wildlife adaptation to extreme environments in the TP. ...
Tibetan naked carp Gymnocypris przewalskii is an ideal model system to study highland adaptation of fish, because it evolved specific genetic and phenotypic characteristics to adapt to chronic cold and alkaline environments in Lake Qinghai. MicroRNAs (miRNAs) are small noncoding RNAs that regulating gene expression post-transcriptionally in a wide range of biological processes. In this study, we focus on the role of miRNAs in adaptation of G. przewalskii to extreme conditions in Lake Qinghai. We generate the first miRNAome of G. przewalskii in Schizothoracinae fish. Using several genomic resources, we inferred 341 conserved miRNAs belonged to 152 miRNA families and 43 novel miRNAs in G. przewalskii, and also identified 15 teleost-specific miRNAs. Using a large scale of conserved miRNAs, we constructed a high-confidence phylogenetic tree between teleost and mammals than mitochondria and nuclear genes. In addition, we found that several miRNA family (e.g. miR-10 and let-7) members highly expressed in G. przewalskii, which may function in multiple biological processes. Finally, we predicted a total of 34,258 miRNA targets genes. Conserved miRNAs target genes participating in signal transduction, cell differentiation and biosynthetic process, and showed signature of functional constraint. While novel miRNAs in a species displayed species-specific targets and involved in ion binding, transport and oxidoreductase activity, may affect the expression patterns of targets with signature of gene family expansion or positive selection under extreme environment. Taken together, this study demonstrated that miRNAs may involve into roles of adaptation of G. przewalskii to highland aquatic environment, and also provide insights into miRNA regulatory network in Schizothoracinae fish as a case study.
... As the largest salt lake in China, Lake Qinghai is highly saline (up to 13‰) and alkaline (up to pH 9.4) water environment, a typical salt lake with unusually high sodium, potassium and magnesium concentration [16,17]. Lake Qinghai used to be freshwater and connected to the Yellow River, while during the late well-known geological events "Gonghe Movement" (15 mya), Lake Qinghai was separated with the upper reaches of the Yellow River [17,18]. During the early to late Holocene, G. przewalskii has gradually evolved from the freshwater fish to tolerate high salinity and alkalinity [17,19]. ...
... c Venn diagram showed shared and distinct genes under the annotations of NR, Swiss-Prot, eggNOG and KEGG databases. d Sequence number distribution of unigene ORF annotated by MAKER, TransDec and ESTScan recorded as a tetraploid without a reference genome [18], therefore, we applied the comparative transcriptomic analysis to understand the genetic forces of its adaptation to the aquatic environment in Lake Qinghai. In current study, we present the first reference transcriptome of G. przewalskii, and characterized its genetic features relative to other available fish genomes. ...
... G. przewalskii is the newly formed fish species in family Schizothoracinae during the separation of Lake Qinghai from the Yellow River [10,12,16,18]. Based on mitochondrial genomes, evidence suggested that the split of two cyprinid fish G. przewalskii and C. carpio occurred approximately 68 mya in accordance with the early uplift of the TP around 50 mya [5]. ...
Background:
Understanding the genetic basis of adaptation to high altitude life is of paramount importance for preserving and managing genetic diversity in highland animals. This objective has been addressed mainly in terrestrial fauna but rarely in aquatic animals. Tibetan Schizothoracinae fish is the ideal model system in evolutionary biology, carrying key insights into evolutionary genetics of speciation and adaptation at high altitude. Gymnocypris przewalskii is the newly formed Schizothoracinae fish species in the Tibetan Plateau, inhabits chronic cold, extreme saline and alkaline aquatic environment in Lake Qinghai, thus evolving the unique genomic signatures to adapt extremely severe environments.
Results:
To characterize its genomic features, we assembled de novo transcriptome of G. przewalskii from Lake Qinghai. Intriguingly, by comparative genomic analyses of G. przewalskii and 8 other fish species, we identified potential expansions in gene families related to energy metabolism, transport and developmental functions, possibly underlying the adaptation to these environmental stresses. Through comprehensive molecular evolution analyses, we found that sets of genes controlling mitochondrion, ion homoeostasis, acid-base balance and innate immunity show significant signals of positive selection. Compared to previous studies on highland fishes, we failed to identify any positively selected genes related to hypoxia response.
Conclusions:
Our findings provide comprehensive insights into the genetic basis of teleost fish that underlie their adaptation to extreme high altitude aquatic life on the Tibetan Plateau.
... Taxonomically, Triplophysa is the most complicated group of superfamily Cobitoidea. Triplophysa is mainly distributed in rivers and lakes in the Qinghai-Tibetan Plateau (QTP) and its adjacent regions (Zhu, 1989;Wu and Wu, 1992;He, 2008;Prokovfiev, 2010). It contains approximately 170 currently described species, including 140 valid species, most of which are distributed in China (Prokovfiev, 2006;He et al., 2011;Froese and Pauly, 2015). ...
... The traditional species identification of Triplophysa usually needs the specialized morphological and anatomical knowledge (Zhu, 1989;Wu and Wu, 1992;He, 2008;Prokovfiev, 2009;Prokovfiev, 2010), which is mainly based on external morphological and internal anatomical diagnostic characters, including the shape characters of trunk, caudal peduncle and head, eye diameter and its position in head, shape and relative position of fins, structures of air-bladder and intestine and etc. These morphological characters also should be combined together to identify Triplophysa species. ...
... Most of the species were obtained from Sichuan Province, and some were collected from Tibet, Gansu, Qinghai, Yunnan and Xinjiang, China. Specimens were identified by more than two people, respectively, based on morphological characters (characters of the shape of trunk, caudal peduncle and head, eye diameter and its position in head, shape and relative position of fins, structures of air-bladder and intestine) according to Zhu (1989) and Wu and Wu (1992). Several specimens that have the same morphological characteristics and could not be reliably identified to species were showed as Triplophysa sp. and controversial samples were not adopted. ...
... The genus Gymnocypris Günther, 1868 (Cypriniformes: Schizothoracinae) has a wide distribution across the Qinghai-Tibet Plateau (QTP) and surrounding areas, such as the upstream of the Yellow River and the Yangtze River, as well as many isolated lakes (Wu & Wu 1992; Chen & Cao 2000; Qi et al. 2006). Gymnocypris are the dominant fishes in the QTP because they are well adapted to the harsh plateau eco-environment, with cold, hypoxic conditions and strong ultraviolet radiation. ...
... Debate on the taxonomy of the genus Gymnocypris is still ongoing. Eleven species and subspecies were proposed by Chen & Cao (2000), whereas Wu & Wu (1992) classified Gymnocypris into fourteen species and subspecies. Furthermore, the classification of Gymnocypris waddelli Regan, 1905 (Regan, 1905) is also controversial. ...
... Furthermore, the classification of Gymnocypris waddelli Regan, 1905 (Regan, 1905) is also controversial. Wu & Wu (1992) considered that this species was composed of two subspecies, G. w. waddelli and G. w. pinggi Tchang et al. 1964 based on the existence of horny layer on the inner side of the lower jaw (Wu & Wu 1992). However, Chen & Cao (2000considered the whole populations to comprise a single species. ...
Gymnocypris waddelli, a highland cold-water fish, is distributed among rivers and lakes of the southern Qinghai-Tibet Plateau. Although previously described as G. waddelli, specimens from the Pengqu River are morphologically distinguish-able from those from Lake Yamzhog Yumco, which is the type locality of G. waddelli. We investigated morphological variations of G. waddelli specimens from Pengqu River and Lake Yamzhog Yumco using not only traditional morphological methods but also newly-developed geometric morphometric analysis; furthermore, mitochondrial Cytochrome b (Cyt b) gene analysis was employed to explore the phylogenetic position of the Pengqu River population. Our morphological analyses suggested that G. waddelli from the Pengqu River had an obtuse snout, nearly straight oral fissure, shorter lower jaw than upper jaw, broad mouth and sparse inside gill rakers of the first arch relative to the Lake Yamzhog Yumco population. The strongly supported monophyly of Pengqu population according to mitochondrial datasets was obtained, indicating genetic differences between Pengqu River and Lake Yamzhog Yumco populations. Given their substantial genetic and morphological divergence, specimens from Pengqu River warrant recognition as a distinct species, here described and named Gymnocypris pengquensis.
... The genus Gymnocypris Günther, 1868 (Cypriniformes: Schizothoracinae) has a wide distribution across the Qinghai-Tibet Plateau (QTP) and surrounding areas, such as the upstream of the Yellow River and the Yangtze River, as well as many isolated lakes (Wu & Wu 1992; Chen & Cao 2000; Qi et al. 2006). Gymnocypris are the dominant fishes in the QTP because they are well adapted to the harsh plateau eco-environment, with cold, hypoxic conditions and strong ultraviolet radiation. ...
... Debate on the taxonomy of the genus Gymnocypris is still ongoing. Eleven species and subspecies were proposed by Chen & Cao (2000), whereas Wu & Wu (1992) classified Gymnocypris into fourteen species and subspecies. Furthermore, the classification of Gymnocypris waddelli Regan, 1905 (Regan, 1905) is also controversial. ...
... Furthermore, the classification of Gymnocypris waddelli Regan, 1905 (Regan, 1905) is also controversial. Wu & Wu (1992) considered that this species was composed of two subspecies, G. w. waddelli and G. w. pinggi Tchang et al. 1964 based on the existence of horny layer on the inner side of the lower jaw (Wu & Wu 1992). However, Chen & Cao (2000considered the whole populations to comprise a single species. ...
Gymnocypris waddelli, a highland cold-water fish, is distributed among rivers and lakes of the southern Qinghai-Tibet Plateau. Although previously described as G. waddelli, specimens from the Pengqu River are morphologically distinguishable from those from Lake Yamzhog Yumco, which is the type locality of G.waddelli. We investigated morphological variations of G. waddelli specimens from Pengqu River and Lake Yamzhog Yumco using not only traditional morphological methods but also newly-developed geometric morphometric analysis; furthermore, mitochondrial Cytochrome b (Cyt b) gene analysis was employed to explore the phylogenetic position of the Pengqu River population. Our morphological analyses suggested that G. waddelli from the Pengqu River had an obtuse snout, nearly straight oral fissure, shorter lower jaw than upper jaw, broad mouth and sparse inside gill rakers of the first arch relative to the Lake Yamzhog Yumco population. The strongly supported monophyly of Pengqu population according to mitochondrial datasets was obtained, indicating genetic differences between Pengqu River and Lake Yamzhog Yumco populations. Given their substantial genetic and morphological divergence, specimens from Pengqu River warrant recognition as a distinct species, here described and named Gymnocypris pengquensis.
... Tsao et al (Cyprinidae: Schizothoracinae) are endemic fish that are sympatric distributed in Lake Langcuo in Tibet, China (Wu and Wu 1992). Morphological difference was investigated (Wu and Wu 1992), and more evidence was required to explain the relationship between these two sympatric fish. ...
... Tsao et al (Cyprinidae: Schizothoracinae) are endemic fish that are sympatric distributed in Lake Langcuo in Tibet, China (Wu and Wu 1992). Morphological difference was investigated (Wu and Wu 1992), and more evidence was required to explain the relationship between these two sympatric fish. In the present work, we obtained G. chui and G. scleracanthus from the Lake Langcuo, Qinghai-Tibet Plateau and illustrated their different karyotypes, which helps to explore their karyotypic evolution and contributes to cytogenetic information for members of the subfamily Schizothoracinae. ...
... The different numbers and positions of the rRNA genes provided useful information for understanding the evolutionary relationships among closely related species (Rubert et al. 2011; Cardoso et al. 2013). The fish of the subfamily Schizothoracinae (Family: Cyprinidae) are important members of the ichthyofauna in the Qinghai-Tibet Plateau and its surrounding areas, where they are widely distributed in a variety of rivers and lakes (Wu and Wu 1992; Chen and Cao 2000). Currently, this subfamily includes 15 genera and over a hundred species distributed all over the world (Mirza 1991; Wu and Wu 1992; Chen and Cao 2000 ). ...
Schizothoracinae is a subfamily of naked carp which is widespread throughout the Qinghai-Tibet Plateau region. Cytogenetic analyses were performed on two sympatric species of naked carp, Gymnocypris chui and G. scleracanthus from the Lake Langcuo, Qinghai-Tibet Plateau. The results showed G. chui and G. scleracanthus had the same chromosome number (2n = 92), but different karyotypes:, (36m + 16sm + 12st + 28a) for G. chui and (26m + 12sm + 18st + 36a) for G. scleracanthus, respectively. The six loci of 45S ribosomal genes (rDNA) were detected through fluorescent in situ hybridization, and their locations were highly conserved between two species. This study depicted the chromosomal characteristics of the Schizothoracinae species and improved our understanding about the relationships and the evolution of two sympatric species. © 2016 Dipartimento di Biologia Evoluzionistica, Università di Firenze
... Schizothoracinae fishes are mainly distributed in the Central and East Asia, such as Qinghai-Tibet Plateau and its adjacent areas (Wu and Wu, 1992; He and Chen, 2006 ). Karyotype studies and DNA content measurements have shown that Schizothoracinae fishes are tetraploid, hexaploid or octoploid (Zan et al., 1985Zan et al., , 1986 Li et al., 1987; Yu et al., 1987 Yu et al., , 1990 Wu et al., 1999). ...
... Gymnocypris chui Tchang, Yueh et Hwang, 1964 (Cyprinidae: Schizothoracinae) is an endemic fish that is only distributed in Lake Langcuo in Tibet, China (Chen and Cao, 2000). Studies on G. chui are rare and only morphological descriptions have been made (Zhang et al., 1964; Wu and Wu, 1992 ). The fish is characterized by a restricted distribution, cold-adapted, low growth rate and late sexual maturity as an adaptation to its harsh environment (Wu and Wu, 1992; Chen and Cao, 2000). ...
... Studies on G. chui are rare and only morphological descriptions have been made (Zhang et al., 1964; Wu and Wu, 1992 ). The fish is characterized by a restricted distribution, cold-adapted, low growth rate and late sexual maturity as an adaptation to its harsh environment (Wu and Wu, 1992; Chen and Cao, 2000). Because of these life-history characteristics, G. chui is vulnerable to and particularly threatened by environmental deterioration, exotic species invasions and the overexploitation of the fishery resources. ...
... The wide distributional range of these species and their limited ability to migrate make this genus of obvious biogeographical interest. Additionally, being confined to high altitudes and high latitudes, these species have evolved unique morphological and physiological adaptations to their plateau environment and play a significant role in the trophic web of freshwater communities within the Qinghai-Tibetan Plateau (Wu & Wu 1992; Qi et al. 2012). Schizopygopsis, therefore, is a good model group with which to investigate how paleo-drainage changes linked to historical uplifting within the Qinghai-Tibetan Plateau can influence speciation. ...
... Wu (1964) first described the taxonomy of the genus Schizopygopsis based on morphological and anatomical characteristics , recognizing six species: S. stoliczkae Steindachner , 1866; S. kessleri Herzenstein, 1891; S. pylzovi Kessler, 1876; S. malacanthus Herzenstein, 1891; S. thermalis Herzenstein , 1891; S. kialingensis Tsao & Tun, 1962; and a subspecies of S. malacanthus (S. malacanthus chengi Fang, 1936). Later, Wu & Wu (1992) proposed a new morphological phylogeny containing nine species in which they (i) assigned the species Herzenstein microcephalus Herzenstein, 1891, and S. younghusbandi Regan, 1905, to the genus Schizopygopsis, (ii) elevated S. malacanthus chengi to species status, (iii) subsumed S. kessleri as synonymous to S. pylzovi and (iv) included a new species, S. anteroventris Wu, Tsao, Zhu & Chen, 1979. Based on gross morphology, Wu & Wu (1992) showed there were four major clades within the genus Schizopygopsis: (i) a primitive clade consisting solely of S. kialingensis and characterized by a narrow, slender horny sheath on the lower jaw and slender pharyngeal bone, which are distributed in rivers from 1300 to 3000 m above sea level; (ii) a clade consisting of S. pylzovi, S. chengi and S. malacanthus, characterized by a broad and flat horny sheath on the lower jaw, broad pharyngeal bone and more than 16 gill rakers on the outer row of the first gill arch, which are distributed in rivers from 2200 to 4400 m above sea level; (iii) a clade consisting of S. anteroventris, S. younghusband and S. thermalis, characterized by a broad and flat horny sheath on the lower jaw, broad pharyngeal bone and less than 14 gill rakers on the outer row of the first gill arch, which are distributed in rivers from 3000 to 4500 m above sea level; and (iv) a clade consisting of S. stoliczkae and S. microcephalus that possess highly specialized examples of morphology, such as a broad horny sheath on the lower jaw, markedly broad pharyngeal bone and a mixed number of gill rakers on the outer row of the first gill arch, which are distributed in rivers from 3500 to 5000 m above sea level. ...
... Later, Wu & Wu (1992) proposed a new morphological phylogeny containing nine species in which they (i) assigned the species Herzenstein microcephalus Herzenstein, 1891, and S. younghusbandi Regan, 1905, to the genus Schizopygopsis, (ii) elevated S. malacanthus chengi to species status, (iii) subsumed S. kessleri as synonymous to S. pylzovi and (iv) included a new species, S. anteroventris Wu, Tsao, Zhu & Chen, 1979. Based on gross morphology, Wu & Wu (1992) showed there were four major clades within the genus Schizopygopsis: (i) a primitive clade consisting solely of S. kialingensis and characterized by a narrow, slender horny sheath on the lower jaw and slender pharyngeal bone, which are distributed in rivers from 1300 to 3000 m above sea level; (ii) a clade consisting of S. pylzovi, S. chengi and S. malacanthus, characterized by a broad and flat horny sheath on the lower jaw, broad pharyngeal bone and more than 16 gill rakers on the outer row of the first gill arch, which are distributed in rivers from 2200 to 4400 m above sea level; (iii) a clade consisting of S. anteroventris, S. younghusband and S. thermalis, characterized by a broad and flat horny sheath on the lower jaw, broad pharyngeal bone and less than 14 gill rakers on the outer row of the first gill arch, which are distributed in rivers from 3000 to 4500 m above sea level; and (iv) a clade consisting of S. stoliczkae and S. microcephalus that possess highly specialized examples of morphology, such as a broad horny sheath on the lower jaw, markedly broad pharyngeal bone and a mixed number of gill rakers on the outer row of the first gill arch, which are distributed in rivers from 3500 to 5000 m above sea level. Wu & Wu (1992) proposed morphological trends in the evolution of some traits, such as the broadening of the horny sheath on the lower jaw and the broadening of the pharyngeal bone, and noted an increase in the altitudinal habitat preferences of the clades (the most basal group in this genus occurs at lowest altitude, while the most highly specialized group is restricted to the highest altitude). ...
Freshwater fish belonging to the genus Schizopygopsis are widespread in drainages throughout the Qinghai-Tibetan Plateau and, thus, a model group with which to investigate how paleo-drainage changes linked to historical uplifting within the Qinghai-Tibetan Plateau influence speciation. To date, the phylogenetic and taxonomic relationships within Schizopygopsis remain controversial. In this study, we constructed a comprehensive molecular phylogeny of Schizopygopsis based on six mitochondrial gene sequences. We compared the taxonomic relationships revealed by this phylogeny with those obtained from morphological data. We also used this phylogeny to assess the extent to which the evolution of Schizopygopsis has been driven by paleo-drainage changes linked to uplifting of the Qinghai-Tibetan Plateau. Results indicated that all Schizopygopsis taxa formed a monophyletic group comprising five major clades, which were inconsistent with the taxonomic relationships based on morphology for this group. Our results also strongly supported the validity of S. anteroventris and S. microcephalus as distinct species within Schizopygopsis. Molecular calibrations showed that species within the middle Yangtze species diverged earlier (~4.5 Mya) than species within the Indus River (~3.0 Mya), the Mekong River (~2.8 Mya) and the Tsangpo + Salween rivers (~2.5 Mya). The most recent evolutionary splits occurred among species from the upper and lower Yangtze River, the Yellow River and the Qiadam Basin at about 1.8 to 0.3 Mya. Our molecular evidence and use of the molecular clock calibration have allowed us to associate speciation events within the genus Schizopygopsis to the formation and separation of paleo-drainage connections caused by tectonic events during the uplifting of the Qinghai-Tibetan Plateau (~4.5 Mya). This work underlines the dominant role of vicariance in shaping the evolutionary history of the genus Schizopygopsis. Further research using multiple loci and more extensive sampling will reveal a more complete picture of the phylogenetic relationships and biogeography of Schizopygopsis fishes.
... These fishes are the only taxon within the most successful family Cyprinidae that have well adapted to the hostile environment of the Tibetan Plateau (He, et al. 2004). The schizothoracine fishes dominate the plateau lakes and torrential mountain streams of the Tibetan Plateau (He and Chen 2006) and have evolved a number of unique traits to adapt to the hypoxia and cold environment (Wu and Wu 1991). Therefore, they have been considered as excellent models to investigate high altitude adaptation of fishes. ...
... Thus, it was suggested that the three phases of uplift of the Tibetan Plateau have contributed to the speciation of the schizothoracine fishes. The species Gymnodiptychus pachycheilus, belonging to the specialized schizothoracine fishes, distributes only in the headwater area in the northeast of the Tibetan Plateau with elevations of 2750-3750 m (He, et al. 2004) and is the most dominant group of the ichthyofauna of the Yellow River (Wu and Wu 1991). However, human activities, including overexploitation and habitat destruction, have affected this species considerably, which makes G. pachycheilus listed as an endangered species in the " China Species Red List " (Wang and Xie 2004). ...
... Here, using the next-generation sequencing technology, we have generated and annotated the first comprehensive transcriptome resources for a schizothoracine fish (G. pachycheilus), which is endemic to the Tibetan Plateau and shows many unique traits to adapt to highland environments (Su, et al. 2014; Wu and Wu 1991). We generated more than seven thousand pairwise orthologous genes between zebrafish and over six thousand orthologous genes among other fish genomes, which are important bases for comparative genomic studies of adaptation in fishes. ...
Elucidating the genetic mechanisms of organismal adaptation to the Tibetan Plateau at a genomic scale can provide insights into the process of adaptive evolution. Many highland species have been investigated and various candidate genes that may be responsible for highland adaptation have been identified. However, we know little about the genomic basis of adaptation to Tibet in fishes. Here we performed transcriptome sequencing of a schizothoracine fish (Gymnodiptychus pachycheilus) and used it to identify potential genetic mechanisms of highland adaptation. We obtained totally 66,105 assembled unigenes, of which 7,232 were assigned as putative one-to-one orthologs in zebrafish. Comparative gene annotations from several species indicated that at least 350 genes lost and 41 gained since the divergence between G. pachycheilus and zebrafish. An analysis of 6,324 orthologs among zebrafish, fugu, medaka, and spotted gar identified consistent evidence for genome-wide accelerated evolution in G. pachycheilus and only the terminal branch of G. pachycheilus had an elevated Ka/Ks ratio than the ancestral branch. Many functional categories related to hypoxia and energy metabolism exhibited rapid evolution in G. pachycheilus relative to zebrafish. Genes showing signature of rapid evolution and positive selection in the G. pachycheilus lineage were also enriched in functions associated with energy metabolism and hypoxia. The first genomic resources for fish in the Tibetan Plateau and evolutionary analyses provided some novel insights into highland adaptation in fishes and served as a foundation for future studies aiming to identify candidate genes underlying the genetic bases of adaptation to Tibet in fishes.
© The Author(s) 2014. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.
... Tibetan loaches (Cobitoidea: Triplophysa) are important components of the ichthyofauna on the Tibetan Plateau (Chen, Chen, & Liu, 1996;Wu & Wu, 1992;Zhu, 1989). The northeastern margin of the Tibetan Plateau has many climatic zones that span the elevational gradients, and the Tibetan loaches in this area stem from the same species pool and have undergone similar evolutionary histories (Feng et al., 2017;He, Chen, & Chen, 2006). ...
... The study area is in the northeastern margin of the Tibetan Plateau (32°14′-40°36′N, 94°19′-106°08′E) with a total area of approximately 469,000 km 2 (Figure 1). The altitudes of the drainage systems in this region range from 600 to 4,300 m (a.s.l.), and the systems were treated as a single unit as they were historically connected (Chen et al., 1996;Wu & Wu, 1992;Zhu, 1989). Nineteen valid species have been detected in this region (Feng et al., 2017). ...
It is widely believed that species richness patterns (SRPs) are shaped by both ecological and evolutionary processes. However, the relative roles of these processes remain unclear, especially for aquatic organisms. In this study, we integrated ecological and evolutionary measures to tease apart the relative influences of these factors on the SRP of Tibetan loaches along an extensive elevational gradient. We found that the Tibetan loaches displayed a richness pattern that peaked at midelevations. The mean annual temperature (MAT), mid-domain effect (MDE), and summed age of colonization (SAC, complex of colonization age and colonization frequency) were the main drivers, accounting for 85%, 51%, and 88% of the variations in the SRP, respectively. The three predictors had very high combined effects (MAT-MDE-SAC, MAT-SAC, and MDE-SAC were 44%, 38%, and 6%, respectively). Our analyses suggested that energy input, time-for-speciation, and species dispersal may directly guide the SRP or mediate it by geometric constraints. Conclusively, the SRP of the Tibetan loaches with elevation is the outcome of interactions between biogeographical processes and regional ecological conditions.
... It has been reported that the current phylogenetic pattern of the extant schizothoracine is driven by the environmental changes and river system transition caused by the uplift of the TP Li, Tang, Zhang, & Zhao, 2016;Zhao et al., 2011). Based on the studies of schizothoracine, we hypothesized that the current phylogenetic pattern of S. stoliczkai also reflects the ancient geographic and climate changes in the northwest of the TP (McQueen, Post, & Mills, 1986;Wu & Wu, 1992). To test this assumption, we collected 403 samples from all the recorded inhabits of S. stoliczkai in China (Figure 2) (Wu & Wu, 1992 ...
... Based on the studies of schizothoracine, we hypothesized that the current phylogenetic pattern of S. stoliczkai also reflects the ancient geographic and climate changes in the northwest of the TP (McQueen, Post, & Mills, 1986;Wu & Wu, 1992). To test this assumption, we collected 403 samples from all the recorded inhabits of S. stoliczkai in China (Figure 2) (Wu & Wu, 1992 ...
Schizopygopsis stoliczkai (Cyprinidae, subfamily Schizothoracinae) is one of the major freshwater fishes endemic to the northwestern margin of the Tibetan Plateau. In the current study, we used mitochondrial DNA markers cytochrome b (Cyt b) and 16S rRNA (16S), as well as the nuclear marker, the second intron of the nuclear beta-actin gene (Act2), to uncover the phylogeography of S. stoliczkai. In total, we obtained 74 haplotypes from 403 mitochondrial concatenated sequences. The mtDNA markers depict the phylogenetic structures of S. stoliczkai, which consist of clade North and clade South. The split time of the two clades is dated back to 4.27 Mya (95% HPD = 1.96–8.20 Mya). The estimated split time is earlier than the beginning of the ice age of Pleistocene (2.60 Mya), suggesting that the northwestern area of the Tibetan Plateau probably contain at least two glacial refugia for S. stoliczkai. SAMOVA supports the formation of four groups: (i) the Karakash River group; (ii) The Lake Pangong group; (iii) the Shiquan River group; (iv) the Southern Basin group. Clade North included Karakash River, Lake Pangong, and Shiquan River groups, while seven populations of clade South share the haplotypes. Genetic diversity, star-like network, BSP analysis, as well as negative neutrality tests indicate recent expansions events of S. stoliczkai. Conclusively, our results illustrate the phylogeography of S. stoliczkai, implying the Shiquan River is presumably the main refuge for S. stoliczkai.
... Fish of the subfamily Schizothoracinae (Teleostei: Cyprinidae) are mainly distributed in rivers on the Qinghai-Tibetan Plateau and its peripheral areas [1] in China. These fish are well adapted to the harsh conditions of the Plateau [2] and have evolved many specific traits to adapt to an environment that exposes them to low temperatures, high levels of radiation, and hypoxia [1] . ...
... Fish of the subfamily Schizothoracinae (Teleostei: Cyprinidae) are mainly distributed in rivers on the Qinghai-Tibetan Plateau and its peripheral areas [1] in China. These fish are well adapted to the harsh conditions of the Plateau [2] and have evolved many specific traits to adapt to an environment that exposes them to low temperatures, high levels of radiation, and hypoxia [1] . As a consequence , Schizothoracinae fish are regarded as excellent models to study high altitude adaptations in animals [3]. ...
... Tibetan high-altitude lakes are typically oligotrophic, and have a high pH and alkalinity, which is different from many European and Arctic lakes. In the unique environment hundreds of endemic fish species breed (Wu and Wu, 1992). The organisms in lakes of the TP typically have relatively low growth and metabolic rates, which further complicate the transfer dynamics and extend the residence time of POPs along the food chains. ...
... As shown in Table S8, the food items found in our fish samples were dominated by aquatic insects, shrimp, benthic invertebrates and sediment, which had an accumulative contribution of more than 85%. Similar food diet compositions were also reported for other Tibetan fish in previous literatures (Wu and Wu, 1992; Qing et al., 2001). The food web structure also exerts great influence on POPs bioaccumulation (Bentzen et al., 1996). ...
... Fish of the subfamily Schizothoracinae (Teleostei: Cyprinidae) are mainly distributed in rivers on the Qinghai-Tibetan Plateau and its peripheral areas [1] in China. These fish are well adapted to the harsh conditions of the Plateau [2] and have evolved many specific traits to adapt to an environment that exposes them to low temperatures, high levels of radiation, and hypoxia [1] . ...
... Fish of the subfamily Schizothoracinae (Teleostei: Cyprinidae) are mainly distributed in rivers on the Qinghai-Tibetan Plateau and its peripheral areas [1] in China. These fish are well adapted to the harsh conditions of the Plateau [2] and have evolved many specific traits to adapt to an environment that exposes them to low temperatures, high levels of radiation, and hypoxia [1] . As a consequence , Schizothoracinae fish are regarded as excellent models to study high altitude adaptations in animals [3]. ...
Schizothorax prenanti (S. prenanti) is mainly distributed in the upstream regions of the Yangtze River and its tributaries in China. This species is indigenous and commercially important. However, in recent years, wild populations and aquacultures have faced the serious challenges of germplasm variation loss and an increased susceptibility to a range of pathogens. Currently, the genetics and immune mechanisms of S. prenanti are unknown, partly due to a lack of genome and transcriptome information. Here, we sought to identify genes related to immune functions and to identify molecular markers to study the function of these genes and for trait mapping. To this end, the transcriptome from spleen tissues of S. prenanti was analyzed and sequenced. Using paired-end reads from the Illumina Hiseq2500 platform, 48,517 transcripts were isolated from the spleen transcriptome. These transcripts could be clustered into 37,785 unigenes with an N50 length of 2,539 bp. The majority of the unigenes (35,653, 94.4%) were successfully annotated using non-redundant nucleotide sequence analysis (nt), and the non-redundant protein (nr), Swiss-Prot, Gene Ontology (GO), and Kyoto Encyclopedia of Genes and Genomes (KEGG) databases. KEGG pathway assignment identified more than 500 immune-related genes. Furthermore, 7,545 putative simple sequence repeats (SSRs), 857,535 single nucleotide polymorphisms (SNPs), and 53,481 insertion/deletion (InDels) were detected from the transcriptome. This is the first reported high-throughput transcriptome analysis of S. prenanti, and it provides valuable genetic resources for the investigation of immune mechanisms, conservation of germplasm, and molecular marker-assisted breeding of S. prenanti.
... The genus Triplophysa is a strongly diverged fish group, with 137 currently recognized species, most of which occur on the Tibetan Plateau and adjacent regions (Froese and Pauly 2014; Zhu 1989). As the primary component of the fish fauna on the Tibetan Plateau, Triplophysa fishes evolved specific morphological characteristics for adaptation to the highland environment, such as gradually disappeared scales (scaleless) for withstanding cold, abundant blood vessels in gill filament and pituitary for efficient breathing, black peritoneum for responding to ultraviolet (UV) radiation, and secondary sexual characters of male for reproduction (He, et al. 2006; Liu, et al. 2009; Ren, et al. 2011; Wu and Wu 1992; Zhu 1989). Therefore, these plateau-dwelling loaches are an iconic symbol for studies of highland adaptations in fishes; however, the genetic bases for those adaptations remain unknown. ...
... The genus Triplophysa is a strongly diverged fish group, with 137 currently recognized species, most of which occur on the Tibetan Plateau and adjacent regions (Zhu 1989; Froese and Pauly 2014). As the primary component of the fish fauna on the Tibetan Plateau, Triplophysa fishes evolved specific morphological characteristics for adaptation to the highland environment, such as gradually disappeared scales (scaleless) for withstanding cold, abundant blood vessels in gill filament and pituitary for efficient breathing, black peritoneum for responding to ultraviolet radiation, and secondary sexual characters of male for reproduction (Zhu 1989; Wu Y and Wu C 1992; He et al. 2006; Liu et al. 2009; Ren et al. 2011). Therefore, these plateau-dwelling loaches are an iconic symbol for studies of highland adaptations in fishes; however, the genetic bases for those adaptations remain unknown. ...
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.
... Fishes of the genus Schizothorax Heckel, 1838, possess two pairs of barbels, 3 or 4 rows of pharyngeal teeth and two rows of enlarged scales along the vent (Chen & Cao, 2000; Chu & Chen, 1989; Day, 1878; Tilak, 1987; Wu & Wu, 1991). The taxonomy of Schizothorax is contentious (Chen & Cao, 2000; Wu & Wu, 1992; Tilak, 1987; Day, 1878). ...
... Specimens previously identified as Schizothorax griseus from different drainages often appear superficially similar to each other. However, examination of a large series of specimens from different drainages shows that these fishes in fact represent several distinct species., 1986; Huang, 1989; Mo in Chu & Chen, 1989; Wu & Wu, 1991; Chen & Cao, 2000 ). Based on our examination , it is clear that the specimens from this region labeled S. griseus are not conspecific with the species by this name from the Yangtse River. ...
The identity of Schizothorax griseus Pellegrin, 1931, is clarified and the species redescribed. Three new species previously identified as S. griseus are described: S. nudiventris, from the Lancang Jiang, China; S. heterophysallidos, from the Nanpan Jiang, China; and S. beipanensis, from the upper Beipan Jiang, China, The group comprising Schizothorax griseus, S. nudiventris, S. heterophysallidos and S. beipanensis can be diagnosed from other members of this genus by the absence of an obvious horny sheath on the lower jaw; lower lip developed with three labial lobes in mature individuals; postlabial groove continuous, with a small labial lobe present in the middle of the lower lip; last unbranched dorsal-fin ray strong, its posterior edge with numerous serrae; and scales absent on ventral surface between pectoral fins in adults (except in 5. griseus). Schizothorax griseus differs from S. nudiventris, S. heterophysallidos and S. beipanensis by the presence (vs. absence) of concealed scales in the skin on the ventral surface between the pectoral fins in adults; the presence (vs. absence) of a shallow ethmoidal groove before the nostrils; and having barbels much longer than eye diameter (eye diameter 33.4-93.7 % (vs. 57.2-160.0) of maxillary-barbel length). Schizothorax nudiventris is distinguished from S. heterophysallidos and S. beipanensis in having only the proximal 3/4 (vs. entirety) of the last unbranched dorsal-fin ray strong; pelvic-fin origin opposite or posterior (vs. opposite or anterior) to vertical through dorsal-fin origin; and irregular black spots present (vs. absent) on side of body. Schizothorax heterophysallidos is distinguished from S. griseus, S. nudiventris and S. beipanensis in having a larger posterior chamber of the air bladder (vs. posterior chamber as large as, or slightly larger than, anterior one), length of posterior chamber 3-6 (vs. 2) times length of anterior chamber. Schizothorax beipanensis is distinguished from S. griseus by the absence (vs. presence) of scales on the thorax in mature individuals; absence (vs. presence) of black spots on side of body; and having the maxillary barbel 58.5-120.1 % SL (vs. 33.4-93.7 % SL)
... Both plants and animals have endemic representatives living in the plateau at present. When focusing on the recent fish fauna living in the cold waters on the plateau, the schizothoracins (Cyprinidae) is the most important component, comprising the majority of the fish fauna there (Wu and Tan 1991;Wu and Wu 1992). The distribution of schizothoracins is strictly confined to the Tibetan Plateau and the surrounding Central Asia highlands (Cao et al. 1981;Wu, 1984). ...
... Focusing on the recent fish fauna of the Tibetan Plateau and its surrounding area, cyprinines living at high altitude have more vertebrae than those at low altitude. (Wu and Wu 1992;Yue 2000). As to the fossil, T. tchangii with 33 vertebrae represents Paleogene fish in tropic-subtropic lowland warm water, similar to recent South Asia before the Tibetan Plateau began to uplift, while P. macrocephalus with 46-48 vertebrae represents early Neogene fish in at least moderate height cool water after the Tibetan Plateau began to uplift. ...
A new Oligocene-aged genus and species of cyprinid fish, Tchunglinius tchangii, from the Nima Basin in the center of the Tibetan Plateau is described. The new genus is assigned to the subfamily Cyprininae because of its protractile mouth, spoon-shaped pharyngeal teeth, dorsal fin originating anterior to the insertion of the pelvic fin, dorsal fin with four unbranched rays and anal fin with three unbranched rays. This genus differs from other cyprinine genera on the characteristic combination of large head and low body; also, the head length is larger than the body depth. Other differences include the following: the last unbranched ray of both dorsal and anal fin is smooth and articulated; it has an eight-branched ray in the dorsal fin and a five-branched ray in the anal fin; and it has five supraneurals, five hypurals and 33 vertebrae. Tchunglinius tchangii is closely related to recent small-bodied South-Asian cyprinine genera such as Puntius in small body size; therefore, the fossil reflects the Paleogene tropical-subtropical lowland fish fauna present there before the uplift of the Tibetan Plateau.
... P. kaznakovi prefer to consume aquatic insect larvae and benthic invertebrates such as Limnodrilus, the larvae of Diptera and caddisflies, and with a minor addition of diatoms and detritus. S. thermalis feeds mainly on Oscillatoria, diatoms and detritus, followed by larvae of chironomid and Dipteran, water beetles and crustaceans (Wu and Wu, 1992). In Tibet, S. nukiangensis begins upstream reproductive migration with the rise in water temperature in April, and spawns mainly from March to June. ...
... In Tibet, S. nukiangensis begins upstream reproductive migration with the rise in water temperature in April, and spawns mainly from March to June. P. kaznakovi and S. thermalis breed from April to May, and from April to August, respectively (Wu and Wu, 1992). Some studies have focused on the molecular phylogeny of these three fish species (He et al., 2004;Chen, 2006, 2007). ...
Length-weight relationships (LWR) for three cyprinid fish species collected from the headwaters of the Nujiang River in Tibet, China, were determined. The values of parameter b in the LWR equations were estimated as 2.54 for Schizopygopsis thermalis, 3.3 for Ptychobarbus kaznakovi, and 2.74 for Schizothorax nukiangensis, respectively. These are the first LWR records for the three species.
... It has experienced many tectonic movements and magmatic activity, with a complex geological structure and rich sedimentary rocks [24,25], as a multi-stage sedimentary basin. There are more than 30 salt lakes of different sizes distributed in the basin [26,27]. The Mahai Salt Lake is located in the Saishiteng Depression of the fault block on the northern margin of the Qaidam Basin [28,29] (Figure 1) [30,31]. ...
There are considerable reserves of low-grade solid potash resources in the shallow part of Mahai Salt Lake in the Qaidam Basin, and the lithium brine resources resulting from solid–liquid conversion and mining are quite abundant. The comprehensive utilization of these resources is an important and urgent problem. In this study, to fully utilize these resources, the shallow low-grade solid potash ore in Mahai Salt Lake was used for systematic simulated ore dissolution experiments, combined with geochemical and X-ray diffraction analyses. The following key results were obtained: (1) Most Li+ in the Mahai mining area was deposited on the soluble salt minerals in silt or clay, and the appropriate concentration of solvent can help to dissolve more Li+ and K+; (2) the saturation time of Li+ was longer than that of K+. Therefore, the dissolution time for the mine can be appropriately extended during the production process to dissolve more Li+; (3) the solid–liquid conversion aqueous solution mining method can separate the lithium part of clay deposits and is associated with salt rock in the brine, which is a potential lithium resource. These experimental results provide a theoretical basis for salt pan production.
... In addition to potassium, it is an important liquid mineral resource abundant in sodium, lithium, and rubidium (Chen et al, 1981). Porosity determines the ability of an aquifer to store liquid resources and, under certain conditions, it also controls the ability to retain, release, and transport liquids (Wang, 1986;Xiao, 2010). ...
Underground brine is an unusual water resource that contains abundant mineral resources. It is distributed widely in the Qaidam Basin, western China, a hyperarid inland basin located in the northern Tibetan Plateau. Pores in the brine storage medium act as storage space and transmission channels of underground brine. Therefore, the porosity of brine storage medium determines its ability to store brine. In this study, Mahai Salt Lake was used as the research area as a modern saline lake located in the north area of the Qaidam Basin. A total of 100 porosity samples were collected from eight sampling points in two profiles of the research area at sampling depths of 1.30–314.78 m. The porosity distribution characteristics and influencing factors in brine storage medium were analysed according to the measured porosity data. Based on analysis of the pore structure characteristics, the brine storage medium contains intercrystalline pores, unlike conventional freshwater storage mediums. Moreover, the primary salt rock is susceptible to dissolution by lighter brine, facilitating the formation of secondary porosity. Due to the formation of secondary pores, a porosity greater than 20% remains even at buried depths greater than 100 m. Based on the geological statistical analysis, due to the geographic location, salt formation time, and depositional environment, the porosity values of Mahai Salt Lake do not exhibit a wider distribution, but also show more extreme values than a nearby salt lake. Based on the porosity characteristics by depth, due to the presence of secondary pores, flooding, stratigraphic static pressure, and other factors, porosity shows fluctuations with increasing depth.
... This result show that evolutionary relationship is very close between S. waltoni, C. carpio, and B. rerio, consistent with the fact that three species belong to the Cyprinidae family. 33 The potential functions of all unigenes were predicted using the COG database. In all, 11 334 unigenes were grouped into 25 COG classications (Fig. 3) in S. waltoni. ...
Schizothorax waltoni (S. waltoni) is one kind of the subfamily Schizothoracinae and an indigenous economic tetraploid fish to Tibet in China. It is rated as a vulnerable species in the Red List of China's Vertebrates, owing to overexploitation and biological invasion. S. waltoni plays an important role in ecology and local fishery economy, but little information is known about genetic diversity, local adaptation, immune system and so on. Functional gene identification and molecular marker development are the first and essential step for the following biological function and genetics studies. For this purpose, the transcriptome from pooled tissues of three adult S. waltoni was sequenced and analyzed. Using paired-end reads from the Illumina Hiseq4000 platform, 83 103 transcripts with an N50 length of 2337 bp were assembled, which could be further clustered into 66 975 unigenes with an N50 length of 2087 bp. The majority of the unigenes (58 934, 87.99%) were successfully annotated by 7 public databases, and 15 KEGG pathways of immune-related genes were identified for the following functional research. Furthermore, 19 497 putative simple sequence repeats (SSRs) of 1–6 bp unit length were detected from 14 690 unigenes (21.93%) with an average distribution density of 1 : 3.28 kb. We identified 3590 unigenes (5.36%) containing more than one SSR, providing abundant potential polymorphic markers in functional genes. This is the first reported high-throughput transcriptome analysis of S. waltoni, and it would provide valuable genetic resources for the functional genes involved in multiple biological processes, including the immune system, genetic conservation, and molecular marker-assisted breeding of S. waltoni.
... Rapid cooling commenced at ca. 17 Ma as a result of basin incision and sediment evacuation . (Wu & Wu, 1992), the Kailas fish fauna is characterized by low species diversity and represented by cyprinids (Order Cypriniformes, Family Cyprinidae; Fig. 11). The dominant modern fish on the Tibetan Plateau are schizothoracines (Cyprinidae, Subfamily Schizothorinae; known as snow trout) endemic to the plateau and its surrounding areas, and probably evolved from another cyprinid subfamily Barbinae (sensu stricto) adapting to environmental changes that accompanied the development of the plateau. ...
The Himalayan-Tibetan Plateau is Earth's highest topographic feature, and formed largely during Cenozoic time as India collided with and subducted beneath southern Asia. The >1300 km long, late Oligocene-early Miocene Kailas basin formed within the collisional suture zone more than 35 Ma after the onset of collision, and provides a detailed picture of surface environments, processes, and possible geodynamic mechanisms operating within the suture zone during the ongoing convergence of India and Asia. We present new geochronological, sedimentological, organic geochemical, and palaeontological data from a previously undocumented 400 km long portion of the Kailas basin. The new data demonstrate that this part of the basin was partly occupied by large, deep, probably meromictic lakes surrounded by coal-forming swamps. Lacustrine facies include coarse- and fine-grained turbidites, profundal black shales, and marginal Gilbert-type deltas. Organic geochemical temperature proxies suggest that palaeolake water was warmer than 25°C, and cyprinid fish fossils indicate an ecology capable of supporting large fish. Our findings demonstrate a brief period of low elevation in the suture zone during Oligocene-Miocene time (26-21 Ma) and call for a geodynamic mechanism capable of producing a long (>1000 km) and narrow basin along the southern edge of the upper, Asian plate, long after the onset of intercontinental collision. Kailas basin deposits presently are exposed at elevations >6000 m, requiring dramatic elevation gain in the region after Kailas deposition, without strongly shortening the upper crust. Episodic Indian slab rollback, followed by break-off and subsequent renewal of flat-slab subduction, can account for features of the Kailas basin. This article is protected by copyright. All rights reserved.
... Термальный лжеосман, Schizopygopsis thermalis herzenstein (Cyprinidae). Род Schizopygopsis включает 8 видов, населяющих высокогорные азиатские реки [43]. Радиация рода была во многом увязана с тектоническими перестройками речной сети Центральной Азии, обусловленной поднятием Тибетского плато и формированием Гималаев [44][45][46][47]. ...
Геотермальные регионы отличаются подтоком подогретых вод и газов из недр к земной поверхности, что оказывает отепляющее влияние на экосистемы. В горячих источниках, теплых ручьях, подогретых озерах и болотах формируется необычная фауна, которая очень давно привлекает внимание зоологов и биогеографов. Многие из термальных популяций гидробионтов были описаны как локальные эндемичные таксоны видового или подвидового ранга на основании морфологических признаков. Однако их статус был предметом длительных дискуссий. В обзоре обобщены результаты молекулярных исследований различных видов пресноводных рыб, которые были обнаружены в термальных местообитаниях. Показано, что некоторые из них на самом деле представляют собой внутривидовые формы широко распространенных видов. Такие формы имеют четкие морфологические отличия от зональных популяций, но генетически идентичны или же очень близки к ним. Ряд других видов действительно представляет собой дивергентные филогенетические линии, которые можно рассматривать как локальные термофильные эндемики. Наибольшее число таких эндемиков обитает на юге США и в Мексике. Высокий уровень эндемизма фауны рыб в термах этих регионов может быть обусловлен их древностью, а также сходством условий среды зональных пустынных водоемов с термальными системами. Термальные водоемы Евразии, Северной и Центральной Америки наиболее успешно осваивают различные представители карпообразных рыб. В отдельных термах Крайнего Севера Евразии также встречаются популяции лососеобразных и колюшкообразных рыб. Субтропические термальные источники в Южной Америке активно заселяют харацинообразные, сомообразные и окунеобразные рыбы. Гидротермальные системы можно рассматривать как своего рода «эволюционные ловушки» для пресноводных рыб, из которых практически невозможно вернуться в зональное местообитание, поскольку эволюция в термах идет по пути специализации, адаптации к уникальному и очень локальному набору условий.
... For example, the eastern Himalayas support the highest plant diversity and richness on Earth, with four of the 34 biodiversity hotspots located in the Tibetan Plateau and adjacent areas (Myers et al., 2000; Xu and Wilkes, 2004). In term of fish, almost half of the native species in this region are endemic (72 of 152), most of them highly specialized and tightly adapted to the high elevation and mountainous environments (Wu and Wu, 1992). Growth is linked to other fitness-determining features dependent on size, reproduction, survival and longevity (Birkeland and Dayton, 2005 ). ...
... The genus Triplophysa Rendahl, 1933, is one of the largest groups in the family Nemacheilidae, including approximately 125 valid species, more than 85% of which are so far known from China (Froese & Pauly 2011;He 2008;Yang et al. 2012). It is known primarily from the Qinghai-Tibet Plateau and adjacent areas (Zhu 1989;Wu & Wu 1991), and distributed in the upper and middle Yangtze River, Nujiang River (upper Salween River), Lancangjiang River (upper Mekong River), Red River, Yellow River, and Pearl River drainages of China, upper Indus and Tigris River drainages of West Asia, and in river drainages of Central Asia as well (Zhu 1989;Zhou & Cui 1997;Prokofiev 2006). Triplophysa is uniquely distinguished by having a marked sexual dimorphism, males with an area of breeding tubercles between snout and eye on each side of head, and a thickened tuberculate pad on the dorsal surface of the outer broadened pectoral-fin rays (Zhu 1989). ...
A new species of nemacheilid loach, Triplophysa longliensis, is described from Yudonghe River, a small tributary of Pearl River in Guizhou Province, China. It can be distinguished from other valid Triplophysa loaches by the following combination of characters: body smooth and scaleless; head tapering; lips thin and smooth; posterior chamber of gas bladder highly developed, long, bag-shaped, tip reaching origin of pelvic fin; intestine short, bending in zigzag shape behind stomach; insertion of pelvic fin posterior to dorsal-fin origin; dorsal-fin origin closer to snout tip than to caudal-fin base; caudal fin deeply forked, upper lobe obviously longer than lower one; pelvic-fin tip reaching to anus.
... In the genus Schizothorax, interspecific haplotype sharing is a ubiquitous pattern in the same drainage 12,13,42 . First, species living in the same river drainage with a large distribution range may exhibit morphological variations 43 , and the shape of the mouth and lips (important characteristics used for fishes' diets and species identification 44 ) can vary depending on the developmental stages of individuals 45 , which may result in a lack of consensus regarding their taxonomy and lead to misidentification. Second, the pattern may also be attributed to rapid radiation 12 . ...
Nujiang River (NR), an essential component of the biodiversity hotspot of the
Mountains of Southwest China, possesses a characteristic fish fauna and contains
endemic species. Although previous studies on fish diversity in the NR have
primarily consisted of listings of the fish species observed during field
collections, in our study, we DNA-barcoded 1139 specimens belonging to 46
morphologically distinct fish species distributed throughout the NR basin by
employing multiple analytical approaches. According to our analyses, DNA barcoding
is an efficient method for the identification of fish by the presence of barcode
gaps. However, three invasive species are characterized by deep conspecific
divergences, generating multiple lineages and Operational Taxonomic Units (OTUs),
implying the possibility of cryptic species. At the other end of the spectrum, ten
species (from three genera) that are characterized by an overlap between their
intra- and interspecific genetic distances form a single genetic cluster and share
haplotypes. The neighbor-joining phenogram, Barcode Index Numbers (BINs) and
Automatic Barcode Gap Discovery (ABGD) identified 43 putative species, while the
General Mixed Yule-coalescence (GMYC) identified five more OTUs. Thus, our study
established a reliable DNA barcode reference library for the fish in the NR and
sheds new light on the local fish diversity.
... The major sympatric species living in the upper Yellow River, Gymnocypris eckloni eckloni Herzenstein, 1891, Platypharodon extremus Herzenstein, 1891 and Triplophysa pseudoscleroptera (Zhu & Wu, 1981), have no estimates in Fishbase. All three species are endemic to China and the Yellow River drainage (Wu and Wu, 1991). The first two are from Cypriniformes, Cyprinidae, and the last from Nemacheilidae. ...
Length-weight relationships (LWRs) of three Chinese endemic fish species (Gymnocypris eckloni eckloni Herzenstein, 1891, Platypharodon extremus Herzenstein, 1891 and Triplophysa pseudoscleroptera (Zhu & Wu, 1981)) were analyzed, collecting from the upper Yellow River (Xunhua and Guide Counties, Qinghai Province). Totally 347 specimens monthly collected by gill nets with 40 mm mesh size and traps with 5 m length from August to October 2014, were used to estimate the relationship parameters. The allometric factor b values ranged from 2.96 in T. pseudoscleroptera to 3.33 in G. eckloni eckloni. The condition factor a values varies between 0.0063 and 0.0175 in three species. Three WLRs of fishes distributed in the upper Yellow River were firstly reported and will fill in some of the empty spaces on endemic species in the Fishbase.
... Triplophysa fishes, also known as Plateau-dwelling loaches, are mainly distributed at high altitude rivers and lakes on the Qinghai-Tibetan Plateau (QTP) and its peripheral regions (Zhu, 1989; Prokofiev, 2001; He et al., 2011). The elevation in this area ranges from 700 to 5000 m, and the high altitudes are accompanied by hypoxia and low temperatures (Wu and Wu, 1992 ). As representatively endemic fishes of the QTP, Triplophysa dalaica (Kessler, 1876) (Cypriniformes: Balitoridae: Nemacheilinae) is adapted to the cold and hypoxic conditions of high-altitude habitats. ...
... Heckel (1838) for the first time reported ten species of schizothoracines in the genus Schizothorax from Kashmir (S. plagiostomus, S. sinuatus, S. curvifrons, S. longipinnis, S. niger, S. nasus, S. hugelii, S. micropogon, S. planifrons and S. esocinus). Schizothorax taxonomy is controversial (Mirza 1991;Talwar and Jhingran 1991;Wu and Wu 1992;Chen and Cao 2000), and the phylogenetic relationships and biogeography of this group are unclear. According to Raina and Petr (1999) it is often difficult to decide whether these are different species, different phenotypes of single species or an intermediate situation between the two extremes. ...
Despite numerous studies on the taxonomy of a highly complex group of schizothoracine (snow trouts), with over five recognized species from Kashmir, India (Schizothorax niger, Schizothorax esocinus, Schizothorax plagiostomus, Schizothorax curvifrons and Schizothorax labiatus) based on traditional morphological data, the relationships between these species is poorly understood and the taxonomic validity is still under debate. To resolve the evolutionary relationships among these species, we sequenced mitochondrial fragments, including 16Sr RNA, Cytb and the D-loop. Separate analyses of 16S and Cytb showed intermixing of the species and 16S was found more conserved than Cytb. The D-loop was found highly variable and showed length variation between and within species. Length variation was observed in di-nucleotide (TA)n microsatellite repeats with a variable number of repeat units (n = 7–14) that did not show heteroplasmy. Central conserved sequence blocks (CSBs) in D-loop sequences were found comparable to other vertebrate species. All phylogenetic reconstructions recovered the focal taxa as a monophyletic clade within the schizothoracines. Analyses with combined mitochondrial data sets showed close genetic relationships of all the five species. In addition to a close relationship between S. niger and S. curvifrons, two distinct groupings of S.
ecoscinus and S. plagiostomus were supported by all the analyses. This study gives an insight into molecular phylogeny of the species and improves our understanding of historical and taxonomic relationships derived from morphological and ecological studies.
The reproductive characteristics of Gymnocypris firmispinatus were determined from 582 individuals collected in the Anning River, China. The sex ratio (male: female) was 1:1 for the overall population but 3.1:1 for the mature group. Females reached a larger total length and total weight (242 mm and 148.17 g) than males (163 mm and 41.58 g). Lengths and ages at maturity were estimated to be 83.4 mm and 2.4 years for males, 130.7 mm and 5.9 years for females, respectively. Based on the analyses of gonad development and the size distribution of oocytes, G. firmispinatus spawned from March to May with high degree of the spawning synchronicity. The opposite tendency between gonado-somatic index and hepato-somatic index from January to March in females indicated that the energy requirement for the oocytes growth may be derived from the liver. In addition, the estimated mean fecundity and mean relative fecundity were 1227 and 29.7 eggs per g total weight. The fecundity of G. firmispinatus increased linearly with increasing of total length, total weight and ovary weight. This study provides details about the reproduction suggesting that G. firmispinatus might be especially vulnerable to exploitation in the Anning River.
Myoglobin (Mb) is an oxygen-binding hemoprotein that was once thought to be exclusively expressed in oxidative myocytes of skeletal and cardiac muscle where it serves in oxygen storage and facilitates intracellular oxygen diffusion. In this study, we cloned the coding sequence of the Mb gene from four species, representing three groups, of the schizothoracine fish endemic to the Qinghai-Tibetan Plateau (QTP), then conducted molecular evolution analyses. We also investigated tissue expression patterns of Mb and the expression response to moderate and severe hypoxia at the mRNA and protein levels in a representative of the highly specialized schizothoracine fish species, Schizopygopsis pylzovi. Molecular evolution analyses showed that Mb from the highly specialized schizothoracine fish have undergone positive selection and one positively selected residue (81L) was identified, which is located in the F helix, close to or in contact with the heme. We present tentative evidence that the Mb duplication event occurred in the ancestor of the schizothoracine and Cyprininae fish (common carp and goldfish), and that the Mb2 paralog was subsequently lost in the schizothoracine fish. In S. pylzovi, Mb mRNA is expressed in various tissues with the exception of the intestine and gill, but all such tissues, including the liver, muscle, kidney, brain, eye, and skin, expressed very low levels of Mb mRNA (< 8.0%) relative to that of the heart. The trace levels of Mb expression in non-muscle tissues are perhaps the major reason why non-muscle Mb remained undiscovered for so long. The expression response of the Mb gene to hypoxia at the mRNA and protein levels was strikingly different in S. pylzovi compared to that found in the common carp, medaka, zebrafish, and goldfish, suggesting that the hypoxia response of Mb in fish may be species and tissue-specific. Notably, severe hypoxia induced significant expression of Mb at the mRNA and protein levels in the S. pylzovi heart, which suggests Mb has a major role in the supply of oxygen to the heart of Tibetan Plateau fish.
Background:
Genome-wide studies on highland adaptation mechanism in terrestrial animal have been widely reported with few available for aquatic animals. Tibetan Schizothoracinae species are ideal model systems to study speciation and adaptation of fish. The Schizothoracin fish, Gymnocypris przewalskii ganzihonensis had underwent the ecological niche shift from salt water to freshwater, and also experienced a recent split from Gymnocypris przewalskii przewalskii. In addition, G. p. ganzihonensis inhabited harsh aquatic environment including low temperature and hypoxia as well as other Schizothoracinae species, its genetic mechanism of highland adaptation have yet to be determined.
Results:
Our study used comparative genomic analysis based on the transcriptomic data of G. p. ganzihonensis and other four fish genome datasets to investigate the genetic basis of highland adaptation in Schizothoracin fish. We found that Schizothoracin fish lineage on the terminal branch had an elevated dN/dS ratio than its ancestral branch. A total of 202 gene ontology (GO) categories involved into transport, energy metabolism and immune response had accelerated evolutionary rates than zebrafish. Interestingly, we also identified 162 genes showing signature of positive selection (PSG) involved into energy metabolism, transport and immune response in G. p. ganzihonesis. While, we failed to find any PSG related to hypoxia response as previous studies.
Conclusions:
Comparative genomic analysis based on G. p. ganzihonensis transcriptome data revealed significant genomic signature of accelerated evolution ongoing within Tibetan Schizothoracinae species lineage. Molecular evolution analysis suggested that genes involved in energy metabolism, transport and immune response functions in Schizothoracin fish underwent positive selection, especially in innate immunity including toll-like receptor signaling pathway genes. Taken together, our result as a case study in Schizothoracinae species provides novel insights in understanding the aquatic animal adaptation to extreme environment on the Tibetan Plateau, and also provides valuable genomic resource for further functional verification studies.
Environmental acclimation is important episode in wildlife occupation of the high-altitude Tibetan Plateau (TP). Transcriptome-wide studies on thermal acclimation mechanism in fish species are rarely revealed in Tibetan Plateau fish at high altitude. Thus, we used mRNA and miRNA transcriptome sequencing to investigate regulation of thermal acclimation in larval Tibetan naked carp, Gymnocypris przewalskii. We first remodeled the regulation network of mRNA and miRNA in thermal acclimation, and then identified differential expression of miRNAs and target mRNAs enriched in metabolic and digestive pathways. Interestingly, we identified two candidate genes contributed to normal skeletal development. The altered expression of these gene groups could potentially be associated with the developmental issues of deformity and induced larval death. Our results have three important implications: first, these findings provide strong evidences to support our hypothesis that G. przewalskii possess ability to build heat-tolerance against the controversial issue. Second, this study shows that transcriptional and post-transcriptional regulations are extensively involved in thermal acclimation. Third, the integrated mRNA and microRNA transcriptome analyses provide a large number of valuable genetic resources for future studies on environmental stress response in G. przewalskii and as a case study in Tibetan Schizothoracine fish.
The present research was conducted to study the morphology, histology and enzymatic activities of the digestive tract of Gymnocypris eckloni by light and transmission electron microscopes as well as by enzyme assays. The digestive tract of G. eckloni consisted of the oropharyngeal cavity, oesophagus and intestine. The wall of the digestive tract was composed of mucosa, submucosa, muscularis and serosa but lacked muscularis mucosa and glands. The stratified epithelium of the oropharyngeal cavity and oesophagus contained numerous mucous cells. Taste buds were found in the epithelium of the oropharyngeal cavity. A large number of isolated longitudinal striated muscular bundles were present in the submucosa of the oesophagus. The mucosal epithelium of the intestine was composed of simple columnar cells containing absorptive, goblet and endocrine cells. Numerous mitochondria and endoplasmic reticulum were observed in the absorptive cells, especially in the anterior intestine. From the anterior to the posterior intestine, the number and length of mucosal folds and microvilli decreased, but the number of goblet cells increased. The intestinal coefficient was 2.38. Maximum trypsin activity was measured in the anterior intestine, while the lowest lipase and amylase activities were tested in the middle and posterior intestines, respectively. The results provided experimental evidence for evaluating physiological condition of G. eckloni digestive tract, which will be useful for improving current rearing practices and diagnoses of digestive tract diseases.
The length-weight (LWR) and length-length relationships (LLR) were estimated for three endemic fish species, including Schizothorax waltoni Regan, 1905, Schizothorax oconnori Lloyd, 1908, and Schizothorax macropogon Regan, 1905 in the Yarlung Tsangpo River. A total of 399 specimens were collected using gillnets and cast nets during February to August 2012 and March to May 2013. No information regarding length?weight and length?length relationships was reported previously in FishBase for these three endemic species.
This study presents length-weight relationships (LWRs) for two sympatric species of the subfamily Schizothoracinae (Cyprinidae), Gymnocypris chui and G. scleracanthus, captured in Lake Langcuo in Tibet, China. A total of 193 specimens were collected in June and July of 2014 and 2015 using gill nets of different mesh sizes (mesh size: 2 × 2 cm, 3 × 3 cm). Specimens included 76 G. chui and 117 G. scleracanthus. The values of parameter b in the LWRs equations were estimated as 2.875 for G. chui, and 2.773 for G. scleracanthus, respectively. These are the first LWRs records for the two sympatric species.
The genus Schizothorax (Cyprinidae), one of the most diverse genera of ichthyofauna of the Qinghai-Tibetan Plateau (QTP), is a good candidate for investigating patterns of genetic variation and evolutionary mechanisms. In this study, sequences from the mitochondrial control region, the cytochrome b gene, and two nuclear genes were used to re-examine the genetic diversity and investigate the evolutionary history of the Schizothorax species complex inhabiting the Lancang River. Three maternal clades were detected in the Schizothorax species complex, but frequent nuclear allele sharing also occurred among the three maternal clades. A discrepancy between topologies of mitochondrial and nuclear loci might result from introgression or/and incomplete lineage sorting. The divergence of the clades of the Schizothorax species complex was closely related to the Late Pliocene and Early Pleistocene orogenesis of the QTP and Southwest Mountains of China. Demographic analyses indicated that the species complex subsequently persisted in situ with stable populations during Pleistocene glacial cycling, which suggested that Pleistocene climate changes did not exert a remarkable influence on the species complex. Our study provides a comprehensive analysis of the genetic diversity and evolutionary history of the Schizothorax species complex in the Lancang River.
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.
The focus was on the length–weight relationships of three schizothoracinae species endemic to Tibet, including Schizothorax oconnori Lloyd, 1908, Ptychobarbus dipogon (Regan, 1905) and Schizopygopsis younghusbandi Regan, 1905, all of which are characterized by slow growth, late maturation and vulnerability to the environment (Ma et al., 2010, 2012; Duan et al., 2014). Among them, Schizothorax oconnori is an endangered fish and listed in the China species Red List (Wang and Xie, 2004, 2009). Samples were obtained by drift net fishing (mesh size 2 cm × 3 cm; 50 m net length) in November 2008. The r2 value was 0.94, 0.97, 0.98 and the b value 3.51, 3.12, 3.16, representing Schizothorax oconnori, Ptychobarbus dipogon, and Schizopygopsis younghusbandi, respectively.
The morphology and intraspecific structure of Triplophysa orientalis inhabiting the inland basins of Tsaidam (northeastern edge of the Tibetan Plateau) and the basin of the upper reach of the Huang He River in China were studied. Significant morphological differences between the populations from the inland basins and the Huang He River were revealed; the latter were distinguished as a separate subspecies T. o. hwanghoensis subsp. n. Intermediate character of some traits of the new subspecies between the nominative subspecies and T. hutjertjuensis was found; as a result, the status of the latter was reduced to the subspecies level. The synonymy of T. o. elongata with the nominative subspecies was confirmed. The differences between T. orientalis and T. obscura—morphologically poorly distinguishable species, sympatric in the basin of the upper reach of the Huang He River—were defined more exactly.
Schizothorax prenanti (S. prenanti), one of the important endemic commercial fish in China, is mainly distributing in the upstream of the River Yangtze and the tributaries. The wild population is facing serious challenges of germplasm degeneration due to the overfishing, water pollution and construction of hydropower stations; therefore, it is very urgent to develop genetic resource of S. prenanti to protect the wild population. In this study, we used Illumina Hiseq2500 sequencing to develop single nucleotide polymorphism (SNP) markers in S. prenanti. From 37,785 unigenes with functional annotation, 857,535 putative SNPs were identified. Among them, 33 SNPs from immune-related genes were randomly selected and 20 loci exhibited significant polymorphisms in genotyping by Sequenom MassARRAY. As far as our best knowledge, this is the first report about the SNP markers development in S. prenanti based on Illumina RNA sequencing. These SNP markers should not only be useful for population conversation, but also for construction of genetic linkage map and economic performance improvement of S. prenanti.
The water level oscillation of endorheic lakes and extent change of glaciers associated with the Asian monsoon are known as prominent representatives of climatic and environmental events in the Tibetan Plateau during the Quaternary. However, details process in spatial and temporal changes are still debated. We use the schizothoracines as a palaeoclimatic proxy to test two hypotheses concerning the evolution of Quaternary glaciations and lakes of the Changtang Plateau: (1) the Tibetan glaciations generally tended to decrease since the middle Pleistocene; (2) the lakes expansion was driven by summer monsoon rainfall. Based on a wide range-wide sampling throughout in the Changtang Plateau and its adjacent drainages, we constructed phylogeny and demographic histories of schizothoracines in the Changtang Plateau. Our results showed that the populations of the exorheic rivers and lakes in southern Tibet possessed higher genetic variability, earlier coalescent and expansion times than those of the endorheic lakes in the Changtang Plateau. Population expansions are highly consistent with phases of strong summer monsoon and high lake level during interglacial stages. The maximum growth rate intervals showed three pulses from 64.7 to 54.8, 39.6 to 31.0, and 14.9 to 2.4 kya respectively. The significant positive correlations were found between regional precipitation and genetic diversity, as well as coalescence time of populations in the endorheic lakes. We suggested that the demographic history of the schizothoracines reflects the spatial and temporal changes in climate and lake level, in particular, in regional precipitation gradients associated with changes of the South Asian monsoon, and supports the climatic hypothesis of a general diminishing tend in Tibetan glaciations in the Tibetan Plateau since the middle Pleistocene.
The results of a phylogenetic analysis of the Asian catfish family Sisoridae are presented in this study. The phylogenetic relationships of 106 (out of the 246) species of sisorid catfishes (representing over 40 % of the species diversity) were elucidated utilizing 197 morphological characters. Although a parsimony analysis failed to fully resolve the relationships of the 106 species in this study, nearly all of the genera analyzed (20 out of 22, with the exception of Ayarnangra and Erethistes) were recognized as natural; diagnoses for all 23 sisorid genera are provided. Novel generic interrelationships within the family were also recovered in this study. Two clades within the Sisoridae were recovered (Glyptosterninae and Sisorinae), with the Sisorinae being recovered as composed of three subclades (Bagariini, Erethistini and Sisorini). Diagnoses for these clades are provided, and aspects of the phylogeny in relation to the historical biogeography, as well as the evolution of body size and the thoracic adhesive apparatus in the group are also discussed.
Common economic aquatic products are important contributors to the human food supply. However, with the rapid globalization of the aquatic products industry, aquatic products market has become increasingly disordered. Therefore, an accurate and convenient method for identifying common economic aquatic products is important and necessary in many areas. DNA barcoding, which constitutes the analysis of a short fragment of the mitochondrial cytochrome c oxidase subunit I (COI) sequence, has been widely used in species identification. To discriminate common economic aquatic species using DNA barcoding, we collected 534 COI barcode sequences of 66 common species consisting of 39 fish, 9 crustaceans and 18 mollusks. The intraspecific genetic distances based on the Kimura 2-parameter (K2P) model were less than 1.37% for fish, 7.32% for crustaceans and 3.40% for mollusks, whereas the intragenus distances ranged from 3.91% to 13.82% for fish, 14.99%-16.17% for crustaceans and 14.82%-16.36% for mollusks. The average intraspecific K2P distance was also compared with the average intragenus distance. The taxonomic resolution ratio values obtained for fish, crustaceans and mollusks were 58.50, 21.59 and 27.63 respectively, which are higher than the threshold of (10×). A neighbor-joining (NJ) tree based on the K2P distance, and a maximum likelihood (ML) tree, based on the GTR + I + G model, were constructed, and all of the species could be identified unambiguously in the trees with several branches exhibiting high bootstrap values. Our results demonstrated high efficiency of DNA barcoding as an efficient molecular tool for the identification of common economic aquatic products, and 8 substitute species were successfully detected in 66 species. Our analyses also indicated that the common aquatic products trade industry could be effectively monitored and managed by DNA barcoding. Therefore, a simple identification database of common economic aquatic products was constructed.
Yang, Jian, Chen, Xiaoyong, Yang, Junxing (2008): Clarification of the nomenclatural status of Gymnodiptychus integrigymnatus (Cypriniformes, Cyprinidae). Zootaxa 1897: 67-68
Length–weight (LWRs) and length–length relationships (LLRs) were estimated for four important endemic fish species representating two genera and one family from the upper Yellow River in the Tibetan Plateau, China. Three of the species are endemic to the Tibetan Plateau, and the fourth is endemic to the Yellow River. The b values of all species were within expected ranges, varying between 2.54 and 3.33. The LLRs were highly correlated. The data of the four species represent the first description of their length–weight and length–length relationships.
D. maculates is a kind of specialized Schizothoracinae fish has been locally listed as a protected animal in Xinjiang Province, China. Ili River located in north of Tianshan Mountain and Tarim River located in north of Qinghai-Tibetan Plateau were two main distribution areas of this fish. To investigate the genetic diversity and genetic structure of D. maculates, four populations from Tarim River system and two populations from Ili River system were collected in this study. A 570-bp sequence of the control region was obtained for 105 specimens. Twenty-four haplotypes were detected from six populations, only Kunes River population and Kashi River population shared haplotypes with each other. For all the populations examined, the haplotype diversity (h) was 0.904 8±0.012 6, nucleotide diversity (π) was 0.027 9±0.013 9, and the average number of pairwise nucleotide differences (k) was 15.878 3±7.139 1. The analysis of molecular variance (AMOVA) showed that 86.31% of the total genetic variation was apportioned among populations, and the variation within sampled populations was 13.69%. Genetic differences among sampled populations were highly significant. F
st statistical test indicated that all populations were significantly divergent from each other (P<0.01). The largest F
st value was between Yurungkash River population and Muzat River population, while the smallest F
st value was between Kunes River population and Kashi River population. NJ phylogenetic tree of D-loop haplotypes revealed two main clades. The neutrality test and mismatch distribution analysis suggested that the fish had went through a recent population expansion. The uplift of Tianshan Mountain and movement of Qinghai-Tibetan Plateau might contribute to the wide genetic divergence of D. maculates in northwest China.
The Yangtze River (6,380 km long) is the longest river in Asia and the third-longest one in the world. Its river basin (a complex riverine–lacustrine network) is especially rich in fish fauna, representing high species richness and endemism, and therefore is a globally significant area for preserving fish biodiversity (Dudgeon 2000; Park et al. 2003). However, during the past several decades, loss of fish biodiversity in the Yangtze River Basin has been accelerated by a series of direct and indirect effects of human activities and environmental changes, e.g., disappearance, shrinkage, and fragmentation of habitats for fish spawning, feeding and migration, overfishing, water pollution, and invasion of exotic species (Zeng 1990; Xie and Chen 1999). Despite numerous publications on ichthyological research in the Yangtze River Basin since the 1950s, synthesis and analysis or assessment of fish distribution patterns and quantification of major threats to fishes are still limited, which in t ...
The identity of Pseudecheneis sulcata is clarified in this study, and the species is redescribed. Pseudecheneis sulcata (from the Brahmaputra River drainage) can be distinguished from congeners in having a unique combination of the lack of a prominent bony spur on the anterodorsal surface of the first dorsal-fin pterygiophore, presence of a first dorsal-fin element, bifid neural spines on the complex vertebra, the neural spines of the last 2–3 preanal and first 6–7 postanal vertebrae gradually increasing in height, separate pelvic fins, a less convex snout when viewed laterally, presence of pale spots on the body, 36–39 vertebrae, 12–14 transverse laminae on the thoracic adhesive apparatus, pelvic-fin length 21.2–28.7% SL, pectoral-fin length 121.6–156.3 % HL, length of adipose-fin base 17.8–22.7% SL, length of caudal peduncle 25.0–28.3% SL, depth of caudal peduncle 4.0–5.2% SL, and eye diameter 8.8–10.6% HL. Pseudecheneis eddsi, new species, is described from tributaries of the Ganges River in Nepal. Pseudecheneis eddsi can be distinguished from congeners by a unique combination of the presence of a prominent bony spur on the anterodorsal surface of the first dorsal-fin pterygiophore, presence of a first dorsal-fin element, bifid neural spines on the complex vertebra, the neural spines of the last 2–3 preanal and first 6–7 postanal vertebrae gradually increasing in height, separate pelvic fins, gently rounded snout when viewed dorsally, presence of pale spots on the body, 36–39 vertebrae, pelvic-fin length 18.0–20.9% SL, pectoral-fin length 114.9–156.0% HL, length of adipose-fin base 19.5–24.3% SL, length of caudal peduncle 25.2–27.8% SL, depth of caudal peduncle 3.5–5.3% SL, and eye diameter 9.6–12.8% HL. Pseudecheneis stenura, new species, is also described from the Irrawaddy River drainage in southwestern China. Pseudecheneis stenura can be distinguished from congeners by a unique combination of the presence of a prominent bony spur on the anterodorsal surface of the first dorsal-fin pterygiophore, presence of a first dorsal-fin element, bifid neural spines on the complex vertebra, the neural spines of the last 2–3 preanal and first 6–7 postanal vertebrae gradually increasing in height, separate pelvic fins, presence of pale spots on the body, 38–40 vertebrae, pelvic-fin length 20.4–24.3% SL, pectoral-fin length 160.4–196.9% HL, length of adipose-fin base 18.8–23.7% SL, length of caudal peduncle 30.3–34.5% SL, depth of caudal peduncle 2.9–3.6% SL, and eye diameter 9.2–12.8% HL. A key to the species of Pseudecheneis is provided.
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