Abstract:The speciation analysis of cadmium in seaweed(including Porphyra haitanensis, Laminaria japonica,Undaria pinnatifida and Sargassum fusiforme)was firstly conducted using sequential chemical extraction considering that high content of cadmium in some seaweed had seriously affected the edible safety,export and industry development of seaweed in our country.The results showed that many forms of cadmium were in the four kinds of seaweed,and the greatest amount of cadmium was in the extraction of 1 mol/L NaCl,followed by 2% HAC and both forms accounted for 76.3%-92.9% of the total cadmium.The cadmium content in the extraction of 0.6 mol/L HCl,deionized water and 80% ethanol was much smaller.80% ethanol could extract the ionized cadmium(Cd²⁺)which only accounted for 0.4%-9.2% of the total cadmium,and especially for laver,ionized cadmium was all bellow 1%.Present experiment further proved that using total cadmium content as the detection standard could not accurately reflect the edible safety of the seaweed,so a more accurate limit standard and a quick detection method of the ionized cadmium for seaweed should be urgently researched and established in order to guarantee the fast development of the industry and export economy of the seaweed in China.

Abstract:At present,with the development of industry and agriculture,heavy metal contamination of environment is intensifying,and the toxic effects on the human beings have attracted extensive attention.For the development of new adsorbent,reducing the pollution of heavy metals in water body,the chitosans were used to investigate the adsorptions of two metals of Cd2+ and Pb2+ in an aqueous solution.The absorption properties of chitosan were evaluated by the effects of pH,temperature,reaction time,adsorbent dose and initial metal ion concentration.The results showed that at pH 7-8 and pH 5-6,the chitosan had the best absorption of Cd2+ and Pb2+,respectively; low temperature was beneficial to absorption; the maximum absorption of Cd2+ was at 8 h,but of Pb2+ it always increased in the experimental period; the absorption of Cd2+ and Pb2+ was enhanced with the increase of chitosan amount; initial metal ion concentration had little effect to Cd2+,but at high metal concentration,the absorption of Pb2+ was significantly reduced.At the same time,the dynamical and the equilibrium isotherm adsorption studies of Cd2+ and Pb2+ followed the Lagergren second-order kinetic equation and the Langmuir isotherm equation in the concentration range studied,respectively.Conclusion:the adsorption capacity of chitosan is different with the changes of metal ions,in single metal solution,the adsorption capacity of chitosan for Cd2+ is stronger than Pb2+.Finally,this work systematically studies the adsorption conditions and performance of chitosan for Cd2+ and Pb2+ which may provide theory basis for chitson as heavy metals adsorbent.

Abstract:Chlorella vulgaris,an unicellular microalgae,displays high growth rate under autotrophic and heterotrophic conditions.In addition,C.vulgaris has been proved to possess a good tolerance to high levels of Se based on the previous study,which indicates that the alga is a good hatcher for organic selenium conversion.However,few researches on the biological effects such as the alga growth,the Se conversion,the intracellular enzymes and the species of organic selenium of C.vulgaris exposed to Se were reported.Hence,some biological effects of the alga after exposure to Se(Ⅳ)were investigated in this study. C.vulgaris was cultured and exposed to selenium(Na₂SeO₃)at different concentrations(0,5,10,20,30 mg/L).For investigating the influences of Se on the algal growth and the biochemical effects,the biomass,the intracellular selenium contents,the activities of glutathione peroxidase(GSH-Px)and superoxide dismutase(SOD),and the Se species in cells were assayed,respectively.The results showed that high level(30 mg/L)of Se would inhibit the growth or even facilitate the death of the alga.The total intracellular selenium contents,and the activities of GSH-Px increased with the increase of the selenium concentrations.For example,the activities of intracellular enzymes under the stress of Se at 5,10,20,30 mg/L were 5.59,6.98,11.32,11.52 times compared with those of the control groups.But the activities of SOD increased only when the concentration of stressed Se was more than 20 mg/L.Three main species of intracellular selenium,analyzed with a hyphenated method of SE-HPLC-ICP-MS,were found in C.vulgaris exposed to Se.About 16% of organic selenium was found to be converted in C.vulgariswhich is hopeful to be used as a good biohatcher for the conversion of organic selenium.

Abstract:The spottedtail goby,Synechogobius ommaturus(Richardson)is a large,commercially important,benthic fish in the family Gobiidae,which inhabits Asian inshore waters of the Northwestern Pacific,from Japan and China to Indonesia.With the development of fishery resource,S.ommaturus is becoming an important marine food and will face higher fishing pressure.It is,therefore,very important to investigate the genetic variance and population structure of this species in order to provide the background information for the management of the species.Until now studies on S.ommaturus mainly focused on the biology and chromosome,and there are no genetic investigations for this fish.In the present study,genetic diversity of S.ommaturus and genetic differentiation between two geographical populations were analyzed.A 478 base pair(bp)fragment of the hypervariable portion of the mtDNA control region was sequenced and sequences were edited and aligned by DNA Star software.Genetic diversity indices such as number of haplotypes,polymorphic sites,transitions,transversions,indels,haplotype diversity,nucleotide diversity and the mean number of pairwise differences were obtained using the program Arlequin version 3.0.A NeighbourJoining(NJ)tree of the control region haplotypes was constructed using MEGA 3.0 and evaluated with 1 000 bootstrap replicates,and Acanthogobius flavimanus was served as the outgroup.Genetic differentiation between two populations was evaluated with the pairwise fixation index F_ST by Arlequin version 3.0.Historical demography of S.ommaturus was examined by neutrality tests and mismatch distribution analysis.The results of present study showed that haplotype diversity(0.006 3±0.003 8),nucleotide diversity(0.889 5±0.050 8)and the mean number of pairwise differences(3.000 0±1.634 3)of Dandong population were higher than those of Tianjin population.The topology of the NJ tree rooted with the outgroup A.flavimanus was shallow,and there were no significant genealogical branches or clusters corresponding to sampling localities.The pairwise fixation index F_ST (0.239 5)revealed significant genetic differentiation between these two populations.The exact test of population differentiation(non-differentiation exact Pvalues)following sequential Boferroni correction showed significant differences(P<0.01)among two populations,which rejected null hypothesis.Both mismatch distribution analysis and neutrality tests showed that S.ommaturus has experienced a recent population expansion.The observed value of the age expansion parameter(τ)was 2.508 and the time since population expansion was estimated to be 52 400-104 900 years ago.During the glacial period,with the decline in sea level,most of the Chinese continental shelf was exposed and the distribution of S.ommaturus would have been displaced to the south.These surviving individuals may have recloned north with the rise in temperature.The results suggested that the Pleistocene ice ages had a major effect on the present genetic structure of S.ommaturus. Apart from historical events,environmental factors were believed to be the important factors for shaping the contemporary phylogeographic pattern of S.ommaturus and there are some barriers to prevent gene flow between Dandong and Tianjin populations.

Abstract:Based on the data collected from the fishing ground of tuna longliners in the Southerncentral Indian Ocean during September 2008 to April 2009,the present study compares and analyzes the catchability and selectivity to hooking species for 3 hook types(traditional tuna hook,“J”type hook and circle hook).The results show that (1) for traditional tuna hook,the proportion of bigeye tuna(Thunnus obesus,BET)and blue shark(Prionace glauca,BLS)is higher than other species in the catch composition and “J”type hook and circle hook have a similar hooking proportion for the above two species,however,for albacore(Thunnus alalunga, ALB),the traditional tuna hook has the highest hooking proportion and followed by “J”type hook and circle hook.(2) the traditional tuna hook has the highest survival rate and the “J”type is lowest for BET,the survival rate of “J”type hook is slightly higher than that of circle hook and the traditional tuna hook is the lowest for ALB,the survival rate of circle hook is highest and followed by traditional tuna hook and “J”type hook for BLS.(3) the average fork length(FL)of ALB for “J”type hook is slightly larger than that of traditional tuna hook and circle hook,traditional tuna hook is larger than circle hook and “J”type hook for BET and “J”type is larger than circle hook and traditional tuna hook for BLS.(4) significant difference has not been found for the FL distribution of ALB,BET and BLS for 3 hook types.

Abstract:Using PCR amplification and sequencing,642 bp of cytochrome c oxidase subunitⅠ(COⅠ)partial sequences and 1 138 bp of Cytb partial sequences were obtained from Oplegnathus fasciatus.In COⅠ sequences,a total of 21 polymorphic sites defined 11 distinct haplotypes.And 4 transition loci,5 transversion loci and no insertions and deletions were found in them.The average content of A,T,G and C was 24.5%,30.6%,18.8%,and 26.1%,respectively.In Cytb sequences,26 polymorphic sites and 11 haplotypes were defined,and 4 transition loci and 3 transversion loci were found.The average content of A,T,G and C was 24.9%,28.3%,14.8% and 32.0%,respectively.The mean haplotype diversity(Hd),nucleotide diversity(Pi),and the average number of nucleotide difference(K)in COⅠ and Cytb sequences were 0.795,0.008 83,5.667 and 0.770,0.003 54,4.025,respectively.The results suggested that both COⅠ and Cytb gene showed high level of genetic diversity in O.fasciatus.These results provide basic information for the genetic resource protection and phylogenetic study of this species.

Abstract:Migratory route of the greater yellow croaker,Larimichthys crocea,in the the East China Sea(ECS)and the Yellow Sea(ESYSP)was re-analyzed with fishing data collected during 1971-1982.Only one population,the ECS-ESYSP population was determined in the sampling areas.Two wintering grounds of the population were located,the offshore wintering ground lies in the waters of 30°00′-32°00′N,124°00′-126°00′E,and the nearshore wintering ground lies near the outside of the forbidden fishing zone line in the midsouthern ECS.The offshore group began spawning migration during March and April towards the waters of west Zhoushan islands and Changjiang estuary,in which they merged with the fishes,come from the nearshore group from the mid-southern ECS.Some continued to migrate northward into the waters of the Lvsi Fishing Ground,some westward to the waters of Daiquyang,Huangzeyang and Damuyang near the Zhoushan islands for spawning in May.After spawning,these fish groups moved north-east to nearshore waters of the south Yellow Sea for feeding and growing.They finally came to 34°00′N waters near the forbidden fishing zone line in September.Under the influence of cold northwest monsoon after October,the population returned to the Changjiang Estuary.From there,fishes split into two major groups,one swam eastward back to wintering ground in offshore waters,the other moved back to the wintering ground in nearshore waters in the mid-southern ECS.The parts of group wintering in waters of the mid-southern ECS to and fro between wintering grounds and nearby spawning grounds,such as the waters of the Maotouyang in Sanmen Bay,the Dongtouyang at Oujiang Estuary,and the Guanjingyang in Sansha Bay.The groups grew up in waters nearby the spawning ground.

Abstract:The lipopolysaccharide and beta1,3glucan-binding protein(LGBP)is a pattern recognition receptor which is fundamental for the innate immune response of crustaceans.A pair of primers were designed according to LGBP cDNA and were used for ORF amplification.Then the fragment was subcloned into pET-22b(+)and expressed in Escherichia coliBL21(DE3)plysE.We got a 41 ku clear visible band in the expected position by SDSPAGE detection,which indicated that it was the same as the expected molecular weight,and the negative controls were blank.Expression of recombinant protein induced under different conditions indicated that lower concentration of IPTG(0.4 mmol/L)and lower temperature 30 ℃ could reduce the expression of background effectively by SDS-PAGE detection.The purified recombinant protein was used as antigen to prepare antiserum in mouse directly.Four weeks later,a polyclonal antiserum was obtained and it was specified by Western-blotting analysis.At last,three types of Gram-negative bacteria(Vibrio parahaemolyticus, V.alginolyticus, E.coli),four types of Gram-positive bacteria(Bacillus subtilis,B.megaterium,B.cereus,S.aureus)and one fungus(Sac charomyces cerevisiae)were utilized to analyze pET-LGBP binding activity.Our data suggested that pET-LGBP was able to bind S.cerevisiae,B.megaterium,V.Parahaemolyticus,V.alginolyticus and E.coli.

Abstract:Viral infection is one of the major causes for the huge economic losses in shrimp farming.A multiplex reverse transcription polymerase chain reaction(mRT-PCR)was developed for simultaneous detection of 4 major shrimp viruses including infectious hypodermal and hematopoietic necrosis virus(IHHNV),Taura syndrome virus(TSV),white spot syndrome virus(WSSV)and yellowhead virus(YHV)in this research.Four sets of specifically designed oligonucleotide primers were used in the assay and each of them could amplify viral nucleic acids by PCR products with different sizes,such as:508 bp for TSV,435 bp for WSSV,301 bp for IHHNV and 614 bp for YHV.Specificity of multiplex RT-PCR nucleic acids of individual virus amplified in PCR reaction containing 4 primer sets were performed and they were highly specific and no specific bands were amplified from other penaeid shrimp pathogenic bacteria.Multiplex RT-PCR for detection of two,three or four types of different viruses in a single reaction system,the corresponding DNA samples of IHHNV(I)and WSSV(W)and cDNA of TSV(T)and YHV(Y)were randomly mixed and amplified using four primer sets.The sensitivity of the multiplex RT-PCR was 0.1 pg for IHHNV,1 pg for TSV,0.02 pg for WSSV and 0.2 pg for YHV.In the field application,49 samples were examined by multiplex RT-PCR.The results were consistent with those results of the single PCR detection.It indicated that this multiPCR method is superior in terms of sensitivity,specificity rapidity and simplicity,and is potentially a valuable diagnostic tool for shrimp viral infections.

Abstract:Amplified fragment length polymorphism(AFLP)technique was applied to assess the genetic variation among 4 fast growth families of Tegillarca granosa(J5♂×Z19♀,Z7♂×J26♀,S1♂×Z3♀,S6♂×Z22♀)so as to establish and select superior families. A total of 506 AFLP loci amplified with 9 pairs of primers were obtained from 124 individuals,and the polymorphic loci percentage reached 72.53%.The percentage of polymorphic loci of 4 families ranged from 51.14% to 60.75%.Nei’s genetic diversity index and Shannon’s genetic information index of 4 families indicated that the level of genetic diversity from high to low was J5♂×Z19♀＞S6♂×Z22♀＞S1♂×Z3♀＞Z7♂×J26♀.The gene differentiation coefficient G_ST value and AMOVA analysis indicated that the genetic variation mainly came from individuals within families.Genetic division coefficient F_ST (0.383 7)indicated that there was certain genetic differentiation that existed among the four families.Cluster analysis by NJ and UPGMA methods based on genetic distance revealed the relationship between 4 families.S1♂×Z3♀ and S6♂×Z22♀ were clustered together firstly because of the nearest genetic relationship(0.089 6),and then clustered with Z7♂×J26♀.J5♂×Z19♀ was not clustered into any clade because the phylogenetic relationship between J5♂×Z19♀ and other families were more distant(0.120 1-0.125 4).Additionally,of all 506 detected bands,40 family-specific bands were found to distinguish the four families from each other.Therefore,superior family could be selected from optimum breeding pairs of high level of genetic diversity which would be good for genetic improvement of T.granosa,by analyzing genetic structure of reproductive families.

Abstract:Influences of vacuum packaging(VP),air packaging and modified atmosphere packaging(M1,50%CO₂+50%N₂;M2,75%CO₂+25%N₂)on the quality of surimibased product fish balls were studied in refrigeration(3±0.5) ℃ storage.Microbiological(total viable counts,Micrococcus,Photobacterium phosphoreum,lactic acid bacteria, Pseudomonas andSaccharomyces)analysis,chemical and physical indices(pH,TVB-N,whiteness,hardness,springiness and chewiness)test and sensory evaluation were performed.The microbiological analysis results showed that the dominant microbial floras of the fish balls were Micrococcus,Photobacterium phosphoreum and lactic acid bacteria,and the secondary floras were Pseudomonas,Saccharomyces under air packaging or vacuum packaging.Photobacterium phosphoreum and, lactic acid bacteria took the first account of floras followed by Micrococcus in fishballs with MAP1 and MAP2.Compared with the fish-balls packaged by vacuum or air,the samples packaged by modified atmosphere had more positive value in microbiology counts,TVB-N value,pH,whiteness and sensory value.The effect of different packagings on the quality of the fish balls at (3±0.5) ℃ followed the order:75%CO₂+25%N＞50%CO+50%N＞VP＞Air,and the shelflife was 49 days,42 days,21 days and 14 days,respectively.

Abstract:Single nucleotide polymorphism(SNP)has very broad prospects in the research fields of population genetics of aquacultural species,molecular marker-assisted breeding and biological evolution.The development of SNP markers is normally obtained through genome sequencing,by sequence comparison.However,for the species for which no large-scale genome sequencing has been carried out,using EST database is often an important way for the development of SNP markers.In this study,the SNP genotyping assays and development of SNP markers for blue mussel(Mytilus galloprovincialis)were conducted through expressed sequence tags(ESTs)database mining.Some 19 709 EST sequences of blue mussel from the GenBank were clustered into 2 486 contigs,of which 963 contained four or more ESTs.After manual quality filtering,4 833 putative SNPs were identified from these SNP-containing contigs.The average putative SNP frequency was one per 129.2 bp of contig sequences.C/T and A/G with high frequency account for 28.8% and 27.4%,respectively.31 of the putative SNPs were chosen for validation by allele specific PCR with melting temperature(T_m)-shift analysis,and 14(47%)of them were polymorphic with the minor allele frequency ranging from 0.083 to 0.446.The observed heterozygosity and expected heterozygosity were distributed from 0.166 7 to 0.615 4 and 0.155 4 to 0.503 2,respectively.Six primers(20%)amplified no any product and 10(33%)were monomorphic.BLASTX showed that significant hits for all 14 genotyped SNP-containing contigs,12 of which were located in coding regions and all resulted in a synonymous substitution.The result of present study shows that ESTs could provide effective means for SNP identification in species with limited genome sequence resources,and T_m-shift analysis is a simple,efficient and reliable SNP genotyping method for non-model organisms.

Abstract:The ultrastructure of spermatozoon and the cytological change of fertilization process in Meretrix lamarkii were systematically studied by electron microscope and fluorescence microscope.The results indicated that the mature spermatozoon(45.2-47.7 μm in total length)of M.lamarkii, belonging to the primitive type,consists of head,middle piece and tail.The head,like a long cocoon in shape(2.5 μm in length),is composed of acrosome and nucleus.The acrosome is conical in shape and has a subacrosomal space inside.Nucleuses are cylindrical with finegrained dense chromatin,having front nuclear pocket and posterior nuclear pocket.The centriolar complex,including proximal and distal centrioles,and surrounding 5 spherical mitochondrias,make up the short middle piece.The tail,a whiplike flagellum,consists of axoneme that is a typical “9+2” microtubular structure and wrapped by an wavy plasma membrane.The cytological change of nuclear behavior during fertilization and early cleavage was observed under the fluorescence microscope.Like most of marine mollusks,the unfertilized mature eggs of M.lamarkii were globular and remained at the metaphase of the first maturation division.At water temperature of 27-28 ℃,artificial insemination was conducted.6 min after fertilization,sperm has penetrated into cytoplasm of egg and activated the maturation division.The fertilized eggs released the first polar body about 12-15 min and the second polar body about 20-25 min after fertilization.About 30 min,sperm nucleus and the haploid female nucleus developed into the male and female pronuclei.35 min,the male and female pronuclei matched into an association nucleus after their chromosomes formed respectively in the center of egg.40-45 min,the chromosomes were separated equally into two daughter cells which are different obviously in size.55-60 min,the second cleavage finished and formed four daughter cells,one big and three small.The process of the second cleavage was fundamentally similar to the first cleavage.75-80 min,the third cleavage which belongs to the type of spiral holoblastid cleavage was completed.In addition,the polyspermy with an incidence of about 1% in the process of fertilization was also observed.Though the polyspermy didn’t affect the formation of male pronuclei,it significantly affected the process of the maturation division and the first cleavage as a result of abnormal chromosome division.

Abstract:The yield of freshwater fish has reached more than 20 million tons in China,accounting for about 50% total output of the world fisheries production.The proportion of aquatic product processing is about 80% in developed countries,while the proportion of deep processing of aquatic products in China is only 30% out of total production.Low percentage of freshwater fish deep processing,which has only about 10%,is mainly because of its unpleasant earthy flavor and lack of attraction to many consumers.Thus,the study of earthy taste and odor of freshwater fish not only enriches the theoretical knowledge of flavor chemistry,but also provide an effective solution to the current situation of low proportion of fish processing.Grass carp is one of the most major freshwater fish species in China.In this paper,the different parts of cultured grass carp were used as research object which were killed by exsanguinations or knockhead.The volatile compounds in different parts of grass carp meat were compared by electronic nose.The volatile compounds of grass carp meat were extracted and concentrated by solid phase micro-extraction(SPME).Then the volatiles were identified by gas chromatographymass spectrometry(GC-MS).The results of electronic nose showed that exsanguination had effect on the volatile compounds of dorsal meat and belly meat,and little effect on red meat of grass carp.There are 27,29 and 47 kinds of volatile compounds identified in dorsal meat,belly meat and red meat of grass carp killed by exsanguination,respectively.Meanwhile,there are 42,41 and 43 kinds of volatile compounds identified in dorsal meat,belly meat and red meat of grass carp killed by knockhead,respectively.Among these components,most of them were volatile carbonyl components and alcohols and their content is above 90%.The results also show slaughter measure had effect on the volatile compounds of dorsal meat and belly meat,and little effect on red meat of grass carp.There are 46 kinds of volatile compounds identified in blood of grass carp,among them 34 kinds are aromatic hydrocarbon and the relative content could reach 75.59%.Therefore,the exsanguination was suggested to apply ahead of processing and consumption of grass carp which will improve food safety and product flavor.

Abstract:Time of sex differentiation,as well as effects of 4-nonylphenol(NP)on growth and sex differentiation in juvenile Macrobrachium rosenbergii were studied by morphologic observation and histological sections.Ten zoea were collected randomly every 3 days,fixed in Bouin’s solution,then embedded in paraffin and sectioned.Transverse sections were stained with hematoxylin and eosin to identify its sex differentiation time.Juvenile M.rosenbergii were divided into 5 groups(n=200 per group):control,5,15,45,and 135 μg/L NP,respectively.All these juvenile M.rosenbergii were immersed in different doses of NP solutions for 30 days,and 50% NP solutions were renewed every 2 days to keep NP’s steady concentration.Ten juvenile M.rosenbergii were collected randomly from each group on 15,20,25,and 30 d,and both the body mass and length were measured respectively for the assessment of NP on growth.Thirty juvenile M.rosenbergii were collected randomly from each group on 30 d to identify their sex by outward features(gonopore,appendix masculine,etc)under anatomical lens,and 10 were fixed,embedded and sectioned to observe its gonad histology.Data were subjected to oneway analysis of variance followed by Duncan’s multiple rang test.Results showed that primordial germ cells(PGCs)appeared in 15 d larva; however,genital duct,a wrinkled and pimply plastron,and a sunken basal part on the 4^{th-5th walking legs appeared in 24 d larva in some M.rosenbergii.In addition,a rudiment of the appendix masculine on the internal of the 2nd-pleopod was found in 45 d larva in some M.rosenbergii,and gonads could be identified easily as testis and ovary,respectively. M.rosenbergii larvae were not affected in their body weight and length if treated by NP less than 15 d,however,they were inhibited significantly in a dosedependent manner if treated more than 20 d(P<0.05).Spermatogonium and oogonium were observed respectively in the testis and ovary in the control group on 30 d,however,gonads unidentified as male and female were found in the NPtreated groups,and the quantity of sex-unidentified M.rosenbergii increased with the doses of NP.Results suggested that the time of sex differentiation of larval M.rosenbergii occurred between 21 to 45 d larva and the change of external forms occurred before that of the internal forms.Furthermore,growth and testis development were inhibited possibly because of NP interfering with the processes of molt and vitellogenin synthesis.}

Abstract:Shrimp proteins have been recognized as an important source of food allergens.The objective of this study was to analyze the immunocompetence and texture changes of shrimp allergen after different thermal processings.In this study,three heat methods were chosen to investigate their impacts on the immunocompetence of shrimp allergen,which included boiling,steaming,and autoclaving.After four different heating time,the total proteins and content of the major allergen were profiled by sodium dodecyl sulfate polyacrylamide gel electrophoresis(SDS-PAGE).The changes of immunocompetence of shrimp allergen were determined by Western-blotting and ELISA.In the meantime,texture profile analysis(TPA)was adopted to compare the quality changes of the processed shrimps.The results showed that the major allergen protein was still present in all of the total proteins of shrimps.Moreover,there was a new protein with molecular weight of 25-35 ku,which took on high immunocompetence.However,based on the results of Western-blotting and ELISA,the immunocompetence of the allergen protein was all reduced after the three thermal processings.In addition,different processings had different impact on the immunocompetence.Among the three methods,autoclaving had the best reducing effect towards immunocompetence of shrimp allergen.Cooking 5 min with autoclave could reduce 78% of the immunocompetence,while boiling and steaming for the same period could reduce 53% and 23% of the immunocompetence respectively.Moreover,when the autoclaving time was extended to 30 min,97% of the immunocompetence was lost.Nevertheless,the results of TPA showed that the quality of shrimp had been destroyed during the autoclaving.The rigidity and chewiness of the shrimp was greatly reduced after the autoclave processing.It is concluded that autoclave can greatly reduce the immunocompetence of shrimp major allergen protein at the expense of destroying the texture.The parameters of the autoclave are suggested to be optimized to reduce the immunocompetence and keep good texture and nutrition.

Abstract:To evaluate effectiveness of enhancing and restocking stock of sea cucumber Apostichopus japonicus,it is necessary to find an effective and secure way to mark sea cucumber’s soft body wall which rejects external objects and heals up quickly.In this study,juveniles of sea cucumber(3.45±1.34) g were immersed in calcein(200 mg/L)for 24 h,and their ossicles were examined under Nikon 80i fluorescence microscope to judge calcein’s effectiveness.Then,influence of calcein concentration(normal concentrations including 50,200,400 mg/L;and high concentrations including 500,750,1 000 mg/L)and immersion time(8,24,48,72 h)on antioxidant enzymes SOD,CAT,and GSH-Px were studied to test its security.The results revealed that ossicles in upper layer of dermis of sea cucumber’s body wall,tentacle,podia and parapodia could be dyed by calcein,and showed green under fluorescence microscope with optical filter(λ:Ex 450-490 nm)7 days after being immersed in calcein solution.Brightness of stained ossicles was diversified because of immersion duration and ossicles’ maturation degree.In this study,both normal and high concentrations of calcein had no significant impact on activities of SOD and GSH-Px(P>0.05),while activity of CAT was restrained in 1 000 mg/L concentration treatment(P<0.05).Immersion duration had significant impact on activities of all three enzymes.Activity of SOD was significantly lower in the 72 h treatment than in other ones(P<0.05);activity of CAT declined with increasing immersion duration; and activity of GSH-Px in the 24 h treatment was significantly higher than in the 48 h one(P<0.05).Interaction between immersion duration and calcein concentration had significant impact on activities of SOD and CAT(P<0.05),and showed no significant effect on that of GSH-Px(P>0.05).The result indicated that calcein concentration lower than 750 mg/L and immersion time around 24 h influenced activity of all three enzymes less and marked ossicles effectively for examining.It is still necessary to take other factors such as oxygen into consideration for sea cucumber’s survival.

Abstract:According to the field sampling survey and data analysis,the fuel consumption of China marine fishing vessels is 6.37 million tons per year,trawler and gillnetter are the major fuel consumers,and account for 58.8% and 22.2% in fuel consumption respectively; the calculated total fuel consumption of China fishing vessels is 7.90 million tons per year,the total energy consumption in the field of fishery production amounts to 17.54 million tons of Standard Coal Equivalent,in which fishing,aquaculture and aquatic products processing account for 66%,21% and 13% respectively.Using per 10 000 YUAN production value as the indicator,the level of energy utilization of fishery and its major areas were analyzed comparatively.Based on the comprehensive analysis of the overall level of China fishery energy saving & emission reduction,this paper pointed out that the main areas for the reduction of energy consumption is trawler and gillnetter,and the main area for controlling fishery discharge is pond culture and industrial aquaculture; and the standardized fishing vessel technology,GFRP fishing vessel technology and recirculating aquaculture technology are the main technical supports to promote fishery energy saving & emission reduction.This paper also introduces the general situation of the energy saving technologies and measures in European fishing industry,and puts forward the proposals for the fishery development objectives and key measures.

Abstract:Porphyra haitanensis is an economically important marine crop in southern China.Due to global warming it is highly desirable to select or breed new lines of P.haitanensis that can tolerate higher water temperatures; and to use these for cultivation.We observed the physiological responses of gametophytic blades of an F₄ high temperature tolerance line(Z-61)and a wild-type line.These were grown at normal temperature(21 ℃),and at high temperatures(26 ℃ and 30 ℃),for 0,2,4,6,8,and 10 days.Changes in physiology were measured,including free radical content,H₂O₂,malondialdehyde(MDA)and proline levels,and also the activities of superoxide dismutase,peroxidase,and catalase.Physiological changes within the Z-61 gametophytic blades were as follows:high temperature stress→levels of reactive oxygen species(ROS)increased→cell membranes were damaged by oxidation and MDA levels increased→cells received signals of excessive ROS→antioxidation and osmoregulation systems began to clean out excessive ROS→free radical levels declined.We compared the responses of Z-61 and wild-type lines to high temperatures.The Z-61 line is able to initiate both antioxidation and osmoregulation.The wild-type line,however,can only initiate osmoregulation when under high temperature stress.The background activities of the antioxidation systems also show notable differences between the two types.These differences may be the cause that the wild-type is not able to tolerate high temperatures.Our results may lay a foundation for understanding the principles of high temperature tolerance in P.haitanensis,and may suggest some directions for future breeding.

Abstract:In this study,the amount of damage to Porphyra yezoensis by ultraviolet radiation(UVR)was assessed by analyzing the photochemical efficiency and pigment concentration between different blade parts under laboratory conditions.All parts of the blade were exposed to either PAB(PAR+ UV-A+UV-B)(280-700 nm)a full spectrum or partial PAR(395-700 nm)spectrum using cutoff glass filters.It was observed that PAB caused a more significant decrease in the optimal photochemical efficiency than PAR in all blade parts,followed by a lower recovery toward the initial values.Marked differences of the optimal photochemical efficiency between all parts of blade under UV exposure were observed.Apical parts were more resistant but had quicker recovery,basal parts were more sensitive to PAB and had slower recovery.After different radiation treatment,phycoerythrin(PE)and phycocyanin(PC)are more sensitive to PAB treatment and increased significantly in all parts of blade.The PE and PC contents of apical parts had extreme increase,while no remarkable differences of Chlorophyll a and carotenoid were observed.Determination of mycosporine-like amino acids(MAAs)before and during exposure to solar simulated irradiation showed no remarkable differences.The MAAs contents increased from basal to apical parts.Above all,the different parts of Porphyra yezoensis displayed bigger dissimilarity in the photosynthetic physiology characteristics.We presumed that the strategies to cope with UV radiation may including sheltering effect,accumulateing UV absorbing substance and dynamic photoinhibition.

Abstract:In order to optimize the indoor culture conditions of growth and synchronous reproduction of Sargassum thunbergii, young seedlings with 5 cm length were used as materials to investigate the effects of different temperatures(15,20,25 ℃),illumination intensity［60,100,160,200 μmol/(m²·s)］and nutrient ratio［KNO₃(mg)∶KH₂PO₄(mg)=10∶1,5∶1,1∶5,1∶10］on the growth and sexual reproduction synchronization by measuring the growth index,observing the morphological changes as well as the formation of reproductive organs and reproductive characteristics.This investigation focused on the optimal combinative conditions of indoor growth,reproduction of seedlings,early development of receptacles and synchronization of fertilization.The results indicated that the gradation of different environment factors that influenced the length growth rate of S.thunbergii was temperature>nutrient ratio>illumination intensity,and the factors that influenced the growth rate of mass was temperature>illumination intensity>nutrient ratio.Low temperature could induce the rapid emergence of pneumathode.The formation of branchlets had more relation to nutrient ratio and in general,the higher proportion of KH₂PO₄ in nutrients resulted in later emergence of branchlets.Temperature effect was more significant for receptacles emergence time in our results and zygotes formation and release were also regulated by temperature conspicuously.The higher the culture temperature,the slower the growth rate of receptacles and the later the time of egg fertilization.The pigment content decreased with increasing the illumination intensity.Using culture conditions control for the alga thalli,indoor culture of this species could be done 3-4 months earlier than thalli matured in nature to complete its life cycle.For mature thalli of 1g wet,an average of about 300 seedlings could be collected from the substrate well.So it was possible that the generation of different positions and organs of S.thunbergii could be induced by controlling the culture conditions in laboratory to achieve early development of receptacles and synchronization of fertilization.The data could be used for theoretical and practical references for the technical route of large-scale cultivation of highquality S.thunbergii seedlings.