Abstract:Adiponectin is an abundantly secreted adipokine from the adipose tissue of mammals, and plays central roles in the regulation of glucose and lipid metabolism. The biological function of adiponectin is mediated by at least two putative receptors (AdipoR1 and AdipoR2). In order to investigate the molecular regulatory mechanisms of lipid metabolism and liver lipid accumulation in fish, the full-length cDNA sequences of adiponectin receptor1-B (AdipoR1-B) from grass carp has been identified by rapid amplification cDNA ends (RACE), and the structural features of the gene and its encoded protein have been analysed through bioinformatics methods. Using the method of real-time PCR, the expression pattern of AdipoR1-B in nineteen different tissues of grass carp has been studied, and the expression levels of AdipoR1-B in the liver of grass carp under different nutrient conditions with high carbohydrate (H-CHO), high lipid (H-LIP) and high carbohydrate & high lipid (H-CHO & H-LIP) have been studied. The result revealed that the obtained cDNA of AdipoR1-B in grass carp was 2186 bp in length, which consisted of a 1122 bp open reading frame (ORF), encoding 373 amino acids. Alignment based on amino acid sequences showed that grass carp AdipoR1-B had a homology of 81.0%-94.1% to its counterparts in other fishes. Phylogenetic analysis showed that grass carp AdipoR1-B clustered with that of zebrafish. The AdipoR1-B mRNA could be detected in all the examined tissues of grass carp. But the expression level in liver was the highest, followed by central nervous system and red muscle. Compared with the control group, the expression levels of AdipoR1-B in the H-LIP and H-CHO & H-LIP groups had increased significantly. This result suggested that adiponectin may improve the utilization of lipid in grass carp and it may be involved in the lipid metabolism process in fish. The research data can enrich the knowledge of lipid metabolism regulation mechanism of fish, and lay a foundation for the further functional research of the adiponectin/AdipoRs system in fish.

Abstract:To investigate the germplasm resources and genetic diversity of the wild population Parapenaeopsis hardwickii, 558 base of the 16S rRNA and 688 bp base of the COⅠ gene sequences were obtained from P. hardwickii wild populations by PCR amplification. T, C, A and G base content of 16S rRNA gene sequences were 35.76%, 19.48%, 26.74% and 17.88%, while COⅠ gene sequences were 35.36%, 12.68%, 30.54% and 21.43% respectively. One haplotype and no polymorphic sites were detected in 16S rRNA gene sequences, while 7 haplotypes and 6 polymorphic sites were in COⅠ gene sequences, including 5 singleton variable sites and 1 parsimony informative sites. The variations of COⅠ gene sequences were more than 16S rRNA gene sequences, showing that COⅠ gene sequences were adaptive for genetic diversity analysis in P. hardwickii. The molecular phylogentic analysis based on 16S rRNA and COⅠ gene sequences were not consistent with each other, indicating that P. hardwickii was a sole branch in the genus Parapenaeopsis, and had closer relationships with Parapenaeopsis tenella and Parapenaeopsis hungerfordi. Based on the genetic distance of COⅠ gene sequences, the differentiation time of 12 shrimp species were deduced, and the results showed that the radiation differentiation time of genus Parapenaeopsis was between the Late Miocene Epoch and the Early Pliocene Epoch.

Abstract:Glycoprotein is the most important surface antigen of infectious haematopoietic necrosis virus (IHNV), and it has been served as the major gene for virus detection and vaccine development. The specific PCR primers for IHNV glycoprotein gene replication were designed based on the plasmid containing IHNV-Sn1203 glycoprotein gene. The PCR product was ligated to yeast surface display vector pYD1 and the recombinant plasmid pYD1-G was transformed into EBY100 cell. The transformed EBY100/pYD1-G cell was induced by galactose and the protein expression was detected by cell immunofluorescence, Western Blotting and flow cytometry. The cell immunofluorescence result showed that the transformed EBY100 cell presented a red fluorescence, and Western blotting analysis obtained a specific glycoprotein band. Both of these two results indicated that the glycoprotein was successfully displayed on the surface of yeast cell. The flow cytometry analysis showed that the glycoprotein expression was increased with the galactose induced time, and the maximum expression was obtained at 48 h. The successful display of glycoprotein on the yeast surface laid a foundation for live oral vaccine development.

Abstract:In order to give an insight into decomposition of ATP related compounds in stored fish, we re-examined ATP-related compounds and K-value change in bastard halibut (Paralichthys olivaceus) muscle when stored in different stored conditions focusing on the IMP decomposition by HPLC, and further studied factors that affect these changes, aiming at providing scientific guidance for preservation of fish. The result showed: Storage of flounder muscle block at 0℃ accumulated IMP as a major component indicating a quick conversion of ATP to IMP through ADP and AMP. IMP content decreased slowly in an early phase, while it dropped rapidly at the final stage of the storage (10 days) showing biphasic change. In ground fish meat, ATP degraded faster but there was no change in other ATP related compounds. Adding antibiotics (chloramphenicol) to samples at 0 d to prevent the growing of microorganism. It was obvious that IMP content decreased much slowly in the presence of the antibiotics showing linear change. When ground meat added with detergent (5% Triton X-100) to break cell membrane structure at 0 d, IMP decomposition was quicker than the control. Inclusion of Triton X-100 to ground meat also accelerated IMP decomposition at 10 and 20℃. The results indicated that the shape of stored fish affected ATP degradation but hardly had any effect on IMP decomposition. IMP decomposition in the later phase included the reaction by the exogenous enzyme coming from the microorganism growing at later phase. The existence of microorganism in later stored phase is the main factor that affected change of IMP decomposition. Modifying character of cell membrane by detergent also had effect on IMP decomposition.

Abstract:The defender against cell death 1 (DAD1) is a regulatory protein to inhibit the apoptosis process. The full-length cDNA of Haliotis diversicolor DAD1 (HdDAD1) was cloned by RACE according to DAD1 partial sequence of transcriptome. HdDAD1 was 553 bp, with a 339 bp open reading frame encoding a protein of 112 aa (HdDAD1). HdDAD1 contains a conserved DAD domain, with 3 transmembrane spans. Quantitative real-time PCR results indicated that HdDAD1 could be detected in all examined tissues, with the highest expression level in digestive tract, gill, hemocyte, mucus gland and kidney. There was also expression of HdDAD1 in different developmental stages. HdDAD1 expression level of larva stages was the highest, that of gastrula stage was middle, that of other stages was the lowest. HdDAD1 could respond bacterial challenge/thermal/hypoxia stress. There was significant up-regulation of HdDAD1 at 12 h after Vibrio parahaemolyticus challenge. HdDAD1 was significantly up-regulated, when water temperature rose from 25 to 28℃. The expression of HdDAD1 also significantly increased, when water temperature was 31℃ for 4 and 96 h. At 4 and 96 h post hypoxia stress, HdDAD1 significantly increased, too.

Abstract:Litopenaeus vannamei contains abundant phospholipids (PL), especially rich in polyunsaturated fatty acids (PUFA), which was easy to be hydrolyzed during storage and to produce free fatty acids (FFA). The increase of FFA leads to flavor, color and other changes, which affects the quality of aquatic products. Therefore in recent years, some information regarding the changes of lipids in aquatic food during handling and storage has been reported, such as L. vannamei, Pacific white shrimp and so on. However, the limited information on PL hydrolysis mechanism during storage is available, which is mainly owing to the complex system of PL hydrolysis and the lower content of phospholipases and lipase in aquatic food than mammals and microbes. Fortunately, electrospray ionization tandem mass spectrometry (ESI-MS/MS) has demonstrated high accuracy and reproducibility in phospholipids analysis, which brings potentiality for the study of the PL hydrolysis. Thus, to better understand the hydrolysis mechanism in sea foods during storage, we established a model system of phospholipids hydrolysis for the first time, which avoided the barrier of the complex system. We had extraction and purification of the phospholipases and PC from L. vannamei, and measured the enzyme activity of purified phospholipases. What's more, a fast and efficient "shotgun" lipidomics strategy was applied to analyze the levels and changes of PL, lysophosphatides (LPL) in L. vannamei. And the content of free fatty acids was analyzed by gas chromatography-mass spectrometry (GC-MS). The results showed that the phospholipases extracted from L. vannamei included lipase, phospholipase A₁ (PLA₁), phospholipase A₂ (PLA₂), phospholipase C (PLC) and phospholipase D (PLD), among them PLA₂ had the highest enzyme activity. And in the reaction system, the content of PC decreased from 516.45 to 146.14 mg/g. Meanwhile, FFA had a significant increase from 36.42 to 568.57 mg/g, and PUFA increased by 280.5 mg/g. Furthermore, the study showed the close correlation between PC hydrolysis and PLA₂ (R=0.91) by measuring the enzymes activities before and after hydrolysis reaction. Besides, PLA₁ also showed the relatively close relationship with the PC hydrolysis compared to PLA₂. These information, mentioned above, suggested that aquatic phospholipases can hydrolyze phospholipids and produce a series of hydrolyzates, mainly including LPL and FFA. In a word, this study indicated the hydrolysis mechanism of phospholipids in aquatic products was correlated with the activities of lipid hydrolytic enzymes during storage, and PLA₂ was crucial to the hydrolysis of PC, which laid a theoretical foundation for the aquatic food storage and phospholipids research. Therefore, the suppression of lipid hydrolysis and the study of the complete hydrolysis mechanism will be a means to maintain the quality of aquatic food stored in ice, which may be a significant research direction in the future.

Abstract:Based upon contigs coding for centromere specific proteins (CENPs) from a pyrosequencing transcriptome of Saccharina japonica, gene-specific primers were designed for the three centromere specific protein gene cloning from S. japonica. Three CENPs genes, named as SjCENH3, SjNuf2 and SjNCD80 were cloned by using the technique of Polymerase Chain Reaction. The open reading frame of the cloned full-length cDNAs were 432, 1365 and 2172 bp in length, encoding putative proteins composed of 143, 454 and 723 amino acids, respectively. Homologous sequence alignments show: SjCENH3 include the diversity of the N-terminal region and C-terminal histone fold domain (HFD), and HFD including four αhelixes (αN helix, α1 helix, α2 helix and α3 helix) and two loops (Loop1 and Loop2). But compared to H3, SjCENH3 amino terminus is slightly longer and there is no similarity between them, while the sequence of histone fold domain α1-helix, α2-helix and Loop1 are more variable. The main domains of SjNuf2 are Nuf2 domain, Spc7 and SPT2. The main domains of SjNdc80 are SPT2, Spc7, Ndc80_Hec, FoP_duplication and Kin17_mid. Neighbor-Joining (NJ) phylogenetic tree inferred from the putative proteins of CENH3, Nuf2 and NCD80 genes of S. japonica and other species indicated that SjCENH3 and SjH3 genes were divided two clades: CENH3 and H3 clade. H3 is highly conserved across species, while CENH3 differences among species are relatively large. Nuf2 and Ndc80 from different organisms could be significantly divided into two clades, angiosperms and algae. They both may have relations of co-evolution. This study first reported the characteristics of three centromere protein-coding genes SjCENH3, SjNuf2 and SjNdc80, providing a good basis to locate the centromere position by immunofluorescence technique and to get the centromeric DNA sequence by chromatin immunoprecipitation and to analyze chromosome karyotype using preparation of antibodies specific for the corresponding proteins of S. japonica.

Abstract:Marine Ranching is the artificial fishing site where fishery resources are scientifically bred and managed by fully using natural productivity of certain sea areas, based on principles of marine ecology and modern marine engineering techniques. It is characterized with the goal of enhancing stockment, definite boundary and ownership and resources managed in a scientific way. Besides, seedlings are artificially bred or domesticated, released or transplanted into open sea, and mainly fed with natural live feed. As early as 1965, Mr. Tseng Chengkui (Zeng Chengkui), a Chinese marine scientist, originally put forwards the idea of building artificial ranch in the ocean by planting and cultivating marine creatures. Since 1980s, the Chinese marine ranch construction has experienced three industrial forms including artificial reefs, stock enhancement and systematical ocean ranching. In spite of the great achievement, it is still facing problems including too broad application of its defination, lack of overall planning and feasibility studies, neglecting its ecological role as well as project evaluation and system management. In future, the development of marine ranching in China should recognize the importance of ecosystem, balance industrial arrangement both on the land and in the sea, comprehensively consider the primary, secondary and tertiary industry, realize four modernizations and encourage innovation for leaping development to realize both economic and ecological benefits.

Abstract:In the present research, the filaments of Scytosiphon lomentaria collected from the northern coastal area (Yantai, Qingdao) and the southern coastal area (Zhoushan, Wenzhou)of China, respectively, were used as the experimental materials. The effects of different light intensity [7.2, 21.6, 36.0, 50.4, 64.8, 86.4, 108.0 and 129.6 μmol/(m²·s)] and different photoperiod (8L:16D, 10L:14D, 12L:12D, 14L:10D and 16L:8D) on the growth and development of filaments of the northern S. Lomentaria(Yantai and Qingdao) and the southern S. lomentaria (Zhoushan and Wenzhou) were studied by means of isolation and culture, mainly to find out the differences among them. Results indicated that: (1) Light intensity had significant influences on the growth of filaments of S. lomentaria, neither higher light intensity [≥108.0 μmol/(m²·s)] nor lower light intensity [≤21.6 μmol/(m²·s)] were suitable for the rapid growth of filaments; (2) Cultured for 20d, the increasing ratio of filament biomass and daily average growth rate of filaments of the northern and the southern S. lomentaria had reached the maximum under the condition of 64.8 μmol/(m²·s); (3) The optimum light intensity on the development of filaments of the northern and the southern S. lomentaria was 36.0 μmol/(m²·s), and cultured for 20 d, the sporangial branchlets ratio of filaments of S. lomentaria collected from Yantai, Qingdao, Zhoushan and Wenzhou had reached the maximum under the condition of 36.0 μmol/(m²·s), and the values were 34.72%±0.91%, 35.06%±1.17%, 35.37%±0.59% and 34.33%±0.41%, respectively; (4) Cultured for 20 d, the increasing ratio of filament biomass and daily average growth rate of filaments of the northern S. lomentaria had reached the maximum under the condition of 14L:10D, and the values were 82.75%±2.39%, 3.00%±0.36% and 81.28%±4.53%, 3.04%±0.49%, while the southern S. lomentaria had reached the maximum under the condition of 16L:8D, and the values were 89.52%±0.88%, 3.18%±0.30% and 88.66%±7.09%, 3.22%±0.26% respectively; (5) The appropriate photoperiod on the development of filaments of the northern S. lomentaria was 8L:16D-10L:14D, while the appropriate photoperiod on the development of filaments of the southern S. lomentaria was 10L:14D-12L:12D.

Abstract:To investigate the effects of muscular nutritional components and fish quality of grass carp (Ctenopharyngodon idella) in ecological model of cultivating grass carp with grass, the ecological grass mainly fed with grass and feed grass carp fed with artificially formulated feed, respectively 16 individuals, were randomly selected to measure some indicators. These indicators included water holding capacity and texture profiles parameters in muscle, contents of nutritional components, mineral elements, amino acids and fatty acids in muscle. The results showed no significant difference in hepatosomatic index and shell rate between ecological grass carp and feed grass carp. Compared with these feed grass carp, significantly lower value in drop loss, no significantly lower value in flesh leaching loss, no significantly higher value in liquid loss and no significant difference in pH value were observed in muscle of ecological grass carp. Hardness, springiness, cohesiveness, gumminess and resilience in muscle had no significant difference between ecological grass carp and feed grass carp. The content of crude fat in muscle of ecological grass carp was significantly lower than that of feed grass carp, while the contents of moisture, ash and crude protein in muscle had no significant difference. The contents of phosphorus (P) and iron (Fe) in muscle of ecological grass carp were significantly higher than those of feed grass carp, and the contents of magnesium (Mg), manganese (Mn) and chromium (Cr) in muscle of ecological grass carp were very significantly higher than that of feed grass carp. The compositions of amino acids of ecological grass carp and feed grass carp were basically the same, containing 17 amino acids, wherein the essential amino acids in muscle is 6.85% and 6.27%, respectively. The essential amino index (EAAI) of feed grass carp (77.29) was higher than that of ecological grass carp (76.07). The ecological grass carp and feed grass carp both contained 19 fatty acids where in the contents of palmitic acid, arachidonic acid (ARA), linoleic acid (LA), oleic acid, docosahexaenoic acid (DHA) and stearic acid were high, as the main fatty acid. The contents of eicosapentanoic (EPA) + docosahexaenoic acid (DHA) had significance difference (were 8.95% and 10.70%, respectively). These results indicated that there was no significant difference in muscular texture profiles. The ecological grass carp had characteristics of higher water-holding ability, lower content of fat and higher content of mineral elements than those in muscle of feed grass carp.

Abstract:Onchidiidae which is widely distributed in China and rich in resources is one kind of economic gastropoda with nutritional value, despite reports for molecular biology, ecology, developmental, physiological and ecological breeding field of research. The analysis of biochemical components of Onchidiidae is conductive to its development and utilization of resources. In view of this, this study determined and compared four different species of Onchidiidae (Peronia verruculata, Onchidium struma, Platevindex mortoni and Paraoncidium reevesii) of total fat (TF) content, lipid and fatty acid composition. The experiments were conducted to investigate total lipid(TL) class and fatty acid composition of Onchidiidae by GC-MS and others. Results show that: ① Four different onchidiids muscle total fat are mainly composed of phospholipids (PL), free fatty acid (FFA), cholesterol (Cho) and triglyceride (TG); the PL/TL content of P. verruculata’s muscle tissue is as high as 73.12%, significantly higher than the other three species (P<0.05); the PL/TL content of O. struma muscle tissue is only 26.23%, significantly lower than the other three species (P<0.05); the TG/TL content of O. struma muscle tissue amounted to 2.75% of muscle tissue, significantly higher than the other three species (P<0.05); FFA/TL of P. verruculata’s muscle tissue is as high as 19.16%, significantly higher than the other three species (P<0.05). ② The fatty acid composition of muscle tissue of four different onchidiids is more balanced (S:M:P close to 1:1:1). The total saturated fatty acids in muscle tissue (Σ SFA) levels of O. struma and P. verruculata were above 35%, Σ SFA of P. mortoni muscle tissue is only 29.58%, significantly lower than the other three species (P<0.05); the four species of Onchidiidae total monounsaturated fatty acid (Σ MUFA) content were similar; the total polyunsaturated fatty acid content of P. mortoni’s muscle tissue is 34.25%, significantly higher than the other three species (P<0.05). The C20:4n6 (ARA) of P. mortonian in muscle tissue content and the C22:5n3 (DPA) of P. reevesii’s muscle tissue were significantly higher than that of the other three onchidiids, C20:5n3 (EPA) content in four onchidiids were significantly higher than the C22:6n3 (DHA). Studies have shown that four species contained higher ω-3 polyunsaturated fatty acids, which suggests that onchidiids’ muscle tissue has high lipid nutrition value, in addition, the composition of lipid and fatty acid of all four has a significant difference, may be related to its habitats and species diversity. The purpose of this study was to evaluate the nutritional value of different kinds of Onchidiidae, provide theoretical basis for the development and utilization of its resources, and provide theory support for the ecological culture and enhancement.

Abstract:Normally, catch per unit effort (CPUE) is the total catch in a specific period (such as, year, month or season) divided by the total amount of effort used to harvest the catch in the corresponding period. As an index of measuring the abundance variation of fishery resources, CPUE is often used for fishery stock assessments. As a living marine resource with aggregation trait, the abundance of Antarctic krill has a significant spatial-temporal variation. Additionally, particularities of this species and fishery characteristics result in remarkable uncertainty in efficiently measuring the variation of abundance. Thus, this review provides detailed information on four methods to calculate CPUE of Antarctic krill fishery and summarizes the characteristics, advantages and disadvantages of these methods, and further analyzes the impacts of estimating CPUE of Antarctic krill fishery in view of temporalspatial scale and environmental factors. The suitability and feasibility of CPUE being considered as an index of abundance were also discussed. In recent years, Antarctic krill fishery has attracted more attention worldwide, however, there is no consistent argument on how to include fishery survey data into krill fishery stock assessment, which hampers the development of ecosystem-based Antarctic krill fishery management. The conclusion derived from this review can provide ideas for conducting better stock assessment and abundance estimation of Antarctic krill resources.

Abstract:Euphausia pacifica is a key species of zooplankton in the Yellow Sea ecosystem. To estimate the biomass and distribution of E. pacifica is essential for better understanding local ecosystem structure and energy flow. However, due to its avoidance to zooplankton net, it is difficult to quantify the krill biomass using traditional vertical net sampling method. Based on acoustic and biological data of E. pacifica swarms collected in the Yellow Sea in January 2010, the target strength (TS) of E. pacifica at 38 and 120 kHz was analyzed using SDWBA theoretical model. Moreover, the E. pacifica swarms were identified using dB-differencing method based on 38 and 120 kHz acoustic data and the krill density in the sound scattering layers (SSL) was estimated subsequently. Numerical simulation showed that the TS of E. pacifica was sensitive to its orientation and length distribution. The TS at 120 kHz was obviously higher than 38 kHz, while the difference decreased with increasing krill length. A linear relationship with an intercept of 14.1 dB was observed for the mean volume backscattering strength (MVBS) between the two frequencies. Based on 120 kHz data, the density of E. pacifica in the SSL was estimated between 1.8 and 2351.8 ind/m³ with a mean of 255.1 ind/m³. This paper preliminarily introduced the species identification and density estimation of E. pacifica based on the dB-differencing method, which provides useful reference for the acoustical estimation of zooplankton biomass. To improve the accuracy and precision, further investigations on the parameters in the TS model and the target discrimination method are needed.

Abstract:The issue of climate change is a hot topic in the international community in recent years. Ocean is the main carrier for the climate system to store energy; the implications of climate change to marine fish in general must not be neglected. The changing of climate affects the changing of the low frequency climate variability patterns and marine environmental factors. Through the direct effect to individual or indirect effect transferred by ecosystem food chain, marine fish have been affected by these changes, including fish physiology (growth, breeding, migration), phenology, the abundance and distribution of resources, as well as marine ecosystem, and finally all those brought influence on fishery resources management. By collecting relevant literature domestic and abroad, this paper focuses on, four aspects i.e., abundance and distribution of resources, marine ecosystem, and fishery resources management, reviewed the impact of climate change on fisheries resources, so as to cope with climate change, and provide research foundation for realizing the sustainable development of fishery resources.

Abstract:To assess the ecological risk of stock enhancement, an ecological risk assessment (ERA) system was constructed based on the analysis of the past literatures, field survey and expert consultancy. The system constructed using analytic hierarchy process (AHP) method was applied to 5 zoobenthos. The results showed that: the risk grade of Coelomactra Antiquata, Anthocidaris crassispina, Meretrix lamarckii, Babylonia lutosa was medium, and that of Paphia undulate was low. The construction of this risk assessment system will provide beneficial suggestions in the future stock enhancement.