Abstract:For studying the fish community characteristics influenced by the habitat variation in Yangtze River Estuary,which could be used to determine how to manage its fish resources usefully,fishes from Yangtze River Estuary were collected during summer(the second half month of May to August 2010)and autumn(September 2010)every week(every half a month in the first half of August).During the study periods,39 species belonging to 6 fish ecological guilds and 20 families,12 orders were identified,most of them were marine migrant fishes (17 species) and estuarine resident species(14 species),and Engraulidae had the highest numbers of fishes(6 species),then followed by Gobiidae and Sciaenidae(4 species).Cochran and Friedman test was used to indicate that species composition or numbers of each guild in each month between May and September had no significant difference,respectively.Marine migrant taxa were both the most important guild of abundance or catch in each month,and average abundance or catch per net showed no statistical variations between May and August,but it was higher in September than that from May to August(except average abundance in July).Significant difference occurred in abundance or catch rank in each guild.Percentages of juveniles of 6 importantly commercial species(Big head croaker Collichthys lucidus,Japanese grenadier anchovy Coilia nasus,Osbeck’s grenadier anchovy Coilia mystus,silver pomfret Pampus argenteus, dark pomfret Pampus cinereus, and Bombay duck Harpodon nehereus) were examined to exhibit the variability in rank-distributions,C.lucidus and C.nasus declined,by contrast,C.mystus increased,P.argenteusoccured from May to August,while P.cinereus was observed during August to September. C.nasus spawn in fresh water,but C.mystus breed in the Estuary,which would reflect the temporal or spatial segregation of species of fishes belonging the same genus and were considered the ecological lysimilar,impling that they may reduce the competition for food or space during peak recruitment.According to the synthetic abundance method,dominant species dominated more than 95% of synthetic abundance,but no significant difference was observed among dominant species composition in each month.In addition,cluster analysis and non-metric multi-dimension scaling plot ordination of Bray-curtis similarity method based on abundance and catch showed that community could be divided into 2 groups on 60% similarity level,group Ⅰ consists of samples between May and the first half month of August,while group Ⅱ consists of fishes from the second half month of August to September.When compared with the previous study,although Yangtze River has still been the nursery and feeding ground for importantly commercial fishes,community structure has varied,and the major difference that could be observed is that the absence of rare species such as hilsa herring Macrura reevesii, Chinese sturgeon Acipenser sinensis.The study might reflect the degradation of fish resources due to overfishing,water pollution and large-scale hydrological project construction.

Abstract:Artificial reef was used in marine ranch to improve the marine ecological environment and enhance the fishery resources.Attractive effects of artificial reef may be attributed to creating habitat,shelter and spawning ground for the various kinds of fish,therefore positively affect the breeding and growth of the fish.In recent years,artificial reef construction programs have been rapidly developed in China.However,the knowledge of the effect of artificial reef on marine ecological environment is limited.The present study aimed to determine the influence of materials,structure and combination on the attractive effects of the artificial reefs and therefore provide useful data and information for the development of artificial reef construction.In the present study,the effects of ten kinds of artificial reef models with different shapes,which have been deployed in Yangmeikeng reef area,on the behavioral responses of the fish Sparus macrocephalus and the fish attraction effects of the artificial reef models were analyzed and compared with those without the artificial reef model in the trough.The result showed that in the condition without the artificial reef model in the trough,the fish liked to stay in radius of the center trough area within 40-70 cm.while the fish are more dispersed in the trough.After the artificial model was put into the troughs,the fish liked to stay in radius of the center trough area within 20-50 cm while No.1 reefNo.8 reef were put into the trough,the fish liked to stay in radius of the center trough area within 10-40 cm while No.9 reef and No.10 reef were put into the trough.The average occurring rate of the fish inside and near the reef areas all increased,while comparing fish occurring rates in artificial reef areas with or without artificial reef.The analysis results showed that all of the ten artificial reef models have obvious attraction effects on S.macrocephalus, especially for model NO.10.Its attraction effects ramk from strong to weak,respectively No.10 Reef>No.9 Reef>No.1 Reef>No.2Reef>No.7 Reef>No.4 Reef>No.5 reef>No.6 reef>No.8 reef>No.3 reef.The present study aims to determine the influence of materials,structure and combination on the attractive effects of the artificial reefs and thus provide useful data and information for the development of artificial reef construction.

Abstract:The objectives of this work were to study the effects of salinity change on the physiological chemical factors of Epinephelus coioides juvenile (body weight: 19.59 ?0.25g) by a biochemical analysis. The gill Na /K -ATPase, plasma glucose, aspartate carbamyl transferase (AST) , the activity of SOD and lysozyme of Epinephelus coioides juvenile were assayed after treated with salinity [(4，14，24 and 34 as contro1)] in 1, 3, 6 and 9 d At the same time, the gill chloride cells were observed using an H-E staining. The results showed that Na /K -ATPase activity in all groups showed similar tendency and the concentration reached the maximum level on 3rd day, then decreased and keep it constant on 6th day. The number of gill chloride cells did not show significant difference in salinity 24, but decreased slightly in salinity 14 during the experiment period. The changes in number, nucleus size and color of gill chloride cells in salinity 4 were observed on 6th day. The serum glucose level in all groups showed similar tendency and the concentration reached the maximum level on 6th day, after then decreased. The serum AST level showed similar tendency both in salinity 24 and in salinity 4 and the concentration reached the maximum level on 9th day. However, the serum AST level continuously decreased in salinity 14 during the experiment period. The hepatic SOD activity in all test groups showed a tendency of decreasing at the beginning and increase later, and reached the minimum level on 3rd day. There were significant differences in the hepatic SOD activity among all test groups (P <0.05). The serum lysozyme activity in all test groups showed a tendency of increasing at the beginning and reached the maximum level on 6th day, then decreased and gradually stable. There were significant differences in serum lysozyme activity among all test groups (P <0.05). When the salinity gradually decreased from 34 to 24, 14 and 4, these physiological chemical indicators showed similar tendency in all test groups, suggesting that E. coioides is typical of broad salinity fish and possesses good adaptability to low salinity. The results showed that E. coioides juveniles could adapt to the water body of salinity 4 under salinity domestication.

Abstract:Through the investigation on the enclosure phytoplankton community in pearl mussel ponds,we comparatively studied the different effects of silver carp(Hypophthalmichthys molitrix),bighead carp(Aristichthys nobilis)and the pearl mussel Hyriopsis cumingii on quantity,biomass and dominant species of phytoplankton,and the effects of the two carps on the phytoplankton in mussel ponds.The results showed that the density and biomass of phytoplankton in mussel monocultured pond(10#)are significantly higher than those in high density of silver carp monocultured pond(12#)(P<0.05),the density and biomass of cyanobacteria in mussel pond is significantly higher than those in high density silver carp pond(12#)and low density bighead carp pond(13#)(P<0.05),the density of chlorophyta in mussel pond is significantly lower than that in low density silver carp pond(11#)(P<0.05).The density of phytoplankton in mussel culturing pond(10#)is significantly higher than that in low density of silver carp coculturing pond(15#,16#)and bighead carp pond(17#,18#)(P<0.05),the density and biomass of cyanobacteria in mussel pond is significantly higher than that in silver carp pond(15#,16#)and bighead carp pond(17#,18#)(P<0.01),the density of chlorophyta in mussel pond is significantly lower than that in high density silver carp pond(16#)and low density bighead carp pond(17#).The impact on phytoplankton among mussel,silver carp and bighead carp is different from each other.The introduction of bighead carp or silver carp to enclosures of H.cumingii could effectually control algae especially Cyanobacteria(Microcystic aeruginosa)and promote the growth of Chlorophyta(Scenedesmus quadricauda)and finally help pearl mussel culture.The density and biomass of phytoplankton all decreased along with the increased density of silver carp while the increased density of bighead carp promoted the growth of Euglenophyta (Euglena viridis).

Abstract:The tissue structure of the reproductive system of Hemifusus ternatanus was studied by anatomical and histological techniques,and the shape of its reproductive system was described.The features are discussed in its reproductive system.The results showed that:the male reproductive system of H.ternatanus consists of the testis,vas deferens collecting duct,seminal vesicle,vas deferens,seminal vesicles,and the transfer device; the female reproductive system of H.ternatanus is composed of the ovaries,the fallopian collecting duct,albumen gland,gland wrapped around the eggs,black gland,transfer capsule,the vagina and proleg mouth.Transfer device is a unique structure of H.ternatanus,which has not been reported in other gastropods.The proleg mouth only disappeared in the female,and is the only morphology symbol that can distinguish male and female.The protein gland secretes strong eosinophilic material in reproductive season,the gland wrapped around the eggs secretes strong basophilic substances.The black gland was first discovered in H.ternatanu, and its specific functions should be studied further.

Abstract:The full-length cDNA sequence of Toll-like receptor 9(CiTLR9)gene was identified from grass carp(Ctenopharyngodon idella)gill by homologous cloning and rapid amplification cDNA ends(RACE).The CiTLR9 cDNA was 3 468 bp,encoding 1 058 amino acid(aa)residues,including signal peptide,16 leucine rich repeat(LRR)motifs,one transmembrane zone and one Toll/IL-1 receptor(TIR)domain.The molecular weight of the deduced protein is 121 921 u,and the isoelectric point is 8.80.The amino acid sequence of CiTLR9 possessed 85%,82%,55%,and 55% identity with the TLR9s of Cyprinus carpio,Danio rerio,Salmo salar and Oncorhynchus mykiss respectively.CiTLR9 protein firstly clustered with TLR9s in Cyprinidae species,Cyprinus carpio and Danio rerio in the phylogenetic analysis.CiTLR9 mRNA was detected in all the tested 15 tissues(blood,brain,eye,foregut,midgut,hindgut,gas bladder,gill,head kidney,trunk kidney,heart,hepatopancreas,muscle,skin,spleen)by semi-quantitative real-time RT-PCR,highly in gill,blood and head kidney.The results serve further studies on functions of TLR9 and exploitation of immunostimulators in grass carp.

Abstract:Rapeseed meal is used widely in fish feed,but contains a variety of harmful substances,and this restricts its use.So,a 10week feeding experiment was conducted to evaluate the effects of dietary rapeseed meal levels on growth,liver tissue structure and some nonspecific immunity indices of juvenile GIFT tilapia(Oreochromis niloticus)［initial body weight(4.82±0.46) g］.Five isonitrogenous(crude protein 34%)and isoenergetic(total energy 19.2 kJ/g)diets were formulated to contain rapeseed meal 15.0%(control group),30.0%,45.0%,60.0%,75.0% respectively.The results showed that weight gain rate(WGR),specific growth rate(SGR),feed efficiency ratio(FER)and protein efficiency ratio(PER)of GIFT tilapia decreased with increasing the level of rapeseed meal levels,60.0% and 75.0% group were significantly lower than those in control group(P<0.05),30.0% and 45.0% group had no significant differences with the control group(P>0.05).No significant differences in hepatosomatic index(HSI),viscerosomatic index(VSI)and survival rate(SR)were observed among treaments.Proximate composition in whole body of GIFT,crude protein content of 60.0% group was significantly higher than that in the control group(P<0.05),crude fat content of 60.0% group was significantly lower than that in 30.0% group,no significant differences in moisture and ash was observed among treaments(P>0.05).The number of hepatocytes with empty vacuoles degeneration and nuclear migration increased progressively with the increasing the level of rapeseed meal,liver tissue structure damaged increasingly.In serum,alkaline phosphatase(ALP)activity increased with the increasing of the rapeseed meal levels,75.0% group was significantly higher than that in the control group(P<0.05),while superoxide dismutase(SOD)activity declined with the increasing the level of rapeseed meal,60.0% group was lowest,and has significant difference with control group(P<0.05).In this condition,a percentage of no more than 45.0% of dietary rapeseed meal in juvenile GIFT tilapia was advisable.

Abstract:The normalized cDNA library from liver of Sinonovacula constricta was constructed using the SMART cDNA construction kit and large numbers of colonies were randomly picked and sequenced.Two EST sequences with high homology with β-actin gene of other species were found and then the complete express sequence of one from S.constricta was obtained by PCR and 5′RACE, named β-ACTIN 1.The cDNA of this gene was 1 552 bp,which consists of a 73 bp 5′ untranslated region(UTR),a 1 131 bp open reading frame(ORF)and a 348 bp 3′ UTR.The translated protein is composed of 376 amino acids,with 41.95 ku molecular weight,and its calculated isoelectric point was 5.23.Compared with the other 7 molluscs of amino acid sequences,the amino acid sequence of β-ACTIN 1 inS.constricta has twelve specific amino acid residues:Ile179,Glu229,Ser232,Pro236,Ile248,Asn272,Cys273,Val283,Ser320,Ser325,Val330,Pro339,respectively.Meanwhile,the amino acids sequence of β-ACTIN 1 in S.constricta shared the high similarity with the other 7 molluscs(more than 97%).Phylogenetic analysis suggested that S.constricta clustered with mollusca firstly,and then clustered with arthropoda,finally clustered with fish,amphibians,mammals.The quantitative reverse transcriptase(qRT-PCR)analyses showed that the expression level of β-ACTIN 1 gene was not stable in different tissues and after the Vibrio anguillarum induced in S.constricta. So this β-actin gene was not suitable as an internal control.

Abstract:Farnesoic acid O-methyl transferase(FA-O-MeT)catalyzes the methylation of farnesoic acid(FA)to methyl farnesoate(MF).Here we analyzed the activity of FA-O-MeT in mandibular organs(MOs)of Procambarus clarkii by the radiochemical assay,and also detected the regulation of eyestalk factor on the activity of FA-O-MeT.This work showed that there was no significant difference between the right and the left MO in the FA-O-MeT activity(P>0.05); During the different ovary developmental stages,the enzyme activity was also at different levels,and there was a peak at the secondary vitellogenesis stage,to 61.75 pmol/(p·h);Eyestalk factor removal increased FA-O-MeT activity,and the peak appeared on the 5th day.Furthermore,incubation MOs in the DMEM with the SG extracts significantly decreased the FA-O-MeT activity(P<0.01).These results indicated that the activity of FA-O-MeT is closely related to ovarian development and is negatively regulated by X-organ sinus gland complex in the eyestalk.

Abstract:The cpsE gene of Streptococcus agalactiaevirulent strain isolated from tilapia was amplified by PCR with specific primers and cloned into pMD19-T vector.The recombinant plasmid was strongly confirmed by PCR combined with restriction enzyme digestion(BamHⅠ and Hind Ⅲ).Molecular characterization analysis of cpsE gene was performed by bioinformatics tools like Clustal X 2.0,MEGA 4.1, Bioedit 7.0,TMHMM,NetPhos 2.0,NetNGlyc 1.0,SignalP 3.0 Server,PSIpred,SAM_T08 and CUSP.Results indicated that amino acid sequence deduced by cpsE of tilapia S.agalactiae was highly conserved and has revealed a surprising degree(100%)of homology among strains isolated from human and other mammals.Polypeptide analyzed in this study contained a Glycosyltransferases superfamily conserved domain that functioned as enzyme that catalyzed the transfer of sugar moieties from activated donor molecules to specific acceptor molecules.Moreover,the polypeptide possessed 3 phosphorylation sites which related to posttranslational modification.The hydrophilic regions were larger than hydrophobic regions and transmembrane domain was predicted to exist in polypeptide chain.The analysis of codon bias demonstrated the codon usage frequency of cpsE of tilapia S.agalactiaewas distinctly different and it preferred to perform in eucaryote.

Abstract:The growth rate and biomass,contents of arachidonic acid(AA)and other fatty acids in Myrmecia incisa Reisigl H4301,a freshwater green microalga rich in AA,were comparatively studied while cultured between nitrogen and phosphorus starvation under different light intensities.It was found that either nitrogen or phosphorus starvation could cause a reduced growth rate of this microalga as well as a resultant biomass.If grown under a lower light intensity［60 μmol photons/(m²·s)］,the lowest average growth rate［0.025 g/(d·L)］of this microalga resulted from phosphorus starvation,which was nearly half of the growth rate while grown in a complete BG11 medium.Both of nitrogen and phosphorus starvation could increase the contents of total fatty acids and AA,however,when this alga was exposed to low light intensity the positive effect of phosphorus starvation was limited.High light intensity［200 μmol photons/(m²·s)］was not beneficial to the synthesis and accumulation of AA no matter how this microalga was cultured in the complete or nitrogenfree or phosphorus-free media.The AA content gradually increased accompanying with a decrease of linoleic acid content during the starvation.However,the oleic acid percentage also gradually increased which limited more significantly the accumulation of AA in this microalga grown under phosphorus starvation than nitrogen one.Based on the composition changes of every species of fatty acids,the main synthesis metabolic pathway of AA suggested that it proceeded from linoleic acid to γlinolenic acid and then to 20∶3ω6 under nitrogen or phosphate starvation,and that the Δ6 desaturase was a rate-limiting enzyme.The step in which ω3 desaturase played was down regulated by nitrogen or phosphorus starvation,thus ensuring the synthesis and accumulation of AA positively.Nitrogen starvation blocked the protein synthesis,and phosphorus starvation caused the disorders of nucleic acid,carbohydrate and energy metabolism,which resulted in the slow growth rate and the synthetic conversion of compounds into ones without nitrogen or phosphorus as components.In such a case of nutrient starvation,therefore,the increase of total fatty acids and AA contents in this microalga was enhanced.This research will lay a foundation for the further understanding of the promotion mechanism of fatty acid contents especially of AA in M.incisa by a nutrient stress,and for manipulation and optimization of AA commercial production on a large scale.

Abstract:Ribulosel,5bisphosphate carboxylase/oxygenase(Rubisco)is a key enzyme in photosynthesis,and its small subunit gene rbcS can affect the carboxylation catalytic efficiency and CO₂/O₂ specificity of the enzyme.We cloned and described the rbcS gene and promoter from Dunaliella parva. Based on the highly conserved nucleotide regions of known rbcS,a pair of specific primers were synthesized to amplify 380 bp cDNA and 1 841 bp DNA sequence in Dunaliella parva.Then the 5′ genomic DNA and 3′ cDNA sequences were cloned by Genome walking and rapid amplification of cDNA ends(RACE)technology.Based on the sequences of the 5′- and 3′-termini,primers were synthesized to obtain the full-length genomic DNA and cDNA.The full-length rbcS cDNA contained 570 bp open reading frame(ORF)(GenBank accession no.HQ315783),294 bp of 3′-noncoding region.The full-length rbcS genomic DNA was 2 031 bp.In addition,a 476 bp promoter was obtained.Similarity analysis revealed that the highest identity was found between D.parva and Dunaliella salina.The D.parva rbcS also showed wide similarity with other green algae.This study laid foundation for further research on the function analysis and overexpression of rbcS genes,genetic manipulation of Rubisco.In addition,high levels of expression have made the promoter of the rbcS gene an attractive candidate to drive expression of transgene.Therefore the D.parva rbcS promoter after optimization should facilitate the development of transformation system of halotolerant algae and efficient expression of transgene.

Abstract:A 1 250 bp coding region of grass carp reovirus(GCRV)VP6 protein was amplified by RT-PCR and cloned into pEGFP-N1 vector for the construction of recombinant plasmid pEGFP-N1-VP6.After being identified and confirmed by PCR reaction with specific primer paires,10fold serial dilutions of plasmid pEGFP-N1-VP6 were used as standard templates for Taq Man real-time PCR to quantify the virus genomic copy number and generate standard curve.Herein,a Taq Man real-time PCR of detecting GCRV was developed.It had a good linear relationship between the initial templates and C_t values with a detection range from 1×10¹ copies/μL to 1×10⁶ copies/μL,the correlation coefficient(R²)was 0.998 09 and the slope value of standard curve was -3.373.The assay for specificity of the method established revealed that the TaqMan real-time PCR had a specific detection of GCRV,but had no detection signals to spring viremia carp virus(SVCV)and infectious hematopoietic necrosis virus(IHNV).The Taq Man real-time RT-PCR assay described here with high sensitivity and accuracy is considered to be a powerful tool for the rapid detection and quantification of GCRV both in vivo and in vitro.

Abstract:The Pacific oyster Crassostrea gigas is a major aquaculture species in China and around the world.A serious problem in Pacific oyster farming is the occurrence of summer mortalities.Heavy summer mortalities have been observed in cultured Pacific oysters in US,China and France.While the causes for the summer mortality are not well understood.The production and use of triploid oysters may help to reduce summer mortalities.The goal of this study is to determine if heterosis exists between US and China populations of the Pacific oyster and if the interstrain hybrid triploids have greatly improved performance compared to diploids.Hybrid crosses of Pacific oysters between diploids from China and diploids as well as tetraploids from America were conducted.Four groups were produced:Chinese diploid ♀×Chinese diploid ♂,American diploid ♀×American diploid ♂,Chinese diploid ♀×American diploid ♂ and Chinese diploid ♀×American tetraploid ♂.Heterosis and triploid advantage of experimental groups were studied for traits such as fertilization and hatching success,survival,larval and juvenile growth.Our results show that heterosis in diploid hybrid progeny varied among traits and developmental stages:1.21% for larval growth,34.47% for larval survival and 20.39% for juvenile growth.The triploid advantage was significant for all traits and stages,except D larval size(5.19%)and larval growth(4.00%).Triploid advantages for larval survival,larval growth and juvenile survival were 19.92%,30.18% and 54.43%,respectively.The highest triploid advantage(202.96%)was observed in wet weight of juveniles at Day 200.Heterosis and the triploid advantage were stronger at juvenile stages than at larvae stages.Our results suggest that the hybrid triploid Pacific oysters between Chinese diploid females and American tetraploid males have greatly improved growth and survival compared to all diploid groups.Production of triploids through interstrain crossing may be the best way for producing triploids for aquaculture.However,at Day 200 when the triploid advantage was 202.96% in growth and 73.6% in survival,the diploid heterosis was only 3.75% and -26.25%,respectively.This finding suggests that the superior performance of the triploids may not be caused by the same heterosis observed in diploids.It is possible that heterosis in triploids is different from heterosis in diploids.We did not have pure-line triploids as controls in this study.Further studies are needed to determine to what degree that heterosis contributes to the superior performance of hybrid triploids.

Abstract:The Portunus trituberculatus from Zhoushan is seasonally infected by a parasitic dinoflagellate of the genus Hematodinium sp. Dinoflagellates were found in haemolymph and tissues of infected crabs where the parasite proliferates and causes mortalities.Monoclonal antibodies(McAbs)used to detect infection include a morphological index(pleopod diagnosis)and several immunoassays.The monoclonal antibodies against Hematodinium sp. were developed by fusing SP2/0 cells with splenocytes of 8-week-old female BALB/c mice immunized with soluble antigen of Hematodinium sp..Indirect EnzymeLinked Immunosorbent Assay(ELISA)was used to screen hybridoma cells and limited dilution method was performed to subclone the positive clones.After three cycles of subcloning,three McAbs against Hematodinium sp.were selected and designated as 2B₂,3G₄ and 4G₇ respectively.The three McAbs in culture liquid were proved to have high ELISA titers and inducing ascites by using it.The ELISA titer in culture liquid and ascites were 5.12×10^-4 and 8.00×10^-4 in the indirect ELISA,respectively.By using the immunoglobulin subtypes kit,three McAbs were identified to be IgG.Identification of the monoclonal antibody specificity via indirect fluorescenceantibody examination showed that Hematodinium sp.was specific labeled with bright yellow green under UV,while the normal haemocytes remained dark.Through monoclonal and polyclonal antibodies,double antibodybased sandwich enzyme-linked immunosorbent assay detecting Hematodinium sp. was built.The positive compatibility rate of the double sandwich ELISA was 100%.Results showed that the monoclonal antibody characterized by high valence and high specificities,can be used to diagnose Hematodinium sp. in P.trituberculatus at an early stage.

Abstract:In order to improve the phenotypic characters of cow strain of Manila clam Ruditapes philippinarum, hybridization and inbreeding effects of this strain were investigated between two generations by establishing inbreeding groups(F₂₂,F₃₃),hybrid groups(F₂₃,F₃₂)and control groups(C₂₂,C₃₃)with the parent of full-sib F₁ and F₂ (the upselection rate 10%),in July 2010.The results showed that the growth character and survival rate of larvae were partially improved,whereas the juveniles growth character was not increased by hybridization.The little growth heterosis was observed on larvae(0.95±1.23);the heterosis of larvae for F₂₃ was(0.36±0.59),that of F₃₂ was(1.56±1.96).The survival respectively was observed on juveniles(-2.90±3.20),the respectively of juveniles for F₂₃was(-4.60±3.21),that of F₃₂ was(-0.75±10.13).The midparent survival rate of larvae and juvenile were(9.43±4.41)and(8.66±12.25);the survival rate for F₂₃ were(0.77±3.60) and (6.70±8.81),that of F₃₂ were (20.93±7.92) and (10.94±16.28).The mating strategy was the major factor for hybrid effects during the larval period,then the maternal effect became the major factor for that during juvenile period.Growth of two generations was improved by inbreeding,but the survival rate of two generations was inbreeding depression.Generations F₂₂,F₃₃ were inbreeding depression on larvae,inbreeding depression rates of growth were(5.17±4.38)and(4.99±2.72);juveniles period of growth did not show inbreeding depression,inbreeding depression rates were(-0.79±13.66)and(-0.93±12.85).The inbreeding depression rate of survival for F₂₂ was(0.16±5.82) and (9.98±10.04) between larvae and juvenile,then these of F₃₃ were (19.33±11.28) and (13.08±16.17) respectively.The generation effect was the major factor for inbreeding effects.The phenotypic characters of this strain were effectively improved by close combination of upselection,hybridization and inbreeding.

Abstract:In order to study the activity of shrimp allergens in freezethaw cycles, Penaeus vannamei were used to extract allergen,respectively stored at -3 ℃,-20 ℃ and -80 ℃ for one to five cycles.For the purpose of exploring the best activated condition of the allergen extract,protein concentration was determined by BCA;SDS-PAGE electrophoresis was used to evaluate protein composition;indirect ELISA and Western-blotting were used to survey allergens activity.The results showed that when shrimp allergen extract was in the cycle of freezing and thawing for five cycless at -80 ℃,-20 ℃ and -3 ℃,the protein concentration decreased by 33.1%,30.0% and 24.2% respectively.The major allergen bands were degraded ,when the shrimp protein extract was freezed and thawed for four cycles at -80 ℃ and -20 ℃,on the other hand the major allergen bands didn’t change at -3 ℃ for five cycles of freezing and thawing.The allergenic activity of shrimp protein extract had reduced when freezed and thawed for five cycles at -80 ℃ and -20 ℃ and three cycles at -3 ℃.The major allergen Western-blotting bands disappeared when five cycles of freezing and thawing were advanced at -80 ℃ and -20 ℃,while the major Western-blotting bands didn’t change at -3 ℃.Therefore,when the allergens protein was storaged,the cycles of freezethawing should be reduced to ensure the allergenic activity of shrimp didn’t change,then at -80 ℃ and -20 ℃ within four freeze thaw cycles and at -3 ℃ less than two freeze-thaw cycles were allowed.

Abstract:Fishery science and management are progressively switching their attention from single species to ecosystems,and increasing the need for research of fish community.Based on the data collected by trawl surveys in May and October of 2006 in the Yellow Sea off Shandong,fish community patterns such as species compositions and spatial pattern were analyzed.In the investigated area,35°00′-38°00′N,120°30′-124°00′E,45 sample stations were set up.The survey data were standardized by sweep area and capture coefficient.The capture coefficient was set to 0.55 for pelagic fish and 0.35 for near demersal fish and 0.25 for demersal fish.The index of relative importance(IRI)was calculated to determine the importance of the species.Species were defined as dominant species when IRI value is more than 1 000.Important species were defined for those IRI value being grealer than 100 but no more than 1000.The multivariate statistical analyses include cluster analysis,NMDS,SIMPER and BIOENV to analyze the pattern of community compositions.The species,whose cumulative biomass less than 0.01% or frequency less than 5%,were excluded from multivariate statistical analyses.The abundance biomass comparison(ABC)curves and W-statistic,generated by PRIMER,were used to analyze the communities’ disturbed states.The results showed that a total number of 61 species belonging to 57 genera,37 families and 13 orders were collected,50 in springs and 50 in autumns.The dominant species were Pacific sandeel(Ammodytes personatus),Japanese anchovy(Engraulis japonicas) and fang’s blenny(Enedrias fangi) in spring, and were Japanese anchovy and Japanese sardinella(Sardinella zunasi)in autumn.The important species were Pacific cod (Gadus macrocephalus)in spring,and were yellow croaker(Larimichthys polyactis), silver pomfret(Pampus argenteus),Pacific sandeel and rednose anchovy(Thrissa kammalensis)in autumn.The fish communities were predominant by little,low-valued species.In spring,the average body weight of 18 species was no more than 10 grams,and 12 species in autumn.The fish community in the survey waters can be grouped into two assemblages through the clustering and NMDS results.The group Ⅰ,which contains 22 stations in spring and 17 stations in autumn,was in the coastal waters near the land and the group Ⅱ,which contains 15 stations in spring and 21 stations in autumn,was farther away.The dissimilarity between group Ⅰ and group Ⅱ was 73.94% in spring and 55.97% in autumn.The relationship between fish community pattern and water depth was dominant through the BIOENV program.The abundance curves were above the biomass curve and the W-statistic value was below zero in all groups in spring and autumn.We can conclude that:(1) There were many reasons for the low level of species of this survey,but overfishing and environmental degradation were the important one.(2) Fish community can be grouped into two assemblages according the water depth,but there exists no clear border between them.Most species existed in the two assemblages simultaneously.(3) The fish community in the Yellow Sea off Shandong was seriously disturbed.Miniaturization of fish community was serious.