Effect of Two Substrate Types on Feeding Efficiency by Juvenile Chinese Sturgeon Acipenser sinensis on Barcheek Goby Rhinogobius giurinus

We conducted experiments in an artificial stream tank with wild juvenile Chinese sturgeon Acipenser sinensis captured in the Yangtze Estuary to test the null hypothesis that their feeding efficiency on Barcheek goby Rhinogobius giurinus was not affected by sand vs. smooth glass substrate. Gobies are among the most common prey eaten by wild juvenile A. sinensis in the estuary. Test results found neither substrate type significantly affected feeding efficiency by juveniles. Previous research found a strong innate habitat preference of A. sinensis for sand substrate. The present results indicate that the preference for sand is not related to efficiently capturing R. giurinus on sand, but is an adaptation predisposing juvenile A. sinensis to seek sandy substrate where R. giurinus and other benthic forage are the most abundant in the Yangtze Estuary.

Prediction of Secondary Structure and B Cell Epitope of GH Protein from Acipenser sinensis

[ Objective] The aim was to predict the secondary structure and B cell epitope of growth hormone （GH） protein from Acipenser sinensis. [Method] With the amino acid sequence of GH protein from A. sinensis as the base, the secondary structure of GH protein from A. sinensis was predicted by the method of Gamier-Robson, Chou-Fasman and Karpius-Schulz, and its cell epitope was predicted by the method of Kyte- Doolittle, Emini and Jameson-Wolf. [Result] The sections of 18 -23, 55 -55, 67 -73, 83 -86,112 -114,151 -157 and 209 -211 in the N terminal of GH protein molecule had softer structure and these sections could sway or fold to produce more complex tertiary structure. The sections of 19 -23, 51 -71,84 -95, 128 -139, 164 -176 and 189 -195 in the N terminal of GH protein could be the epitope of B cell and there were flexible regions in these sections or near these sections of GH protein molecule. So the dominant regions could be in these sections or near these sections. [ Conclusion] The research provided the basis for the preparation of monoctonal antibody of GH protein from A. sinensis and provided the reference for the discussion for the molecular regulation mechanism of A. sinensis.

Full-length cDNA Cloning and Tissues Expression Analysis of Ferritin Gene from Acipenser sinensis

According to the conserved sequence of the ferritin gene, a homologous sequence was obtained from the EST database through a BLAST search against the GenBank database. This sequence was amplified with the method of RT-PCR, false sequencing was corrected, and full length eDNA of the ferritin subunit from the Chinese sturgeon was obtained. After being submitted to the GenBank database, the sequence accession number EU348782 was assigned. With the length of 896 bp, this eDNA includes entire coding regions of 53 lbp, which encodes 176 amino acids （aa）. The molecular weight was predicted to be 20339.9Mr and the theoretical isoelectric point 5.66. It shares 82.9% protein sequence homology with the ferritin of the Atlantic salmon. This gene is expressed in many organs of the Chinese sturgeon, for example, the liver, pancreas, muscle, brain, heart and gastric mucosa. The highest expression level was found in the pancreas and the heart, while the muscular tissue showed the lowest. Homology modeling was used to predict the 3-D structure of the protein, which included 5 alpha helices and 10 turns. The ferritin protein structure could be overlapped and showed high similarity with that of human, flog and bacteria. It was revealed that this kind of ferritin was highly conserved in structure and function.

Assessing the genetic diversity of the critically endangered Chinese sturgeon Acipenser sinensis using mitochondrial markers and genome-wide single-nucleotide polymorphisms from RAD-seq

As a living fossil, the endangered Chinese sturgeon(Acipenser sinensis) has been considered a national treasure in China. Here,the famous Gezhouba Dam and Three Gorges Dam on the Yangtze River were built in 1988 and 2006, for economic purposes.The natural population of Chinese sturgeon has declined since then, as these dams block its migratory route to the original spawning grounds in the middle reaches of the Yangtze River. In 2013 and 2014, there was an absence of spawning where it typically happened near the Gezhouba Dam. Nevertheless, from April to June in 2015, over 1,000 larvae with different body lengths(10–35 cm) were detected along the Shanghai Yangtze Estuary; but only little is currently known about the population genetic structure of the Chinese sturgeon. Herein, we inferred population genetic parameters from 462 available Chinese sturgeon specimens based on a 421-bp fragment of the mitochondrial DNA(mtDNA) D-loop region and 1,481,620 SNPs(singlenucleotide polymorphisms) generated by restriction site-associated DNA sequencing(RAD-seq). For the D-loop dataset, 15 haplotypes were determined. Randomly picked 23 individuals, representing the 15 D-loop haplotype groups, were subsequently used for further RAD-seq validation. The average nucleotide diversity calculated from the mtDNA and RAD datasets was 0.0086 and 0.000478, respectively. The overall effective female population size was calculated to be 1,255 to 2,607, and the long-term effective population size was estimated to range from 11,950 to 119,500. We observed that the genetic variability and the effective female population size of the current population in the Yangtze River are severely low, which are similar to the data reported over 10 years ago. The deduced relatively small effective population of female fish, limiting the genetic connectivity among Chinese sturgeon, should be considered a serious threat to this endangered species.

肝胆病变中华鲟幼鱼血液生化指标初步研究

使用全自动血液生化分析仪检测了肝胆病变中华鲟(Acipenser sinensis)幼鱼[体长(52.6±5.1)cm,体质量(1299.5±385.2)g]的主要血液生化指标。结果显示,与健康中华鲟相比,患病中华鲟血液中的谷丙转氨酶(ALT)、谷草转氨酶(AST)、乳酸脱氢酶(LDH)、尿素(UREA)、胆汁酸(TBA)、钾(K+)、钙(Ca2+)等指标明显升高,且差异极显著(P<0.01);肌酸激酶(CK)、α-淀粉酶(α-AMY)、总胆红素(TBIL)等的含量有所升高,但差异不显著(P>0.05);总蛋白(TP)、白蛋白(ALB)、球蛋白(GLO)、葡萄糖(GLU)、总胆固醇(CHOL)、甘油三酯(TG)、高密度脂蛋白胆固醇(HDL-CHOL)、钠(Na+)、氯(Cl-)等指标明显降低,且差异极显著(P<0.01);碱性磷酸酶(ALP)含量有所降低,但差异不显著(P>0.05)。

CALCULATION OF FLOW FIELD AND ANALYSIS OF SPAWNING SITES FOR CHINESE STURGEON IN THE DOWNSTREAM OF GEZHOUBA DAM

The Chinese sturgeon （Acipenser Sinensis） is one of the unique and important fishery resources in China. Since the construction of the Gezhouba Dam, the traditional migration route of the sturgeon has been blocked; consequently, the length of natural spawning sites is reduced from 800 km in the past to less than 5 km at present. As an endangered species, the Chinese sturgeon has become one of the most conserved aquatic species. In this article, the flow field of its spawning states in the downstream of Gezhouba Dam was simulated and analyzed using N-S equations and k-ε turbulence model. Volume Of Fluid （VOF） method with the Finite Volume Method （FVM） was used to simulate the water-air two-phase flow to examine the computed area. On the basis of the ecological-hydraulic characteristics of Chinese sturgeon, the features of the flow field were investigated to provide theoretical support for the proper management of the Three Gorges Reservoir.