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Acipenser baerii is one of the most important sources of caviar production. However, the population of the A. baerii is constantly being reduced in recent years due to dam construction, overfishing, and water pollution. Insufficient molecular markers have limited the effective conservation and management of this species; In the present study, we reported the isolation and characterization of 34 SNP markers in A. baerii; The minor allele frequency ranged from 0.050 to 0.483. The observed heterozygosity varied from 0.100 to 0.933, while the expected heterozygosity ranged from 0.097 to 0.508. Polymorphic information content ranged from 0.090 to 0.375. Seven loci showed significant deviations from the HWE after Bonferroni correction; The novel polymorphic SNPs will be helpful for the future study on molecular-aided breeding, population conservation, and construction of genetic linkage map for this species.

Rice-crayfish (Procambarus clarkii) coculture is an effective farming mode and has been promoted in various regions of China. However, infection in crayfish can be a significant economic drain. We found crayfish infected with Vibrio parahemolyticus (VP), and to understand the molecular mechanisms of the immune responses of crayfish to VP infection, Illumina sequencing was employed to identify changes in the mRNA of hepatopancreatic tissue. A total of 47.30 and 43.01million high-quality transcriptome reads were generated from the hepatopancreatic samples of the experimental group (EG) and control group (CG), respectively. We found 5559 genes were significantly differentially expressed, including 2521 up-regulated genes (45.35%) and 3038 down-regulated genes (54.65%). These genes were enriched in 126 GO terms and 76 KEGG pathways (P ≤ 0.05), including the MAPK and PI3K-Akt signaling pathways and cell adhesion molecules, with 23 up-regulated genes and 3 down-regulated genes related to immune responses in the EG relative to the CG. Histopathological analysis revealed that the epithelial cells of the hepatopancreatic tubules in the EG were severely atrophic, necrotic, and exfoliated, resulting in thin and collapsing hepatopancreatic tubules. The expression patterns of 8 differentially expressed genes involved in immune responses were validated by quantitative real-time RT-PCR. These results provide a valuable basis for the immune responses of crayfish to acute hepatopancreatic necrosis disease at transcriptome level.

Chemical oxygen demand and ammonia nitrogen were key water pollutants under state control, and key factories were required to conduct online monitoring. In order to evaluate the accuracy of the online instrument, the online equipment comparison monitoring of 20 key factories in 8 industries was conducted for 4 years. The wastewater of factories in the same industry has similar contaminant discharge concentration. The mean value of relative error absolute value was below 20% for medium and high concentration of chemical oxygen demand (above 30 mg/L) and ammonia nitrogen (above 1 mg/L) in water samples. For high chlorine concentration and coloured water samples, the online monitoring error was large, so the method needs to be improved.

Schizopygopsis chengi baoxingensis is endemic to the Baoxing River in China and may become an endangered species due to its very narrow habitat and the construction of hydropower dams. In this study, we successfully sequenced the first mitochondrial genome of S. c. baoxingensis. The mitogenome is 16,787 bp in length, containing 13 protein-coding genes, two rRNA genes, 22 tRNA genes and a control region (D-loop). The overall base composition of the H-strand is 28.5% A, 26.2% T, 18.4% C, and 26.9% G, with a slight AT bias of 54.7%. The sequenced mtDNA genome of S. c. baoxingensis is similar in gene arrangement to that of other cyprinidaes except for a 191 bp non-coding region found between tRNA(Thr) and tRNA(Pro).

Mathematical model is formulated for description of thermophysical processes at laser welding of metal plates for the case when modifying nanoparticles of refractory compounds (nanopowder inoculators – NPI) are introduced into the weld pool. Specially prepared nanoparticles of refractory compounds serve here as crystallization centers, i.e. in fact they are exogenous inoculants on which surface clusters are grouped. This can be used to control the melt crystallization process and formation of its structure, and, therefore, properties of the weld seam. As an example, calculation results of the butt welding of aluminum alloy and steel plates are presented. The results of calculation and experimental data comparison are shown.

Elongate loach (Leptobotia elongata (Bleeker)), an endemic fish species to China, is a famous ornamental freshwater fish. Here, a comparative study of mtDNA control region (D-loop) (835 bp) sequences was performed to analyze its wild population structure and evaluate the genetic diversity for 110 individuals from five locations in the upper reaches of the Yangtze River, China. A total of 49 polymorphic sites and 45 haplotypes yielded high haplotype diversity (h = 0.952), but low nucleotide diversity (π = 0.00454) as that of many fish species. Sequence divergences between haplotypes ranged from 0.0033 ± 0.0011 to 0.0050 ± 0.0012 in intra-groups, and from 0.0037 ± 0.0.0011 to 0.0050 ± 0.0012 between groups. Significant values of Tajima’s D (−1.86383, P 0.05), and estimates of gene flows among groups were extremely high (Nm = 28.88), suggesting low genetic divergence between populations in the species. The lack of genetic differentiation among groups is most likely due to the combined gene flow from the downstream movement of eggs and larvae with currents and the upstream or downstream migration of adults throughout the distribution. These groups of L. elongata distributed in upper reaches of the Yangtze River should be considered as a single management unit.

Garra kempi, a small-sized economic fish, is mainly distributed in Tibet of China. In this study, we successfully sequenced the first mitochondrial genome of G. kempi. The mitogenome is 17 104 bp in length, containing 13 protein-coding genes, two rRNA genes, 22 tRNA genes, and 2 control regions (D-loop). Unlike the typical mitochondrial genome organization in vertebrate, the tRNAPro gene of G. kempi is located between two control regions, and a 246 bp repeat unit is identified in the second control region. In this paper, we utilized 12 protein-coding genes of G. kempi and other 10 closely species to construct the species phylogenetic tree to verify the accuracy of G. kempi.

The ya-fish, Schizothorax prenanti, is a well-known commercial cold-water fish species with the hexaploid karyotype distributed in the upper reaches of the Yangtze River and its tributaries on the western Sichuan Plateau in China. The complete mitogenome of S. prenanti is 16,587 bp in length, containing 37 genes of 13 protein-coding genes, 22 tRNA genes, 2 rRNA genes and a control region (D-loop). The gene nucleotide composition of S. prenanti is 29.6% A, 25.4% T, 27.1% C and 17.9% G, with a slight AT bias of 55.0%. The complete mitogenome sequence of S. prenanti could provide useful data for further studies on genetic structure and diversity, as well as the artificial cultivation and breeding of S. prenanti.

The Liobagrus marginatus is an economic fish which distribute in the upstream of Yangtze river and its distributary. For its taste fresh, environmental pollution and overfishing, its population declined drastically and body miniaturization in recent decades, so it is essential to protect its resource. In this study, the complete mitochondrial genome sequence of Liobagrus marginatus was sequenced, which contains 22 tRNA genes, 13 protein-coding genes, 2 rRNA genes, and a non-coding control region with the total length of 16,497 bp. The gene arrangement and composition are similar to most of other fish. Most of the genes are encoded on heavy-strand, except for eight tRNA and ND6 genes. Just like most other vertebrates, the bias of G and C has been found in statistics results of different genes/regions. The complete mitochondrial genome sequence of Liobagrus marginatus would contribute to better understand population genetics, evolution of this lineage, and will help administrative departments to make rules and laws to protect it.

The Elongate loach (Leptobotia elongata) belongs to family Cobitidae, which is endemic to the middle and upper reaches of the Yangtze River in China. In this study, the complete mitochondrial genome of L. elongata was sequenced. It was determined to be 16,591 bases. The nucleotide sequence data of 12 heavy-strand protein-coding genes of L. elongata and other 12 Cobitidae species were used for phylogenetic analyses. Trees constructed using Bayesian and maximum parsimony showed a similar topology demonstrating that L. elongate was clustered in subfamily Botiinae being sister to the subfamily Cobitinae. The trees also suggested that the genera Cobitis were polyphyletic.

Principal component analysis (PCA) were applied to assess surface water quality of the Songhuajiang River basin, China. Thirteen physical-chemical parameters in 25 stations were collected monthly during the period of 2008. Three factors were extracted by PCA, which explained 83.79% of the total variance. The first factor (PCA1) was positive correlated with permanganate index, BOD 5 , NH 3 -N, COD Cr , TN, and had negative loading on DO. The second factor (PCA2) captured variables of heavy metals, while pH, petroleum accounted for the greatest loading for factor 3(PCA3). Twenty five monitoring sites were clustered into three clusters based on 9 water quality parameters which were exceeded the water quality standards. The GIS maps of point source pollution yield and fertilizer pollution yield, together with water monitoring sites were applied to identify the main pollution sources. Industrial wastewater, agricultural activities and urban runoff influenced most of water quality variables. In high pollution area and moderate pollution area, multiple source pollution dominated. In low pollution area, the main pollution source was non-point source. These results provide information that can help local government to make better pollution control strategies for the Songhuajiang River basin.

The beardless sucking bard, Garra imberba, is an important economic freshwater fish with very limited yield. In this study, we successfully sequenced the first mitochondrial genome of G. imberba by PCR. The mitogenome is 16,600 bp in length, containing 13 protein-coding genes, two rRNA genes, 22 tRNA genes and a control region (D-loop). The overall base composition of the H-strand is 31.5% A, 26.7% T, 16.1% C, and 25.8% G, with a slight AT bias of 58.2%. Most of the genes are encoded on heavy strand, except for eight tRNAs (tRNA(Gln), tRNA(Ala), tRNA(Asn), tRNA(Cys), tRNA(Tyr), tRNA(Ser), tRNA(Glu) and tRNA(Pro)) and ND6 genes.

The stress state in the upper crust of the China mainland is discussed on the basis of in situ stress data measured by both hydrofracturing and overcoring techniques during the last ten years. From these measurements, it appears that the horizontal stresses are characterized by strong directionality, which varies from region to region. The maximum horizontal shear stress increases linearly with depth and its gradient varies with region. Both the vertical gradients of the maximum horizontal shear stress and the horizontal principal stress are much higher in West China than in East China. Many data show that the direction of the maximum horizontal principal stress, related to the geological structure and recent crustal deformation within the area, is almost uniform over vast regions.