Abstract:) expressed inprokaryotic cells was washed by a gradient of urea concentrations and then purified by Ni-NTA agarose affinitychromatography. The target protein appeared as a single peak when eluted by 300 mmol/L imidazole in affinitychromatography. SDS-PAGE analysis and gel-filtration HPLC on a TSK-GEL G2000SWxl column revealed thatrecombinant CAT L was highly purified, and the molecular weight was about 28 kD with purity greater than 95%.The activity assay with Z-Phe-Arg-MCA as a substrate indicated that the recombinant CAT L could combine withits endogenesis inhibitor of Cystatin at a 11 ratio, and thus took on the biological activity of cysteine protease.Balb/C mice were immunized by the purified protein to obtain antiserum, and ELISA showed that the titer of CATL antiserum was higher than 1512000. Western blotting showed that the CAT L polyclonal antibody was highlyspecific for recognizing recombinant CAT L protein expressed in prokaryotic cells. Immunohistochemistry analysisindicated that this antibody also recognized endogenous CAT L protein expressed in the hepatopancreas, muscle,small intestine, heart, and spleen of Jian carp. Based on these results, the polyclonal antibody obtained in thisstudy could be used to detect CAT L expression and distribution in different tissues of fish based on protein level.

Abstract:(Perciformes, Odontobutidae), is a small demersal freshwatergoby and has recently been considered a promising candidate for aquaculture in China. However, until nowthere has been limited genetic information regarding was obtained by primer-walking PCR amplification, and the mtDNA lengthwas 16846 bp. Then, mtDNA structure, gene rearrangement mechanism, and application in phylogenetic reconstructionwere analyzed. The mtDNA of contained 37 genes (13 protein-coding genes, two rRNAs,and 22 tRNAs) and non-coding control regions. In addition to Gln), all other components were encoded on the heavy strand. Allprotein-coding genes initiated with the typical ATG sequence except CO I (with GTG) and (with ATA).These 13 protein-coding genes had TAA, TA−, and T− as termination codons. Because of shuffling rearrangementof different tRNAs, the classic mtDNA arrangement HSL (tRNA). Consequently, 320 bp and 42 bp anonymous regions were inserted between tRNAand tRNA, respectively. However, the content of A+T (55.3%) was higher thanthat of G+C (46.7%), and it was similar to other fish mtDNA. Among the 112 analyzed Perciforme fish species,only 13 (11.61%) experienced mtDNA gene rearrangement. In particular, the gene rearrangement of (KF154120), which indicatesthat this is an important molecular ‘tag’ for the evolution of the . Selection pressure and geneticdiversity analyses of the 13 protein-coding genes revealed that might be suitable molecular candidatemarkers for reconstructing phylogenetic relationships in the Gobioidei family. In the ML phylogenetic tree for10 species of Gobioidei based on

Abstract:Tumor necrosis factor receptor-associated factor 6 (TRAF6) and transforming growth factor-β-activatedkinase 1 (TAK1) are important adaptor molecules in Toll-like receptor (TLR) signaling pathways. To better understandthe biological role of these two genes in immune response, we cloned ) using homologous cloning methods and rapid amplification of cDNAends. We also detected the expression patterns of these two genes in different tissues at different developmental stages.The full-length cDNA sequence of was 1956 bp, including a 1731 bp open reading frame (ORF) that encoded aputative 576 amino acid protein. TRAF6 contained one RING domain, two zinc fingers, one coiled-coil region, and oneMATH domain; this structure is highly similar to that of TRAF6 in other species. The conserved motifs of TRAF6likely indicate that its functions are similar to those of other mammal TRAF6s. The full-length cDNA sequencewas 2519 bp, including a 1731 bp ORF that encoded a putative 576 amino acid protein. TAK1 contains a conservedserine/threonine protein kinase catalytic domain and a coiled-coil region. The highly conserved domains indicate that allTAK1s have a similar function. Phylogenetic trees showed that both TRAF6 and TAK1 in In addition, the expression patterns of these two genes were examinedin different tissues and developmental stages. was expressed in all tested tissues, and the highest expressionwas in the gills followed by the intestines. in the gills and kidneys were consistent with the essential role of the two genes in the TLR/Toll-likereceptor signaling pathway, which is pivotal in both innate and adaptive immune responses. wereexpressed throughout developmental stages, including unfertilized eggs, indicating maternal inheritance of . The expression of maternal mRNA throughout development demonstrates the potential role of . These results indicate that TRAF6 and TAK1may play crucial roles in immune responses and might be involved in half-smooth tongue sole development. This studyprovides a theoretical basis for understanding the roles of these two genes in

Abstract:White spot syndrome (WSS), an epizootic disease, has been prevalent in cultured shrimp in China since 1992and results in high mortality. The economic loss caused by white spot syndrome virus(WSSV) is extensive and has beenharmful to shrimp aquaculture worldwide. Poly-β-hydroxybutyrate (PHB) is a polymer of the short-chain fatty acidβ-hydroxybutyrate. β-hydroxybutyric acid can promote food digestion, nutrient absorption, and protein and mineralutilization. This study was conducted to investigate the anti-WSSV effects of PHB on and relative expression ofnon-specific immune genes in WSSV-infected were supplied with 0.0%(control group), 0.5%, 1.0%, 2.5%, 5.0%, or 10.0% PHB in artificial compound feed at a daily ration of 5.0% bodyweight. After WSSV challenge, survival rates, mean survival time, relative percent survival (RPS), and number ofWSSV copies were compared. The relative expression of the genes that encode superoxide dismutase (were analyzedby quantitative real-time reverse transcription PCR. The results showed that there was no difference in survival ratesamong different treatments (expression levels in 1.0% PHB were higher than that in the control group. The expression level of reached the acme at 6 h, 6 h, 3 h, and 6 h, respectively. After WSSV infection, dropped rapidly within 3 hand then steadily decreased after reaching the acme at 12 h. In addition, the gene expression levels of PHB-fed shrimpswere higher than the control group. Consequently, PHB can help improve immunity and treat WSSV infections.

Abstract:is a marine teleost that is economically important throughout the world. The specieshas a high nutritional value and is processed into a variety of products. As a result of the increase in fisheries targetingthis species, the abundance of wild populations has declined. Our laboratory has successfully carried out artificialbreeding and rearing of However, we observed significant mortality as a result of immune systemdysfunction. To improve artificial breeding techniques for , the molecular mechanisms and expressioncharacteristics of immune-related genes needs to be understood. Interferon regulatory factor 3 (IRF3) is a member ofthe interferon regulatory factor family. It is an important transcription factor for the expression of the interferon α/βgene and plays an important role in the host antiviral response mechanism. We obtained a cDNA sequence of IRF3 gene for the first time using gene cloning. The sequence was 1878 bp in length with a whole openreading frame (ORF) of 1377 bp that encoded a 459 amino acid protein. The molecular weight of the encoded proteinwas ~51 kDa. Amino acid sequence alignment revealed that the protein included a DNA binding domain (DBD) containingfive conserved tryptophan residues and a conserved C-terminal IRF association domain (IAD). The phylogenetictree revealed that the IRF3 of was clustered with the IRF3 of other species, distant from IRF1 andIRF2. The tissue and age-specific expression of IRF3 was detected using absolute quantitative PCR. Additionallytheeffect of interferon during the larval stages was analyzed. The expression levels were highest in the gonad, liver, andthymus. The copy number of IRF3 in the different tissues was: 231.244 copies/ng, 516.649 copies/ng, 695.158 copies/ng, 2128.273 copies/ng, 198.548 copies/ng, 101.758 copies/ng, 419.927 copies/ng, 13.016 copies/ng, 1102.775 copies/ng, and 13.016 copies/ng in the intestine, heart, thymus, gonad, gill, muscle, spleen, brain, liver, and kidney, respectively.The expression of IRF3 was detected in fertilized eggs and remained relatively constant to 5 d post-hatching (dph)but increased by 25 dph. The copy number of IRF3 at different ages was: 6.189 copies/ng, 6.809 copies/ng, 8.066 copies/ng, 5.009 copies/ng, 5.009 copies/ng, 10.390 copies/ng, and 10.390 copies/ng in the fertilized egg, 1 dph, 5 dph, 9dph, 17 dph, 25 dph, or 33 dph, respectively. Our results suggest that the gonad, liver, and thymus are the primary organsfor IRF3 expression. Additionally, our results suggest that interferon plays an antiviral role at 25 dph. The resultsof this study lay the foundation for further study of the mechanism of interferon action during the early development of

Abstract:Cyclin Y is a newly discovered cell cycle-related protein that plays an important role during embryonic development,cell cycle progression and development, and disease. Current research on cyclin Y is very active but no datahave been reported on cyclin Y in crustaceans. Gonads of the black tiger shrimp, , mature if the eyestalk is removed. Thus, the full-length cyclin Y cDNA sequence from (denoted as Pm-cyclin Y) was obtainedusing the rapid amplification of complementary DNA ends method to better understand the potential function ofcyclin Y in the regulation of shrimp reproduction. The full-length cDNA sequence was 1578 bp and contained 108 bp5′ untranslated region (UTR) and a 439 bp 3′UTR. The open reading frame was 1029 bp and coded 342 amino acids(aa). A bioinformatics analysis showed that the amino acid coding sequence had a conserved cyclin box and the homologousprotein box structure domain was 172–257 aa. The predicted molecular weight was about 38.7 kD, and thetheoretical isoelectric point was 6.64. A real-time quantitative polymerase chain reaction analysis detected significantlyhigher Pm-cyclin Y mRNA expression in the ovary than that in other tissues. Pm-cyclin Y mRNA was expressed in theovary at five different developmental stages, and the expression level was highest during phase III. The study abtainedrecombinant expression Pm-cyclin Y in prokaryotes and offered theoretical basis for further research on Pm-cyclin proteinfunction. These results provide a basis for further functional studies of Pm-cyclin Y.

Abstract:) immune system, geneexpression was analyzed in different developmental stages and tissues. Four tissues of grass carp at different timesafter challenge with the pathogenic bacterium were analyzed by real-time quantitativeRT-PCR. The 642 bp Open Reading Frame (ORF) region of grass carp was expressed using prokaryoticexpression technology. The fusion protein had a relative molecular mass of 40 kD. Real-time quantitative RT-PCRanalysis indicated that the mRNA level in embryos gradually increased during embryogenesis from cleavageto fry stages after fertilization, with the highest level in the fry stage. In adult fish, the transcripts were found to be highly abundant in liver; moderatelyabundant in the head kidney, spleen, and intestine; and least abundant in the eye and bladder. After challenge withmRNA level in the head kidney, liver, spleen, andintestine significantly increased (expression in the liver was significantly increased at 12 hpost-treatment; followed by a decrease at 24 h post-treatment; another increase at 48 h, with a maximum level at72 h post-infection; and the high expression level was maintained at 96 h and 7 d post-treatment. There was significantup-regulation in the intestine at 12 h post-treatment, with a maximum level at 48 h post-treatment; significantdown-regulation at 72 h and 96 h; and the expression regressed to the initial level by 7 d. In the spleen,mRNA level increased at 4 h post-treatment, with a maximum level at 12 h; then, there was significantdown-regulation at 24 h and 48 h; and the expression regressed to the initial level by 7 d. Bacterial infection canincrease plays an important role inthe innate immune response of grass carp.

Abstract:, germplasm, it is urgent for the pearl industry toselect varieties with optimal traits. Analysis of genotype and environment interactions is important for verifyingand promoting elite varieties, for selecting breeding varieties suited to specific environments, and for determiningbreeding objectives. In this study, we selected three typical families (F, and F) with fast, median, and slowgrowth that were cultured in Li’an (Lingshui, Hainan), Tandou (Zhanjiang, Guangdong), and Bailong (Fangcheng,Guangxi) for 1 year. Eight hundred individuals per family were cultured in each location. The three familie lineswere started in January, 2012. Multiple analysis of variance (ANOVA) and additive main effects and multiplicativeinteractions (AMMI) were used to analyze the effects of genotype-by-environment (G×E) interaction on differentgrowth stages. Results showed that the growth rate of different generation had the fastest growth rate with regard to total weight, whereasF2 had the fastest growth rate with regard to shell length, shell height, and shell width. Intotal, the proportions of genotypic(G), environmental(E), and G×E interaction variances were 72.47%–88.55%,9%–24.13%, and 3.32%–4.04% for the four traits, respectively. In different growth stages, genotypic variance reducedfrom 92.32%–98.66% to 32.45%–68.10%. Instead, environmental variance increased from 0.11%–1.27% to24.41%–62.26%, and G×E variance increased from 0.79%–3.9% to 3.84%–7.51%. Analysis of AMMI biplots offour traits showed that F2 was the most stablefamily. Above all, the effect of G×E interaction was small. Family greatly contributed to phenotypic variation. Ourobservations provide support for selective breeding of this animal.

Abstract:, is one of the most economically important farmed shrimpspecies worldwide, which has the higher yields and lower production cost, and it is mainly distributed from theGulf of California to the Pacific coastal waters of northern Peru. In 1998, was introduced to China,but the long-term sustainability of white shrimp farming is currently under threat because of variation in size ,vulnerability of farmed stocks to disease and many other germplasm recession-related problems. The current statusof white shrimp aquaculture highlights the need for a systematic stock improvement program to improve economicallyimportant traits. The cultivation of strongly resistant, fast growing new shrimp strains is key to maintainingsustainable development of the breeding groups to improve growth, disease resistance, and other quantitativetraits that yield genetic improvement. Although the domestic germplasm mainly comes from anAmerican source, there has been substantial genetic improvement of , including production of newstrains such as “in section No. 1, ” “ZTE No. 1, ” “Kehai No. 1, ” and “Gui Hai No. 1, ” which were obtained fromdistant groups by hybridization. Heterosis can effectively improve growth potential and increase production,which is one of the most important goals of animal and plant breeding. Crossbreeding has been used in aquacultureto exploit hybrid vigor in crossbred offspring that show better performance and increased fitness compared withtheir purebred parents. In the present study, we used genetic resources from different geographical strains of whiteshrimp from Miami, Hawaii, and Thailand in a complete diallel cross (Griffing I). In this study, we analyzed theeffect of heterosis on growth rate and body weight at parental- and hybrid-strain juveniles, adults, and reserve seedstages. The results showed that the ranges of least squares means of different mating combinations among thesestages were 5.86–12.15 g, 14.79–28.82 g, and 38.25–54.74 g, respectively, and the ranges of growth rate were3.40–5.70%/d, 1.11–2.56%/d, and 0.33–0.68%/d, respectively. Least squares means of hybrid strains were higherthan those of inbred strains. Heterosis analysis showed positive mid-parent heterosis and heterobeltiosis for bodyweight of hybrids with a diminishing trend over time. The highest heterosis occurred in hybrid offspring that werecrosses of female individuals of the Miami population with male individuals of the Hawaiian population. At eachgrowth stage, least squares mean of offspring of the Miami population and average of the parents were higher thanthose of the average of all 3 parent populations. Increase in proportion of Miami and Hawaiian parents when producingcrosses will help improve offspring growth performance. Our study provides theoretical basis and technicalparameters for constructing a base breeding population of white shrimp in the future.

Abstract:is the second largest cultivated alga in China, with economic valuerelated to agar production and bioremediation potential by eliminating eutrophication. It is important to establish a geneticbreeding system for (GL) to promote sustainable development of themariculture industry. In the present study, 3 productive characters of the Fgeneration of GL gametophytes, includinglinear growth rate, branch number, and central base diameter, were analyzed and evaluated using the DTOPSIS comprehensiveevaluation method to convert qualitative comprehensive traits of Fvalue, which is necessary to determine an ideal solution to improve breeding. Thus, characters of all strains werecomprehensively analyzed and provided evidence for future cultivar hybridization and selection. Among the 100 individuals tested, the linear growth rate ranged from 2.0%/d to 7.3%/d, with an average of4.76%/d (standard deviation, 1.28). Its variable coefficient was 26.79%, and that the difference among individuals wassignificant. Branch number was unevenly distributed with extremely substantial variation. The mean value was 1.93with a range from 1 to 5, standard deviation of 0.8, and variable coefficient of 41.17%; this was the most substantialvariation and a relatively large variation range. The average central base diameter was 1.8 mm, with a range from 1.4 mm to2.2 mm, and standard deviation of 0.18. Its variable coefficient, 9.87%, had the lowest variation range and least variancedifference among the three productive characters. All of the above three characters had normal distributions: Mostof the linear growth rates of Fgametophytes distributed between 3.0%/d and 6.0%/d; 40% of individuals had 2branches after 28 days of culturing; and central base diameter mostly distributed between 1.6 mm and 2.1 mm. Standarddeviation analysis revealed large variation in the range of characters of the Fgeneration of these gametophyte plants.Based on DTOPSIS comprehensive analysis, three productive characters of Fgeneration gametophytes were comprehensivelyevaluated, and 100 strains were ranked based on their value. The results showed that strains 20, 47, 93, 6,and 31 were superior to the others because they had higher values, which indicates that they have a balance of advantageousgrowth rate, branch number, and central base diameter. These strains could be exploited for genetics-basedbreeding before they reach maturity. In addition, adjacent strains ranked by DTOPSIS analysis had similar values,whereas strains at either extreme showed substantial difference, which was consistent with the normal distribution. GL gametophytes of the three productive characters indicates that strains with substantialcharacter differences can be chosen as parents for hybridization to obtain improved varieties. DTOPSIS analysisintuitively measured comprehensive traits of Fgametophytes, which provides a theoretical basis for subsequent researchon strain selection and further construction of a

Abstract:The purpose of this research was to study the bacterial community structure in digestive tract and enzymeproduction capacity of enzyme-producing bacteria, and provide reference for selection and application ofprobiotics for carnivorous fish culture. In this experiment, samples of juvenile saladfish ()stomach, pyloric caeca, foregut, midgut, and hindgut were obtained in recirculating aquaculture systems. Bacterialcommunity structure was analyzed using 16S rDNA-PCR. The enzyme-producing bacteria were isolated and identifiedby isolating and screening enzyme-producing bacteria. Moreover, the enzyme activities were tested.Twenty-seven strains were isolated and cultured under experimental conditions, including 13 strains of , which accounted for 48.2%, 18.5%, 25.9%, 3.7%, and 3.7%, respectively, of the isolated bacteria.The sequence homology of corresponding genes was greater than 98%. Fifteen strains produced enzymes and accountedfor 55.6% of all bacteria; these bacteria included 7 strains of . Among these bacteria, 13 strains can produce bothprotease and amylase, whereas 4 strains can produce protease, amylase, and lipase. Among the enzyme-producingbacteria, 5 strains can produce 3 enzymes and 9 strains can produce 2 enzymes. Moreover, the bacteria in themidgut and hindgut were most abundant, and those in the stomach, diverticulum pyloricum and foregut were lessabundant; the bacteria that produce lipase were concentrated in the midgut. Protease and amylase were the mainenzymes produced by these bacteria; these two enzymes were highly productive, with protease activity up to(87.7321.134) U/mL and amylase activity between (77.176±0.599) U/mL and (73.458±0.574) U/mL. Only onestrain produced cellulase, and the activity was low. Under the experimental conditions, the isolated bacteria wereall culturable. However, non-culturable bacteria cannot be isolated. Moreover, some culturable bacteria in the digestivetract could not be isolated because of limited testing conditions such as temperature, pH, culture medium,and other factors that may affect normal bacteria growth. In addition, isolation and identification took place underaerobic conditions, which is not similar to real gut conditions; thus, a large number of anaerobic bacteria were notisolated. Therefore, further investigation is needed to determine the actual bacterial community structure of the digestive tract. Our data showed that the bacterial community structure of the digestive tract directly affectedthe activity and diversity of exogenous digestive enzymes. This research provides a theoretical basis forselection of enzyme-producing bacteria in recirculating aquaculture conditions.

Abstract:To explore the relationship between osmoregulation and long-chain polyunsaturated fatty acid(LC-PUFA) biosynthesis in rabbitfish (), an 8-week feeding trial was performed in juvenilerabbitfish with diets that contained fish oil (FO) or a blend of vegetable oils (VO; perilla and canola oils) at threesalinities: 10, 20, and 32. The growth performance, fatty acid composition of gill phospholipids, and activity andexpression levels of gill NaATPase (NKA) under different treatments were analyzed. The results showed that,at the same salinity, there was no effect of dietary lipid source on growth performance (0.05), whereas n-3LC-PUFA content in gill phospholipids in the FO dietary groups was significantly higher than those in VO treatments(0.05). In particular, although the contents of n-6 LC-PUFA in VO-fed fish were lower than in FO-fedfish, the opposite was observed for n-6 LC-PUFA contents. Furthermore, the activity and mRNA expression levelsof gill NKA in VO groups were significantly higher than those in FO groups (0.05). Under different salinities,the growth indexes at a salinity of 10 were significantly lower than those at salinities of 20 and 32 in both dietarygroups (0.05), whereas the LC-PUFA contents, and activity and mRNA expression levels of NKA in fish fedVO were significantly higher than that in fish fed VO (0.05). In addition, there were no significant differencesin either of the higher two salinities treatments (0.05). The results indicate that a salinity of 10 may not suitablefor rabbitfish culture. Furthermore, FO-derived diets can improve n-3 LC-PUFA content in gill phospholipids,which helps maintain membrane lipid fluidity and osmotic balance. Alternatively, VO-derived diets can regulateosmotic pressure by synthesizing n-6 LC-PUFA to up-regulate NKA expression and activity.

Abstract:Nutrition is an important factor that restricts the normal growth of fish fry. In the nutrition transitionperiod or feeding conversion process, it is crucial that the larval, juvenile, and young fish have access to adequatenutrition. Groupers are ferocious, carnivorous marine fish; if food supply is not sufficient, they feed on their ownlarvae and juveniles, and breeding efforts undergo substantial loss. In this research, we studied the feeding habitsand growth characteristics of larval, juvenile, and young fish of the FEpinephelus fuscoguttatusE. lanceolatus ) cross using artificial ecological methods. The larvae were fed when their mouths opened, andsamples selected from the breeding pool every afternoon after the larvae were fed. We sampled every day beforethe larvae were 10 days old; then, we sampled every 2 days. Each sample consisted of about 15 fish. All sampleswere used to test how much the fish ate. Other indexes were tested with other samples, the number of samplesranged from 10 to 100. After sampling, we observed morphological characteristics of the fish fry using a dissectingmicroscope, dissected the digestive tract under the dissecting microscope, and recorded amount of bait that hadbeen consumed. The results showed that: (1) the larval grouper started feeding 3 days after hatching when the watertemperature was approximately 29––s first bait wasthe ss type rotifer, followed by the L type rotifer, brine shrimp, and compound feed. The 3-day-old larvae werevery weak, with a feeding rate of 32% and repletion rate of 25%. The 5-day-old larvae were more dynamic thanthe 3-day-old larvae, with a feeding rate of 81.82% and repletion rate of 36.36%. The feeding rate was above 90%when the larvae were older than 7 days old, and the repletion rate was above 90% when the larvae were older than9 days old. (2) With growth and development of fish fry, the average feeding amount changed. The larvae required2 h 30 min to achieve satiation at 10 days old, and digestion took 1 h 45 min. The juveniles required 35 min toachieve satiation at 34 days old, and digestion took 3 h 20 min. Young fish required 30 min to achieve satiationand 10 h 25 min for digestion at 48 days old. (3) The correlations between net weight (. In this paper, feeding habits and growth characteristics were observed to provide a theoreticalbasis for large-scale breeding of FE. lanceolatus

Abstract:(Clupeiformes, Engraulidae) is a highly commercial migratoryfish species in the Yangtze River. Because of adverse human activities such as overfishing, productionhas sharply declined. Investigating the large-scale distribution of this fish is very important for evaluationof its resources and habitat. Previous evidence revealed the existence of anadromous in Poyang Lake; thisstudy was conducted to confirm whether there is also anadromous in the Xinjiang River. An electronprobe microanalyzer was applied to analyze Sr and Ca microchemistry patterns in otoliths of collectedfrom the Ruihong section of the Xinjiang River (the most distant branch of Poyang Lake, ~1000 km from theYangtze River estuary) near Yugan County in Jiangxi Province. Line transect results clearly showed a complexSr/Ca ratio (i.e., Sr/Ca) pattern, including low-ratio freshwater habitat (Sr/Ca×in the XinjiangRiver. Home spawning is thought to be the main reason for such a long migratory for the anchovy in the XinjiangRiver, resulting from natural selection for relatively stable spawning conditions. A 1000-km migratory distancereflects an extremely strong migration ability of , which is a relatively small fish. The anchovies enter intothe Xinjiang River to visit habitat required for spawning and early life stages, and there are likely spawninggrounds of anadromous

Abstract:, Pcc) is naturally gynogenic, and gynogenic Pcc producedby artificial breeding can theoretically produce solely female offspring. In laboratory culture, a higher proportionof male fish occurred in Fprogenies compared with pond culture conditions. A higher proportion of males was foundin the Fprogeny under laboratory culture (43.6%) compared with pond (4.7%) conditions. To determine the cause ofthis variant sex ratio, ovarian gene expression profiles were detected and compared between the male and female Fprogenies for different culture conditions. Results showed that expressions of most testicular sex differentiation-related,steroid receptor, and steroidogenic genes in PccFoffspring were significantly higher than those in ovaries under laboratoryculture conditions, except for Pcc-. With respect to pond culture conditions, expressionsof most testicular sex differentiation-related and steroid receptor genes in PccFoffspring were significantlyhigher than those in ovaries, except for Pcc-.Amounts of the steroidogenic genes had reversed expression patterns (male<female). The gene expression profiles forsteroidogenesis and transcriptional regulation of aromatase were different in the gonads of Fprogenies between laboratoryand pond culture conditions. The variant sex ratio may be attributed to the differential gene expression of bothsteroidogenic enzymes and transcription factors of aromatase under different culture densities, which may be associatedwith the regulation and/or synthesis of endogenous steroid hormone levels and related to different sex ratios.

Abstract:Polycyclic aromatic hydrocarbons (PAHs) are a large group of anthropogenic pollutants that contain two ormore fused aromatic rings in linear, angular, or clustered arrangements. PAHs are introduced into marine environmentsthrough events such as atmospheric deposition, accidental oil spills, transport accidents, combustion of fuels, municipal,and urban runoff. PAHs elicit particular concern, and 16 PAHs were listed as priority pollutants by the US EPA becauseof their health risk as potential carcinogens and mutagens. Because of their lipophilic properties and resistance to degradation,PAHs can accumulate in organic tissue. Consequently, alarming concentrations of these compounds have beenfound in many marine species. Levels, composition profiles, and health risk assessment of PAHs were studied in 24species of marine organisms collected from Zhanjiang mangroves. PAH concentrations were determined using gaschromatography coupled with mass spectroscopy. The results demonstrated that the total concentration of PAHs in 11 speciesof marine fishes, 3 species cephalopods, 6 species crustaceans, and 4 species shellfish ranged from 191–491 ng/g, respectively, and their average levels were 349.2 ng/g,420.9 ng/g, 424.3 ng/g, and 455.9 ng/g, respectively. The average PAH concentrations differed among species and inthe following decreasing order: shellfish>crustaceans>cephalopods>marine fishes. Compared with PAH levels of othercoastal areas of the world, the PAH levels from Zhanjiang mangroves were low to moderate. The composition of PAHswas characterized by three rings of PAHs. Potential risk assessments demonstrated that the levels of benzo[a]pyrene infishes, cephalopods, crustaceans, and shellfish from Zhanjiang mangroves were within the EU limits and wereconsidered acceptable (<10

Abstract:Fishery forecasting is an important component of fisheries science. It has vital significance for fisheryproduction and management. is an important target for Chinese squid jigging fleets in the southwestAtlantic Ocean. Some previous studies employed various approaches to forecast optimal fishing groundsbased on environmental factors, such as sea surface temperature (SST), sea surface height (SSH), and chlorophyll-aconcentration (Chl-a). These approaches use experiential knowledge obtained from historical fisheries andenvironmental data to forecast fishing grounds, but there is no research on how to select the most appropriate spatialand temporal scales or environmental data to forecast models. In this study, models were constructed based on differentenvironmental factors with various spatial and temporal scales to better forecast optimal fishing grounds inthe southwest Atlantic Ocean.In this study, historical fishing data from Chinese mainland squid jigging fleets from 2003 to 2011, sea surfacetemperature (SST), sea surface height (SSH), and chlorophyll-a (CHL-a) data were divided into different temporal andspatial scales. Temporal scales included monthly, ” 0.25°°° × environmental factors were divided into four categories, including I (SST), II (SST and SSH),III (SST and Chl-a), and IV (SST, SSH, and Chl-a). A total of 24 models were constructed using error backpropagationartificial neural network; model training, validating, and testing were completed in Matlab. Mean square error andaverage relative variance (ARV) were used to evaluate accuracy, and sensitivity analyses were used to evaluate theinterpretation of models for fishing grounds. The results indicated that the fishery forecasting model with maximum accuracy and minimum ARV wasconstructed by two models, one was with a 1.0° ×SST”monthly” 0.25°”environmental factor. Sensitivity analyses using those two models showed that models with different temporal andspatial scales expressed different habitat suitability. This research revealed that when models had the same temporal scales, there were no proportional or inverserelationships between spatial scale and model accuracy, when models had same spatial scales, there was no proportionalor inverse relationships between temporal scale and model accuracy. Additionally, more environmental factors were notalways better; sometimes more environmental factors increased the difficulty of model fitting. In summary, consideringthe temporal and spatial scale of fishing and environmental data was needed to construct fishing ground forecastingmodels for

Abstract:) is one of the most economically important fish species in the East ChinaSea and supports one of the most valuable fisheries in China. From 1990 to 2012, the total catch for this fisheryranged from 0.39 to 0.91 million tons. However, most studies on this fishery concentrated on feeding habit, variationsof catches, trophic composition, and the stock-recruitment relationship. For management, yield per recruitand surplus production models were applied to analyze the data of this fishery and provide a rough MSY estimateof approximately 7.5tons. Until now, reports on the use of stock assessment models for this fishery are limited,and no uncertainty assessment has been undertaken. Therefore, Bayesian state-space modelling was appliedto the catch and catch per unit effort(CPUE) data for this fishery. A state-space model describes the dynamics oftwo related processes: the observation process, which is a function of the unobserved state process, and the stateprocess, which describes the unobserved population dynamics in terms of biomass or abundance. In the presentstudy, the PellaTomlinson surplus production model was used for the state process. We used Bayesian inferencebecause it can take into account more uncertainties that are linked to parameters. In this study, four models wereconstructed based on Markov Chain Monte Carlo simulation with a mix of information and non-information priors.Marginal posterior distributions of model parameters, biological reference points (BRPs), and unobserved variableswere based on 250000 iterations after discarding the first 50000 burn-in iterations to ensure no persistentinitial pathologic behavior. Results showed that the best-fit of the four models was model 1, with lognormal priorsfor the intrinsic rate of increase ’s method was applied for convergence diagnostics, and WINBUGS software computed the results of theautocorrelation diagnostics. The parameters in model 1 were best fit and passed all the diagnostics. The prior distributionshad a significant impact on the results of , which indicates that the data are sensitive to the typeof prior distributions of indicate that the data provide more information than the prior distribution for Bayesian analysis. BRP resultsshowed that hairtail stock was overfished from 1995 to 2010 (catch over maximum sustainable yield) and faced aserious threat from 2000 to 2006 (fishing mortality coefficient over ). The stock was in a good state in 2012but required persistent management. Because of possible statistical distortion, the results of MSY and may beoverrated. The estimated results from 2004 to 2012 also have uncertainties, because the hairtail fishery in the EastChina Sea was also influenced by monsoon, precipitation, and other environmental factors.

Abstract:This paper addresses the spatiotemporal distribution characteristics of zooplankton abundance and seasonalchanges in fish egg and larval density based on data from four oceanographic surveys in Guangxi offshore waters in theNorthwest Beibu Gulf during the winter, spring, summer, and autumn of 2012. Additionally, the relationships between environmentalfactors, water masses, and, in particular, zooplankton were explored. The results revealed that zooplanktonabundances were 337.35 ind/m, and 14.78 ind/min the winter, spring, summer, and autumn,respectively. The zooplankton numbers between spring and summer, and between autumn and winter significantly changed,but remained steady between winter and spring, and summer between and autumn. The peak zooplankton abundance periodin this water body was winter, which occurs a season before that in the East China Sea. In the investigation area,, an economically important fish species, exhibited obvious seasonal distribution characteristics: Capturerates in winter and spring were higher than those in summer and autumn, which was consistent with the seasonal variationcharacteristics of zooplankton. High quantities of zooplankton in the winter and spring provided sufficient food to supplementfish populations and therefore provide a valuable resource for fish reproduction and growth. Northwest Beibu Gulf ismainly affected by coastal water, offshore current and mixed water. Coastal water is composed of sea water and mixedwater that is diluted by terrestrial runoff to the sea. A high salinity offshore current that is composed of offshore water runsinto the Beibu Gulf from the bay mouth. Mixed water composed of coastal and offshore water converges in the continentalshelf area. In the winter and spring, zooplankton distribution characteristics were similar; higher numbers of zooplanktonwere recorded in gulf and coastal waters than in inshore waters. However, zooplankton abundance in inshore waters wassignificantly higher than those in gulf and coastal waters during the summer and autumn. Sea water and mixed water in thisarea are affected by seasonal changes in coastal waters; the dominant species succession consisted of warm temperate neriticspecies in spring, warm water offshore species in summer and autumn, and warm water neritic species in winter. The dominantspecies were in the winter, spring, and summer and autumn, respectively.The ecological adaptability of the main dominant species determined the spatial and temporal distribution of these species,which in turn determined the zooplankton distribution characteristics. The combination of internal (ecological adaptation) andexternal (seasonal environmental change) factors resulted in the zooplankton distribution variation observed in this study. Thesefactors also likely drove seasonal species succession in this area. Zooplankton are a vital food source for most fish species duringtheir larval periods. Variations in zooplankton distribution and quantity can be either directly or indirectly affected by fish ingestion,migratory and catch behavior, and feeding period. Fish egg and larval densities were 6.83 ind/m,and 0.20 ind/mfrom winter to autumn; seasonal trends were highly consistent with those of zooplankton. A strong positive correlationindicates that rich food sources of zooplankton facilitate both fish egg and larval development.

Abstract:Because of changing fishing grounds for Japanese common squid, this study analyzed marine environmentdata retrieved from remote sensing information technology, production data of fishing catches in Japan Seafrom November to December in 20102013 were analyzed to determine resource abundance, change of time andspace of fishing ground centroids, and the relationships with influential environmental factors. The analyzed fisherieswere located in the central and southern sea waters in the Sea of Japan. Using a production-centered method,statistical interpolation, and mathematical statistics, a Generalized additive models (GAM) model was establishedbased on Catch per Unit Effort (CPUE) as the dependent variable and main environmental factors as the explanatoryvariables. Previous studies showed that the fishery centroids slightly differ every year, concentrated around132°′N. The model also showed that optimal sea surface temperature ofJapanese common squid fishing grounds was 16–, and optimal chlorophyll a concentration was 0.37.Regression analysis between CPUE and marine environmental data indicated that sea surface temperature and thespatial distribution factor on the CPUE were highly significant; in addition, chlorophyll a concentration was notsignificant. Sea surface temperature was relatively high in 20102013. Chlorophyll aconcentrations were lower in 2010 than in other years. Current partition was more apparent from 2010–2011; inthe north, the Tsushima warm current and east North Korea warm current were strong from 2010–2013, when the Riman cold current was stronger in the south. The scope ofenvironmental differed over 4 years, which included Tsushima warm current; when the east North Korea warmcurrent and Riman cold current flowed across each other, favorable conditions were provided for fishery formation.Different factors affected monsoon intensity and global climate in different years. Each year, the ocean fisheryenvironmental factors were slightly different, and the influence on fishery resources was difficult to estimate.

Abstract:occurred in Wenchang,Hainan Province, China in 2014. In this study, the moribund tilapias were collected from different farms for bacteriaisolation. Most of the moribund tilapias displayed typical clinical signs, such as melanosis, corneal opacity,and swimming abnormalities. A total of 19 isolates (TC-1, TC-2, BL1441 WT1459) wereisolated from the liver, kidney, spleen, eye, and brain of the diseased tilapia; then, these isolates were identified bymorphological observation, physiological, and biochemical characteristics, and sequence analysis of the 16S rRNAgene. All of the isolates were identified as –WT1459 strains grew slowly and couldnot utilize trehalose and ribose. In addition, TC-1, TC-2, and BL1441–’WT1459 isolates did not exhibit hemolysis. The geneticcharacteristics of these isolates were analyzed by multilocus sequence typing (MLST), molecular serotyping, andvirulence-related gene sequencing. The results indicated that TC-1, TC-2, and BL1441–S. agalactiae WT1459 isolates were rare typesof Ib-ST261 BL1448 isolates, and the virulence-relatedgenotype of these strains was +. Despite the fact that thenumber of the virulence-related genes of the WT1451 strain was less than that of the BL1441 strain, the formerwas more virulent than the latter in tilapia. In this study, the virulence tests were conducted by intraperitoneal injectionof the BL1441 and WT1451 strains in tilapia. The results of the challenge experiments showed that theWT1451 strain possessed stronger pathogenicity to tilapia than that of BL1441 strain. The WT1451 strain caused85% mortality in tilapia at a dose of 4.5CFU/mL. The BL1441 strain showed weak virulence in tilapia, withcumulative mortality of 65% at a dose of 4.5CFU/mL postchallenge. In summary, the 19 strainsisolated from tilapia in Wenchang were divided into two genotypes based on physiological and biochemical characteristics,16S rRNA gene sequences, hemolysis activity, molecular serotyping, and PCR screening of virulence-related genes. Although reports on the Ib-ST261 strains in tilapia are rare worldwide, thesestrains were highly virulent in tilapia. Therefore, it is very important to obtain data on the epidemiology ofIb-ST261 strains in tilapia in China. To the best of our knowledge, this is the first report on the hypervirulentIb-ST261 strain of , which was isolated from tilapia in China. This study provides aframework for the exploration of epidemiological analysis, vaccine development, prevention, and treatment of

Abstract:Based on major capsid protein (MCP) gene sequences of Chinese giant salamander iridovirus (GSIV) inGenBank, specific primers were designed, and the full-length was cloned into the eukaryotic expression vector pcDNA3.1 (+) to construct the recombinant expression vectorpcDNA-MCP. Giant salamander () muscle (GS-M) cells were transfected with the recombinant expressionvector, pcDNA-MCP. At 48 h and 72 h post-transfection, MCP protein expressions in GS-M cells were detectedby indirect immunofluorescence assay. The results showed that the protein expression level at 72 hpost-transfection was significantly higher than that at 48 h post-transfection; western blot assay also confirmed the specificexpression of MCP in GS-M cells at 72 h post-transfection. The eukaryotic plasmid pcDNA-MCP was used as aDNA vaccine to immunize Chinese giant salamanders by injection in dorsal muscle at a dose of 20 g/ind; then, peripheralblood from Chinese giant salamanders in both tested and control groups was collected on day 1, day 3, day 7,day 14, day 21, day 28, and day 35 post-immunization for hemocyte count, classification, and serum-neutralizing antibodytitration. The red and white blood cell counts showed significant increase in numbers of erythrocytes and leukocytesin the peripheral blood of immunized Chinese giant salamanders on day 5 and day 7 post-immunization (±0.76)%,respectively, at day 5 and day 7 post-immunization, and both significantly changed compared with the control group(±︰31.55)]. PCR results revealed thatpcDNA-MCP was distributed in the muscle, liver, spleen, and kidney from day 1 to day 28 post-vaccination. RT-PCRresults revealed that was expressed in all of the above tissues at day 7 and day 28 post-vaccination. A challengetest was conducted at day 28 post-immunization and produced a relative survival of 73.3%. This study provides a fundamentalbasis for the application of the pcDNA-MCP plasmid as a potential DNA vaccine to prevent and control GSIVinfection in Chinese giant salamanders in the future.

Abstract:Fish disease has become an increasingly prominent problem in aquaculture development and causessevere economic damage to fisheries. is an important fish pathogen that causes hemorrhagingand septicemia in many cultured fishes. The infection kinetics of WJ-8, that was transformed with aplasmid encoding green fluorescent protein (pEGFPuv-Kar). The purpose of this investigation was to fully elucidatethe pathogenesis of septicemia in blunt-snout bream and provide basic data on pathogenic factors of .Fish were divided into three experimental groups: group A, water temperature 25℃℃GFP μfor 24 h, and bacteria was counted and then transferred to a fish culture tank at afinal concentration of 10CFU/mL. The bacteria bath challenge was maintained for 30 min for groups A and B butnot for group C. Then, fish were transferred to tanks with clean water and the original water temperature wasmaintained. The bacterial counts from the blood, spleen, kidney, gills, intestine, and muscle were detected at 2 h, 4h, 8 h, 12 h, and 24 h after challenge. Bacteria were detected in both infected groups (A and B) but not in the uninfectedcontrol group (C) at all times during the experiment. An increased number of bacteria was observed in thegills of fish in groups A and B (0.05), whereas large numbers of bacteria were also noted in the spleen, kidney,and intestine. There were more bacteria that attached to and proliferated on the fish gills at 32. Thebacterial counts for group B were significantly higher than those of groups A and C (in blunt-snout bream, and high watertemperature is associated with heightened infection risk.

Abstract:) is a cold-water marine fish. In recent years, with the expansion and improvementof turbot farming, bacterial disease has severely affected turbot development, especially in larvae. Becausethe fish have the special requirements for the living environment, disease occurrence is the result of interactions amongfish, pathogens, and the environment. The gastrointestinal flora plays an important role in fish growth and development,and is closely related to disease occurrence. Therefore, it is necessary to investigate the gastrointestinal flora of larvalfish. In this study, factors that influence gastrointestinal microflora formation and succession in turbot larvae were investigatedby high-throughput sequencing. The intestinal tract microflara and their relationships with different developmentstages (e.g., larvae and fertilized eggs), chlorella, rotifer, artemia, pellet feed, and tank inlet water were analyzed.The results revealed that the intestinal tract microflora of turbot larvae was stable after initial feeding and wasdirectly affected by bacteria in fertilized eggs. Meanwhile, microflora structure was stable during turbot larval developmentand barely influenced by the bacteria in water and feed. The dominant bacterium was at arelative proportion of up to 45%65% in larval intestines. In addition, the relative abundance of this bacterium in fertilizedeggs reached 10.4%. Basing on these results, we suggest that the gastrointestinal tract of turbot larvae may be selectivefor the colonized bacteria. Some bacteria in water and feed, such as the