Abstract:Fish perceive light intensity and wavelength mainly through visual opsins. The 1 317 bp full-length SWS1 cDNA sequence of Paralichthys olivaceuswas first cloned in this research containing 1 077 bp length ORF, encoding 358 amino acid of cone opsin. It indicated that the larval flounder have the potential ability to perceive ultraviolet rays. In addition, qRT-PCR showed that the related expression of rod opsin RH1 and SWS1 had no significant changes. While the related expression of cone opsin genes RH2 and SWS2 was significantly enhanced from first hatched larvae to 13th day after hatching(DAH) larvae; LWS gene was significantly enhanced from DAH6, and then descend to DAH13 slowly. In eyes, furthermore, RNA whole mount in situ hybridization revealed that the signals of opsin genes were mainly expressed in the peripheral retina and crystal and SWS2 expressed later than other opsin genes. Unexpectedly, the expressions of opsin genes were found in skin, fins, gills, intestine and other tissues extensively.

Abstract:Meganuclease I-SceI is an endonuclease, which is derived from the intron of mitochondrial 21S rRNA gene of Saccharomyces cerevisiae and has been applied to transgenic study in recent years. Usually, to use this system, target plasmid and I-SceI protein were microinjected together. However, preparation of the I-SceI protein for microinjection is laborious and time consuming. Replacing the protein by I-SceI mRNA would be more convenient. In this study, the transgene of fluorescence protein was mediated by I-SceI mRNA to assess its transgenic efficiency in zebrafish. First, helper plasmid with I-SceI coding sequence pCS2-I-SceI was constructed and I-SceI mRNA was transcripted in vitro. Donor plasmid, pI-SceI-EF1α-eGFP and pI-SceI-EF1α-RFP donor plasmid with I-SceI recognition sites, EF1α promoter and eGFP(RFP) gene were constructed, and co-injected with I-SceI mRNA into the 1-2 cell stage fertilized eggs of Danio rerio. The concentrations of donor plasmid and I-SceI mRNA were 50 ng/μL and 100 ng/μL respectively. The eGFP fluorescence expression rate was 75.86% in 48 h. The fluorescence can be observed in the head, body and tail of zebrafish and became stronger and stronger with the development of embryos. Our data suggest that I-SceI can efficiently mediate gene transfer and has the potential to apply in the transgene of economic fish.

Abstract:Growth differentiation factor 9(GDF9) and bone morphogenetic protein 15(BMP15) play important roles during follicular development and maturation in teleosts. In this study, we analyzed the expression pattern of type Ⅰ and Ⅱ receptors of GDF9 and BMP15 during follicle development of gibel carp. The results revealed that the expression levels of TGF-βR1a, BMPR1Ba and BMPR1Bb mRNA were first decreased and then increased during development of follicles. TGF-βR1b mRNA levels were significantly increased at the late stage of follicle development, but the expression levels of BMPR2a and BMPR2b were gradually decreased with the development of follicles. TGF-βR1b, BMPR1Bb, BMPR2a and BMPR2b mRNA were mostly expressed in follicle layer cells, but TGF-βR1a and BMPR1Ba mRNA were expressed in both oocytes and follicle layer cells. These results indicated GDF9 and BMP15 might be involved in the development of follicles by a potential paracine/autocrine signal pathway.

Abstract:In present study, the expression differences of myostatin(MSTN) in various tissues of Eriocheir sinensis during molting cycle were analyzed by qRT-PCR. The results showed that,(1) EsMSTN(Eriocheir sinensis MSTN) had its highest expression level in muscle, while higher expression levels were also observed in thoracic ganglia and brain ganglia at stage C, suggesting its physiological function was not restricted to muscle.(2) EsMSTN was expressed the highest at AB and the lowest at D stage of molting cycle in muscle, suggesting that EsMSTN might be a positive growth regulator in E. sinensis, involved in the significant expansion and severe atrophy of the muscle at AB stage and D stage, respectively. Whereas in hepatopancreas and epithelium, EsMSTN mRNA expression levels were the highest at AB stage, and the lowest at C or D stage, due probably to cell proliferation at AB stage in these tissues. In addition, the peak value of EsMSTN mRNA in thoracic ganglia occurred at stage AB and its lowest expression level was observed at stage D, which implied that EsMSTN may regulate the nerogenesis in this tissue positively.

Abstract:In order to testify the correlations between Antarctic fish HSP90β protein and coldness adaptation, we cloned the complete open reading frame of the HSP90β gene from an Antarctic icefish, Chionodraco hamatus and investigated the prokaryotic expression of C. hamatus-HSP90β protein under cold stresses. As a control, the ORF of Oreochromis niloticus HSP90β was also cloned. Results showed that the coding region of C. hamatus HSP90β gene is 2184 bp in length, encoding 728 amino acids. Multiple sequence alignment results showed that C. hamatus HSP90β shared more than 87% identities with other fishes. Protein domain analysis showed that C. hamatus HSP90β possessed the conserved domain of the HSP90 family, and showed highly conserved in the important functional site. Recombinant pET28-CH-HSP90 and pET28-ON-HSP90 prokaryotic expression plasmids were constructed and expressed in Escherichia coli to testify the function of C. hamatus HSP90β under 4℃ stress. Results showed that the survival rate of C. hamatus-HSP90β group was significantly higher than that of the O.niloticus-HSP90β and the control group. Our results indicated that C. hamatus HSP90β protein possessed more remarkable protective effects against cold stress and HSP90β protein might be involved in cold adaptation physiological process in C. hamatus.

Abstract:The morphometric differences among the three populations of red tilapia from Chinese Taiwan, Israel and Malaysia were studied with one-way ANOVA, cluster analysis and principal component analysis. Regression analysis was used to compare the impacts of morphological traits on body weight among three populations of red tilapia and establish the multiple regression equations. Analysis of meristic characters indicated that there were no significant differences among these strains. In the morphological traits which had higher value of correlative coefficient to fillet yield, there were significant differences between Chinese Taiwan strain and Israel strain, Malaysia strain. Cluster and principal component analysis showed that morphological characters were rather similar between Israel strain and Malaysia strain, from which Chinese Taiwan strain was different. Three principal components were constructed of which the contributory ratio, from high to low, were 34.804%, 16.667% and 12.974%,summing up to 64.446%. The results of regression analysis revealed that body length, body width and caudal peduncle depth were the key impact factors to body weight of the strains from Chinese Taiwan and Israel, and the traits affecting the body weight of Malaysia strain most converted to body length, body depth and body width. The results of multi-variant indicate that there are some morphological differences among the three populations of red tilapia and the indicators of morphological traits were body depth, head length, caudal peduncle depth, snout length and total length.

Abstract:As white spot syndrome virus(WSSV) and infectious hypodermal and hematopoietic necrosis virus(IHHNV) were both shrimp-infecting viruses and should be reported to the OIE.A follow-up investigation of prevalence of WSSV and IHHNV in P. vannamei cultured in freshwater in Shanghai was carried out in 2014. Results showed that the average single infection rate of WSSV and IHHNV was 42.6% and 38.5% respectively, while co-infection rate of the two viruses was about 20.5%. The prevalence of IHHNV-WSSV co-infection was positively correlated with that of WSSV. Analyses of histopathology and cumulative mortality indicated, although the cumulative mortality of shrimp in the IHHNV-WSSV group was always lower than that in the WSSV group at the same time point, gill tissues of moribund shrimp in the two groups were both damaged seriously, and no significant difference between them was found. The activities of immune-related enzymes(superoxide dismutase and acid phosphatase) demonstrated, compared to the single infection of WSSV, the dual infection of IHHNV and WSSV was able to activate the body's immune system faster and kept the immune response at a higher level during a short period; however, IHHNV-WSSV usually led to an higher and longer immune suppression post activation, which, together with the dual damages caused by IHHNV and WSSV,suggested that co-infection of IHHNV-WSSV would cause greater economic losses than a single infection.

Abstract:In order to explore the community structure of zooplankton in Xizi Lake and its relationship with environmental factors, the species structure,dominant groups and distribution of zooplankton in Xizi Lake were investigated in December 2014 while RDA analysis was conducted to grope for the nexus between dominant species and main water environmental factors. Totally 6 investigation sections which contained 18 sampling points were set in the national aquatic germplasm reserve of Xizi Lake. The results indicated that 33 species of protozoa(51.56%), 19 species of rotifer(29.69%), 7 species of copepoda(10.94%)and 5 species of cladocera(7.81%) were comprised. The dominant species of both core area and experimentation area were protozoa and rotifers. The range of zooplankton density was 1 755.25-7 023.38 ind/L and the average was 3 483.44 ind/L. The range of zooplankton biomass was 0.36-5.34 mg/L and the average was 1.67 mg/L. Community richness index(R) ranged from 1.02-1.96 while the average was 1.37; Shannon index(H') ranged from 2.02-3.47 and the average was 2.72; Evenness index(E) ranged from 0.59-0.85 and the average was 0.72. Under the common influence of both the degressive pressure of predators and the decrease of food resources, small individuals like protozoa and rotifers could benefit from the external winter circumstances of the reserve, and as a result, ecological dominance of zooplankton community were inclined to aforementioned groups. Besides, impacted by hydrological characteristics, the number and biomass of zooplankton species and diversity index of the southern part excelled those of the northern and central parts as a whole.

Abstract:An investigation was conducted in Yangcheng Lake from July to November, 2014, Pearson correlation analysis and redundancy analysis(RDA) were applied to analyze the relationship between the phytoplankton community structure and water parameters. 142 species, 68 genera and 8 phyla were identified, including Chlorophyta(63 species, accounting for 44.37%), Bacillariophyta(27 species), Cyanophyta(22 species). The number of Chlorophyta was the highest in dominant species, while Cyanophyta was with the highest density. 61.11% of the dominant species were indicating algae of rich nutritional water. Abundance and biomass of phytoplankton during summer [averaging(3.99±4.00)×10⁶ cell/L and(1.41±1.05) mg/L, respectively] were considerably higher than those during autumn. Besides, algal density was mainly composed of Cyanophyta, while biomass was mainly composed of diatoms. The results showed that the water quality in Yangcheng Lake was moderately-polluted and the water during autumn was better than summer. The results of Pearson correlation analysis showed that the primary factors affecting the structure of phytoplankton community were identified to be pH, Tem and NO₂^--N content during summer. Contents of NO₂^--N, COD_Mn, DTN and DTP were the main factors affecting the structure of phytoplankton community during autumn. RDA results indicated that the key environmental factors influencing the phytoplankton assemblages were Tem, TN and DTP, whereas pH, Tem, DO and DTN were the key factors during autumn.

Abstract:To accurately evaluate the comprehensive toxicity of treated printing and dyeing effluents, the 96-hour acute toxicity tests were conducted with juvenile Exopalaemon carinicauda, Portunus trituberculatus, Cynoglossus semilaevis, Mugil cephalus, Sinonovacula constricta, and Bullacta exarata, and the toxicity unit classification system and potential ecotoxic effects probe(PEEP) were used to evaluate the biological toxicity of treated printing and dyeing effluents. The results showed that the major physical and chemical characteristics of treated printing and dyeing effluents conform to the standards of “Discharge standards of water pollutants for dyeing and finishing of textile industry” and “Integrated effluents discharge standard” except aniline, but the content of aniline was very low. The 96-hour acute toxicity tests showed that the sequence of acute toxicity level was C. semilaevis >E. carinicauda >M. cephalus >P. trituberculatus >S. constricta >B. exarata, and the treated printing and dyeing effluent was classified as moderate toxicity grade with the value of 4.16 by toxicity unit classification system, meanwhile, the value of PEEP was 4.72, being classified as highly toxic grade. The biological monitoring methods can be used to estimate synthetic toxicity of treated printing and dyeing effluents completely.

Abstract:Dry deposition fluxes of heavy metals in Zhoushan sea area were calculated through a single point of dry deposition model based on the monitoring data of selected heavy metal elements in atmospheric particulate matter(Cu, Pb, Zn, Cd) in Shengshan Island in four seasons(February, May, August and October)from 2004 to 2013. The results showed that, the magnitude order of monthly and yearly dry deposition fluxes of heavy metal elements in the atmospheric was Cu(14.15 mg/m²) >Zn(2.16 mg/m²) >Pb(1.40 mg/m²) >Cd(0.022 mg/m²),the corresponding concentration of which was less than the limit value of China's air quality standards. Cu accounted for 80% of the total metals. Monthly flux variation of heavy metals in recent years was complex, the data in winter and spring was higher than that in autumn and summer for the early phases(2004-2008); while the trend turned higher in summer and winter for the late period(2009-2013). Compared with other sea areas,both the monthly and annual deposition fluxes of Cu are higher than those in Pearl River Delta, Tianjin Port, Fujian Xinghua Bay, just below the Qingdao sea area; while Pb, Zn, Cd values are far less than those sea areas, but have little difference with the ocean monitoring values.

Abstract:A 50-day feeding trial was conducted to investigate the effect of partial replacement of fish oil with vegetable oil on growth, muscle and liver total lipid and fatty acid of larvae Larmichthys crocea(initial weight 0.65g±0.11g).Six isonitrogenous and isoenergetic experimental diets were formulated.The control feed(Group A) was formulated with 6% fish oil, whereas the other 5 experimental diets were formulated by replacing the fish oil with 16.67% rapeseed oil(Group B),33.33% rapeseed oil(Group C),50% rapeseed oil(Group D),66.67% rapeseed oil(Group E), and 66.67% blended vegetable oil(Group F,palm oil:perillaoil:rapeseed oil=3.6:2.5:1),respectively. Results showed that these replacements(Group B,C,D,E and F) did not significantly influence the final weight, weight gain, specific growth rate compared with Group A; the survival rate of Group C, D and E was lower than Group A;the feed coefficient had no significant difference among the six experimental groups.Partial replacement of fish oil with vegetable oil significantly influenced the content of muscle protein, and Group A had the lowest content of muscle protein(58.9%±0.41%); ash had no significant difference among the six experimental groups. Though there was no significantly influence on the content of total lipid on muscle and liver among six experiment groups, the composition fatty acids was significant influenced. With the increasing replacment by rapeseed oil, the contents of 18:3n3 in muscle and the contents of 18:1,18:2n6,18:3n3 in liver were significantly increased, whereas the contents of EPA and DHA were significantly decreased. Compared with the same level of rapeseed replaced group, the contents of EPA,DHA in muscle and the contents of 18:3n3 in liver in blended vegetable oil group were significantly increased, whereas the contents of EPA and DHA in liver were significantly decreased. This study suggested that replacing 66.67% fish oil with rapeseed oil or with blended vegetable oil fed larvae Larmichthys crocea for 6weeks did not influence its growth, but reduced its nutritional value of fatty acid.

Abstract:In order to investigate the effects of dietary bile acid on growth, body composition, fatty enzymatic activities and biochemical indices of turbot Scophthalmus maximus L. juveniles, five isonitrogen and isocaloric diets containing graded levels of bile acid(0.00%, 0.03%, 0.06%, 0.09%, and 0.12% of dry matter) were formulated(named D1, D2, D3, D4, and D5, D5 as control group). Each diet was assigned to triplicate tanks of turbot juveniles with initial body weight 26.5 g for 56 days. The results showed that:(1) Growth performance and figure indices were increased by dietary bile acid, and indices of D3, D4, D5 groups were significantly higher than D1 group, but there were no differences among them.(2) Crude lipid and crude ash contents of whole fish were decreased, while crude protein increased by dietary bile acid; Crude lipid of muscle decreased, while crude protein and crude ash increased.(3) Lipase and lipoprotein lipase activities increased at first and kept stable then, but hepatic lipase activities kept increasing.(4) Alanine aminotransferase and asparate aminotransferase activities were decreased while alkaline phosphatase activity was increased by dietary bile acid; total protein and albumin contents increased while triglyceride, total cholesterol, high density lipoprotein cholesterol, and low density lipoprotein cholesterol decreased by dietary bile acid.(5) Cumulative mortalities of D3, D4 and D5 groups were significantly lower than that of D1 group after being infected with Vibrio anguillarum for 48 hours. With WGR as evaluation indicator, broken-line regression analysis showed that the optimum dietary bile acid of turbot with body weight 26.5 g was 0.09%.

Abstract:To clarify the distribution and abundance of Coilia nasus larvae and juveniles, 8 stations were set along the southern branch of Yangtze River Estuary from March to September 2014 . A total of 1270 individuals of C. nasus were collected at the spring tides by a larval net(1.3 m mouth-diameter, mesh aperture 0.5 mm). The body length ranged from 3.56-50.88 mm, with developmental stages from yolk-sac larvae to juveniles. A total of 1 013 individuals of C. nasus were collected at flood tide. The average density was 0.27 ind/m³, the average body length was 10.00 mm. The highest average density was 0.268 ind/m³ at station 8, average body length was 9.44 mm. St. 6-8 were simultaneously sampled at ebb tide, and a total of 163 individuals of C. nasus were collected. The average density was 0.01 ind/m³, the average body length was 20.08 mm. At St.8, a total of 94 individuals of C. nasus were collected at night time. The average density was 0.056 ind/m³ at flood tide and 0.003 ind/m³ at ebb tide, both smaller than the day time. The average body length at flood tide was 13.86 mm, the average body length at ebb tide was 22.01 mm. Compared with the study on the surf zone, the average body length of C. nasus larvae and juveniles in the southern branch of Yangtze River estuary was smaller,and it is necessary to protect the early resources of C. nasus.

Abstract:The investigation on fish resources in Yankou reservoir was carried out in March, May, July, September, November 2013 separately, in order to reveal the characterization of fish community, resources status and growth performance of main fish species.452 fish specimens were measured and identified, which belonged to 5 orders,8 families and 37 species.Cyprinidae was the largest order,which accounted for 75.7% . Siluriformes accounted for 13.5%, and Perciformes accounted for 5.4%. Salmoniformes and synbranchiformes accounted for 2.7%,respectively.The ecological type analysis revealed that the community was dominated by carnivorous and omnivorous fish. There were 5 dominant fishes by analyzing the index of relative importance, which were Hypophthalmichthys molitrix, Aristichthys nobilis, Hemiculterlla wui, Culter alburnus and Distoechodon tumirostris. Three diversity indexes including species richness index(D),Shannon-Wiener index(H') and species evenness index(J') were used to analyze diversity characteristics of the fish community. And the values of D,H' and J' varied from 2.09 to 6.05,0.87 to 1.42 and 0.41 to 0.92 respectively.The growth equation of body length and weight for H. molitrix were L_t=73.591[1-e^{-0.265(t+0.136)}] and W_t=5.911[1-e^{-0.265(t+0.136)}]^2.812, respectively; and for A.nobilis were L_t=73.256[1-e^{-0.318(t+0.12)}]and W_t=7.625[1-e^{-0.319(t+0.012)}]^3.07, respectively. In Yankou reservoir, Hypophthalmichthys molitrix and Aristichthys nobilis grew relatively fast from 1 to 4 years, and their inflecting point were 3.795 and 3.327,respectively. The most appropriate catching age was 5 years for the two aquatic environmental protection oriented fishes in order to get the best effect on algal bloom control and economic benefit.

Abstract:The distribution of stable carbon and nitrogen isotope composition(δ¹³C and δ¹⁵N) and ratios of carbon to nitrogen(C:N) with fork length were studied to investigate the characteristics of stable isotope of skipjack, Katsuwonus pelamis, collected from Fish Aggregating Devices(FAD), based on the survey data of purse-seine fishery in the Western and Central Pacific Ocean from February to March 2013. The results showed that the mean value of fork length was(44.30±7.85) cm, ranged from 31.0 to 65.0 cm in fork length, with the dominant fork length of 40.1 to 50.0 cm accounting for 45.12% of the total samples. The mean value of δ¹³C was(-15.94±0.59)‰, and it was significantly influenced by fork length(F=10.92, P<0.05). The differences among the mean values of δ¹³C from each fork length class were very small and it indicated that the sources of initial diets were similar for all samples. The δ¹⁵N was significantly influenced by fork length(F=16.72, P<0.05). The mean value of δ¹⁵N was(17.50±1.81)‰ and it was greater in small skipjacks, which indicted that the trophic position of skipjack is higher in small scale than in larger scale. The mean value of C:N ratios was(3.06±0.05)‰, and it was significantly influenced by fork length(F=4.21, P<0.05). The mean value of C:N ratios decreases with the increase of the fork length, which indicated that nutritional status of skipjack reduced by fork length class.

Abstract:Based on the catch data collected by Chinese Pacific saury fishing vessels from July to December 2013 and sea surface temperature(SST), chlorophyll-a concentration(Chl.a) and sea surface height(SSH) data derived from satellites, this paper analyzed the distribution of fishing ground of Pacific saury and their relationship with marine environmental factors by using the method of fisheries geographic information system software and mathematical statistics. The results indicated that the production varies with the season, and it was the highest between September and November in the waters near 40°N-47°N,147.5°E-162°E. The movement of barycenter of catch could be divided into three stages: first, it had a tendency to move from south to north in July and August; afterwards, it moved from northwest to southeast in August and October; finally, it moved from west to east from October to December. The range of SST, Chl.a, SSH in the fishing grounds were 10-15 ℃, 0.5-1.0 mg/m³, 0-±2 0 cm respectively, and the optimum ranges of above three factors were 11-13 ℃, 0.6-0.8 mg/m³, 5-±15 cm respectively. According to K-S test(P<0.01), the ranges of SST, Chl.a, SSH in each month are reasonable, and SST, Chl.a, SSH can be chosen as indicators to predict the fishing ground of saury.

Abstract:In this research,polysaccharides from Pyropia yezoensis were separated by four ultrafitration membranes in different molecular weight cut-off(MWCO) to obtain five parts of relative molecular weight :PPⅠ(MW≥100 000), PPⅡ(MW:50 000-100 000), PPⅢ(MW:10 000-50 000), PPⅣ(MW:5 000-10 000) and PPⅤ(MW≤5 000),for further study,the antioxidant activity of PP with different molecular weights was determined. The results showed that PP with different molecular weights all have antioxidant capacity in the experimental concentration range of PP,they all have good hydroxyl radical(·OH) scavenging activity, superoxide anion(·O₂^-) radical scavenging effects and DPPH radical scavenging activity, and scavenging rate increased with increasing concentration of polysaccharides, showing a dose-effect relationship; antioxidant activity was related to the size of its relative molecular weight, and the antioxidant activity of small molecular polysaccharide PPⅤ(MW≤ 5 000) was best, significantly higher than the greater molecular weight PPⅠ(MW≥100 000). Ultrafiltration technology could achieve good separation of PP, it could be used as a new method for the development and utilization of the active component from Pyropia yezoensis, and the PP of MW below 5 000 was the main active component and worthy of exploitation in future.

Abstract:In order to solve the problem of the labour-intensive and inefficiency during the harvesting process in pond farming, a monorail transporter used for pond fish is designed. This monorail transporter is driven by worm gear and belt. The monorail is set up in accordance with the terrain of the pond, to meet the transportation demand of high-drop condition. The chassis designs with the slot can prevent the monorail transporter from rolling over and deorbiting during the runtime. The monorail transporter controlled by manual is taken as research object, and the wireless remote control technology is used . According to the actual test results, with the capacity of 120 kg towards to uphill, uphill angle between 30° to 40°, speed at 0.4-0.8 m/s, and only 3 operators, transferring the fish of weight 4 800 kg from the pond to the vehicle was completed within 40 min. The system operation is reliable and suitable for raising the fish from the pond.

Abstract:The oscillating hydrofoil of tide energy collection system establishes the movement equation which includes the pitch and the heave. However, the difference of induced drag between the 3D model and 2D model influences the energy conversion efficiency of system directly. Therefore, the paper establishes the 3D trapezoid hydrofoil hydrodynamic model based on the blade element theory. The simulation of the model takes the 3D unstructured gird and dynamic mesh technique, focuses on the effect of trapezoid ratio to the movement and energy conversion efficiency. The results show: Adapting dynamic mesh to simulate the hydrodynamic characteristics of 3D trapezoid oscillating hydrofoil has acquired the same motion as 2D model; The induced drag of oscillating hydrofoil changes the stable oscillating frequency and pitching amplitude and influences the energy conversion efficiency of system; With the decrease of trapezoid ratio, the energy conversion efficiency of oscillating hydrofoil will increase at first and then decline,with the maximum value at point of 0.5. Trapezoid foil design provides a feasible direction for the optimization of oscillating hydrofoil model.