Ultrafast sound production mechanism in one of the smallest vertebrates.

Motion is the basis of nearly all animal behavior. Evolution has led to some extraordinary specializations of propulsion mechanisms among invertebrates, including the mandibles of the dracula ant and the claw of the pistol shrimp. In contrast, vertebrate skeletal movement is considered to be limited by the speed of muscle, saturating around 250 Hz. Here, we describe the unique propulsion mechanism by which Danionella cerebrum, a miniature cyprinid fish of only 12 mm length, produces high amplitude sounds exceeding 140 dB (re. 1 µPa, at a distance of one body length). Using a combination of high-speed video, micro-computed tomography (micro-CT), RNA profiling, and finite difference simulations, we found that D. cerebrum employ a unique sound production mechanism that involves a drumming cartilage, a specialized rib, and a dedicated muscle adapted for low fatigue. This apparatus accelerates the drumming cartilage at over 2,000 g, shooting it at the swim bladder to generate a rapid, loud pulse. These pulses are chained together to make calls with either bilaterally alternating or unilateral muscle contractions. D. cerebrum use this remarkable mechanism for acoustic communication with conspecifics.

Redescription of Cyprinion muscatense (Teleostei: Cyprinidae) with the first phylogenetic analysis of the genus.

Members of the genus Cyprinion (Cypriniformes: Cyprinidae) are found in the Indus River basin west to the Arabian Peninsula and the Tigris-Euphrates River drainages (Persian Gulf basin). The taxonomic status of Cyprinion including Cyprinion muscatense is poorly understood when compared to other cyprinid genera. C. muscatense has been considered as a member of the Cyprinion watsoni-microphthalmum group and a valid species endemic to the Arabian Peninsula. Here, we redescribe C. muscatense based on an integrative morphological and molecular approach and freshly sampled material from several localities in the Oman Mountains ecoregion. The results showed that C. muscatense is distinguished from the other Cyprinion species in the Arabian Peninsula by having a short, thin, and slightly serrated last unbranched dorsal fin ray; the lower number of circumpeduncular scales; lateral line scales; and also scales between the lateral line and the dorsal-fin origin. Subterminal mouth, presence of one pair of small barbels at the mouth corner, 3-4 unbranched and 9½-10½ dorsal-fin branched rays, 12-14 pectoral-fin rays, 7-8 pelvic-fin rays, 2-3 unbranched and 6½-7½ branched anal-fin rays, and 37-40 lateral line scales are other morphological characteristics of C. muscatense. C. muscatense is also well distinguished by molecular characters among its congeners. The first molecular phylogenetic analysis of the genus, covering all currently recognized Cyprinion species except for C. watsoni, is also presented. C. muscatense is resolved as the sister species to another endemic fish of the Arabian Peninsula Cyprinion mhalense, with a Kimura-2-Parameter model distance of 5.3%.

Dynamic mRNA and miRNA expression of the head during early development in bighead carp (Hypophthalmichthys nobilis).

BACKGROUND: Head of fish species, an exquisitely complex anatomical system, is important not only for studying fish evolution and development, but also for economic values. Currently, although some studies have been made on fish growth and body shapes, very limited information is available on the molecular mechanism of head development. RESULTS: In this study, RNA sequencing (RNA-Seq) and small RNA sequencing (sRNA-Seq) technologies were used to conduct integrated analysis for the head of bighead carp at different development stages, including 1, 3, 5, 15 and 30 Dph (days post hatch). By RNA-Seq data, 26 pathways related to growth and bone formation were identified as the main physiological processes during early development. Coupling this to sRNA-Seq data, we picked out six key pathways that may be responsible for head development, namely ECM receptor interaction, TNF signaling pathway, osteoclast differentiation, PI3K-Akt signaling pathway, Neuroactive ligand-receptor interaction and Jak-STAT signaling pathway. Totally, 114 important candidate genes from the six pathways were obtained. Then we found the top 20 key genes according to the degree value by cytohubba, which regulated cell growth, skeletal formation and blood homeostasis, such as pik3ca, pik3r1, egfr, vegfa, igf1 and itga2b. Finally, we also acquired 19 key miRNAs playing multiple roles in the perfection of various tissues in the head (such as brain, eye and mouth) and mineralization of head bone system, such as let-7e, miR-142a-5p, miR-144-3p, miR-23a-3p and miR-223. CONCLUSIONS: Results of this study will be informative for genetic mechanisms of head development and also provide potential candidate targets for the interaction regulation during early growth in bighead carp.

The subgenomes show asymmetric expression of alleles in hybrid lineages of Megalobrama amblycephala × Culter alburnus.

Hybridization drives rapid speciation by shaping novel genotypic and phenotypic profiles. Genomic incompatibility and transcriptome shock have been observed in hybrids, although this is rarer in animals than in plants. Using the newly sequenced genomes of the blunt snout bream (Megalobrama amblycephala [BSB]) and the topmouth culter (Culter alburnus [TC]), we focused on the sequence variation and gene expression changes in the reciprocal intergeneric hybrid lineages (F1-F3) of BSB × TC. A genome-wide transcriptional analysis identified 145-974 expressed recombinant genes in the successive generations of hybrid fish, suggesting the rapid emergence of allelic variation following hybridization. Some gradual changes of gene expression with additive and dominance effects and various cis and trans regulations were observed from F1 to F3 in the two hybrid lineages. These asymmetric patterns of gene expression represent the alternative strategies for counteracting deleterious effects of the subgenomes and improving adaptability of novel hybrids. Furthermore, we identified positive selection and additive expression patterns in transforming growth factor, beta 1b (tgfb1b), which may account for the morphological variations of the pharyngeal jaw in the two hybrid lineages. Our current findings provide insights into the evolution of vertebrate genomes immediately following hybridization.

Rapid adaptive radiation in a hillstream cyprinid fish in the East African White Nile River basin.

Adaptive radiation of freshwater fishes was long thought to be possible only in lacustrine environments. Recently, several studies have shown that riverine and stream environments also provide the ecological opportunity for adaptive radiation. In this study, we report on a riverine adaptive radiation of six ecomorphs of cyprinid hillstream fishes of the genus Garra in a river located in the Ethiopian Highlands in East Africa. Garra are predominantly highly specialized algae-scrapers with a wide distribution ranging from Southeast Asia to West Africa. However, adaptive phenotypic diversification in mouth type, sucking disc morphology, gut length and body shape have probably been found among these ecomorphs in a single Ethiopian river. Moreover, we found two novel phenotypes of Garra ("thick-lipped" and "predatory") that had not been discovered before in this species-rich genus (>160 species). Mitochondrial and genome-wide data suggest monophyletic, intrabasin evolution of Garra phenotypic diversity with signatures of gene flow from other local populations. Although sympatric ecomorphs are genetically distinct and can be considered to being young species as suggested by genome-wide single nucleotide polymorphism data, mitochondrial DNA was unable to identify any genetic structure suggesting recent and rapid speciation events. Some data suggest a hybrid origin of the novel "thick-lipped" ecomorph. Here we highlight how, driven by ecological opportunity, an ancestral trophically highly specialized lineage is likely to have rapidly radiated in a riverine environment promoted by the evolution of novel feeding strategies.

Association between Labeobarbus spp. (Teleostei: Cyprinidae) and environmental variables in the Luhoho basin (Eastern Congo River basin; DRC).

The African cyprinid genus Labeobarbus is characterized by a high polymorphism in mouth morphology. The association between four species of this genus (two chiselmouths, one rubberlip with a well-developed fleshy mental lobe on the lower jaw, i.e., a fleshy appendage on the chin, and one usually with a poorly developed one) and 26 environmental variables was investigated in four affluents of the Luhoho River in the Albertine Highlands of the Upper Congo basin. A combination of univariate and multivariate analyses suggested that differences exist in habitat composition at localities where different Labeobarbus species were reported, and within different mouth phenotypes. The association of L. longidorsalis with the presence of cobbles and pebbles and of L. brauni with the presence of boulders suggests that the occurrence of chiselmouths phenotype is associated with stony habitats, whereas phenotypes with a mental lobe, i.e., Labeobarbus longifilis and L. paucisquamatus, mostly occupy habitats without stones. Differences in the distribution between these two species appear to be linked to physico-chemical parameters such as electrical conductivity and water temperature rather than substrate type. The findings of this study are relevant for developing guidelines that aim effective local preservation and conservation of these Labeobarbus species.

Convergent evolution misled taxonomy in schizothoracine fishes (Cypriniformes: Cyprinidae).

Highly specialized grade (HSG; genera Gymnocypris, Oxygymnocypris, Schizopygopsis, Platypharodon and Chuanchia) of the Schizothoracinae (Cypriniformes: Cyprinidae) are endemic to the Qinghai-Tibet Plateau (QTP). Previously, two distinct ecomorphs were recognized according to trophic traits. One was a limnetic omnivore with normal lower jaw morphology, terminal mouth, and moderate or dense gill rakers, mostly inhabiting in open water of lakes, including Gymnocypris and Oxygymnocypris. Another was a benthic feeder with inferior mouth, sparse gill rakers and sharp horny sheath on the lower jaw for scraping of attached prey off hard substrates, including Schizopygopsis, Platypharodon and Chuanchia. However, traditional taxonomy of HSG based on these trophic traits presented extensive conflicts with the molecular studies in recent years. The possible cause could be convergent evolution in morphology, retention of ancestral polymorphisms or mitochondrial introgression, but these hypotheses could not be assessed due to incomplete taxon sampling and only mitochondrial data employed in previous works. Here, we conducted the most comprehensive molecular analysis on HSG fishes to date, using four mitochondrial loci and 152,464 genome-wide SNPs, and including 21 of 24 putative species and one undescribed Schizopygopsis species. Both SNP and mtDNA trees confirmed extensive paraphyly of genera Gymnocypris and Schizopygopsis, where species often were clustered together by watershed instead of by genus. Basal split into the north clade B and the south clade C (ca. 3.03 Ma) approximately by the Tanggula-Tanitawen Mountains in SLAF tree coincided with a violent uplift of the QTP during the phase A of 'Qingzang movement' (ca. 3.6 Ma). Ancestral state reconstruction of the trophic ecomorph showed that the limnetic omnivore ecomorph had evolved repeatedly in clade B and C. Furthermore, we presented a striking case of convergent evolution between two 'subspecies' Gymnocypris chui chui and G. chui longimandibularis, which had diverged as early as two million years ago (ca. 2.42 Ma). Ecological analyses revealed that similar food utilization, particularly in zooplankton, was the main underlying driving force. This work showed an example of taxonomy with the most extensive errors at the genus/species levels due to convergent evolution and suggested that trophic traits could be misleading in fish taxonomy. Therefore, we propose a major generic revision for HSG species.

Adaptive Evolution of the Eda Gene and Scales Loss in Schizothoracine Fishes in Response to Uplift of the Tibetan Plateau.

Schizothoracine is the predominant wild fish subfamily of the Tibetan plateau (TP). Their scales, pharyngeal teeth and barbels have gradually regressed with increasing altitude. Schizothoracine have been divided into three groups: primitive, specialized and highly specialized. Ectodysplasin-A (Eda) has been considered as a major gene that contributes to the development of skin appendages. The present study cloned the Eda genes of 51 Schizothoracine fish species which represent the three groups and five Barbinae species. Phylogenetic analyses indicated that Eda may have acted as the genetic trigger for scale loss in the Schizothoracine. Furthermore, 14 single nucleotide polymorphisms (SNPs) and two deletions (18 bp and 6 bp in size), were also detected in the Eda coding sequence of the highly specialized group compared to the primitive group. The same SNPs and two indels result in four non-synonymous and two G-X-Y and 1 XY motif indels, which possibly contribute to significant structure changes in the Eda gene. The domain including (G-X-Y)n motif in the Eda gene is relatively conserved amongst teleosts. Based on the above results, we hypothesize that the evolution of Eda gene might be associated with the scale loss in Schizothoracine fishes in response to the phased uplift of the TP.

A new redfin species, Pseudobarbus skeltoni (Cyprinidae, Teleostei), from the Cape Floristic Region, South Africa.

A new cyprinid species, Pseudobarbus skeltoni sp. nov, is described from material recently collected in the upper Riviersonderend River (a major tributary of the Breede River system) and the Krom River (a tributary of the Molenaars River in the upper Breede River) in the Cape Floristic Region of South Africa. The new species is readily distinguished from congeners, except P. burgi and P burchelli, by having two pairs of prominent oral barbels. Pseudobarbus skeltoni can be distinguished from P. burgi and P burchelli by the following combination of characters: distinctive terminal (vs. subterminal) mouth in adults; mouth inferior in sub-adults and young adults of P skeltoni but lower lips are unretracted (vs. retracted) and lack a distinct cartilaginous plate; snout prominent; more slender head (head depth 64.2% of HL, vs. 70.1% of HL in P. burchelli and 74.1% of HL in P. burgi); and a longer head relative to standard length (30.5 % vs. 26.8% in P. burchelli and 25.8% in P. burgi). The new species attains the largest size of any Pseudobarbus. The restricted distribution and the small remaining population sizes of P skeltoni indicate that this species is highly threatened and requires immediate conservation attention.

Spectacular morphological novelty in a miniature cyprinid fish, Danionella dracula n. sp.

Danionella dracula is a new species of sexually dimorphic, miniature and highly developmentally truncated cyprinid fish. Compared with its close relative, the zebrafish Danio rerio, it lacks 44 bones or parts thereof and represents one of the most developmentally truncated vertebrates. Absence of the majority of bones appears to be due to developmental truncation via terminal deletion. In contrast to these larval-like features, D. dracula also shows several hyperossifications. Uniquely, among carp-like fishes, male D. dracula have a series of long, pointed odontoid processes on the jaws greatly resembling the jaw dentition of teleosts with true teeth. The anterior-most process in each jaw is extended as a canine-like fang projecting through the epithelium. True jaw teeth are absent from all 3700 species of cypriniforms and were lost at least in the Upper Eocene. It remains to be investigated, however, whether the conserved pathways to regulate tooth development in cypriniforms have been used in D. dracula to form and pattern the odontoid processes. This new species represents a remarkable example linking progenetic paedomorphosis via heterochronic change in developmental timing to the evolution of morphological novelties.

The youngest split in sympatric schizothoracine fish (Cyprinidae) is shaped by ecological adaptations in a Tibetan Plateau glacier lake.

Although new empirical evidence shows that sympatric speciation has occurred in some species, there are few indisputable model organisms for this process of speciation. The two subspecies (Gymnocypris eckloni eckloni and G. e. scoliostomus) of the schizothoracine Gymnocypris fish species complex from a small glacier lake in the Tibetan Plateau, Lake Sunmcuo, fit several of the key characteristics of the sympatric speciation model. We used combined mitochondrial control region sequences and the cytochrome b gene (1894 bp) to address the phylogenetics and population genetics of 232 specimens of G. e. eckloni and G. e. scoliostomus, as well as all of its closely related sister species. We found that: (i) a total of four old lineages were uncovered in the widespread G. e. eckloni, of which only one was shown to be shared with all G. e. scoliostomus individuals and (ii) the new subspecies (G. e. scoliostomus) evolved in Lake Sunmcuo from the ancestral G. e. eckloni population within approximately 0.057 Ma. These two taxa of the species complex are morphologically distinct, and reproductive isolation is further suggested. Ecological disruptive selection based on morphological traits (e.g. mouth cleft characters) and food utilization may be a mechanism of incipient speciation of two sympatric populations within Lake Sunmcuo. This study provides the first genetic evidence for sympatric speciation in the schizothoracine fish.

Cytogenetic survey of species of two distinct genera of Iberian nases (Cyprinidae, Leuciscinae) that hybridize extensively in nature. I. Evidence of a similar and conserved chromosome pattern with some few species-specific markers at macro-structural level.

Pseudochondrostoma duriense and Pseudochondrostoma polylepis hybridize extensively with Achondrostoma oligolepis in natural populations. In this first survey, karyotypes were comparatively analyzed by C-, AgNOR- and CMA(3)-banding procedures in pure (non-introgressed) fish specimens. Leuciscinae pattern was evidenced in the three species: metacentrics and submetacentrics dominance, a big subtelo/acrocentric (marker) chromosome pair and a 2n = 50; small macro-structural differences were observed. Heterochromatin was centromere-associated. Exceptions were found at sm1 and st/a1 long arms and at m1, sm3 and sm6 short arms. The st/a1 band was telomeric in the straight-mouth nases and sub-terminal in A. oligolepis. Multiple NORs of heterochromatic nature were found in sm pairs of the three species. Signals were telomeric except for one pair in A. oligolepis. Two to four structural and two functional NORs were found in P. duriense and P. polylepis, and four to six structural and four functional NORs in A. oligolepis. Species-specific markers will prove useful in hybrid zones' cytogenetic characterization and for in-depth studies of genome compatibility-related issues in future studies.

Molecular cloning, characterization and expression pattern of androgen receptor in Spinibarbus denticulatus.

Androgens play key roles in sex differentiation, gonadal maturation and reproductive behaviors and their actions are generally mediated through androgen receptor (AR). In the present study, isolation, sequencing and characterization of cDNA encoding AR and its temporal and spatial expression profiles in both sexes of Spinibarbus denticulate were carried out. Androgen receptor of Spinibarbus denticulate (sdAR) was 3172bp in length and encoded a 95.4kDa protein of 865 amino acids. Phylogenetic analysis and multiple amino acids sequence alignment indicated the close relationship and high score similarity of sdAR with ARs of other cyprinid species. A single transcript of approximate 3.2kb was identified in testis, liver and brain. RT-PCR assay characterized that sdAR mRNA was broadly distributed in both central nervous system (CNS) and most of peripheral tissues in male fish, while was confined to olfactory, telencephalon and hypothalamus of CNS and peripheral tissues including liver, spleen, head kidney, heart, and red muscle in females. During the embryonic development, sdAR mRNA was firstly detected at 16-cells stage and mid blastula stage with very weak signal. Little or no signal was detected in mid gastrula and neurula stages. The expression was occurred in the following developmental phases as well as in larvae of 4 days post hatching. During gonadal recrudescence process, liver of both sexes and testis were the most AR mRNA abundant tissues. In male fish, abundance of sdAR mRNA significantly varied in pituitary at fully recrudesced stage and brain at late recrudescing phase, respectively. No significant variation was found throughout the ovary recrudesce in each tissue checked. Our present work provided preliminary evidences that AR mediated androgen action on reproduction and development in both sexes of S. denticulate.

Phylogenetic relationships of Cypriniformes and plasticity of pharyngeal teeth in the adaptive radiation of cyprinids.

The Cypriniformes comprise approximately 4,200 species accounting for 25% of the diversity of all freshwater fish, which is widely distributed across the world's continents except Antarctica, South America, and Australia. The highest species diversity is found in Southeastern Asia. Despite its remarkable species diversity and broad-scale geographic patterns of distribution, the evolutionary history of this major freshwater fish group remains largely unresolved. To gain insight of the evolutionary history of Cypriniformes, we present a phylogeny of this group using 1 mitochondrial gene and 15 nuclear genes comprising a total of 14,061 bp. Bayesian inference using all gene fragments yielded a well resolved phylogeny, which is mostly consistent with topologies obtained from Maximum Likelihood analyses. Our results further confirmed the monophyly of Cypriniformes and seven constituent subclades including Cyprinidae, Catostomidae, Gyrinocheilidae, Balitoridae, Cobitidae, Nemacheilidae, and Botiidae. Bayesian divergence time analysis indicated that the origin of the Cypriniformes was about 193 Mya during the early Jurassic, coinciding with the onset of the Pangaea breakup. The basal divergence of Cypriniformes is 154 Mya during the late Jurassic. Our findings from molecular divergence and biogeographical analysis indicate the most likely initial geographical range of the ancient Cypriniformes was both East and South Asia (Southeastern area of Mesozoic Laurasia). Moreover, the burst in species diversity in Cyprinidae afforded by the nearly worldwide colonization is possibly in response to the plasticity of pharyngeal dentition. The present study demonstrates that the Cypriniformes was about 193 Mya during the early Jurassic, coinciding with the onset of the Pangaea breakup. The plasticity of pharyngeal dentition of cyprinids might contribute to the burst and radiation of this lineage. The phylogenetic and biogeographic analyses in this study help to improve our understanding of the evolutionary history of this diverse and important freshwater fish group.

Toxicological effects of irregularly shaped and spherical microplastics in a marine teleost, the sheepshead minnow (Cyprinodon variegatus).

The increasing global contamination of plastics in marine environments is raising public concerns about the potential hazards of microplastics to environmental and human health. Microplastics formed by the breakdown of larger plastics are typically irregular in shape. The objective of this study was to compare the effects of spherical or irregular shapes of microplastics on changes in organ distribution, swimming behaviors, gene expression, and enzyme activities in sheepshead minnow (Cyprinodon variegatus). Both types of microplastics accumulated in the digestive system, causing intestinal distention. However, when compared to spherical microplastics, irregular microplastics decreased swimming behavior (i.e., total distance travelled and maximum velocity) of sheepshead minnow. Both microplastics generated cellular reactive oxygen species (ROS), while ROS-related molecular changes (i.e., transcriptional and enzymatic characteristics) differed. This study provides toxicological insights into the impacts of environmentally relevant (fragmented) microplastics on fish and improves our understanding of the environmental effects of microplastics in the ecosystem.

Danionella dracula, an escape from the cypriniform Bauplan via developmental truncation?

We provide a detailed account of the osteology of the miniature Asian freshwater cyprinid fish Danionella dracula. The skeleton of D. dracula shows a high degree of developmental truncation when compared to most other cyprinids, including its close relative the zebrafish Danio rerio. Sixty-one bones, parts thereof or cartilages present in most other cyprinids are missing in D. dracula. This impressive organism-wide case of progenesis renders it one of the most developmentally truncated bony fishes or even vertebrates. Danionella dracula lacks six of the eight unique synapomorphies that define the order Cypriniformes and has, thus, departed from the cypriniform Bauplan more dramatically than any other member of this group. This escape from one of the most successful Baupläne among bony fishes may have been facilitated by the organism-wide progenesis encountered in D. dracula. By returning in its skeletal structure to the early developmental condition of other cypriniforms, D. dracula may have managed to overcome the evolutionary constraints associated with this Bauplan and opened up new evolutionary avenues that enabled it to evolve a number of striking morphological novelties, including its tooth-like odontoid processes and a complex drumming apparatus.

Squalius namak, a new chub from Lake Namak basin in Iran (Teleostei: Cyprinidae).

Squalius namak, new species, from the endorheic Lake Namak and Kavir basins in Iran, is distinguished from the species of the genus Squalius in the Persian Gulf and the southern Caspian Sea basins by having a wide and thick symphysial knob on the lower jaw, a convex posterior anal-fin margin, a bold, dark-grey or brown, roundish or crescent-shaped blotch at the posterior tip of each flank scale and orange caudal-, anal- and pelvic-fin rays in life. Squalius namak is also characterized by four fixed, diagnostic nucleotide substitutions in the mtDNA COI barcode region.

The beta-actin gene of two species of southern top mouth minnow (Pseudorasbora parva) and the common fat minnow (Rhynchocypris oxycephalus) from the family Cyprinidae.

The beta-actin genes of two species of southern top mouth minnow and the common fat minnow from the family Cyprinidae were amplified and characterized. The exon and intron boundaries of the beta-actin gene matched the consensus acceptor and donor sites according to the GT/AG rule. The amino acid sequence identity between the two species is 100.0% while there is a lower degree of homology with other species in the range of 98.7% to 100.0%. The expression of the beta-actin gene was confirmed in liver.

The Complete mitochondrial genome of Spinibarbus denticulatus (Oshima).

Spinibarbus denticulatus (Oshima) is a rare and commercial fish. The complete mitochondrial genome sequence of S. denticulatus will help us to study the genetic of conversation, such as the genetic diversity and genetic structure, and provides the basis for the study in evolution. In this paper, the complete mitochondrial genome of S. denticulatus was determined to be 16,549 bp in length by Sanger sequencing technology. Thirteen protein-coding genes, 22 tRNA genes and 2 ribosomal genes were characterized. We also analyzed the structure of control region, 6 CSBs (CSB-1, CSB-2, CSB-3, CSB-D, CSB-E and CSB-F) and 1 TAS were identified, the control region also included an AT unit tandem repeat with 17 repeat times.

Paraqianlabeo lineatus, a new genus and species of labeonine fishes (Teleostei: Cyprinidae) from South China.

Paraqianlabeo, new genus, is described from the Chishui-He and Wu-Jiang rivers of the Yangtze River basin in Guizhou Province, South China. This new genus is distinguished from all other labeonine genera by a combination of morphological and molecular evidence. It is distinguished from all other Asian garrains by a unique oromandibular morphology; i.e., an arched, wide, rudimentary sucker formed by raised front and lateral margins of lower lip, postlabial groove and mental groove between middle and lateral lobes of lower lip chevron-shaped; anteroventral margin of rostral cap arched, thin and papillose; rostral cap not overlying upper lip, upper lip connected with lower lip around corners of mouth; well developed upper lip free from upper jaw; lower lip divided into two lateral fleshy lobes and one central plate, these two lateral fleshy lobes small and short, median lobe of lower lip large; anterior and anterolateral edges of upper and lower lip finely papillose; shallow, straight groove between lower lip and lower jaw; lower jaw bears thin, cornified cutting edge. Additionally, scales on mid-ventral region from pectoral fins to pelvic fins subcutaneous and half-hidden; dorsal fin with 3 simple and 7½-8 branched rays. Paraqianlabeo lineatus, new species, type species of this genus, has longitudinal dark stripe along side of body. Analyses of mitochondrial DNA data indicate that this new genus forms a highly diverged lineage within the Garraina group of Labeoninae.