Abstract:The inorganic nutrients in Laizhou Bay was monitored during 2006~2009. The results showed that due to the runoff of Xiaoqing River, the concentration of inorganic nitrogen in the western Laizhou Bay was significantly higher than that in the eastern area in May and August of 2009. Phosphate and silicate in the western Laizhou Bay were significantly higher than those in the eastern area in May, 2009, and no obvious variation in August. In May of 2009, concentrations of inorganic nitrogen in 53.3% of the seawater exceeded the fourth grade of Sea Water Quality Standard, and all samples exceeded the first grade. In August, concentrations of inorganic nitrogen in 34.9% of the seawater exceeded the first grade. Phosphate was generally at a low level; in May 2009 the seawater sample from the estuary of Xiaoqing River exceeded the third grade, and the other samples met the first grade. Combined data of inorganic nitrogen during 2006~2009 showed a gradually increasing trend in May and a decreasing trend in August. Phosphate did not change obviously in May but apparently declined in August. Silicate did not change significantly either in May or in August. The average ratios of nitrogen to phosphate, silicate to phosphate and silicate to nitrogen were 164, 130, and 0.77 respectively. Inorganic nitrogen pollution was serious, phosphorus was a potential limiting factor in the surveyed area, and this trend is supposed to go further in the future.

Abstract:The C-binding, Ag-NORs, and G-banding patterns of the metaphase chromosomes of barfin flounder Verasper moseri were investigated in this study. The results showed that the interstitial regions of most chromosomes exhibited positive C-bands, in which the whole 3rd, 13th, 20th, and 22nd pair of chromosomes showed totally positive C-band, whilst the 1st, 4th and 8th pair of chromosomes only showed positive C-bands in the middle region, the rest with centromeric positive C-bands. However, the 9th pair of chromosomes showed negative result. The C-banding heretochromatin occupied 54.91% of the total chromosome in the present study. Silver staining study showed that most chromosomes featured two silver-stained nuclear organizing regions (Ag-NORs) with the percentage of 87.5%. Accordingly, the interphase nucleus with 2 nucleolus appeared most frequently, thus it is supposed that the barfin flounder bears a pair of Ag-NORs which located at the end of short arm of the submetacentric chromosomes. A total of 59 positive G-bands (37 strong, 22 light) were recorded in 23 pairs of chromosomes. These results would provide basic data for the genomic research and biodiversity conservation of barfin flounder.

Abstract:The genetic structure and variations of the cultured stock and artificial meiogynogenetic population of half-smooth tongue sole Cynoglossus semilaevis were analyzed by using twenty-four microsatellite markers. The results showed that the average numbers of alleles and average effective alleles were 7.0 and 4.8, and 3.935 and 2.411 in the cultured stock and the artificial gynogenetic population, respectively. The mean observed heterozygosity (HO) were 0.713 5 and 0.586 5, respectively. The results indicate that the genetic diversity of the cultured group was much higher than that of the gynogenetic population. Thirteen loci deviated significantly from Hardy-Weinberg equilibrium (HWE) in the gynogenetic population, while one loci deviated from HWE in the cultured group. The coefficient of gene differentiation (GST) was 0.131 0, and the genetic distance was 0.420 0 between the two populations, indicating for a significant genetic differentiation between the two populations.

Abstract:Traceability coding method and identification technology is the key step for the total quality control. According to EAN·UCC-the Global Identification System, this study established the coding method for flounder traceability based on UCC/EAN-128 Bar Code by comparing UCC/EAN-13 to UCC/EAN-128. After the label material was determined, the label was linked to each fish by strapping the label on the fishtail or embedding on different parts of the fish, and after comparison an identification method of flounder traceability was established. This method could provide technical support for flounder traceability and ensure the total traceability from breeding to consumption with electronic information technology. The research and demonstration results indicate that the label abscission rate is less than 2%, and after the labels being soaked for one month, the recognition accuracy of bar code information reached 100%.

Abstract:The steady-state level of the P450arom (P450aromA and P450aromB) mRNAs of male Pelteobagrus fulvidraco cultured at different temperatures and growth conditions were analyzed by RT-PCR, and GSI, HSI, CF, serum sexual steroid hormones testosterone (T) and estradiol (E2) levels were measured by 125I radioimmunoassay (RIA). The spatial expression result showed that P450aromA mRNA was not present in ten tissues of male P. fulvidraco, including spermary, liver, stomach, intestines, gill, heart, spleen, kidney, head kidney, and brain. P450aromB was expressed in brain and intestines. Expression of P450aroms was fist linked to temperature, serum sexual steroid hormones testosterone (T) and estradiol (E2) level. The changes in mRNA level of P450arom shared the same trends with serum E2 and T cultured at different temperatures. Our results suggested that P450aromA may be related with spermatogenesis. The high expression level in the brain of the male fish may be directly involved in the maintaining of sperm vitality and spermiation process. The results showed that higher temperature made more significant effects on sperm vitality and spermiation process.

Abstract:A female specific random amplified polymorphic DNA (RAPD) marker was obtained in blue tilapia Oreochromis aureus through screening 800 random primers. The female specific DNA fragment with a length of 1 488 bp was cloned, sequenced, and converted into a SCAR (Sequence Characterized Amplified Region) marker, SCAROaF1488. A duplex PCR method was developed to amplify SCAROaF1488 together with a 509-bp-long mtDNA 16S rRNA gene fragment which served as a positive control. Two hundred individuals originated from 2 populations, including 100 males and 100 females, were used to verify the reliability of the SCAR marker by using the duplex PCR method. The sex identification test results of 200 fish showed 100% accordance with their phenotypic sex. SCAROaF1488 was successfully amplified in all female but not in male individuals. By contrast, the control fragment was amplified in all the males and females. The female-specific marker SCAROaF1488 developed in the present study can be used for molecular identification of genetic sex in blue tilapia. In addition, this work will provide an important tool for screening and isolation of the sex-determining locus and sex manipulation in this tilapia.

Abstract:Integration threshold is the critical signal level that governs whether or not an echo signal will be included in the echo integration during the post-processing of fisheries acoustic data. It is the Volume Backscattering Strength (VBS) of the weakest echo signal that will be involved in the echo integration process. An appropriate integration threshold may effectively remove noise and non-target signals while keep the signals from target species intact, thus improve the accuracy of acoustic estimation of fishery resources. In order to study the methods for the selection and optimization of the integration threshold for a scattered target distribution, the functional relationship between the VBS and the Target Strength (TS) was derived based on basic concepts and formulas in fisheries acoustics, and two methods, namely the TS-Length empirical relationship method and the in situ TS data method, were proposed for the determination of integration threshold. The application of both methods was then demonstrated in the anchovy Engraulis japonicus survey in the Yellow Sea. It provides an effective reference for the definition and optimization of integration threshold in the post-processing of fishery acoustic data with the scattered target distribution.

Abstract:The ocean is becoming more and more acidic in unprecedented speed in the history of the earth resulting from emissions of CO2 by human activities. The survival state of calcification organisms such as shellfish may be threatened by marine acidification. So the calcification rate and respiratory rate of Chlamys farreri were investigated using the alkalinity anomaly technique at different pH. It was found that calcification rate and respiration rate decreased significantly as pH declined. Calcification rate decreased by 33% when the pH of water was down to 7.9. At pH 7.3, calcification rate was almost 0, and respiratory rate (RC) and O2 consumption rate (RO) were reduced by 14% and 11% respectively. As marine acidification intensifies, the metabolic pathways of C. farreri also changed. All changes above may threaten the survival of C. farreri in the future.

Abstract:The farming of the clam Meretrix lyrata has been successfully developed since 1987 and brought high economic and social benefits to the coastal communities. As a highly valued fishery resource especially in Vietnam, recently M. lyrata has become another new aquaculture species with a potential for large-scale farming in the South China Sea and a good market prospects. In this study, by adopting the ecology experimental methods, the effects of seawater temperatures, salinities, pH, and microalgae densities on the clearance rates of M. lyrata were investigated, which are expected to provide insight on culturing capacity, feeding behavior and energy of M. lyrata and references for healthy culturing and extension of M. lyrata.The results showed that the clearance rates of M. lyrata (P＜0.01) at three sizes were significantly affected by varied temperature (13～33℃), salinity (13～33), pH (7～9), and diet density(2.5×10⁴～10×10⁴ cell/ml). The maximum clearance rates of the large, medium, and small sized M. lyrata were 1.06, 1.78 and 2.42 L/g·h at 28℃respectively, 0.35, 0.65 and 1.05 L/g·h at salinity 23, 1.26, 1.67 and 2.02 L/g·h at pH 8,1.29, 2.07 and 2.29 L/g·h at microalgae density of 10×10⁴ cell/ml.These results indicate that the optimum feeding environmental conditions were: temperature 28℃, salinity 23, pH 8 and microalgae density 10×10⁴ cell/ml. These results indicate that the sensitivity of the large, medium and small sized M. lyrata to temperature, salinity, pH or microalgae density appeared in the following order: large size＜medium size＜small size.In addition, medium and small sized individuals had frequent feeding activity and stronggrowth vitality.

Abstract:The growth and survival rates of larval seahorses, Hippocampus kuda Bleeker, were studied under industrial culture conditions of different temperature, salinity, light intensity, and stocking density. The results showed that the optimum temperature for the growth of the larval seahorses was 28℃, and the larval seahorses preferred high and stable salinity (above 20). Till 60 days, the seahorses which were reared at a salinity of 30 grew faster and the survival rate was the highest. Low light intensity was more suitable for their growth, and the most suitable stocking density was 250 ind./m3.

Abstract:o investigate the removal efficiency of nutrient by macroalgae, six species of algae, including Mazzaella japonica, Ulva pertusa, Sargassum thunbergii, Bangia fuscopurpurea, Helminthocladia australis, and Ahnfeltiopsis flabelliformis, were cultured in natural seawater for 72 h, and then the concentrations of ammonia, nitrate, and phosphate in the culture media were measured respectively. The results showed that compared with the other species, M. japonica and U. pertusa showed much higher efficiency in removing all three nutrients. The percentages of the three nutrients absorbed by M. japonica and U. pertusa in 72 h were 98.0% and 97.1% of ammonia, 76.9% and 82.0% of nitrate，90.8% and 86.9% of phosphate, respectively.

Abstract:o determine the selection marker of N. oculata, the sensitivity to 5 antibiotics (Neomycin, Streptomycin, Hygromycin, Spectinomycin, and Zeocin) was determined in this study. For each antibiotic, liquid medium and solid medium were both adopted with the same concentration gradient. The concentration gradient of Neomycin and Streptomycin was 0, 100, 200, 400, 600, and 800μg/ml, while that of Hygromycin was 0, 25, 50, 100, 125, and 150μg/ml, and that of Spectinomycin was 0, 40, 80, 100, 150, and 200μg/ml. The concentrations of Zeocin were much lower, which were 0, 0.1, 0.2, 0.4, 0.5, and 1μg/ml. It was found that N. oculata is not sensitive to Neomycin, Streptomycin, Hygromycin or Spectinomycin, but highly sensitive to Zeocin. Zeocin can completely inhibit the growth of N. oculata when its concentration is 0.5μg/ml in solid medium or 1μg/ml in liquid medium. Zeocin could serve as a selection reagent in the genetic transformation of N. oculata, and the ble gene could be the selection marker.

Abstract:A Chlorella strain 2003ZGH023 was cultured at modes of photoautotrophic (light, basic nutrient formula), mixotrophic with high carbon level (light, basic nutrient formula, 8 gram organic carbon per liter), mixotrophic with low carbon level (4 gram organic carbon perliter), and heterotrophic with low carbon level (darkness, basic nutrient formula, 4 gram organic carbon per liter) respectively. The effects of different trophic modes on the growth performance and nutritional composition of the Chlorella were studied. The results indicated that the addition of organic carbon in culture medium significantly increased the cell density and biomass of the Chlorella. The heterotrophic group had a cell density as high as 54.73×106 cell/ml, and biomass of 6.86 g(dw)/L. The sizes of the Chlorella cells in heterotrophic and mixotrophic groups were larger than that in autotrophic group. The assays on nutrition showed that the protein content of the Chlorella cell declined significantly while the total fat content increased significantly in the heterotrophic modes. The crude protein contents in the photoautotrophic mode, mixotrophic mode with high carbon level, mixotrophic mode with low carbon level and heterotrophic mode were 41.88%±0.14%, 24.60%±0.07%, 21.93%±0.13% and 12.91%±0.35% respectively. The variation of amino acid content in cell at different trophic modes was consistent with that of crude protein. The total lipids in the mixotrophic mode with high carbon group (15.32%±1.58%) and the heterotrophic mode with low-carbon group (14.15% ± 0.93%) were significantly higher than those in the mixotrophic mode with low-carbon group (12.35% ± 0.25%) and the photoautotrophic mode (10.04% ± 0.3%). There were significant differences in fatty acid compositions of cell cultured in different trophic modes. Fatty acids 18∶3n3 and 14∶1 were dominant in photoautotrophic Chlorella. Fatty acids 14∶1 and 18∶1n9 were the majority in the mixotrophic modes. Fatty acids 18:1n9 and 16:0 were the most abundant in the heterotrophic mode.

Abstract:The effects of net mesh size and water depth on the seasonal succession and vertical distribution of fouling organisms were investigated, from June to September, 2007, in a scallop Chlamys farrier raft culture area in Liuqing River estuary, Qingdao, China. Four nets with mesh size of 50.42, 44.40, 22.36, and 12.92 mm were suspended on the raft at five depth (1.3, 2.9, 4.5, 6.1, and 7.7 m), and experimental nets were sampled monthly. The dominant fouling species were Gammaridae and skeleton shrimp in June, and blue mussel Mytilus gallolprovincialis from July to September. The ascidians which were usually the dominant species of fouling communities were rare in the sampling area. The biomass of fouling organisms generally decreased with the increasing water depth. The specific growth rate (SGR) of the fouling biomass was the highest in August, which amounted to 8.77 %/d. The SGR was lowered in September, mainly due to the decreased growth rate of blue mussel. The higher fouling biomass in Liuqing River estuary during summer was mainly due to the blue mussel, the dominant species in the fouling community.

Abstract:A yeast strain YS-185 isolated from the ocean can produce astaxanthin. 26S rDNA sequence analysis showed that the strain belongs to Rhodotorula glutinis. The effects of culture medium components and fermentation conditions on the marine yeast growth and pigment yield were investigated in shake flasks. The results showed that the optimum culture medium for the bacteria growth consisted of glucose (8g/L), peptone (8g/L), and the optimum fermentation conditions were initial pH 5.5, shaking speed 200r/min, inoculum level 8%(v/v), and temperature 20℃. The optimum culture medium for astaxanthin production consisted of glucose (8g/L), peptone (8g/L), and the optimum fermentation conditions were initial pH 5.5, shaking speed 220 r/min, inoculum level 8%(v/v) and temperature 25℃. We found that temperature had significant influence on the bacteria growth and the astaxanthin production based on the data analysis of the orthogonal experiments. An overall 69.7% increase of astaxanthin yield (2.670μg/ml) was obtained compared with that of the original conditions (1.572μg/ml). Marine yeast YS-185 had the potential to produce astaxanthin at a large scale.

Abstract:The aim of the study was to test the influence of baicalin on immune enzymes and detoxification metabolism of shrimp Fenneropenaeus chinensis. Four treatments were designed with different concentrations of baicalin (0, 50, 100, 150 mg/kg) mixed with the raw diet, and the diets were orally fed to healthy F. chinensis. The activities of acid phosphatase (ACP), catalase (CAT), induced nitric oxide synthase (INOS), lysozyme (LSZ), superoxide dismutase (SOD) in haemolymph, hepatopancreas, and muscle were assayed on days 1, 3, 5, 7, 9 and 11. The data indicated that activities of ACP, INOS, SOD in the 100mg/kg and 150 mg/kg treatments increased significantly (P<0.05) compared to the control level after feeding, and achieved the highest level in three days. All activities in the 50mg/kg treatment were not significant higher than those in the control (P>0.05), while increase of activities of LSZ in heamolymph were highly significant (P<0.01) in the 50, 100 and 150mg/kg treatments compared to the control level at the same period. The activities of (ACP and CAT changed most greatly in hepatopancreas, followed by muscle and hemolymph. The activities of INOS, LSZ, SOD changed most greatly in hemolymph, followed by muscle and hepatopancreas. The middle level treatment and high level treatment reduced significantly (P<0.05) below the control level. Results of the infected test showed that the artificial infection with V. anguillarum caused mortality in all groups, but the mortality of the control group was the highest and the mortality of the medium dose was the lowest. The baicalin elevated the protective rate of F. chinensis infected with V. anguillarum. The results showed that baicalin could regulate the immune system of F. chinensis significantly, enhance non-specific immune function and disease resistance, and depress the susceptivity of F. chinensis effectively. All these results would provide a theoretical basis for the preparation of compound Chinese herbal medicine.

Abstract:In the paper, combined enzymes were used for the hydrolysis of Antarctic krill Euphausia superba to obtain polypeptides, and the polypeptides contents and molecular weight distribution were determined by biuret method and liquid chromatography respectively. The antimicrobial activity of peptides and different molecular-weight fractions of polypeptides to six strains including Staphylococcus aureus, Bacillus subtilis, Micrococcus tetragenus, Escherichia coli, Saccharomyces cerevisiae, and Vibrio parahaemolyticus was carried out by the filter paper method. The results showed that polypeptides contents of the hydrolysate was 81.44% and the range of peptides molecular weight was 254~10 000. The polypeptides from Antarctic krill presented obvious antibacterial activity to S. aureus, and fraction Ⅲ（Mr＜3.0×103） showed the strongest antimicrobial activity.

Abstract:Planktonic microalgae in shrimp ponds play the role of primary producers, and have a major impact on material cycle and energy supply of the water ecosystem. The continual and regular surveys on the planktonic microalgae community were conducted in four Litopenaeus vannamai shoal water culture ponds at Guanlida Biotechnology Corporation in Dianbai, Maoming, Guangdong Province. Moreover, the community compositions of planktonic microalgae in shrimp ponds and their characteristics were analyzed. The results showed that a total of 91 planktonic microalgae species were identified during the culture period. Among them, 30 species were Cyanophyta, 15 were Chlorophyta, 37 were Bacillariophyta, 5 were Pyrrophyta, 2 were Euglenophyta, and 2 were Chrysophyceae. The dominant species were Arthrospira platensis, Chlorella pyrenoidosa, Kirchneriella microscopica, Peridinium pusillum, Nitzschia closterium, Lyngbya gardneri, Oscillatoria chlorina, Oscillatoria salina, Nostoc microscopicum, Oscillatoria neglecta, and Oscillatoria willei. During the early culture period, the range of the quantities of planktonic microalgae, the biomass and the diversity index averages were 5.12×104～95.41×104ind/L, 1.95～1.18×102μg/L, and 0.84～2.16, respectively. Chlorophyta and Bacillariophyta often appeared. However, in the middle and final phases, the averagesplanktonic microalgae density, the averages of biomass and the diversity index ranged in 66.11×104～1.28×109ind/L, 13.3～11.87×103μg/L, and 1.64～2.87 respectively, and Oscillatoria gradually became the dominant species. The present study demonstrated that all the planktonic microalgae density, biomass and diversity index showed the same trend that they were generally low at the initial phase of the culture period and became high at the final phase. However, in mid-late July, the planktonic microalgae density and the physical and chemical factors in water fluctuated under the influence of severe weather conditions resulted from typhoon etc.