Abstract:Based on the biological measurement data of small yellow croakers collected in the sea area in the north of 29°N and the east of 127°E in 2004,the trend of annual change of power b was analyzed by Bootstrap method at four different temporal scales including day,week,half-month，and month.The bootstrap analysis showed that the values of power b during the spawning period were significantly smaller than those of the other periods in the same year (P<0.05).When the average b value from the samples was used for the determination of the periods of spawning and non-spawning,only the results based on the time scales of week or longer were reliable.However,when the b value of a single sample was used for the determination,the results based on the time scales of only half month or longer were reliable.The trend of annual change of power b,with low values during April~May and a peak during November~December,became more obvious with the increase of temporal scales.

Abstract:Morphological and quantitative characteristics of Verasper variegatus in early life stages including embryonic development, yolk sac larva, pre-flexion larva, post-flexion larva, and juveniles were recorded. The eggs are 1.75mm 0.08mm in diameter, without oil globule and spherical in shape when they are suspended in sea water. There is negative a relationship between the temperature and the hatching time, and the calculated lower threshold temperature for hatching of embryos is 5.14 ℃. The larvae hatched out 159h post fertilization at temperatures of 11±0.5 ℃, salinity of 31-32, and DO≥5mg/L. The newly hatched larvae is transparent and 4.95±0.15mm in total length. Larval development and growth completely depended on the energy from the yolk sac and oil globe till 7 DAH (days after hatching). Meantime, mouth and anus opened, larvae entered the mixed feeding stage. Larvae entered the complete exogenous feeding stage after the yolk was completely absorbed at 11DAH. The first feeding food was L type rotifers Brachionus plicatilis. Larvae began to feed rotifers at 7 DAH. At 11 DAH, larvae were fed nauplii of brine shrimp Artemia salina at densities of 0.5 1.5 ind./ml till 46 DAH. Weaning to commercial diet started at 31 DAH and larvae fed mainly commercial diet after 40 DAH. There is no swim bladder present all through the early life history. The flexion of notochord started at 17 DAH at a total length of 7.32 0.23 mm (n=30), and finished at 33DAH when the total length reached 11.2 0.33 mm (n=30). Meanwhile, metamorphosis began at 33 DAH and completed at 50 DAH with the left eye moved completely to the right side, and the juveniles entered the bottom life stage. At 70 DAH, lateral line formed and the juveniles entered the young stage with the total length up to 25.3 3.23 mm (n=30), with similar appearance as the adults. The dorsal fin, pectoral fin, pelvic fin, caudal fin, and anal fin reached their full numbers at 70DAH. There were 4-5 black spots on the dorsal and pectoral fins at 45DAH, which is same as the adults.

Abstract:The hatching periods, hatching rate and deformity rate of the fertilized eggs, deformity rates of the post-embryonic larvae and the survival activity index (SAI) of the newly hatched larvae of Epinephelus septemfasciatus were examined at salinities of 10, 15, 20, 25, natural seawater salinities of 30, 35, 40 and 45. The results showed that: 1. the optimum salinity for hatching was between 30 and 35. When the salinity was above 35 or below 25, the hatching rates decreased and the percentage of abnormal larvae increased; 2. the optimum salinity for larval survival was in the range of 30~35, and the SAI values of the fish were 24.7±0.36 and 23.27±3.01, respectively.

Abstract:Experiments were conducted to study the effects of starvation (0, 3, 7, 14, and 21d) on the ratios of liver weight to body weight, stomach weight to body weight, pylorus weight to body weight, and intestine length to body length, and muscle composition in Sebastiscus marmoratus reared in culture water under indoor conditions. We observed that all of the digestive organs atrophied and all the ratios decreased during the starvation period. The ratio of intestine length to body length decreased gradually and showed a significant difference compared to the control group (P<0.05). The ratio of liver weight to body weight decreased most dramatically (P<0.01), showing a decrease of 85.033% at 21d compared to the control group. At the meantime, starvation resulted in the increase of water and ash contents, and the decrease of the protein and fat contents.

Abstract:An anti-bacterial and analgesic bioactive peptide named MAS-Ⅳ-4 was isolated from the skin mucus of M. albus and purified by Sephadex G-50 gel chromatography and DEAE Sepharose Fast Flow ion exchange chromatography. The molecular weight of MAS-Ⅳ-4 was estimated by Tricine-SDS-PAGE as 10.4 kD, and its melting point was measured by microscopic melting point meter as 208~211 ℃. The anti-bacteria activity of MAS-Ⅳ-4 was assessed by determination of the inhibition zone. The results showed that the growth of Aeromonas hydropnila, Staphylococcus aureus and Bacillus subtilis was strongly inhibited by MAS-Ⅳ-4. In addition, the pain threshold of the mice was significantly increased when 0.75 ml or more of MAS-Ⅳ-4 were injected. MAS-Ⅳ-4 also demonstrated weak hemolytic activity and serine protease inhibiting activity.

Abstract:The complete sequences of mitochondrial control region of 53 individuals of Collichtys iucidus from seven populations, Nantong(NT), Qidong(QD), Luchaogang(LC), Wenzhou(WZ), Ruian(RA), Fuzhou(FZ), and Panyu(PY) were obtained by PCR cloning . Sequence lengths of the control region of C. iucidus varied in the range of 778-782 bp, which was mainly caused by the insertion or deletion. The conserved regions, such as TAS and CSB-1,-2, and -3 were identifiable in the control regions of C. iucidus. There were 66 polymorphic sites, which accounted for 8.44% in all sequences, and 33 haplotypes were found in all individuals. The average value of haplotype diversity (Hd) was 0.934 7±0.017 5 and the average value of nucleotide diversity (π) was 0.017 5±0.002 3 for seven populations. The K2-P distance within and among seven populations were 0.001 7～0.022 8 and 0.002 3～0.043 3, respectively. The difference index (FST) ranged betweenin -0.058 4～0.845 8 and the gene flow values were within the range of 0.05～19.62 for the seven populations. AMOVA analysis revealed that the inter-population variance was 74.21% and the intra-population variance was 25.79% (P<0.05). The phylogenetic tree estimated by NJ methods indicated that the C. iucidus individuals from seven populations could be clustered as two clades: the northern clade was formed by Nantong, Qidong, Luchaogang, and Wenzhou populations, while Fuzhou and Panyu popualtions formed the southern clade, and Ruian population was mixed with the above two clades.

Abstract:The two-dimensional gel electrophoresis for the epidermal proteome of Scophthalmus maximus was established and optimized through comparative tests by using different extraction methods, isoelectric focusing programs and sample volumes. The total proteins of the turbot epidermis were extracted by the combination of improved trichloroacetic acid(TCA)/acetone and ultrasonic extractions. The lysis buffer based on the Bio-Rad recommendations was optimized. Protein of 250 μg was loaded on the 17cm pH 4.7 immobilized pH gradients (IPG) strips. The programs for the gel isoelectric focusing were 30V linear ramp, 6h/250V linear ramp, 2.5h/500V linear ramp, 1.5h/1000V rapid, 2h/4000V linear ramp, 3h/8000V rapid, 3h/8000V linear ramp, and 1h/500V 24h. The gel was stained with sliver nitrate, scanned and analyzed using the Image Master 2D Platinum 7.0 software. The two-dimensional gel electrophoresis analysis of the epidermal proteome of the turbot was successfully established with high quality map of separation under the optimization of the experimental conditions, which will be a valuable preparation for further epidermal proteomics research of S. maximus

Abstract:The aim of this study was to establish the relationship between target strength (TS), dorsal-aspect reflections section and weight, body length of yellow croaker Pseudosciaena crocea (Pc) and black rockfish Sebastes schlegeli (Ss). The results showed that both the weight and body length had the quantitative relationship with the target strength. At 50 kHz, the target strength of different body parts of Pc was between -32.85 and -58.01 dB; at 200 kHz, it was -29.3~-56.99 dB. For the Ss, it was -31.74~-75.87 dB, and -31.74~-74.75 dB, respectively. At both 50 kHz and 200 kHz, the TS of the fish belly was maximal and that of the fish tail was minimal. The correlation between the mean lateral TS and the length was positive, for both 50 kHz and 200 kHz. At 50 kHz: TSPc=24.8 logL (cm)-73.9(side direction); at 200 kHz: TSPc=23.9 logL (cm)-71.3(side direction), and at 50 kHz: TSSs=25.7 logL (cm)-69.16 (side direction); at 200 kHz: TSSs=26.4 logL (cm)-70.8 (side direction). The results of the experiments are expected to provide data support for the design of underwater acoustic monitoring instruments.

Abstract:Fenneropenaeus chinensis were fed with norfloxacin (NFLX) at doses of 15mg/kg (low dose group), 30mg/kg (medium dose group), and 60mg/kg (high dose group) for 7 days, respectively. The activities of some non-specific immune response enzymes including superoxide dismutase (SOD), catalase (CAT), lysozyme (LSZ), phosphatase (ACP), and alkaline phosphatase (AKP) in the muscle and gill tissues of the fed shrimps were determined. For the low dose group, the SOD activities in the muscle were significantly lower than that of the control group (P<0.05), while the SOD activities in the gill increased. The activities of CAT and LSZ in the muscle and gill were significantly higher than those of the control group (P<0.05), and the activities of ACP and AKP were inhibited. For the medium dose group, CAT activity in shrimps was significantly higher than that in the control group. The LSZ, and SOD activities in the muscles were first inhibited, and then increased. The SOD, LSZ and CAT activities in the muscle and gill were activated by 60mg/kg NFLX, while the AKP and ACP activities showed no significant difference between the experimental groups and the control (P<0.05).

Abstract:According to the sequence from the electronic cloning, a pair of primers were designed to clone the Arf6 gene in Litopenaeus vannamei by PCR. A 695bp cDNA was obtained, which contained a 96bp 5′ untranslated region (UTR), a 528bp open reading frame (ORF), and a 71bp 3′ UTR. The encoded protein was composed of 175 amino acids, with a molecular weight of 20kDa and the calculated isoelectric point of 8.82. The molecular formula was predicted to be C896 H1426 N252 O255 S8. The deduced amino acid sequence showed that the protein encoded by the Arf6 gene owned a conserved GTP-binding domain, 21 negatively charged residues (Asp+Glu) and 25 positively charged residues (Arg Lys). The obtained sequence was compared with the other species through BLAST analysis, indicating that the amino acid sequence cloned in this study is highly conserved. Phylogenetic analysis based on the amino acid sequences revealed that L. vannamei is closely related to Drosophila melanogaster. Semi-quantitative RT-PCR results showed that the gene was expressed in most of the examined tissues, and the highest expression level was observed in the hepatopancreas, while the lowest in the eyestalk. Arf6 gene expression level in the hepatopancreas of L. vanname that was infected by the taura syndrome virus (TSV) was higher than that of the specific pathogen free L. vanname. The protein functional classification results suggested that the Arf6 plays a potential role in the pathogen host defense systems as an immune response factor.

Abstract:The elimination of ciprofloxacinum residue in Chinese mitten crab Eriocheir sinensis under different culture conditions was studied by using Ultra Performance Liquid Chromatography coupled with Mass Spectrometry (UPLC-MS). The results showed that the elimination was so slow that even at 35-day after administration, the levels of ciprofloxacinum residue in all groups of E. sinensis were higher than the instrument detection limit. The elimination rate was faster at 28℃ than at 22℃, in the fifth stage larvae than in the button crabs, and in outdoor open water than the indoor environment.

Abstract:Spatial distribution of NH⁴-N, NO³-N, NO²-N and PO⁴-P in overlying water and pore water, and the change of TN, TP and TC concentrations in sediments in Grass carp Ctenopharyngodon idellus polyculture ponds were studied by means of land-based enclosure during June~October, 2009. The results showed that: (1) the concentrations of NH⁴-N, NO³-N, NO²-N, and PO⁴-P were 0.056~1.499, 0.022~0.228, 0.049~3.903, and 0.003~1.882 mg/L, respectively. The proportion of NH⁴-N in the DIN increased over time in the horizontal pore water. Different systems showed different vertical distribution of nutrients. (2) During the experiments, the concentrations of TN and TP didn't change significantly. However, the concentration of TC decreased significantly, especially in GSC. It is suggested that the accumulation of organic matter and potential release of NH⁴-N in the underlying water can be reduced effectively in Grass carp polyculture system. Therefore, this system might be applied in aquaculture.

Abstract:The impacts of White Spot Syndrome Virus (WSSV) on the haemocyte phagocytic activity,and the acid phosphate (ACP) and alkaline phosphate (AKP) activities in the hepatopancreas of Procambarus clarkia were examined.The results showed that the immune factors of P.clarkia changed along with the WSSV infection time,and phagocytes activity could reflect the health of shrimps indirectly.However,the variation of the ACP and AKP activity was not obvious and had no apparent tendency during different infection stages.This study provided basic data on immune level change after pathogenic affection.

Abstract:Urea is an important factor for paddy production in paddy-crab ecosystem.However,application of urea may impose negative effects on the growth of crabs.In our research,the effects of different concentrations of urea on the non specific immune system of juvenile Eriocheir sinensis were studied in order to provide necessary theoretical support for setting up regulations for the paddy-crab ecosystem.The juvenile E.sinensis were reared in water containing 0.24,0.48,0.72,0.96,and 1.2 g/L urea respectively for 7 days without feeding.The activities of three enzymes including superoxide dismutase (SOD),catalase (CAT),and glutathione-S transferase (GST),as well as the content of malondialdehyde (MDA) in crab serum were determined.The results showed that the activities of SOD,CAT,and GST decreased gradually in crab serum for all urea concentrations during the experimental period,while the content of MDA increased instead.Also the activities of the above three enzymes showed a decreasing tendency as the urea concentration increased.However,the SOD activity in 024g/L and the GST activity in 0.96g/L urea treatments were significantly higher than those in the other urea treated groups,while the content of MDA in these two treatments decreased.The results suggest that the added urea reduces the E.sinensis's capability of eliminating lipid peroxides,hydrogen peroxide and free radicals.As a result,the non-specific defense system was damaged with the application of urea.

Abstract:The antioxidant peptide ultraflexible nano-liposomes were prepared by using the thin-film dispersion method.The effects of some factors on the encapsulation efficiency,including the ratio of lecithin to cholesterol,temperature,concentration of the antioxidant peptide,rotation speed,pH,and ultrasonic emulsification time,were studied.The formulation was optimized by L9 (34) orthogonal design.The ultraflexible nano-liposomes were mostly unilamellar vesicles and their mean particle size was 255±60 nm.The optimum entrapment efficiency was 58.39%±0.34%.The antioxidant peptide liposome was stable at 4℃.Therefore,the antioxidant peptide ultraflexible nano-liposomes posses high encapsulation efficiency,good stability and reproducibility.

Abstract:The expression levels of proteins in Escherichia coli appear to be preferential for some special codons. In order to enhance the expression level, we designed a partial sequence of the WSSV-VP37 gene based on the codons of E. coli so that its expression level would be optimized. The optimized VP37 fragment was ligated to the expression vector pBAD/gIIIA. Then the resulted recombinant pBAD/gIIIA-VP37p′ was transformed into E. coli Top10 and the cells were induced by L-arabinose. SDS-PAGE analysis showed that the content of VP37p′ constituted 40.5% of the total proteins. Compared with the wild type recombinant pBAD/gIIIA-VP37p, the expression level of the optimized recombinant VP37p′ (40.5% of the total proteins) was significantly higher than that of the wild type VP37p (6.5% of the total proteins).

Abstract:An analytical method was established for the determination of residues of five sulfonamides in sea water by high performance liquid chromatography (HPLC) with ultraviolet detector. The five drugs showed good linear relationship in the range of 0.05～5.00mg/L. The average recovery was 75%～92％ at two concentration levels. The relative standard deviation was less than 10%. The minimum detection concentrations were as follows: sulfadiazine, 20 ng/L; sulfamerazine, 20 ng/L; sulfamethazine, 20ng/L; sulfamethoxazole, 30ng/L; sulfaquinoxaline, 40 ng/L. The results indicate that this HPLC assay is specific, accurate and reproducible.

Abstract:Fish-cake was made of low-cost freshwater silver carp. Single factor experiment and orthogonal design were applied to optimize the critical processing conditions of fish cake using sensory quality and gel strength as the quality indices. The results showed that the optimal parameters of several key steps were as follows: heating (steaming) for 10min→chopping and mixing for 15min→rinsed with freshwater twice→rinsed with 0.5 % saline water. The fish-cake made under these processing conditions showed good sensory quality and relatively stronger gel strength. This fish-cake processing technique is valuable to develop and utilize low-cost freshwater silver carp.

Abstract:A sensitive and specific SYBR GreenⅠreal-time PCR assay for the detection of red-sea bream iridovirus (RSIV) was established.The real time PCR primers were designed according to the conserved region of major capsid protein (MCP) gene by using Primer Express 3.0 software.The RSIV MCP gene was inserted into pMD18-T vector to construct the recombinant plasmid.The resulted plasmid was serially diluted and used as the standards.The relationship between plasmid copy number(X) and Ct value was described as a standard curve: Ct=－3.184 lgX+40.270(with an R2 value of 0.996 9).The detection limit of the assay was 220×10² virus copies per reaction.The assay showed specificity and could not be amplified with RSIV and epizootic haematopoietic necrosis virus (EHNV),lymphocystis disease virus (LCDV),frog virus 3 (FV 3),or soft-shelled turtle iridovirus (STIV).The Tm of the specific product was obtained as 82.5 ℃ through the melting curve analysis.This assay was applied in detecting whether the sea fish samples (stone flounder,turbot,and weever) of 84 batches were infected by RSIV.It was found that the samples of 5 batches presented positive signals,and the virus was quantified by using the obtained standard curve.The results indicate that the real-time PCR assay is specific,sensitive,fast,and accurate and it has great potential in detecting RSIV and studying the pathogenic mechanism of RSIV.

Abstract:Gene chip was prepared with the oligonucleotide probes of 6 virulence genes of Vibrio anguillarum dot-applied on a piece of positively charged nylon membrane using the microcaster manual arrayer, followed by cross-linkage under the ultraviolet light. The detection of V. anguillarum virulence genes was performed by hybridizing with the DIG-labeled PCR products on the membrane chip. Here we report the optimization of the concentration of the probe, the time course of hybridization, and the process of washing steps. After optimization, the hybridization time was reduced to 30min, the concentration of the probe as 50μmol/L, and the process of washing was shortened to 3 steps of only 45 min.