Abstract:Phosphoenolpyruvate carboxylase (PEPC, EC 4.1.1.31) plays an important role in plant carbon metabolism, which can affect protein and lipid metabolism in higher plant, while studies on green alga PEPC are limited. Chlamydomonas reinhardtii is the model organism in green alga, and its chloroplast transformation is mature and efficient.In order to get high expression quality of protein and lipid content, chloroplast transformation method could be applied. In this study, the sequence with 639 bp (about 1/7 length) of C. reinhardtii CS I was cloned, then C. reinhardtii was transformed by the empty plasmid pASapI, vectors pASapI-reve-Crpepc2 and pASapI-forw-Crpepc2, to generate “blank,” “forward,” and“reverse” mutants by particle bombardment, respectively.The relative expression of Crpepc2 were detected with RT-qPCR, it showed that Crpepc2 expression of reverse mutant decreased by 89.97%, and that of forward mutant increased by 201.16%. Mean while the contents of protein and lipid were detected, the data showed that total protein of forward mutant rose by 37.03%, and the lipid content of reverse mutant enhanced by 70.32%, moreover, fatty acid of reverse mutant increased obviously. In conclusion, bacteria type PEPC in Chlamydomonas reinhardtii not only can improve protein and lipid content, but also can make contribution to foreign protein expression and high lipid content engineered microalgae.

Abstract:The mirror carp breeding of generations targeted at Koi herpes virus (CyHV-3) has been carried out to F₃ generation. F₂ and F₃ survival rates are similar and significantly higher than F₁. In this study, theCyHV-3 viral loads and the gene expression of IL-1β, TRAF6, MyD88a, I-IFN and TLR7a are compared by real-time fluorescence quantitative PCR technique. Immune gene expression levels and viral loads in combination with disease resistance survival rates are used to evaluate the disease resistance of different generations. The results showed that: (1) CyHV-3 virus load decreased sequentially in F₁, F₂ and F₃, and F₃ was significantly lower than F₁ and F₂ (P<0.05); (2) Summerlings group wasn't infected CyHV-3, only the expression of TRAF6 gene in F₃ was significantly higher than that in F₁ and F₂ (P<0.05). (3) In the infected group, the levels of IL-1β and MyD88a in F₃ spleen were significantly higher than those in F₁ and F₂ (P<0.05), and TRAF6 was significantly higher than that of F₁ (P<0.05). The expression of IL-1β and TRAF6 in F₃ kidney was significantly higher than that in F₁ and F₂ (P<0.05). There was no significant difference between F₁ and F₂ (P>0.05). The above results show that F₃ disease resistance is significantly higher than F₁, F₂, only the TRAF6 gene was breeding. Based on the fact that F₂, F₃ survival rate was similar and significantly higher than F₁, it can be concluded that F₂ disease resistance is not stable and F₃ resistance has stabilized, and that using the immune gene expression or viral load method to evaluate the disease resistance is feasible.

Abstract:The differences of 14 serum biochemical indexes and vitellogenin content between female and male migratory Anguilla japonica collected at the Yangtze River Estuary were compared, and the function of sex identification on female and male eels were established. The results showed that serum triglyceride (TG), low density lipoprotein (LDL-C), and calcium (Ca²⁺) level of the male eels were significantly higher than those of the female eels (P<0.05), while the albumin (ALB), and glucose (Glu) of the female eels were significantly higher than those of the male eels (P<0.05).There were no significant differences between the female and male eels on the levels of Alanine transaminase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), total bilirubin (T-bil), total protein (TP), creatinine (CREA), total cholesterol (TC), high density lipoprotein cholesterol (HDL-C), and inorganic phosphorus (P) (P>0.05). Vitellogenin level of the female eels was significantly higher than that of the male eel (P<0.05). Base on the differences of the 14 serum biochemical indexes between female and male eels, two functions were established using stepwise discriminant analysis and entering independents together which could be used for sex determination of Anguilla japonica.

Abstract:Two transcriptome assembly strategies (mapping-first and de novo assembly-first) were used in this study to evaluate the applicability on transcriptome study for common carp varieties, using Oujiang color common carp as studied species. Regarding the transcriptome assembly and annotation, our study showed the average length of assembled transcripts using mapping-first strategy (Cufflinks software) was 1 545 bp, the number of annotated transcripts was 77 601. The average length of transcript assembled using de novo assembly-first strategy (Trinity software) was 979 bp, the number of annotated transcripts was 69 406. Considering the gene structure and alternative splicing prediction, our results presented three and four alternative splicing transcripts for every gene for Cufflinks and Trinity assembly, respectively (P<0.001). Meanwhile, the gene structure prediction was more accurate in Cufflinks assembly than Trinity assembly. Our results indicated the longer transcripts, the more annotated transcripts, and transcripts with more accurate gene structure were identified in the transcriptome assembled using mapping-first strategy (Cufflinks software), which is more suitable for the following gene expression analysis. On the contrary, the transcriptome assembled using de novo assembly-first strategy (Trinity software) provided more accurate specific gene sequences, which is vital for evolutionary studies of Oujiang color common carp. Our study demonstrated that both assembly strategies were essential for the Oujiang color common carp transcriptome, and provided guidance for the choice of transcriptome assembly strategies on other varieties of common carp.

Abstract:In order to investigate the breeding performance of Macrobrachium rosenbergii, this experiment was conducted by measuring 5 specialized strains of shrimp Macrobrachium rosenbergii (A, B, C, D, E) of the three consecutive spawning unit weight of fecundity (F_W) ovarian development cycle (C_O), fertilized egg diameter (D_E), vitellogenin (VTG) content, and cathepsin D (CTSD) activity index, and comparative analysis of 5 selection strains of fertility was made, with a view to screening the high fecundity strains of Macrobrachium rosenbergii. The results showed that the absolute fecundity (F), F_W and body weight were positively correlated (P<0.05), F and F_W were also significantly positively correlated (P<0.01). The average value of F_W of the continuous thrice spawning of the 5 selected strains was (1.96-2.30)×10³ eggs/g, the differences between the strains were significant (P<0.05).The F_W of B and D were 2.26×10³ eggs/g and 2.30×10³ eggs/g respectively. The average range of VTG content and CTSD activity in the 5 selected strains were 3.48-5.80 μg/g, 271.81-320.82 U/g, and there was significant difference among the strains (P<0.05),while the highest content of VTG in fertilized eggs was B (5.80 μg/g), the highest CTSD activity was D (320.82 U/g), the second was B (303.09 U/g), and there was no difference between them (P>0.05). The range of Co was 18.8-23.8 d, second time larger than the first (2-8 d), there was no difference (P>0.05) between each strain,which were all significantly lower than those in the control group (P<0.05). The mean value range of D_E was 542.3-552.0 nm, there is no difference among strains, and the average egg diameters of B and D were larger, 551.7 nm and 552.0 nm, respectively. It can be confirmed that among 5 specialized strains of Macrobrachium rosenbergii, the fecundity of B and D is the strongest, A is weak, C and E is the weakest, which can provide basis for breeding of specialized strains of shrimp Macrobrachium rosenbergii.

Abstract:To investigate the differences in the compositon and diversity of bacterial community in the intestine, water and sediment of rice-crab co-culture and crab monoculture models, Illumina sequencing of the V4 hypervariable region 16S rRNA gene revealed extensive changes in bacterial communities. At the phylum level, 7 bacterial phyla were found, including Acidobacteria and Synergistetes in the intestine, Bacteroidetes, Cyanobacteria, Gemmatimonadetes and Armatimonadetes in the water, Planctomycetes in the sediment. At the genus level, there were 14, 18 and 13 bacterial genera in the intestine, water and sediment respectively. No significant differences in the abundance indexes (Chao, ACE) and the diversity indexes (Simpson, Shannon) of the intestinal, water and sediment samples were observed between two production models. Comparative analysis of bacterial groups with significant difference in the water and sediment (Mycobacterium, Rhodobacter, Flavobacterium, Nitrospira, Cyanobacteria, Acidobacteria, Planctomycetes, Tenericutes and Firmicutes)revealed bacterial species that indicate an anaerobic or high nitrite environment was more abundant in the samples of crab monoculture model. The composition of intestinal bacterial community of rice-crab co-culture model was closer to that in wild populations, which also indicated the environment of rice-crab co-culture is healthier than crab monoculture and is beneficial to the growth of Eriocheir sinensis.

Abstract:In order to investigate the growth differences of individuals from larvae to adult stage, the samples were collected on the 28th day, the 38th day, the 48th day, the 58th day, the 68th day and the 73th day. Firstly, take the 28th day sample, calculate the proportion of different weight; According to the first 10% (14), 10% (14) near the middle, the last 10% (14) of weight ranking defines the growth rate is high, middle or low. Secondly,the body length and body weight of the shrimp were fitted by power function and linear regression. Thirdly, all the samples were calculated the absolute growth and relative growth. The results showed different growth rates of three groups at the same growth period (P>95%), the growth rate of different shrimp as a whole to analyze whether there may be some deviation. Secondly, the power function of W_all=1×10^-5L^3.0051, the linear equation y_all=3x-4.92, the linear equation group with different growth rates were y_high=3.41x-5.71, y_middle=3.21x-5.30, y_low=2.92x-4.78; Linear equation of the slope was positively correlated with the growth rate, and three sets of linear equation could more accurately reflect the real growth of shrimp. Also, we found that different growth rate of shrimp absolutely conforms to the actual growth, and growth analysis selecting absolute growth value is more appropriate.

Abstract:In order to explore characteristics of compensatory growth of juvenile Cyprinus carpio haematopterus new strain in cycle of starvation-feeding, we chose 360 juveniles with the initial mean weight of (23.44±3.21) g, and divided them into 4 groups randomly, each group was set to 3 repeats containing 30 individuals. Fish were fed in four feeding schedules as follows: Starvation A:5 days starvation (S)-20 days feeding (F)-5 S-20 F-5 S-20 F; Starvation B: 7 S-28 F-7 S-33 F; Starvation C: 15 S-60 F; Control group Con: 75 F. The experiment lasted 75 days. The results show that: (1) In the recovery of satiation period after starvation, the specific growth rate (SGR) of the A group was 1.70%, significantly higher than that of the group B of 1.08%, group C of 0.87% and Con of 0.60%; (2) During the starvation period, the specific growth rate of body length (SGR_L) of three treatment groups was significantly lower than that of the Con, but significantly higher than Con after refeeding. (3) At the starvation period, the specific growth rate of condition factor K (SGR_K) of group A was significantly lower than those in the group B, C and Con, but significantly higher after the satiation period. (4) the feed rate of A in the treatment group was 8.7%, higher than the other two groups. Based on the SGR as the main evaluation index, the results indicated that the way 5 days starvation (S)-20 days feeding (F) can arouse juvenile Cyprinus carpio new strain to have partially compensatory growth effect and save 8.7% of the feed consumption.

Abstract:In order to assess the effect of dietary taurine supplementation on the growth, body composition, digestive enzyme activity and stress resistance of Litopenaeus vannamei in freshwater, five isonitrogenous and isoenergetic experimental diets based on 10% fish meal formula, supplemented 0% (A), 0.15% (B), 0.30% (C), 0.45% (D)and 0.60% (E)taurine respectively (The taurine contents were orderly 1.42, 3.07, 4.37, 5.79 and 7.48 mg/g diet), were fed to the juvenile shrimp (initial body weight 0.160±0.002 g) for 56 days. Then the growth performance, proximate composition of muscle and hepatopancreas digestive enzyme activity were investigated. The nitrite acute stress test and hypoxia stress test were also conducted. The results showed that: The dietary taurine content had no significant effect on the growth performance of the white shrimp L. vannamei (P＞0.05). The muscular total lipid content of shrimp increased and moisture declined along with the increasing dietary taurine level.The muscular total lipid contents in D and E treatments were significantly higher than those in other treatments (P＜0.05). Muscular moisture in A,B and C treatments were significantly higher than those in D and E (P＜0.05); There was no significant difference in muscular crude protein and ash between the treatments (P＞0.05).The activities of protease and lipase in hepatopancreas increased with the increase of dietary taurine content. D and E treatments displayed significantly higher protease and lipase activities than other treatments (P＜0.05). Stressed with 8.5-9.0 mg/L nitrite, D treatment displayed lower cumulative mortality at 48 h, 72 h and 84 h than other treatments. Under hypoxia stress, C treatment had lower lethal dissolved oxygen concentration than other treatments. It is therefore suggested that supplementation of 0.30%-0.45% taurine in diet containing 10% fish meal (the dietary taurine was between 4.37 and 5.79 mg/g diet) could improve the nitrite tolerance and hypoxia tolerance of the white shrimp L. vannamei in freshwater culture condition.

Abstract:An 8-week feeding experiment was conducted to evaluate the effects of fishmeal replacement by soybean meal (SM) and hydrolyzed soybean meal (HSM) on growth performance, body composition, digestion and metabolism of juvenile hybrid grouper (♀Epinephelus fuscoguttatus×♂Epinephelus lanceolatus).Six isonitrogenous and isoenergetic diets were formulated by replacing 0, 20%, 40%, 60%, 80% of fishmeal protein with soybean meal (SM0 to SM80) and 60% of fishmeal protein with hydrolyzed soybean meal (HSM60) respectively. A total of 540 juveniles (47.18±0.45 g) were randomly assigned into 6 groups with 3 replicates of 30 fish. Results showed as follows: (1) There was no significant influence on growth performance and feed utilization of juveniles in SM20 and SM40 group and the weight gain rate (W_GR), specific growth rate (S_GR), protein efficiency ratio (P_ER) and daily feed intake (D_FI) of the juveniles were significantly decreased in SM60 and SM80 group (P＜0.05). (2) With the increasing of dietary soybean meal content, the crude protein content in whole body decreased and the values of groups SM20-80 were significantly lower than that of the control group (P＜0.05), and the crude ash content in whole body was significantly lower in group SM40-80, and the moisture content in muscle significantly increased while crude protein and crude lipid content significantly decreased in group SM80 (P＜0.05). Dietary inclusion of SM (SM20 to SM80) significantly reduced several amino acid contents of muscle such as Met, Leu and Lys and so on (P＜0.05). (3) Dietary inclusion of SM (SM20 to SM80) significantly reduced intestinal trypsin activity (P＜0.05), and pepsin and intestinal amylase activities decreased significantly in SM60 and SM80 groups (P＜0.05). (4) The activities of alanine transaminase (ALT) and aspartate transaminase (AST) decreased with the increasing of dietary soybean meal content and were significantly lower in groups SM40-80 (P＜0.05),and the activity of Glucose-6-phosphatase (G6PC) was significantly higher in SM20 and SM40 groups. (5) Compared with SM60 group, the W_GR, S_GR and D_FI of juveniles in HSM60 group were significantly increased and F_CR was significantly decreased, and the crude lipid content of whole body and muscle decreased significantly while crude ash content increased significantly. The activities of pepsin, trypsin and amylase were significantly increased (P<0.05), and the activities of AST and ALT were significantly increased and the activity of FAS was significantly decreased (P <0.05). In conclusion, soybean meal can replace 40% of the fish meal and higher replacement level will lower the growth of juveniles and hydrolyzed soybean meal can replace 60% of the fish meal without reducing the growth of juveniles.

Abstract:This paper describes the construction of the simple moveable bio-filters. Additionally, the feasibility of biofilm developed through using tank water for raising prawn broodstock and its nitrification performance were evaluated in a recirculating system stocked with Macrobrachium rosenbergii. Common media such as zeolite, fiber ball and biochemical ring (Total weight 30.9 kg) were put into plastic barrel (Total volume 70 L) to make a simple bio-filter. The two same bio-filters named Ⅰ and Ⅱ were used in current research that served as the recirculation filter. It should be noted that the bio-filter can be placed in a trolly transporting to any tank in aquaculture workshop to treat water. Two culture tanks were used as the main system in which Macrobrachium rosenbergii were grown as a source of waste nutrients. Tank water flowed out of overwintering ponds (4 m³) for broodstock and was mechanically filtered through the simple bio-filters Ⅰ (0.231 m³/h) and Ⅱ (0.138 m³/h) by pumps. The results showed that the biofilm can be developed after about 17 days through using tank water for raising prawn broodstock. Concentrations of TAN and NO₂^--N can be effectively reduced by the simple moveable bio-filters. Resulting average removal rates were 40.23%, 45.3% in TAN and 58.4%, 65.1% in NO₂^--N in 37 d by the two filters Ⅰ and Ⅱ. Average removal rates were 0.138 mg, 0.081 mg TAN/ (m²·d), while 0.053 mg, 0.035 mg NO₂^--N/ (m²·d) by filtersⅠ and Ⅱ. The results of this study showed that filters Ⅰ and Ⅱ have high nitrification efficiency in removing TAN and NO₂^--N, and no significant differences were observed between Ⅰ and Ⅱ (P>0.05).

Abstract:The categories composition and abundance distribution of fish larvae in the Yangtze River Estuary and vicinity waters were analyzed based on data from four seasonal surveys at 504 sampling stations during 2006 to 2007. Eighty-two species of fish larvae were collected, belonging to 16 orders, 48 families. Among them, Perciformes was the most diverse group, with 34 species from 21 families. Scorpaeniformes, including 3 families, 10 species, and Clupeiformes, including 5 families, 8 species, were the next diverse fauna. There was clearly seasonal and spatial variation of theabundance of fish larvae and the number of species of fish larvae. The seasonal abundance of fish larvae was listed as summer (185 ind/100m³) > spring (37 ind/100m³) > autumn (6 ind/100m³) > winter (1 ind/100m³), and they mainly centered in spring and summer. The average abundance of fish larvae was higher in summer than in spring and the distribution areas were more to the west in summer. The number of the fish larvae species was in the order of summer (39 species) > spring (38 species) > autumn (25 species) > winter (16 species). The dominant species were Engraulis japonicas, Coiliamystus, Benthosemapterotum in spring, summer and autumn respectively. Multivariate statistical analysis showed that in spring, the distribution of most species of ichthyoplankton was controlled by depth of water and surface salinity. While in summer, most species preferred the estuarine and coastal waters, which was characterized by higher chlorophyll a concentration and surface temperature.

Abstract:Skipjack tuna (Katsuwonus pelamis) is one of the tuna species in the tropical Pacific waters, and is one of the main fishing targets by Chinese tuna purse seine fleets. In this paper, according to the fishing data during 1995 to 2012 in the Western and Central Pacific Ocean waters (5°N-10°S and 125°E-135°W), combined with the remote sensing data of sea surface temperature (SST) and sea surface height (SSH), the frequency distribution method is used to analyze the suitable environmental range (SST and SSH) for skipjack tuna in the Western and Central Pacific Ocean. And the envelope method is also used to establish the suitability index (SI) based on SST and SSH in each quarter. The habitat suitability index (HSI) model is established to calculate the habitat suitability index by using the method of arithmetic average (AMM) and the geometric average method (GMM), and the catch data in 2013 is used to verify. The results show that the skipjack tuna is distributed in the waters with SST ranging from 28 ℃ to 30.5 ℃ and SSH ranging from 65 cm to 95 cm. In terms of fishing effort (fishing days) used as SI, the external envelope method of SI with SST and SSH is the most suitable. For establishing arithmetic average method of skipjack tuna, the suitable weights of SST in each quarter were 0.7, 0.6, 0.3 and 0.6 in the Western and Central Pacific Ocean. It is concluded that the environmental factors in different seasons have different effects on skipjack tuna distribution in the Western and Central Pacific Ocean.

Abstract:IUU fishing hinders the effective management and conservation of fishery resources. Combating IUU fishing should make efforts in many links. Port state measures combat IUU fishing by eliminating or reducing the quantity of catches from IUU fishing.The Port State Measures Agreement provides a basis in international law for port state measures which came into force in 2016. This paper analyzes the main content of Port State Measures Agreement and the measures which have been adopted by some countries or RFMOs. On this basis, this paper analyzes the effectiveness and limitation of port state measures. As for the effectiveness, for example, port state measures can reduce the occurrence of IUU fishing and improve the possibility of finding IUU vessels; It also can make up for the defects of the flag state jurisdiction. As for the limitation, for example, it's difficult to implement port state measures in a short period of time because of inadeguate execution capacity of many countries; And it is difficult to confirm IUU fishing in the harbor because Port State Measures Agreement has not regulated the traceability information of catches. For China, port state measures can reduce the possibility of vessels which fly China's flag to engage in or support the IUU fishing. It'll perfect the oversight and control systems for fishing if China joins the Port State Measures Agreement. However, if China adopts the port state measures, China also will be faced with some challenges in the comprehensive reform of port supervision system and fishery supervision system and the construction of port state measures ability.

Abstract:This paper summarized the characteristics of the temperature, salinity,surface CO₂ partial pressure (pCO₂) and sea-air CO₂ flux based on the in-situ CTD, CO₂ and others data in the South Yellow Sea during the winter of 2015. The results indicated that the west coast of the Yellow Sea was low temperature and low salt, affected by Yellow Sea Coastal Current. The central part of the southern Yellow Sea was high temperature and high salt, affected by the Yellow Sea Warm Current. In the coast, it was well mixed with generalized temperature and salinity in vertical. The average value of surface pCO₂ was (385.34±43.62)μatm. The distribution of surface pCO₂ had obvious regional differences. In the central sea, the pCO₂ was larger than that of the nearshore. Due to horizontal and vertical mixture of the Yangtze River water and the Yellow Sea Coastal Current, the northern part of the Changjiang River Estuary was atmospheric carbon sink where the maximum flux was 27.81 mmol/ (m²·d). However,overall regional average flux was (-2.47±3.91)mmol/ (m²·d) The higher pCO₂ in the southeastern of Shandong Peninsula controlled by the cold water, correlated to mixture of the high carbonate water brought by the Yellow Sea Coastal Current and the average flux was (0.11±0.80)mmol/ (m²·d). The winter mean flux in the Southern Yellow Sea was (-2.24±3.74)mmol/ (m²·d),which was carbon sink of the atmospheric CO₂.

Abstract:Deep Sea is the key area of marine science research and technology. The exploreto the Challenge Deep, Mariana Trench,the deepest oceans is the landmark and biggest challenge.In order to ensure the safety in deployment of the underwater vessels in the area,the significant wave featuresarestudied with the WAVEWATCH ⅢHindcast Data from NOAA (National Oceanic and Atmospheric Administration) and the remotely-sensed waves productfrom Jason II satellite provided by CNES (French government space agency) and other organizations from February 2005 to July 2015 is analyzed.The results show that the regional average SWH is 1.30 (Jun)-2.53 m (Jan)over the Mariana Trench.Theregional average peak period (Tp) is 8.0 (Jun)-9.6 s (Dec),The maximum monthly significant wave height are 3.03 m, 2.79 m, 2.58 m, 2.19 m, 1.74 m, 1.56 m, 1.68 m, 1.78 m, 1.85 m, 2.22 m, 2.37 m, 2.81 m, and the maximum appears in January (3.03 m), minimum in June (1.57 m).The seasonal variation has a great discrepancy.The maximum average SWH appears in winter, minimum average SWH is in summer. Spring and autumn are transitional period.For the appearance of the Rough waves with 4 m SWH, the frequency is 0.2% to 3.5%, which is more in winter and less in the other seasons.Following the required sea states conditionforsafety launch and recovery of “JIAOLONG” and others hadal submersible,May to Oct would be the practicaloperation period and in the rest months, a good sea condition would be much less.

Abstract:Pathogenic (ATCC 33847: tdh+/trh-/tlh+; ATCC 17802: tdh-/trh+/tlh+) and non-pathogenic (G2: tdh-/trh-/tlh+; G8: tdh-/trh-/tlh+) V. parahaemolyticuss strains were mixed at 9∶1 and 1∶1 ratios and cultured at 37°C in tryptic soy broth (TSB) or cooked shrimp for 10 h. The rate of isolation of the pathogenic strains after 10 h was determined by colony hybridization and PCR method, and the results showed that the isolation rate of the pathogenic strains decreased after co-culturing in TSB and cooked shrimp. The isolation rate of the pathogenic strains was more prominent in the shrimp samples, and when the strain ATCC 17802 was mixed with strain G8 in a 9∶1 ratio in the shrimp samples, no pathogenic strain was detected after 10 h. Negative effects of mixed culture on the growth of pathogenic V. parahaemolyticus are one of reasons for the rare isolation of V. parahaemolyticus from seafood samples.

Abstract:In this study, the technology for the large-scale cultivation of gibel carp brain cells and CyHV-2 by Cephodex microcarrier in suspension system was investigated. The results showed that the Cephodex microcarrier is suitable for the growth of anchorage-dependent GiCB cells. The optimal serum concentration for cells attaching to the Cephodex microcarrier was 10%, the microcarrier concentration was 6 g/L and the density of cells inoculated was 2.5×10⁵ cells/mL. With an intermittent agitation for 2 min at 35 rpm after 30 min stilling culture, the attachment efficacy reached 90% after 8 h cultivation; while in growing period, the optimal speed was 45 r/min for continuous agitation. After infection of GiCB cells on Cephodex microcarrier with CyHV-2 at a multiplicity of infection (MOI) of 0.2, the typical cytopathic effect (CPE) appeared after 5 days post-infection and the virus titer (TCID₅₀/mL) reached 10^6.50±0.30. This study established a solid basis for the large-scale preparation of vaccine against the crucian carp hematopoietic necrosis.

Abstract:To study the quality change of Chinese mitten crab during the frozen storage, sensory and physical and chemical indicators were used to judge the taste period of 180 days of gonad part and 240 days of meats. Fishy smell and rancidodor in the gonad part of crabs were too heavy after 180 days.Crabmeat was not accepted after 240 days because of the ammoniacal smell and fishy smell. The volatile odor substances of Eriocheir sinensis were extracted and detected by Solid-phase microextraction (SPME) and Gas Chromatography-mass Spectrometer (GC-MS) before and after freezing. The compounds were analyzed and selected by odor activity value (OAV). The results showed that the most important substances affecting the odor of Eriocheir sinensis after freezing were Benzaldehyde, Nonanal,2,6-Nonadienal, 1-Octen-3-ol, 2,4-Decadienal and Trimethylamine.