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The fragmentation and homogenization of habitats have seriously affected the fishery resources of the Pearl River. To protect the fishery resources, a novel artificial habitat, constructed using bamboo and palm slices, was deployed in the Youjiang River, a tributary of the Pearl River in China. The results of field and laboratory experiments showed that fish abundance, species richness and Shannon–Wiener diversity index were higher in the artificial habitats than at the control sites. There was no significant impact on fish biomass, as the artificial habitats attracted more Cultrinae and Gobioninae fish that are of a smaller size. Artificial habitats can serve as spawning grounds for fish that produce sticky eggs and refuges that improve the survival rates of juvenile fishes. This study revealed that this novel artificial habitat created suitable habitats and suitable spawning substrate for fish, improved fish richness and diversity in the structureless freshwater ecosystem like the Youjiang River., The fragmentation and homogenization of habitats have seriously affected the fishery resources of the Pearl River. To protect the fishery resources, a new type of artificial habitat, consisting of bamboo and palm slices, was deployed in the Youjiang River, a tributary of the Pearl River, China. This study revealed that the new type of artificial habitat can form new habitats for fish in the Youjiang River.

We assessed the relationship of Schizothoracinae species with other subfamilies Alburninae, Xenocyprinae, Cultrinae and Squaliobarbinae of family Cyprinidae by creating the phylogenetic trees using complete mitogenome and 12S and 16S RNA. Our representative species show the great affiliation with other but separated from a group composed of Metzia mesembrinum, Metzia longinasus, Metzia lineata and Metzia formosae of subfamily Alburninae while other subfamilies formed distinct group. The members of subfamily Schizothoracinae shows separate line of evolution from subfamily Barbinae.

In terms of taxonomic status, common carp ( Cyprinus carpio , Cyprininae) and crucian carp ( Carassius auratus , Cyprininae) are different species; however, in this study, a newborn homodiploid crucian carp-like fish (2 n =100) (2 n NCRC) lineage (F1–F3) was established from the interspecific hybridization of female common carp (2 n =100)×male blunt snout bream ( Megalobrama amblycephala , Cultrinae, 2 n =48). The phenotypes and genotypes of 2 n NCRC differed from those of its parents but were closely related to those of the existing diploid crucian carp. We further sequenced the whole mitochondrial (mt) genomes of the 2 n NCRC lineage from F1 to F3. The paternal mtDNA fragments were stably embedded in the mt-genomes of F1–F3 generations of 2 n NCRC to form chimeric DNA fragments. Along with this chimeric process, numerous base sites of F1–F3 generations of 2 n NCRC underwent mutations. Most of these mutation sites were consistent with the existing diploid crucian carp. Moreover, the mtDNA organization and nucleotide composition of 2 n NCRC were more similar to those of the existing diploid crucian carp than those of the parents. The inheritable chimeric DNA fragments and mutant loci in the mt-genomes of different generations of 2 n NCRC provided important evidence of the mtDNA change process in the newborn lineage derived from hybridization of different species. Our findings demonstrated for the first time that the paternal mtDNA were transmitted into the mt-genomes of homodiploid lineage, which provided new insights into the existence of paternal mtDNA in the mtDNA inheritance.

Distant hybridization is an effective tool to create offspring with different ploidy levels and is widely used in plants and lower organisms. In this study, the diploid gynogenetic grass carp (2nGGC, 2n = 48) and triploid hybrid (3nGT, 3n = 72) progenies of female grass carp (Ctenopharyngodon idellus, GC, Leuciscinae, 2n = 48) × male topmouth culter (Erythroculter ilishaeformis, TC, Cultrinae, 2n = 48) were successfully obtained by distant hybridization. The results regarding the chromosomal number, DNA content, 5S rDNA and fluorescence in situ hybridization (FISH) showed 2nGGC was derived from gynogenesis with 48 chromosomes and not a hybrid of GC and TC, while 3nGT was a triploid hybrid with 72 chromosomes. 3nGT exhibited significant phenotypic differences from GC and TC, but 2nGGC resembled GC. With regard to feeding, both 2nGGC and 3nGT were herbivorous. However, the total amino acid contents in the muscles of both 2nGGC and 3nGT were significantly higher than that in GC (P

The complete mitochondrial DNA genome of Anabarilius brevianalis was determined. The entire mitochondrial genome is 16,610 bp in length and contains 13 protein-coding genes, 2 ribosomal RNA (rRNA) ...

The complete mitochondrial DNA genome of Anabarilius grahami was determined by the primer walking sequence method. The entire mitochondrial genome is 16,612 bp in length and contains 13 protein-coding genes, 2 ribosomal RNA (rRNA) genes, 22 transfer RNA (tRNA) genes, and one control region (CR). As in other teleosts, most mitochondrial genes are encoded on the heavy strand, except for ND6 and eight tRNA genes which are encoded on the light strand. The overall nucleotide composition was 28.9% A, 24.8% T, 27.9% C, and 18.3% G, respectively, with a slight A+T bias (53.7%). Phylogenetic analysis based on 12 concatenated protein-coding genes of the heavy strand shows the evolutionary position of A. grahami is more closely related to two species of the genus Hemiculter within the subfamily Cultrinae.

It is commonly believed that hybridization might lead to the formation of new polyploidy species, but it is unclear whether hybridization can produce a new homodiploid species. Here, we report the spontaneous occurrence of a new crucian carp-like homodiploid fish (2n = 100) that originated from the interspecific hybridization of female common carp (Cyprinus carpio, Cyprininae, 2n = 100) × male blunt snout bream (Megalobrama amblycephala, Cultrinae, 2n = 48). The phenotype and reproductive traits of this new crucian carp-like homodiploid fish were found to be very similar to those of the existing diploid species (diploid crucian carp; Carassius auratus). FISH and 5S rDNA analyses revealed that the genotype of the crucian carp-like homodiploid fish differs from those of its parents but is closely related to that of diploid crucian carp. The results provide evidence of the existence of a possible route through which the distant hybridization of this cross can generate crucian carp. The new type of homodiploid fish is of great value in fish genetic breeding and for studying the early evolutionary process.

We describe the complete mitochondrial genome of the Endangered fish Anabarilius liui yalongensis. It is a circular molecule of 16,608 bp in size, and all genes show the typical gene arrangement conforming to the vertebrate consensus. The cytochrome c oxidase subunit I (COI) sequence of A. liui yalongensis and other 21 species from 14 genera were used for phylogenetic analysis by Bayesian inference and maximum likelihood methods. The topology demonstrated that the A. liui yalongensis clustered with A. grahami are closely to Hemiculter branch within the subfamily Cultrinae.

Toxabramis houdemeri belongs to the genus Toxabramis in the subfamily of Cultrinae (Cyprinidae). We first determine the complete mitochondrial genome of T. houdemeri in this study. It is 16 618 bp in length, with the base composition on the heavy strand: 30.79% A, 16.61% G, 27.29% C, and 25.31% T. It has the typical vertebrate mitochondrial gene arrangement, including 13 protein-coding genes, 22 tRNA genes, 2 rRNA genes, and a D-loop region. Phylogenetic analysis showed that T. houdemeri was clustered into one branch of the subfamily of Cultrinae, and closely related to Hemiculter leucisculus. The present study will contribute to genetic resources conservation of T. houdemeri and studying its population genetic structure and phylogenetic relationships.

The complete mitochondrial genome of Osteobrama belangeri was obtained, using Illumina high-throughput NextSeq 500 with 2 × 150 bp sequencing of mitochondrial DNA. The mitochondrial genome of O. belangeri was 16,602 bp in length (GenBank Accession No. KY887473), comprised of 13 protein coding genes, 22 tRNA genes, 2 rRNA genes and a control region, i.e. D-loop. In present mitogenome, 11 short sequence repeats were identified and validated in silico. The arrangement of genes was found identical to other Cypriniformes fish mitogenomes, available in NCBI database. Phylogenetic relationship established in the present study also supported that genus Osteobrama is member of subfamily Cyprininae (tribe: smiliogastrini) not Cultrinae, which provide useful insights into taxonomic status of the genus.