Abstract:In this paper, histological and electron microscopy observations of the testis and GtH cells were conducted, and ultra-performance liquid chromatography coupled with electronspry ionization-triple quadruple mass spectrometry (UPLC/MS/MS) method was applied to determine the content and changes of 6 steroid hormones in the testis of male farmed mature eels during artificially induced maturation through carp pituitary extract and hCG injection. The results showed that the eel testis developed to fully mature and then absorbed and degraded 10 days post spermiation. The contents of progesterone (P), estradiol-17β (E₂) and estriol (E₃) were below limit of detection. The average contents of testosterone (T), 17α,20β-dihydroxy-4-pregnen-3-one (DHP), and 17α-hydroxypro-gesterone (17α-OHP) were significantly higher than those in the control group. The results indicated that the contents of T, DHP and 17α-OHP were low in the control group, and increased during spermiation and then decreased after spermiation in male eel. The results showed that 17α-OHP, T and DHP might be key elements during testis maturation which are regulated by GtH secretion in the pituitary gland.

Abstract:The full-length cDNA sequence of phytoene synthase (PSY) encoding gene psy in Chlorella vulgaris (C. vulgaris)was isolated by RACE-PCR. The 1605 bp sequence contained a 1245 bp open reading frame (ORF), which encoded a protein composed of 415 amino acids residues. Results of multiple sequence alignment and phylogeny showed that the deduced protein sequence of the C. vulgaris PSY was homologous with other PSY proteins, and clustered into the green algae group. The genetic distances of PSY between C. vulgaris and Chlorella variabilis,Auxenochlorella protothecoides, Chromochloris zofingiensis was 0.173, 0.188 and 0.239 respectively. And those PSYs also kept the high similarity (81%-84%) and identity (69%-76%). The prediction result of subcellular location showed that the amino acids residues from 1^st to 45^th might perform as a chloroplast transit peptide, suggesting that PSY must be translated outside before entering the chloroplast and being active. Analyses of conserved blocks/motifs and tertiary structure modelling indicated that this PSY sequence contained several potential modification sites,with the conserved blocks and characteristic motifs of PSY protein, including two substrate-Mg²⁺ binding sites and two active site lid residues which might mediate binding of substrate and shield highly reactive intermediates from solvent. A specific substrate-Mg²⁺ binding site (the third) was found in the C. vulgaris PSY, and its activity and function was still unconfirmed.Taken together, these results uncovered the full-length cDNA sequence of psy, and predicted the putative structure of PSY protein in C. vulgaris, and thus provided information for over-expression of psy and for enhancing the productivity of carotenoids.

Abstract:VP28 is the envelope protein of white spot syndrome virus (WSSV).After the codon optimization synthesis VP28 gene sequence,and enzyme digestion by restriction enzymes Nde I, Xho I, inserted the correct reading frame sequence into the expression vector-pET-28a(+).After the recombinant plasmid into E. coli BL21 (DE3) was digested by double enzyme and sequencing, it was confirmed that we have successfully constructed VP28 genetic prokaryotic expression vector-pET-28a-VP28.The transferred strain induced by IPTG, SDS-PAGE showed that contains the expected size of about 30 ku protein band, which was mainly expressed in inclusion body form. The recombinant protein was purified by Ni-IDA-Sepharose CL-6B affinity chromatography column and we got the purity of 95% protein finally.Gradiently dilute the purified protein as the quantitative standard curve of Western blotting, to quantify the amount of VP28 expression in transgenic Anabaena sp. PCC 7120.The experiment results showed that the recombinant protein and VP28 expressed in Anabaena sp. PCC 7120 had the same molecular weight.Use the purification of recombinant protein as a quantitative western blotting standard curve, calculate the expression of VP28 in transgenic Anabaena sp. PCC 7120.The largest amount was 5.14 μg/mL, on 17th day, accounting for 1.45% of the total protein concentration.This is not only of great significance to efficient cultivation of transgenic cyanobacteria, but also a foundation to determine the effective dosage of oral vaccine for prawn to prevent and cure white spot syndrome in the future.

Abstract:The germplasm resources of M. rosenbergii are declining in China. To solve this problem, we used 5 strains (A,B,C,D,E) as parents to make complete diallel cross and built 25 mating combinations, whose intraspecific heterosis and genetic correlations of growth traits (body length, carapace width, the first abdominal segment width, the first abdominal segment height and body weight) were analyzed at 90 dph, respectively. The results indicated that the growth traits of all hybrid combinations were better than those of self-combination except D×C. The heterosis was observed in all hybrid combinations, the hybrid combinations of A×E has the greatest heterosis. It can increase the body length by 17.22%, and can increase the weight gain by 71.64%. The heritability was 0.549, 0.548, 0.527, 0.516, 0.580 for body length, carapace width, the first abdominal segment width, the first abdominal segment height and body weight, respectively. The genetic correlation and phenotypic correlation between body length and body weight was the highest (0.752 2 and 0.98), while the genetic correlation between carapace width and first abdomere segment height was the lowest (0.667 5), and the phenotypic correlation between body length and the first abdominal segment height was the lowest (0.924 0). The results would provide theoretic basis for further fast growth selective breeding and hybridization of M. rosenbergii.

Abstract:To explore the effect of sodium bicarbonate on expression of virulence genes from Aeramonas hydrophila, the relative expression levels of three major virulence genes, including hemolysin gene (AHH-1), aerolysin gene (AerA), and elastinase gene (ahyB) in A. hydrophila growing with sodium bicarbonate at 0.024, 0.048, 0.072, 0.096 and 0.120 mol/L were analyzed by fluorescent quantification PCR technique and compared with those of A. hydrophila without sodium bicarbonate as control. The result revealed that the expression levels of AHH-1,AerA and ahyB in A. hydrophila growing with sodium bicarbonate were significantly lower than those of A. hydrophila without sodium bicarbonate. With increasing sodium bicarbonate level, the expression levels of these genes showed a decreasing trend. The results of artificial infection indicated that compared with the A. hydrophila without sodium bicarbonate, median lethal dose of A. hydrophila with sodium bicarbonate was much higher. What's more, with increasing sodium bicarbonate concentration, the median lethal dose of A. hydrophila had a trend to increase gradually, and this means that the virulence of A. hydrophila decreased gradually.

Abstract:The study was based on the successful meiogynogenetic top mouth culter (Culter alburnus). We observed the embryonic development characteristics and timing differences of gynogenetic diploid and haploid, and compared with normal diploid, in order to investigate the influences of cold-shocking of the eggs in C. alburnus and improve management measures of gynogenetic embryo hatching. Also we analysed morphological characteristics of the adult gynogenesis C. alburnus. The results showed that: (1) Compared with normal embryos, the fertilization rate of gynogenetic embryos was lower while the deformity rate was higher. The haploid embryos hatching rate of haploids was lower. (2) Gynogenetic embryos displayed anomalous cells, dissolved yolk sacs, eggs membrane rupture, and haploid syndrome by cold-shocking. The death peak appeared in gustrula stage and prehatching stage for each group. (3) The developmental characteristics of gynogenetic diploids were similar to normal embryos, and gynogenetic embryos developed slowly especially from the beginning of cleavage to gustrula stage. But after the gustrula stage, the development rate was the same as the normal diploid. From the beginning of cleavage to blastula stage, the growth rate of haploid was the same as the normal embryos. But at gastrula stage, it was slower. Other developmental stages were always slow. The haploid syndrome was observed in the haploid larvae. (4) Gynogenesis group had variation characteristics.

Abstract:In this study, growth data at different months of the fourth generation selective group and control group of pearl oyster Pinctada martensii were measured, and the correlation and regression analysis for shell length, shell height, shell width and body weight were conducted. The results showed that correlation coefficients among growth traits of selective group and control group at different months were extremely significant (P<0.01), and were 0.47-0.88 and 0.44-0.92 respectively. In addition to the fact that correlation coefficients between shell width and others traits of selective group at six months were greater than corresponding values of control group, correlation coefficients among growth traits of selective group were less than corresponding values of control group. The multiple regression equations estimated body weight of selective group and control group were significant (P<0.05), and coefficients of determination (R²) were 0.625-0.848 and 0.745-0.902 respectively. Coefficients of determination of selective group were all less than corresponding values of control group. The results of this paper provide theoretical guidance for determining the important target traits in selective breeding of Pinctada martensii.

Abstract:The mono-sex culture of Chinese mitten crab Eriocheir sinensis is a new culture method, and there is increasing interest in the commercialization of this pond-culture technique because of different nutritional requirement and market time for males and females. However, no available information could be found on the effects of mono-sex culture on the culture performance and gonad development of adult E. sinensis. Therefore, the objectives of this study were conducted to investigate the differences of puberty molting rate, survival, weight gain rate (WGR), gonadosomatic index (GSI) and hepatopancreas index (HSI) among all females treatment (AF), all male treatment (AM) and mixture-sex treatment including mixed females (MF) and mixed-males (MM) by the culture experiment and dissection. The results showed that: (1) Despite of males or females, the puberty molting rate of AF and AM was higher than that of mixed-sex culture treatments. However, the only two significant differences were found at the point of 15 d and 20 d, respectively (P<0.05); during the experimental period, the cumulative mortality of AF was higher than that of MF while the final mortality of AM was lower than that of MM. (2) In terms of survival, there was no significant difference in the survival between AF and MF (P>0.05), while AM had the significanttly higher survival than MM; the mono-sex and mixture-sex culture had no significant effects on WGR, with approxiamtely 50% of SGR after puberty molting for both males and females. (3) As for GSI and HSI, mono-sex culture had no significant effect on them, and the GSI of males and females were 7.3% and 2.6%, respectively during 25-40 days of post puberty molting. In conclusion, mono-sex culture can prompt the female puberty molting earlier, improve the male survival compared to the mixture-sex culture, and no negative effect was found in body growth and gonadal development.

Abstract:A 14-week feeding trial was conducted to evaluate the effects of dietary taurine on growth and digestive enzyme activity of Anguilla marmorata with initial body weight 85.95 g. Five experimental diets, which were formulated with 0%, 0.20%, 0.40%, 0.60% and 0.80% taurine respectively, and contained 0.708%, 0.908%, 1.108%, 1.308% and 1.508% taurine (named D1, D2, D3, D4 and D5). The results showed that: (1)With the increasing of dietary taurine, the final weight of the fish first increased then deceased and peaked in D4 group. The weight gain rate (WGR) and specific growth rate (SGR) in D4 group were significantly higher than those in D1 and D2 groups. (2)Crude protein, total lipid and ash contents in muscle were increased and moisture was decreased along with the increasing dietary taurine levels, the crude protein content in D3 group was significantly higher than that in D1 group. (3)The fish fed the diets with 1.108%-1.308% taurine displayed significantly higher amylase activity and protease activity in stomach and intestine and higher lipase activity in liver. It is therefore suggested that the optimum dietary taurine level for Anguilla marmorata is 1.308%.

Abstract:A new type of ecological floating bed system that combined emergent aquatic plant, submerged plant and biofilm was developed in this study.The purification effect of the system was determined all the year round. And the kinetics of TN and NH₄⁺-N treatment,curtailing model and contribution rate of different media were also studied.The results indicated that the new ecological floating bed system has high nitrogen removal rate,of which the contribution rate of the upper layer accounted for 15.6%±1.2%, the middle layer accounted for 37.6%±2.2%, and the lower layer accounted for 23.8%±1.8%. It shows that the middle layer played a major role in nitrogen removal.During the period,the highest removal rate of NH₄⁺-N and TN was over 93% and 94%, respectively.Compared with control, NO. 5 pool wich contains both the middle layer and lower layer got the highest nitrogen removal rate (P<0.10). Curtailing models of NH₄⁺-N and TN were calculated by kinetics curves. The present study provided technical support to the application of the ecological floating bed system in the future.

Abstract:The quantitative impact of land use/cover (LULC) on the receiving water quality is one of research highlights of lake ecology. By using Landsat Thematic Mapper (TM) images and water quality indices (TN, TP, Chl. a, Secchi depth) of four seasons, this paper analyzed the relationship between land use/cover and water quality of Gonghu Bay based on five different buffer zones and the whole bay scale. Results showed that the land use pattern in Gonghu Bay had a significant impact on surface water quality. Construction land and cultivated land had a significant positive effect on water quality in Gonghu Bay, while forest land exhibited significant negative effect on water quality; grass land and non-used land had not significant effect. There was a scale effect between land use pattern and water quality indices in Gonghu Bay. The land use/cover type near to Gonghu Bay had more significant influence on water quality than that away from Gonghu Bay. Studies have shown that the forest land in Gonghu Bay had a strong effect on reducing water and sand, positively improving the receiving water quality. Developing afforestation, returning farmland to forest, and implementing wetland restoration project along the littoral zones within 0-2 km of Gonghu Bay will positively prevent soil erosion and protect the ecological environment.

Abstract:Additives have been used to alleviate the membrane fouling in recent years. The excellent properties of rare earth metals provide the possibility for the mitigation of membrane fouling. In this experiment, a group with lanthanum and a blank group had been set to compare their filtration and compression performance of activated sludge, SMP and EPS concentration at different HRT. The result shows that, at HRT of 6 hours, the sludge total resistance of the former was half of that of blank, and the sludge compression coefficient increased by 34.7% compared with that in the blank group, the sludge specific resistance was about 10% of the blank. The SMP and EPS concentration of former was decreased by 20%, and P/C was more than 2 times that of the blank group. Lanthanum chloride alleviated the membrane fouling by improving the filtration and compressibility, reducing the content of pollutants and changing their relative hydrophobicity.

Abstract:Oscillatoriales is distinct and broad cyanobacterial organism group which has been subject to taxonomical amendments. Based on field material collected from Huangpu River (Shanghai, China) in the summer of 2014, Geitlerinema ionicum belonging to the Geitlerinema,Coleofasciculaceae (Cyanophyta) is reported for the first time in China in this paper,and Geitlerinema ionicum is a newly recorded genus and species of Cyanophyta in China. The morphological characteristics of Geitlerinema and Geitlerinema ionicum were described in detail. According to the cyanobacterial classification system established by KOMAREK & ANAGNOSTIDIS (2005), four species (Osicllatoria acutissima, O. amphibia, O. geminate var. sulphurea, O. quadripunctulata var. unigranulata) previously reported in China should be considered to be attributable to Geitlerinema.

Abstract:Based on the samples collected by Chinese saury fishery fleet from the sea of the northwest Pacific Ocean from June to July and October to November in 2015, with the ratio of statolith maximum width (MW) to total length (TSL) as an indicator of statolith growth,the relationship between of statolith growth, sexual maturity and body size of Cololabis saira in the Northwest Pacific Ocean was analyzed by the analysis of variance. The results showed that statolith of Cololabis saira was flat and oval, its focus was on the backend and it has an apparent rostrum which is longer than the antirostrum; In addition to Ⅳ stage, TSL and MW mean of female and male individual increased with increased sexual maturity level. TSL and MW mean increased obviously from Ⅳ to Ⅴ stages. There was not significant difference between their MW/TSL (P>0.05) for the female and male individuals at four sexual maturity stages, the statoliths of Cololabis saira hardly changed their shape after the sexual maturity stage Ⅰ. As fork length increased, TSL and MW mean of female and male individuals increasd gradually, TSL and MW means had significant difference between fork length groups (P<0.05). There was not significant difference between their MW/TSL (P>0.05) for the female and male individuals in different fork length groups, and growth of MW to TSL (MW/TSL) was not obvious. With the fork length increasing, Cololabis saira statolith grew uniformly from stage Ⅱ of sexual maturity.

Abstract:In this study, we described and analyzed the fisheries biology of blue shark based on the total of 336 samples collected by China's national tuna long-line fishery observers in the Indian Ocean (1°-33°N, 40°-75°W) from October 2012 to September 2014.The results indicated that the dominant fork length of males and females was 150-229.9 cm and 150-250 cm. The captured female-male ratio was near 1:1 and there were no significant differences between the mean fork lengths of male and female. The larger individuals were mainly distributed in the northern Madagascar waters (x=207.6 cm), while the smaller individuals were mainly captured around the southeast Madagascar waters (x=170.9 cm). The mature individuals of bycatch blue shark were much more dominant in northern Madagascar waters than in the Southeast Madagascar waters. Fork length at 50% maturity was estimated to be 183.6 cm for females and 182.3 cm for males. Squid and long-nose lancetfish had the highest occurrence in stomach contents of the blue shark. This study contributed to a better understanding of fisheries biology of the blue shark in the Indian Ocean and would be useful for evaluating the shark's resources.

Abstract:In order to study the mechanical properties of tuna longline hooks, and to verify the accuracy of the finite element analysis method, this study conducted tensile test and ANSYS simulation on the ring hook (Type:3.4-4.5). The results of tensile test and ANSYS simulation were compared and tested by ANOVA. The results showed that: (1) there were no significant differences of the mechanical characteristics e.g. displacement or strain, measured by two methods (P>0.05). The maximum strain area was around the back bent and rear side. The maximum total displacement area was around the front bent and front axle. The maximum displacement in X direction was around the bottom and rear side. The maximum displacement in Y direction was around the back bend and back axle; (2) when the tension was 500, 800, and 1200N, the ring hook's strain was 0.002 76, 0.008 14, and 0.069 94; the displacement in X direction was 1.8, 3.5, and 7.2 mm; the displacement in Y direction was -2.4, -4.6, and -8.7 mm; the total displacement was 2.8, 5.4, and 10.6 mm, respectively; (3) there was a significant linear relationship between the results of tensile test and those of the ANSYS simulation. The displacement in total, X, Y direction, and strain of tensile test were 1.018 9, 1.027 2, 1.019 5, and 1.088 3 times the ANSYS simulation. This study suggested that the ANSYS finite element could be used to analyze tuna longline hooks' mechanical property.

Abstract:In consideration of the stability and safety in the launch and recovery process of a hybrid autonomous and remotely-operated unmanned vehicle (ARV) in the great depth sea, to eliminate the influence of the heave movement of the mother ship, to prevent cable from being damaged and even ruptured, or ARV from being damaged due to cable's uneven tension, this paper presents a passive heave compensation system that adapts to the launch and recovery of the ARV for "11 000 m" full ocean depth, which was developed by Hadal Science and Technology Center of Shanghai Ocean University. The paper first describes the components of the passive heave compensation system and its operating principle. The oil cylinder dimensions were calculated, then,a mathematical model was established and a simulation analysis of the passive heave compensation system was made using the software AMESim.Numerical calculation and analysis results show that the system can meet the requirement of the launch and recovery of the ARV for full ocean depth. Research of passive heave compensation system has analyzed cable tension control by solving the problem about heavecompensation.

Abstract:We found Listeria monocytogenes was still alive after the ultra-high pressure processing. Based on the result of our former experiments, this research aims to investigate whether the ultra-high pressure processing affects the biofilm formation of L. monocytogenes. 2 strains of L. monocytogenes were applied in the research, both serotypes were 4b.Crystal violet staining assay was used to investigate the biofilm forming capacity of 2 strains, while the fluorescent microscopy and SEM were applied to observe the structures of the biofilm. The biofilm forming capacity of WaX12 was higher than ATCC13932. After 100 MPa UHP processing, WaX12 formed more biofilm than the control group, while 200 MPa improved the biofilm forming capacity of ATCC13932. The biofilm formation of both strains reduced after 300 MPa and higher UHP processing. The images of biofilm formation of the 2 strains obtained by fluorescent microscopy and SEM were consistent with the results of crystal violet staining assay. Results suggested that the UHP processing may increase the biofilm formation of L. monocytogenes. If the pressure was lower than 200 MPa, the biofilm formation was strengthened, and reached the maximum after 48 h. It is important to choose proper pressure during UHP processing.

Abstract:Shewanella haliotis has potential biotechnological applications in shrimp culturing and oil pollution abatement. To determine the optimal fermentation medium and culture conditions of Shewanella haliotis, single factor experiments and orthogonal design were conducted. Further confirmation was carried out in 70 L bioreactor under the optimal medium and culture conditions. The results showed that the optimal medium was 6% sucrose, 2.5% peptone and 0.7% CaCO₃ at initial pH 6.8, and optimal culture conditions in shaking flask were 30℃, 130 r/min, 100 mL/500 mL loading volume, 6% inoculum size and 24 h fermentation cycle. The average of final biomass in 70 L bioreactor reached 1.14×10¹¹ cfu/mL. The fermentation optimization provides experiment data for further industrial production.

Abstract:Four-season celery (Petroselinum crispum)is one of high value nutrient and healthy vegetables, with rich nutrition, strong perfume and health care value and is high quality raw material for vegetable juice processing. but low yield of celery juice was one of the main technical bottlenecks restricting the vegetable juice processing. The effects of cellulase adding quantity, enzyme hydrolysis time and enzyme hydrolysis temperature on celery juice yield were studied separately, and response surface analysis was optimized by Box-Behnken design, and interaction of single factor on celery juice yield was analyzed. The regression equation prediction model was established in the paper. The optimum conditions for the application of cellulase in celery juice were as follows:cellulase addition quantity 0.06%, enzymatic hydrolysis time 1.56 h, enzymatic hydrolysis temperature 40.14℃, and the yield of celery juice was 78.38%. The actual yield of celery juice (78.72%±0.25%) was better fitting of the predictive value.

Abstract:In this paper, combined Hg²⁺ specific recognition of thymine with chronocoulometry, we constructed a highly sensitive electrochemical biosensor based on DNA-mediated charge transport for the detection of Hg²⁺ in aqueous solution. DNA duplexs with one T-T base mismatch were assembled onto a gold electrode surface through Au-S bond. Chronocoulometry was used to detect Hg²⁺ in 2 mmol/L[Fe(CN)₆]^3- (0.1 M KCl, pH 7.4) containing 2.0 μmol/L MB. T-T mismatch blocked the internal charge transfer of the DNA duplexs. In the presence of Hg²⁺, the DNA on the electrode surface specifically recognized Hg²⁺ and formed thymine-Hg²⁺-thymine complexs. Thus, internal charge transfer path in dsDNA was formed, significantly improving charge transport onto the gold electrode surface. The results showed the chronocoulometry of DNA-modified gold electrode increased with the increase of Hg²⁺ concentration at the reduction peak of methylene blue (-380 mV). The change of chronocoulometry was linear with regard to lgc_Hg²⁺ over a concentration range from 1.0 n to 10⁴ nmol/L (R²=0.997) and with a detection limit of 0.5 nmol/L (S/N=3). A test for a series of interference metal ions showed that this biosensor based on DNA-mediated charge transport is highly specific and selective toward Hg²⁺.