Abstract:has a wide geographical distribution ranging from south-eastern Siberia and Korea through most parts of China to Vietnam. Besides its nutritive and medical value, the turtle also became a model animal for investigating the development and evolution of their unique body and evolution of other biological as well as immune functions. CD3 molecules which are composed of four chains [γ, δ, ε, ζ(η)] act as markers of T lymphocytes and play important roles in T cell signaling, TCR-CD3 complex assembly and T cell mature. To understand its molecular structures, function and evolution in reptile, we cloned the cDNA sequences of CD3γ/δ, CD3ε and CD3 in the Chinese soft-shelled turtle usingthe SMART RACE technology and analyzed its expression pattern in normal and bacterial infected individuals using real time quantitative PCR (rt-qPCR). The deduced CD3γ/δ, CD3ε and CD3ζ encoded 170 aa, 183 aa and 168 aa, respectively. The CD3γ/δ and CD3ε are structurally related with an extracellular immunoglobulin-like domain, a transmembrane region and an ITAM motif containing cytoplasmic tail. The Di-leucine based internalization motif (D¹³⁸RQNLI) and a potential N-glycosylation site (N⁸¹TS) were also found in CD3γ/δ amino acid sequence, and a proline-rich motif (R¹⁵⁵PPPVP) and ER rention motif (Y¹⁷⁵AGLDSR) were found in CD3ε amino acid sequence with the absence of the potential N-glycosylation site. The deduced CD3ζ amino acid sequence has a different structure with a 10 aa extracellular part, a transmembrane region and three ITAM motifs containing cytoplasmic tail. The phylogenetic tree showed that each chain was clustered together and Chinese soft-shelled turtle had a closer relationship with birds and amphibians. Bioinformatics analysis in genomic sequences showed that CD3γ/δ gene, containing 6 exons and 5 introns, and CD3ε gene, containing 7 exons and 6 introns located and transcribed oppositely in the Chromosome Scaffold JH208224 and CD3ζ gene, containing 8 exons and 7 introns with a big intron 1 (66.3 kB) located in Chromosome Scaffold JH209116.1. These conserved motifs in amino acid sequence and genomic arrangement suggested they were conserved in evolution. Real time quantitative PCR results showed that CD3γ/δ, CD3ε and CD3ζ were highly expressed in spleen, liver, intestine and blood, with lower expression level in thymus, kidney, heart, muscle and lung. However, obviously increased expression of CD3γ/δ (69.3 fold), CD3ε (85.7 fold) and CD3ζ (163.4 fold) were observed in thymus at 12 h after the challenge with , indicating an immune response involving CD3 T cells after bacterial infection. This obtained information will provide an important basis for T lymphocyte function analysis in Chinese soft-shelled turtle.

Abstract:White spot syndrome virus (WSSV) is one of the most virulent viral pathogens of the shrimp-farming industry worldwide, causing high mortality and resulting in serious economic losses. The viral envelope proteins play very important roles in WSSV infection of shrimps. To investigate the interaction between WSSV envelope protein VP110 and gill cell proteins of the Chinese shrimp, , a truncated VP110 protein containing the RGD motif was recombinantly expressed in BL21(DE3) as a fusion protein with Trx/His/S-tag. Using a pull-down assay, two prominent protein bands with molecular weights of 40 kD and 42 kD were identified from gill cell proteins of using recombinant VP110 (rVP110), which were identified as arginine kinase (AK) and was cloned and expressed as a fusion protein with GST-tag using the pGEX-4T-1 vector, and the binding interaction between the recombinant AK (rAK) and rVP110 was further confirmed by a pull-down assay. In an neutralization assay, rAK appeared to be able to partially block WSSV infection and delayed the death of WSSV-infected crayfish. In addition, following WSSV infection, mRNA level in the gills was upregulated compared with the control group, as assessed by real-time quantitative PCR. The AK enzyme activity in the gills was also upregulated. These results suggested that AK in plays a role in WSSV infection.

Abstract:) were produced by gynogenesis, and their growth and hereditary features were compared. The control group was a cross between a gynogenetic female and normal male. Twenty-four microsatellites markers were selected for the analysis. The results showed that 41, 55 and 78 alleles were scored in GI, GH and control group, respectively, with the average number of alleles as 1.7, 2.3 and 3.3. The average observed heterozygosity () among the 24 analyzed loci in the GH group was 0.654 9, which was higher than that in GI (0.419 2), but lower than that in the control group (0.916 7). The average homozygosity was 0.580 7 in GI and 0.345 1 in GH, which were much higher than that in the control group (0.083 3). The average similarity index among individuals in the GI group (0.831 2) was higher than that of the GH group (0.826 1), and both were higher than in the control group (0.6727). The growth rate of the GH group was significantly higher than the GI and control groups (<0.01). According to the result, GH lines have more advantages compared with GI lines and natural mating families(the control group). Hybridization between gynogenetic individuals could be an essential tool for breeding increased growth rates and to increase the genetic similarity of the Japanese flounder.

Abstract:) females grow two to three times faster than males. Thus, the development of an all-female stock would be of significant benefit for aquaculturestock, investigation of sex determination mechanisms is necessary. The Wilms’ tumor suppressor gene () encodes a zinc-finger transcription factor that plays an essential role in organ development, most notably in the kidney and gonad. Despite its importance for sex determination, information on C. semilaevis WT1a gene was obtained by RACE-cloning. Sequence analysis revealed that the full-length cDNA was 1 886 bp containing a 1 470 bp open reading frame (ORF), a 245 bp 5′UTR. This sequence encoded 489 amino acids containing a KTS alternative splice. Two SSR sequences and two transmembrane helix regions were found in the end of the OFR. We infer that they are gene was highly homologous to that of . An NJ-phylogenetic tree indicated that the fish WT1b gene. Real-time quantitative PCR results revealed that was expressed in the six tissues types examined but was far higher in the gonad. Notably, expression in the testis was significantly higher than that in the ovaries and gonads of sex-reversal female fish. It was lowest in the gonad of sex-reversal female fish. Therefore, we can conclude that is a sex-related gene. The gene was expressed in all of the developmental stages analyzed, from early embryo to 66-day-old fry. Its expression level was highest at neurula stage (20 h) and gently in 16–66 days, however, no abnormalities were observed in the key gonad differentiation stages. Therefore, may be not the key gene controlling gonad differentiation. Our results provide a foundation for the development of an all-female stock and future investigations on the sex determination mechanism. Furthermore, we have provided a good method for identifying the key gene controling gonad differentiation.

Abstract:larvae raised under culture conditions were analyzed. From hatching to 56-days-old, ten larvae were sampled every five days, and the dorsal mantle length, mantle breadth, body weight, cuttlebone length, cuttlebone breadth and lamella number were measured. An exponential model could describe the relationships between dorsal mantle length, body weight, lamella number and days, respectively. However, there were two different phases during early development, caused by the perfection of organ development and change in foods. The lamella in the cuttlebone was not deposited daily, which demonstrated the number of lamellae in the cuttlebone did not correspond to the actual age. In addition, allometric growth of the mantle and cuttlebone were discovered, indicating that these important organs, like the swimming organ, had developed prior to others. The present results support the hypothesis that allometric growth patterns also exist in cephalopods during early ontogeny. The data in the present study provide a basis for artificial seed breeding of golden cuttlefish.

Abstract:Exopalaemon carinicauda, which was named is 645 bp, which contains a 184 bp 5′-UTR (untranslated region), 116 bp 3′-UTR, and 345 bp open reading frame (ORF) that encodes 114 amnio-acid polypeptides, which has the molecular mass of 12.85 kD and isoelectric point (pI) of 8.75. Homology analysis revealed that the amnio acid sequences of EcDAD1 had highly identifies with DAD1 of other species, for example, it had 92% identity with DAD1 of , and had 73%−80% identities with DAD1 of other invertebrates. The phylogenetic analysis showed that . The expression level of gene in different tissues were analyzed by quantitative real-time PCR. The results showed that hemocytes, gill, hepatopancreas, muscle, ovary, intestine, stomach and eye stalk, and the the highest expression level of gene was in ovary and white spot syndrome virus (WSSV), the relative expression level of might play an important role in the prawn immune system.

Abstract:Gene pyramiding is a method of obtaining good varieties, which aims to produce individuals with one superior economic trait, according to the optimal breeding scheme involving selection of favorable target alleles or linked markers after crossing basal populations and pyramiding them into a single individual. The largemouth bass () is one of the most important freshwater fish in China. Previous research identified certain molecular markers related to growth traits. In this study, eight molecular markers including four single nucleotide polymorphisms (SNPs) and four simple sequence repeats (SSRs) related to the growth traits of largemouth bass were selected to amplify the genomic DNA of parent largemouth bass. The four SNPs were located in the genes; the four SSRs were located in the genes. Twenty large mouth bass (9 females, 11 males) containing four or even more advantageous genotypes were selected as parents for population reproduction, which were selected from 196 individuals. About 5 000 offspring individuals were cultivated in one breeding pond (1 114 m² ) and fed with frozen fresh fish. After 9 months of cultivation, the offspring had reached a marketable size. Two hundred and eighty-eight individuals were randomly chosen to measure their weight and detect their genotype. The results showed that the number of advantageous genotypes in parents were 1–5 and the frequencies were 20.41%, 41.3%, 30.10%, 8.67% and 1.53% respectively. To aggregate the advantageous genotypes in the offspring, the parents that had 4 and 5 advantageous genotypes were selected. The number of advantageous genotypes was1–6 in all offspring and the average weights of 1 to 6 advantageous genotypes groups were 227.83, 239.56, 258.81, 273.02, 302.50 and 305.60 g, respectively. The number distributions of each population were 6, 100, 110, 44, 20 and 8. The frequencies of each population were 2.08%, 34.72%, 38.19%, 15.28%, 6.94% and 2.78%, respectively. A general linear model (GLM) was used to perform correlation analysis between the number of advantageous genotypes and growth traits. GLM analysis showed that the number of advantageous genotypes related to growth traits was positively correlated with weight. Individuals with five or six advantage genotypes were significantly different (<0.05) with those that had fewer advantageous genotypes. Further analysis suggested that the average number of advantageous genotypes is 2.99 in the offspring, which is truly improved compared with the average number of advantageous genotypes of the parent group (2.36). The results indicated that it was useful to improve the growth trait of largemouth bass using limited advantageous genotypes related to growth traits, which also provided a theoretical basis for gene pyramiding breeding.

Abstract:jian, hybrids() were studied by variance analysis and by three methods of multivariate analysis, based on their morphological characters. There were no significant differences among four groups based on the number of scales on the lateral line, scales above the lateral line, scales beneath the lateral line, spines of pectoral fins and ventral fin(>0.05) except for the number of spines of the dorsal fin, anal fin, and soft rays of the dorsal fin, anal fin, ventral fin and pectoral fins. The cluster results showed that the morphological traits were similar between the parent fish stocks, but quite different from those of the reciprocal hybrids. The discriminant functions of the four stocks were established, and the discriminatory accuracies were 76.7%–96.7%()The total discriminatory accuracy was 87.5%. In the principal component analysis, nine principal components were constructed, and the cumulative contributory ratio was 68.94%. The study would be beneficial for identifying groups, and for determining s and breeding.

Abstract:Cyprinus carpio was studied using 35 polymorphic microsatellite loci, and the average number of effective alleleswas3.042 6. The expected heterozygosity varied from 0.375 0 to 0.827 4, with an average of 0.6493. The polymorphic information content (PIC) ranged from 0.396 to 0.912, with an average of 0.586 9. The results indicated rich polymorphism information content and large genetic diversity in the population. Hardy-Weinberg equilibrium analysis showed that the population was in disequilibrium modewhich indicated that artificial selection had a great effect on the populationThe average fixation index (FIS) was 0.026, which indicated that heterozygote excess existed in the population. Bottleneck analysis illustrated that the population has experienced a bottleneck effect recently The effective population size was 31.2 as assessed by the linkage disequilibrium methodThe study illustrated that this variety has rich genetic diversity. To avoid or reduce the bottlenecks in the next reservation project, protection work should be strengthened to maintain its rich diversity and economic traits.

Abstract:A 30-day experiment was conducted to investigate the effectiveness of bio-floc technology for maintaining good water quality in with average weight of ( farming ponds. The total suspended solids(TSS), total nitrogen (TN) and alkalinity (CaCO₃) were determined every 3 days and microbial communities of the bio-floc were analyzed using the PCR-DGGE (PCR-denaturing gradient gel electrophoresis) every 5 days, respectively. The results showed that water TSS concentration reached a peak value of (419.67±11.5) mg/L on the 9th day, which was significantly (<0.05) higher than that of the other time points. From the 15th day on, the TSS remained at a relatively stable level of 244.67 mg/L. The TN ranged from 6.65 to 11.15 mg/L, and it reached the peak value of (10.11±1.05) mg/L on the 9th day. There was no significant difference in TN between water after the 12th day and water at the beginning of the farming trial (>0.05). Alkalinity in the farming system ranged from 136.68 to 239.20 mg(CaCO₃)/L, which reached maximum peak value of (238.22±5.44) mg (CaCO₃)/L on the 6th day, after which it decreased gradually and then remained stable. Bio-floc had a crude protein content of 30% dry weight. The acquired sequences of 20 bands in 16S rDNA DGGE gel and six bands in 18S rDNA DGGE gel were analyzed by BLAST searches against the NCBI GenBank database. The main prokaryotic microorganisms represented by the 20 main bands in 16S rDNA DGGE gel were Alphaproteobacteria, Betaproteobacteria, Gammaproteobacteria, Deltaproteobacteria, Actinobacteria, and Bacteroidetes. throughout the process of formation of the bio-floc, and was the dominant bacteria on the 5th, 10th, and 15th days. The existence of Alcaligenaceae had some influence on the increase in water alkalinity during this period. We also found that bands 7 and12 represented C, which appeared on the 0th, 5th and 10th days; they disappeared in the late culture period, which indicated that the application of bio-floc technology can control algal growth to some extent. The main Eukaryotic microorganisms represented by the six main bands in 18S rDNA DGGE gel were sp., and belongs to the diatoms, and was present from the 1^stto 15^th days of bio-floc culture. A larger number of sp. existed at the later stage of the bio-floc culture. The results demonstrated that the bio-floc system achieved stable operation state after 15 days. Bio-floc could regulate the water quality and the distribution of bacteria and algae effectively; it could also maintain the balance and development of the whole aquaculture system.

Abstract:Dissolved organic matter (DOM) is abundant in the marine environment, which is one of the largest reservoirs of carbon on the Earth’s surface. DOM plays an important role in the biological chemistry cycles, mediating material flow and energy cycle of the artificial marine ranching ecosystem. In artificial marine ranching, the bottom and other sediments are the direct bait resources of the sea cucumber (). Sediment coming from different areas and origins will directly affect ingestion efficiency and digestibility. In the present study, UV-visible spectroscopy (UV-VIS) and three-dimensional excitation-emission matrix fluorescence spectroscopy (3DEEM) were used to investigate the fluorescence properties of DOM in the intestinal contents of from four different artificial marine ranches. The bait environmental conditions of the were evaluated based on the source and the DOM constituents in the intestinal contents. Spectroscopic characteristics of dissolved organic matter (DOM) were determined using ultraviolet absorbance and fluorescence spectroscopy to investigate spatial distribution of DOM composition. The results indicated that the value of E3/E4 ranged from 1.56 to 2.98, the mean value of the humification level, aromaticity and the relative molecular weight is Laizhou>Shuangdao> Swanlake>Lidao. The results suggested that the baits of from Laizhou sea area might contain more and were more easily enzymatically digested than the baits from other three sea areas. Meanwhile, the baits of from the Lidao sea area may have a higher physiological and biodegradation activity. No significant difference of absorbency was observed at 280 nm, which suggested that has no preference for the dissolved oxygen content in the sediment. 3DEEM scanning indicated an obvious protein fluorescence peak in all images. The diverse sources of protein-like fluorescence indicated that these marine ranche shave diverse and complex diet resources. Overall, the value of f450/f500 ranged from 1.00 to 1.42, and was mostly close to 1.40. This may represent the humus in the DOM coming from terrigenous input, which suggested that the food in the marine ranch is influenced by the terrigenous input, and is easily affected by exogenous disturbance. The baits of are complex and influenced by the environment. Any single resource from the environment cannot describe the constituents of the baits. The DOM extracted from the intestinal contents of provide an overview of the baits in the marine ranches. These results indicated that continuous monitoring of the marine sediment is important for ensuring good quality food sources for the precious marine species in artificial marine ranches.

Abstract:) is an important economic aquatic animal farmed in China, and is increasingly being exported as a worldwide food. is umami, sweet, and rich in nutrients. There is a lack of wild Chinese mitten crab that cannot meet the needs of increasing consumption. Therefore, determining the nutrient requirement for this crab is important for developing its aquaculture. Selenium is a component of the enzyme glutathione (GPx), which can protect cell membranes against oxidative damage. It also converts hydrogen peroxide and fatty acid hydroperoxides into water and fatty acid alcohol using reduced glutathione. However, the requirement for selenium of the Chinese mitten crab is unknown. Organic Se has higher bioavailability than the inorganic Se. Therefore, a 6-week feeding trial was conducted to investigate the effects of dietary Se supplementation on the growth performance, body composition and antioxidant status of juvenile Chinese mitten crabs. Six diets containing 0, 0.2, 0.4, 0.6, 0.8 and 1.0 mg/kg selenium were fed to quadruplicate juvenile Chinese mitten crabs (0.27±0.01) g, respectively, with 30 crabs in every aquarium. The results showed that juvenile fed the diet with 0.4 mg/kg(diet) Se supplementation obtained the highest weight gain, survival rate and whole body crude protein content among the various groups . Hepatopancreas and muscle selenium contents were positively related to the dietary Se supplementation. Both serum and hepatopancreas glutathione peroxidase activities increased with increasing dietary Se level, and peaked at 0.4 mg/kg(<0.05). When dietary Se increased to 0.8 mg/kg, serum glutathione peroxidase activity decreased significantly (<0.05). The highest serum glutathione reductase activity was observed in the crab fed diet of Se level 0.4 mg/kg (<0.05). The malonaldehyde content initially decreased and then increased with increasing dietary Se supplementation. Crabs fed the 0.4 mg/kg diet had the lowest malonaldehyde content, and differed from that of the control and 1.0 mg/kg groups(<0.05). Crabs fed a diet containing less than 0.6 mg/kg selenium had lower glutathione levels compared with crabs fed 0.8 mg/kg and 1.0 mg/kg (<0.05). The results indicated that dietary selenium supplementation of 0.4–0.6 mg/kg (total selenium of 0.43–0.66 mg/kg) can promote growth, use of dietary protein and anti-oxidative ability of juvenile Chinese mitten crabs. Quadrate broken line analysis with serum GPx showed that a level of 0.51 mg/kg selenium supplementation (total selenium is 0.59 mg/kg) could meet the optimal anti-oxidative status

Abstract:To explore the effects of exercise training under different velocities on the , the experimental fish were divided into four groups at (250 bl/s, 1.0 bl/s, 2.0 bl/s, 4.0 bl/s) for 8 weeks, the exercise training induced adaption of the antioxidant enzyme system of muscle, the activity of superoxide dismutase (SOD) and glutathione peroxidase (GSH-P_X) increased with the increasing water velocity, while the activity of catalase (CAT) dropped in varying degrees. No significant differences in the level of (GSH) was observed among the treatments with various velocities. Compared with the control group, the content of the total antioxidant capacity increased in the trained group, the maximum values were in the water velocity of 2.0 bl/s, the second maximum values were in 4.0 bl/s, with significant differences with control . At the end of experiment, the level of MDA in the group of 2.0 bl/s decreased significantly2 increased with the increasing water velocity. Compared with the control group, no significant differences in the content of Bcl-2, Bax and the activity of CK were found among treatments(>0.05), however the ratio between Bax and Bcl-2 of 4.0 bl/s was significantly higher than that of 2.0 bl/s(<0.05). The results showed that the exercise training under 2.0 bl/s could effectively improve the antioxidant function, decrease lipid peroxidation level, and inhibit muscle cell apoptosis of juvenile

Abstract:Electronic nose (E-Nose) technology was applied in this study to detect the aroma profile of abdomen, claw, leg meat and spawn of , which were farmed in Yangcheng Lake, Songjiang and Chongming region within different grades. Results showed that the aroma profile of four edible parts of Yangcheng-Lake-crabs in three grades (special, first and second) could be distinguished well. Soft independent modeling of class analogy (SIMCA) method was applied to establish the recognizing model of Yangcheng-Lake-crabs either on one single part or on multiple parts. By a comparison, the model based on multiple parts turned out to be more effective. Rejection ratio of none-Yangcheng-Lake-crabs reached 100 percent. Meanwhile, a partial least squares regression (PLSR) model was also developed to evaluate the correlation between E-Nose responses and grade scores of . Correlation coefficient was 0.96, manifesting the PLSR model was able to predict grade scores of unknown crab samples.

Abstract:Acipenser schrenckii) broodstock diets on reproductive performance and serum sex steroids levels were studied. Four groups of 48 female broodstocks, with an average body weight of (18.24±2.44) kg, were fed four artificial formulated diets containing 3.1%(SL1), 2.5%(SL2), 1.9%(SL3) and 1.3%(SL4) of n-3HUFA by adding different proportions of refined fish oil and corn oil for a period of 5 months from stage III of gonad development. Their reproductive performance, serum E₂ and T were evaluated. The results showed that after the Amur sturgeons were fed the diets for 5 months, their average body weight increased by 14.5%, while their average body weight dropped by 6.8% after winter and heating processing, with no significant difference between the trial groups (>0.05). Different n-3 HUFA and n-3 PUFA levels in feed had different effects on reproductive performance. The maturity rate and larval survival rate of the SL1 and SL2 groups were significantly higher than those of SL3 and SL4 group (<0.05), while the rates of abnormalities and deformities were significantly lower than that of the SL3 and SL4 group (<0.05). The diameter of the polarization egg of the SL1 group was significantly higher than that of the other groups (<0.05), while average fecundity was higher than other groups, but not significantly (>0.05). The fertilization rate and hatching rate were not significantly different among the trial groups ( level of each group was significantly <0.05), while the serum T level of each group decreased differently compared with before feeding (>0.05); however, no significant difference was found among the trial groups (> 0.05). This study indicated that the mixed oil is better than single fish oil or corn oil as a feed source of fat, the effect of fish oil is greater than that of corn oil in the feed at the same time, and the appropriate requirement forn-3 HUFA is approximately 2.5%.

Abstract:Based on data collected from bottom trawl surveys in Haizhou Bay and the adjacent areas during March, May, July, September and December in 2011, the population parameters of five major fish species (Cynoglossus lighti, ) were analyzed. ) (0.76), followed by values for the other three fish species were less than 0.6. The highest total mortality coefficient((3.53), (1.60) had the lowest had the highest exploitation rates(values for these four species were 0.74, 0.74, 0.73 and 0.60, respectively. However, the lowest E. fangi and (length at first capture) values(145.2, 107.1 and 98.7 mm, respectively). However, values(60.0 and 48.4 mm, respectively). The growth performance indexes ( in different areas had relatively higher values in the lower latitude areas.

Abstract:bottom trawl surveys conducted in the Bohai Sea in August and October of 2009, stomach analysis and prey selectivity indices were used to study the feeding habits of , which is a released fish species. The results showed that fed on seven groups of more than 20 prey species, and mainly fed on shrimp and fish, accounting for 64.93%–76.59% of the total food composition, by percentage of occurrence. Thus, Alpheus japonicas and the gobiidae were the dominant prey species in August; however, Larimichthy polyactis) were the dominant prey species in October. Compared with the study performed in the 1990s, the feeding habits of have varied significantly, feeding on a higher proportion of shrimp prey and fewer fish. The dominant prey species were also different, and anchovy () was no longer the dominant prey species. Latreutes anoplonyx, and the gobiidae, but dislike small yellow croakers in August. In October, they prefer to feed on and small yellow croaker, but dislike . Influenced by the abundance of prey in the environment, there is some difference between the favorite food species and dominant prey species. Prey selectivity of is not entirely determined by the abundance of prey in the environment, but it does have a strong influence. The showed a preference for prey with low abundance in the environment, such as in August, and in October. It also selectively feeds on prey with high abundance in the environment, such as small yellow croaker and gobiidae. It can feed on with a stable proportion in August and October; however, this is not related to their abundance. The results also indicated that seasonal variations in the food composition and prey selectivity of is not only influenced by the abundance of prey in the environment, but also by nutritional requirements and prey selectivity of individual fish. increased slightly in recent surveys, and was restored to some extent by stock enhancement, yet its biomass is still less than 1% of the maximum historical biomass. Therefore, more could be released to restore biomass. The other important aim of this study was to evaluate scientifically and reasonably the ecological capacity for stock enhancement, based on food composition and prey selectivity of . According to the results of this study, combined with its biomass and the evaluation of food consumption, , 2.2 t gobiidae and 1.9 t Sebates schlegeli, the next study needs determine biomass and food consumption of those prey by other predators in the same nutritional niche

Abstract:To establish the growth performance and physiological responses after short-term crowding stress, three Nile tilapia () strains (GIFT tilapia, new GIFT tilapia and Egypt Nile tilapia) were compared in terms of certain body indices. At day 100 of the experiment, tilapias in the experimental group were exposed to short-term crowding stress to evaluate the serum biochemical parameters and liver HSP70 mRNA expression before and after stress. The results showed that GIFT tilapia had the best growth rate, and the growth of New GIFT tilapia ranked second; however, no significant difference was observed between the two strains. The growth rate of Egypt Nile tilapia was the slowest. Viscerosomatic indices of GIFT tilapia and New GIFT tilapia were significantly higher than those of the Egypt Nile tilapia. There was no significant difference in the condition factor among the three groups. At the end of the feeding trial, 40 fish per bucket were exposed to crowding stress (100g/L) for 48h, The effects of a short-term exposure on the physiological responses of fish were determined before stress (0h) and at 6, 12, 24 or 48 h post-crowding. The serum total protein, glucose, glutamic-oxaloacetic transaminase (AST), cholesterol, lysozyme (LSZ) level and hepatic Hsp70mRNA levels in GIFT tilapia and New GIFT tilapia initially increased and then decreased over48 h of crowding stress. Compared with the level at 0 h, the serum cortisol level of the Egypt Nile tilapia was not significantly difference at 48 h post-stress, but the levels in GIFT tilapia and New GIFT tilapia were significantly higher than at 0h. The serum LSZ activity and HSP70 mRNA levels of the Egypt Nile tilapia at 48 h were significantly higher than at 0 h. Overall, the results indicated that short term, high density crowding enhanced the use of serum glucose and triglyceride, but caused liver damage in tilapia. The ability of the Egypt Nile tilapia to resist high density stress is stronger than that of the GIFT tilapia and New GIFT tilapia. Therefore, for intensive culture farming, tilapia should have a reasonable stocking density and less human interference, which will reduce stress responses and healthy breeding of tilapia.

Abstract:Toxic microalgae outbreaks have caused significant economic losses in the Chinese aquaculture industry, including the aquaculture of shrimp. Blooms that involve phycotoxins, especially paralytic shellfish poison(PSP), are dangerous, harm the shrimps and cause losses in marine production. Previous studies mainly focused on the toxic effects on shellfish and fish, rather than shrimp. This study investigated the inductive effect of the toxic dinoflagellate (ATHK), a producer of PSP, on oxidative stress and the expression of a caspase gene (Fenneropenaeus chinensis, an important mariculture species in China. A. tamarense, and individuals cultured with filtered seawater were set as control. Superoxide dismutase (SOD) activity, glutathione S-transferase (GST) activity, malonyldialdehyde (MDA) content and expression in the gills were analyzed at 3, 6, 12, 24, 48, 72 and 96 h after exposure. The results showed that SOD activity, GST activity, MDA content and generally increased at first and then decreased with increasing exposure time. However, when exposed to 1000 cells/mL of , SOD activity increased and then decreased with increasing exposure time, and was significantly(P<0.05) inhibited, except at 3- and 48 h-post treatment. The changes in SOD and GST activities of in this study suggest that these enzymes were actively involved in the detoxification process in gills of F. chinensis exposed to 1 000 cells/mL of increased with increased exposure time, and displayed a time-dependent response relationship. The exposed to was positively and linearly correlated with the MDA content. The current study revealed that exposure to, causing lipid peroxidation (LPO) and upregulation of in gills of the shrimp. The findings from this study demonstrated that SOD, GST and MDA were sensitive and suitable potential oxidative biomarkers of A. tamarense in the short term. Further studies are needed to clarify the mechanism of toxicity of to aquatic invertebrates.

Abstract:fingerlings and on antioxidant enzyme (Superoxide dismutase, SOD; Catalase, CAT) activity changes in fish liver. The histology of experimental fish gills and liver were also analyzed. Fish were exposed to copper sulfate (CuSO₄) solution with Cu²⁺concentrations of 0(control), 0.3, 0.54, 0.96, 1.68 and 3 mg/L. The 50% lethal concentration (LC₅₀) values of copper on were 1.087, 1.062, 1.042 and 0.9 67 mg/L at 24, 48, 72 and 96 h, respectively. The safe concentration of copper for this species at the fingerling stage was calculated as 0.009 67mg/L. The activities of CAT and SOD were significantly enhanced in liver cells after the fish were exposed in CuSO₄ for 12 and 24 h compared with those in the control group (<0.05). Forty-eight hours later, the activities of CAT started to decline, while the activities of SOD did not decrease until 72 h. Overall, the CAT (after 48 h) and SOD (after 72 h) in the liver cells of fish exposed to copper sulfate exhibited lower activities than those in the control group. The changes of CAT activities after 48 h positively correlated with Cu²⁺concentration. Our results indicated that 1.68 mg/L Cu²⁺was toxic to fingerlings, resulting in swollen and denatured epithelium and deformed lamellae of the gills. The hepatic ultrastructural observation sampled from the fish exposed to 3 mg/L Cu²⁺showed significant hypertrophy of liver cells; the mitochondria exhibited vacuolization; vacuoles and lipid droplets occurred in cytoplasm. Copper appeared to induce fatty liver syndrome. We concluded that determining antioxidant enzyme (SOD and CAT) activities and histopathological analysis are important approaches to evaluate the safe concentration of copper for fingerlings.

Abstract:is a major bacterial pathogen that has caused severe economic losses in many species of freshwater, marine and estuarine fish worldwide. ScpB is a highly conserved surface protein among all group B streptococcus (GBS) strains and is an attractive surface-exposed antigen for inclusion among vaccine components against GBS. In this study, the strain isolated from diseased tilapia farmed in Guangdong province, China. The gene contains a 2 799 bp open reading frame (ORF), encoding 932 amino acids. The molecular mass of the deduced protein was 103 kD. Blast analysis showed that it shares high similarity with sequences of human GBSs registered in GenBank. Prokaryotic expression vector pET32a (+) was used to construct a recombinant expression vector pET32a (+)- BL21 (DE3). Colonies containing the recombinant expression vector pET32a (+)-were selected and then induced to express using 0.5 mmol/L IPTG for 8 h at 37. The expressed recombinant protein was purified by nickel chelate affinity chromatography and ultrafiltration tube enrichment. SDS-PAGE analysis and western blotting showed a specific protein band of about 121 kD. The recombinant strain could produce large amounts of ScpB protein, mainly in the form of an inclusion body. To analyze the immunogenicity of the recombinant protein, the purified fusion protein and Freund’s adjuvant were mixed according to a certain proportions to produce vaccines. Three immune dosages, 1μg/g(F1), 3 μg/g(F3) and 5 μg/g(F5) were used. Four weeks after immunization, tilapia were challenged by artificial infection with the GBS ZP-N strain, which was previously isolated and confirmed to be a tilapia pathogen by our laboratory. The recorded relative percent survivals (RPS) of the vaccinated groups ranged from 69.99% to 89%, of which group F5 has the highest RPS. The lysozyme activities, superoxide dismutase (SOD) activities and antibody levels (OD_450nm) were tested weekly until the end of the experiment. The results showed that after immunization, there were significantly higher lysozyme activities, superoxide dismutase (SOD) activities and antibody activities(OD₄₅₀) in the vaccinated fish compared with the control group (<0.01). The results of this study showed that recombinant protein ScpB has a strong immunogenicity and protective effect, laying the foundation for further study of polypeptide vaccines for

Abstract:The glycoprotein (G) is one of the structural proteins on the surface of infectious haematopoietic necrosis virus (IHNV) and has important functions. In this study, the open reading frame of the glycoprotein gene was amplified by reverse transcriptase-PCR (RT-PCR) from isolate IHNV-Sn1203 and cloned into the pET27b(+) vector. The structure and characteristics of the glycoprotein gene were analyzed using bioinformatics software. The results showed that the G gene was 1 527 bp, encoding a 508 amino acid protein, Isolate IHNV-Sn1203 shared closer identity with strains isolated from South Korea, and the homology of at nucleotide and amino acid level of the G gene were 96.68% and 97.05%, respectively. The molecular weight was 56.55 kD and the isoelectric point was 6.15. The glycoprotein was rich inserine, tyrosine, and contained 28 potential phosphorylation sites. According to the protein structure prediction, the glycoprotein may have four N-glycosylationsites and seven O-glycosylation sites. The glycoprotein is hydrophilic, with an N-terminal signal peptide and a transmembrane region from amino acid 483 to 508. The glycoprotein was estimated to be highly antigenic. Phylogenetic analysis showed that isolate IHNV-Sn1203 was in the same branch as isolates from Japan and South Korea, belonging to the JRt genotype. This study established a foundation for research into the genetic background, pathogenesis, and molecular epidemiology of IHNV.

Abstract:The relative expression levels of Toll receptor, immune deficiency (IMD) and lysozyme mRNAs were measured in the gills of the white shrimp (), which were bacterial suspension (low concentration group:Vibrio , respectively. The mRNAs were detected quantitatively with real-time PCR technology at different times after challengerelative expression levels of the Toll receptor and IMD of the shrimp injected with saline did not significantly change. However, trelative expression levels of lysozyme mRNA significantly increased at 36 h after injection. The peaks of the relative expression of the Toll receptor, IMD and lysozyme mRNAs in gills of the shrimps appeared at 24, 42 and 36 h The vibrio dosage did not affect the timing of the peak of the gene expressions. However, Vibrio dosage significantly changed sizes of the peaks of gene expressions (<0.05). The peaks of the gene expression were in the order of high concentration group, the low concentration group and the saline-injected group. In the early stage of challenge, the expression level of the Toll receptor, but not IMD and lysozyme mRNA, was significantly downregulated. Compared with that before challenge, the level of Toll receptor mRNA expression was significantly lower at 2 and 3 h, respectively, in the . The IMD and lysozyme mRNA expression levels of the high concentration group were significantly upregulated at 36 and 12 h, he IMD and lysozyme mRNA expression levels of the low concentration group significantly increased at 42 and 24 h, relative expression levels of the Toll receptor, IMD and lysozyme mRNA in the gills of challenge. Changes in the expressions of these genes depended on the challenge time and challenge dosage of

Abstract:Pagrus major), followed by hydrostatic pressure treatment to block the first mitotic division. The initiation time, duration time and pressure value of hydrostatic pressure were optimized in this study. The results showed that the treatment with hydrostatic pressure (650 kg/cm²) for 6 min starting 60 min after fertilization was the optimal parameters combination. Under this condition the fertilization rate and hatching rate at this scenario were 67.80% and 54.23%, respectively, which were significantly higher than that of all the other treatment groups(<0.05). The embryo not treated by hydrostatic pressure (haploid) were identified via flow cytometer, and its relative DNA content was about half that of normal diploid. The mitotic gynogenetic embryo had the same DNA relative content with normal diploid. The analysis results showed that mitotic gynogenetic diploids could be successfully prepared.