Abstract:Exogenous sex-steroid hormones and Letrozole(LE),a potently synthetic nonsteroidal aromatase inhibitor(AI),interfere in the committed step of the endogenous estrogens synthesis.In the present study,the efficacy of 17α-Methyltestosterone(MT)and Letrozole(LE)on gonad steroidogenic enzyme gene expression was evaluated in Nile tilapia(Oreochromis niloticus).The genetically female tilapia were treated with 17αMethyltestosterone and Letrozole(at a dose of 10 mg/kg).Expressions of cytochrome P450 aromatase(P450arom),11β-hydroxysteroid dehydrogenase type 2(11β-HSD₂)and cytochrome P450 cholesterol-side-chain-cleavage(P450scc)were examined in the gonads after injection treatment for 12 hours,24 hours,48 hours,7 days,14 days and 21 days,respectively.The results showed that the levels of P450arom,11β-HSD₂ and P450scc mRNA were decreased rapidly compared to the untreated group firstly,and then the mRNA levels of the three genes increased to the levels of pretreatment.In the MT-treated group,the mRNA levels of P450scc were first decreased,followed by P450arom and 11β-HSD₂.While in the LE-treated group,the mRNA levels of P450arom and P450scc were firsted decreased,followed by 11β-HSD₂.These results indicated that exogenous androgen or aromatase inhibitor treatment suppresses the expressions of key steroidogenic enzyme genes including P450arom,11β-HSD₂ and P450scc in the female tilapia.Furthermore,it shows that MT may indirectly inhibit the expression of P450arom,while LE directly inhibits the expression of P450arom,and further influences the sex-inversion of fish.The present study suggests that besides steroid hormones,nonsteroidal compounds,such as aromatase inhibitors,have potential for production of monosex population in tilapia.

Abstract:Chinese shrimp(Fenneropenaeus chinensis)is one of the most important aquaculture animals in China.The studies on the innate immune responses of shrimp,especially on immune defense against the main crustacean pathogens,will provide more knowledge of shrimp immunity to prevent infectious diseases.Arthropod innate defence responses［e.g.prophenoloxidase(proPO)activation and Toll pathway initiation］and many other biological processes are mediated by serine proteinase(SP)cascades.If the activity of SPs is out of control,it will be fatal to organisms.Serine protease inhibitors(SPI)play a critical role in precise regulation of SP activity,and also directly participate in the selection and digestion of pathogen.One of the well known SPI is the Kazal-type SPI which are usually multi-domain proteins containing more than one Kazal domain.Each domain contains 50-60 amino acids with six cysteine residues forming a 1-5,2-4,3-6 disulphide bridges resulting in a characteristic three-dimensional structure.The inhibitory specificity of a Kazal domain varies with a different reactive P1 amino acid,which is the second amino acid after the second Cys.However,the knowledge about the Kazal-type SPI in aquatic animals’ innate immunity is limited.In this paper,the fragment encoding the Kazal-type SPI(Fc-Kazal)mature peptide was amplified.It was predicted that the mature peptide was composed of 114 amino acids with a calculated molecular mass of 16.25 ku and a theoretical isoelectric point of 8.9. Fc-Kazal contains two tandem Kazal domains.Each of the domain contains six conserved cysteine residues forming three disulfide bridges(C1-C5,C2-C4,C3-C6),which are identical to those of the classical Kazal-type proteinase inhibitor family members.Semi-quantitative RT-PCR revealed that transcripts of Fc-Kazal were highly expressed in the gills,haemocytes and lymphoid organ.Low expressions could be found in the heart,intestine and hepatopancreas.No expressions were observed in eyestalks,ventral nerve cord and muscle.The recombinant protein was expressed by pCR^?T7/NT TOPO^?TA system.The result showed that the fusion protein(rFc-Kazal)was expressed in the form of inclusion bodies.The LC-ESI-MS analysis showed that three peptide fragments of rFcKazal were identical to the corresponding sequence of Fenneropenaeus chinensis Kazal-type proteinase inhibitor(GI83638451).Fusion protein was purified by immobilized-metal affinity chromatography and Ni-NTA technology.The concentration of purified rFc-Kazal was 0.4g/L.The effect of refolded rFc-Kazal on bacteriostatic activity was assayed in this research.The results indicated that the rFc-Kazal has antimicrobial activity against Vibrio anguillarum,Staphylococcus aureus,Aeromonas salmonicida andBacillus thurigiensis.The results reveal that FcKazal may play an important role in the innate immunity of the shrimp.

Abstract:Based on 8 morphological characters between Japanese Meretrix lusoria and two Chinese species of Meretrix,by means of multivariate morphometrics and traditional taxonomy methods,and then we analyzed with One-Way ANOVA,principal component analysis,cluster analysis,discriminant analysis and Mantel test for investigating morphological variations among them and evaluated Japanese M.lusoria species validities.Results and inference are as follows:(1) One-Way ANOVA showed that there were 5-8 significant differences among 8 morphological characters between Japanese M.lusoria and two Chinese species of Meretrix(P<0.05).(2) Results of cluster analysis showed that six M.meretrix populations formed a separate cluster,among which,the southern populations were a cluster while the northern populations were another.Japanese M.lusoria was close to Changle M.lusoria.(3) In principle component analysis,three principle components were constructed by factor loading.The contribution ratios of four principle components were 34.88%,18.61%,16.89%,respectively,and the cumulative contribution ratio was 70.38%.The three dimensional Scatter diagram further indicated that Japanese M.lusoria and Changle M.lusoria had no overlap with the different M.meretrix populations.(4) Eight discriminant functions of Japanese M.Lusoria and two Chinese species of Meretrix were established,and the discriminant accuracy was 39.09%-100% for P₁ and 47.06%-100% for P₂.The average diseriminant accuracy was 70.60%.The discriminant accuracy of Japanese M.lusoria was 100% and that of M.lusoria was above 91.67%.(5) Results of Mantel test showed that geographical distance and Euclidian distance of all Meretrix populations were significant(r=0.623 7,P<0.01).Above results indicate that Japanese M.lusoria and Changle M.lusoria should belong to M.lusoria,which were the different geographical populations.According to the MAYR 75% rule,the results indicated five out of eight morphological characters were above 1.28,so the difference of the two M.lusoria populations was greater than difference between subspecies.

Abstract:During the process of maturity,a clear change occurred in using food resources with the development of fishes.There is usually an obvious niche shift in different ontogenetic stages,and the living environment and food groups would be converted with the increase of body size.Traditionally the method which is used for food shift is to analyze the contents in stomach and intestines,however,it could not completely show the location of fishes in food web as well as food source.In recent years stable isotopic way has been widely used to research food types of animals in different environments.The stable carbon isotope composition of consumers is able to show where the foods derive from,while the nitrogen isotope composition can show the position of trophic levels in food web.Mongolian culter(Erythroulter mongolicus mongolicus),which is one of the main economic fishes in Xiaojiang River after the ThreeGorges Reservoir accumulated water,plays an important role in aquatic ecosystem.The diet shift of Mongolian culter in various ontogenetic stages has a deep impact on the aquatic ecosystem.Therefore,based on the stable isotope analysis,combined with the identification of contents in stomach and intestines,we herein discussed the Mongolian culter food groups from Quma town and Huangshi town along the Xiaojiang River region so as to provide a theoretic basis for the management of Xiaojiang fishery resources and enhancement and releasing.Our results indicate that the δ¹³ C and δ¹⁵ N values of small Mongolian culter whose length is less than 200 mm are(-24.50‰±1.15‰) and (12.17‰±1.54‰) respectively,they are carnivorously omnivorous with 2.9 of trophic level; those big ones of more than 200 mm in length are(-23.87‰±1.12‰) and (13.54‰±1.12‰) respectively,their trophic level is 3.3 and diet type is carnivorous.The fact that the δ¹³ C and δ¹⁵ N values of large Mongolian culter are significantly higher than that of small ones(P<0.01), showing that a diet transfer took place during their growth,but there is an overlap of isotope values between large and small Mongolian culter for their sharing the foods from the same source.This study helps to predict the “topdown effect” caused by the enhancement and releasing of fishes and a variety of fisheries resources management activities such as fishery capture in Xiaojiang River region.

Abstract:Acute viral necrosis virus(AVNV)was reported as one causative agent responsible for summer mass mortality of adult Zhikong scallop(Chlamys farreri),which is widely cultured along northern China coast.To explore its pathogenesis at the molecular level,we cloned a gene which was predicted to encode AVNV dUTPase based on the genomic sequence of C.farreri AVNV completed by our laboratory.The gene encodes a protein of 248aa with a predicted molecular mass of 26.4 ku.To obtain the C.farreri AVNV Open Reading Frame 074,which probably encodes AVNV dUTPase,a pair of specific primers was designed based on the genomic sequence of C.farreri AVNV.Then this paper amplified the expected DNA by PCR,using the total genomic DNA extracted from infected C.farreri tissues as template.Amplified PCR fragments were subcloned into the prokaryotic expression vector pET-32a(+).After that,we transformed the recombinant plasmid pET32a-dut into E.coli BL21(DE3)strain and expressed it under IPTG induction.SDS-PAGE analysis showed that the molecular mass of the induced recombinant protein was about 46 ku.The Western-blotting and mass spectrometry analysis proved that the expressed protein is the target protein.Then we purified recombinant protein with Co²⁺ purification column and got the recombinant protein with a purity of more than 90%.The analysis of the enzymatic activity indicated that the recombinant dUTPase could specifically catalyse the hydrolysis of dUTP and the activity of enzyme was enhanced by Mg²⁺ while inhibited by EDTA.

Abstract:In order to study the relationship between the ultrastructure,lipid profile of gills and their different habitats,the gills of three typical crabs living in different habitats were chosen as experimental materials.They are Portunus trituberculatus,Sesarma dehaani andEriocheir sinensis,living in the seawater,estuary(or near freshwater)and freshwater respectively.The ultrastructure and lipid profile were also compared by using electron microscope and biochemistry,aimed to provide the basic data for comparative physiology and biochemistry in crustacean,and promote the understanding of the physiological functions of the ultrastructure and lipid profile in gills.The results indicated that the ultrastructure of gill filaments in the different crabs were similar,with cuticle,epithelial cell and a central haemolymph space,but the amount of mitochondrion and the microvilli in the three kinds of crabs had significant difference:the density of mitochondria in the anterior gills of the Chinese mitten crab was significantly higher than the other two crabs(P＜0.05),and in posterior gills of P.trituberculatus was significantly lower(P＜0.05).Besides,P.trituberculatus has lower density of microvilli,compared to the other two crabs.The content of triglyceride(TG)in the anterior of P.trituberculatus was higher than that in the others(more than 3 times,P＜0.05),also the content of cholesterol(Cho)in the gills of S.dehaani was significantly higher than the other two crabs(P＜0.05),while the contents of the phospholipids showed no significant differences between the three kinds of crabs(P＞0.05).The gills of S.dehaani have a significantly higher arachidonic acid(ARA)and total highly unsaturated fatty acids(HUFA)content than that of E.sinensis and P.trituberculatus(P＜0.05).The result shows that the significant differences in the ultrastructure,contents of total lipids and fatty acids contributed to their normal physiological function and their adaptation to their habitats.

Abstract:Pinctada fucata is one of the main shellfishes which produce sea water pearls,and it has high economic value.Shellfish diseases continuing to occur in recent years,we had to strengthen to study the immune system of shellfish.In this test,through researching the related genes C-type lectin from P.fucata, provided some basic theories of molecular assisted selection for P.fucata. We identified and cloned the cDNA of the C-type lectin gene(PoLEC1)from P.fucata by the cDNA library of P.fucata. Sequence analysis showed that PoLEC1 is 998 bp long,a 5′-UTR is 33 bp,and a 3′-UTR is 101 bp,open reading frame is 864 bp,encoding 287 amino acids,the molecular weight is 31.68 ku and the theoretical isoelectric point is about 5.83.The signal peptide in the predicted amino acid is the Met¹-Ser¹⁹,also contains sugar binding sites.Homology analysis showed that the homology of PoLEC1 and other species.Amino acid sequence is between 18.8% and 28.6%,the similarity is between 28.9% and 50.0%.The phylogenetic analysis showed that the PoLEC1 shared the same branch with Chlamys farreri. Tissue expression analysis showed that the PoLEC1 mRNA was expressed in digestive gland,mantle,gonad,adductor muscle,intestine,gills and hemolymphe.Digestive gland expression analysis showed that after stimulation by Vibrio alginolyticusit was significantly reduced in 2 h,and expression was up-regulated in 4 h and 24 h.The prokaryotic expression vector of PoLEC1 was constructed using the mature peptide,and expressed in E.coli. After the preparation of inclusion bodies,purified by IDA HisBind resin and a single protein.And the coagulation test showed that the protein can agglutinate the E.coli significantly.

Abstract:The experiments aim to study the enrichment regularity of inorganic arsenic and total arsenic in kelp by analyzing the variation of inorganic and total arsenic in kelps which are from different maritime regions and different species during their growth.The content of inorganic arsenic is detected by HPLC-AFS,while the content of the total arsenic is examined by hydride atomic fluorescence spectrophotometry inGB/T 5009.11-2003.The results show that the enrichment in kelps of total arsenic displays an increase trend in growing season,whereas the content of inorganic arsenic is decreasing.The percentage of inorganic arsenic in total arsenic decreased from 1.36%-1.47%(March)to 0.41%-0.57%(July).The enrichment of inorganic and total arsenic varies from kelp to kelp even they are cultivated in the same maritime region,meanwhile,the same types of kelps have dramatically different contents of inorganic and total arsenic,which depends on the variety of maritime regions.Judging from the data,the contents of inorganic arsenic in all examined kelps are far below the MRL and will have no negative effects on food safety.The study provides relevant theory foundation for food safety and processing.

Abstract:M7 lysin is located in the mussel sperm acrosome.As an important protein for fertilization,it can dissolve vitelline membrane and determine the specificity of sperm-egg recognition of mussel.At present,the M7 lysin sequences ofMytilus edulis Linnaeus,M.galloprovincialis and M.trossulus have been recognized,but it hasn’t been reported in M.coruscus. In this study,we cloned M7 lysin of M.coruscus with homology cloning method,and it was expressed in E.coli Rosseta(DE3).The results showed that the amplified product was about 540 bp fragment.The further sequencing revealed that the cDNA of open reading frame was 543 bp,and it had high similarity with those of M.edulis,M.galloprovincialis and M.trossulus.The protein included 180 amino acids through online translation,its molecular weight was 20 ku,and its isoelectric point was 8.48.The phylogenetic tree from the amino acid sequence of M7 lysin showed that M.edulis and M.galloprovincialis had closest relationship,followed by M.trossulus, and finally M.coruscus. The results suggested that M7 lysin could be used as molecular markers to study mussel’s evolution.The protein of 25 ku was showed in SDS-PAGE when M7 lysin was expressed in the prokaryotes,which included the amino acid sequences in vector.This band was consistent with the expected molecular weight.Disulfide bonds’ positions in M7 lysin were highly conservative,which was similar to C-type lectin carbohydrates identification area(CRD).We speculated that M7 lysin dissolved the yolk membrane through combining its sugar and sugarbased protein.The conclusions helped us to reveal the mussel’s reproductive mechanism,and further provide a reference for the cross breeding of mussels.

Abstract:A suppressive subtracted cDNA library from the male gametophyte of Laminaria japonica was constructed and two 376 bp expressed sequence tags(ESTs)were screened from this library as a carbonic anhydrase gene due to their 70% identity to Laminaria digitata (GenBank accession number:AJ130777).Combined with the sequences of the ESTs and the conserved region of L. digitata,primers were designed to get part of sequences of the open reading frame(ORF)of CA gene from L. japonica.Based upon this obtained sequence,we designed gene-specific primers and cloned a full length cDNA(GenBank accession number:JF827608)of CA from L. japonica by use of rapid amplification of cDNA ends(RACE).It was composed of 2 804 bp in length,which included 166 bp 5′-untranslated region(UTR),1 765 bp 3′-UTR with a polyA tail at its end and 873 bp ORF.The deduced precursor protein of L.japonica CA consisted of 290 amino acids,which possessed a typical signal peptide cleavage site between 20 Gly and 21 Val.The mature protein after digestion was composed of 270 amino acids,which contained a catalytic active center constituted by 3 His residues and atomic Zn.The molecular weight of the mature protein after digestion was 30.44 ku,and its pI was at 5.06.There was no difference in the sequences of CA gene either from female or from male gametophytes,and there is no intron to separate this gene.Southern-blotting analysis suggested that the CA gene had one single copy.Its homology with α-CA of L.digitata reached 87% in peptide sequence.Neighbor-Joining(NJ)phylogenetic tree inferred from 36 CA protein sequences showed that this cloned CA gene from L.japonica was clustered with other α-CAs,suggesting that it might be α-type and it couldn’t be localized in mitochondria.Quantitative real-time PCR(QRT-PCR)result demonstrated that the diurnal transcripts of this CA gene in the kelp gametophytes cultured under the addition of CO₂ were higher than those cultured only by agitation with filtered air at any sampling time,thus illustrating that this CA might not be extracellular.The CA might be localized on the outer envelope of chloroplasts,therefore,due to the only one signal peptide it possessed,and it could pump the chloroplasts with sufficient CO₂ for photosynthesis.

Abstract:Glutathione S-transferases(GSTs)are a superfamily of multifunctional proteins present in all organisms.GSTs catalyze the conjugation of reduced glutathioe with xenobiotics,to form more soluble,nontoxic compounds,ready to be excreted or compartmentalized.So GSTs are primarily involved in detoxification and antioxidant defense.So far,compared to higher plants and mammals,there is limited information on genes related to detoxification or antioxidant defense from Porphyra yezoensis Ueda.In order to investigate the contribution of GST to detoxification in thalli ofP.yezoensis, molecular cloning and expression analysis of a glutathione S-transferase gene(designated as PyGST)from P.yezoensis were performed.The genomic DNA and cDNA sequences of PyGST were obtained with computer assisted cloning,and characterized using multiple bioinformatic programs.The relative mRNA expression levels of PyGST under lead stress were investigated in thalli of P.yezoensis using realtime quantitative PCR.The PyGST cDNA contained a 624 nt of continuous complete coding region,encoding a polypeptide of 207 amino acids with a calculated molecular mass of 22.6 ku.The alignment of the genomic DNA with the cDNA showed that PyGST contained a 248 bp of intron,whose ends were defined by the 5′-GT and 3′-AG rule.PyGST contained conserved Nand Cdomains of GST family.The amino acids defining the binding sites of glutathione and xenobiotic substrates were also conserved.Sequence comparison of PyGST revealed 28.0%-39.6% and 23.0%-28.5% identity with most algal GSTs and animal Sigma class GSTs,respectively.PyGST was closely clustered with most algal GSTs in the phylogenetic tree.Phylogenetic tree also showed that most algal GSTs including PyGST were distinct from previously described GST classes,but were most closely related to the Sigma class.These features indicated that the PyGST belongs to Sigma-like GST.Lead stress significantly induced the expression of PyGST.The expression levels of PyGST induced by low concentrations of lead were higher than those by high concentrations of lead.Upon lead exposure(10 mg/L)for 12 h,the higher expression levels of PyGST were observed at 6 h and 12 h.These findings indicated that PyGST plays a role in detoxification of lead in thalli of P.yezoensis.

Abstract:Protein preparation is a key step in two-dimensional electrophoresis(2-DE)analysis.In order to establish a suitable protein preparation method for Porphyra haitanensis thalli,three sample preparation methods of plant,trichloroacetic acid/acetone precipitation(TCA/ACE)method,urea/thiourea extraction(UREA/THI)method and phenol extraction methanol/ammonium acetate precipitation method,and three protein lysis buffers were compared.The results showed that the optimal method of proteins preparation of P.haitanensis thalli was extracted using TCA/ACE method and dissolved with the lysis buffer C(7 mol/L urea,2 mol/L thiourea,2%CHAPS,2%TritonX-100,2% IPG Buffer pH 3-10,65 mmol/L DTT).Using this method,the yield was the highest and 2-DE map has the most spots,clear backgrounds,high resolution and great repeatability.At the same time,we also found that using the IPG strips(pH 4-7)in 2-DE analysis can extract the protein of P.haitanensis thalli better than IPG strips(pH 3-10).

Abstract:In the catalog,the red crucian carp(Carassius auratus red var.) with 100 chromsomes belongs to the Cyprinidae,Cyprinidae subfamily,Carassius, with karyotype of 22m+34sm+22st+22t;and the common carp(Cyprinus carpio L.) with 100 chromosomes belongs to the Cyprinidae,Cyprinidae subfamily,Cyprinus,with karyotype of 22m+34sm+22st+22t.The previous studies had indicated that the first(F₁)and second generation(F₂)of hybrid fish of red crucian carp(♀)×common carp(♂)were diploid,and F₂ hybrids could produce unreduced eggs and sperms,which mated each other to form fertile allotetraploid hybrid fish(F₃).In order to explore the pathway of polyploidy occurrence in distant crossing of red crucian caip and common carp and the potential of producing unreduced gametes of F₂ hybrids,we studied the chromosome in embryonic cell of F₁ and F₃ hybrid fish.The result showed that the F₁ embryo was diploid,no haploid and polyploidy embryos were observed.While F₃ embryos showed 100,150,200 and even 300 chromosomes,and it was inferred that the chromosomes number in germ cells of F₂ had doubled one or more times,and the F₂ produced diploid and polyploidy gametes,which mated each other to form F₃ embryos with different ploidy.Taken together,it was concluded that F₁ hybrids which come from crossing parents with similar genome size and karyotype,have not displayed polyploidization,while the diploid hybrid progenies could produce unreduced gametes,they fertilized to form polyploidy fish in F₃.The pathway provided important guidance for the study of breeding polyploidy fish by distant crossing.

Abstract:The sizes and morphological characteristics of blood cells were observed and the patterns of developments of blood cells were ultimately found,through the observation on the smears stained by Wright’sGiemsa of whole blood,head kidney,kidney,liver and spleen in Nibea japonica. The results were as follows:In peripheral blood smears,many kinds of leukocytes cells were also observed that mainly included monocytes,neutrophils,eosinophilic granulocytes and lymphocytes in addition to red blood cells,while no basophilic cell was found.Erythrocyte,lymphocyte and monocyte stemmed mainly from head kidney and kidney,and the next was spleen; but granulocyte originated mainly from head kidney and spleen.The erythron consisted of proerythrocyte,immature erythrocyte and erythrocyte.During maturation of the erythrocyte,the volume of cells shrunk gradually,and the ratio between the volume of cells and nucleus’ decreased at first and then increased.Matured erythrocyte could be proliferated per division except generating from immature erythrocyte.The development of granuloid lineages was divided into five stages:primitive granulocyte,early immature neutrophil,middle immature neutrophil,later immature neutrophil and neutrophil.The development of lymphoid lineages was divided into three stages:primitive lymphocyte,immature lymphocyte,lymphocyte.The development of monocyte lineages was similar to that of lymphoid lineages,and they experienced three stages respectively:primitive monocyte,immature monocyte and monocyte.

Abstract:Using RT-PCR,the partial length vitellogenin(VTG)cDNA sequence and β-actin cDNA sequence of Colisa fasciata were cloned.VTG cDNA sequence contains 3 464 bp nucleotides and encodes 1 150 amino acids.β-actin cDNA sequence contains 1 253 bp nucleotides and encodes 375 amino acids. In vivo and in vitro methods were employed to investigate VTG mRNA expression under exposure to estradiol(E₂),octylphenol(OP),cadmium(Cd²⁺)and perfluorooctane sulfonates(PFOS)and evaluate the estrogenic activity.The results showed that E₂ and OP could induce VTG mRNA expression in dose-dependent way by in vivo and in vitro test. Cd²⁺ could induce VTG mRNA expression only in the low dose by in vivo test,but VTG mRNA expression was not observed in PFOS groups by in vivo and in vitro test.The results indicated that the strength of estrogenic effects was in the order E₂>OP>Cd²⁺. Cd²⁺ estrogenic effects in vivo and in vitroresults are inconsistent,suggesting that the mechanism of Cd²⁺ induced effects of estrogen and E₂ may be different.The results also indicated that VTG cDNA of C.fasciata is very sensitive to environmental hormone and very suitable to be a biomarker for monitoring the environmental hormones.

Abstract:Ozone(O₃)was frequently used in water treatment for industrial aquiculture.Therefore,in order to understand the impacts to ozone on aquiculture species Oplegnathus fasciatus,acute exposure of ozone on juvenile was conducted using self-designed ozone toxicity experimental set-up(authorized Patent Number:ZL 200920122441.3)with various exposure doses(0,0.08,0.13,0.17,0.22,0.28 and 0.32 mg/L)and durations(0.5,1,6,12,18 and 24 h).The impacts of ozone on behavioral responses,mortality,gill histomorphology,and antioxidant enzyme activities were investigated in present study.The results showed the distribution of juvenile O.fasciatus tends to move up to upper layer with increasing ozone exposure doses,in the meanwhile,the respiration rate was sped up and the startle response was slowed down.Moreover,evident dose-response relationship was found between mortality and ozone concentration.The regression equations between mortality and ozone dose at 12 and 24 hours were Y=16.815 8+20.340 5X(r=0.998 7)and Y=17.614 1+17.898 3X(r=0.950 0),respectively.The halflethal concentration(LD₅₀)at 12 and 24 hours were 0.262 5 and 0.197 4 mg/L,respectively.Compared to control,with the increase of ozone exposure dose and duration,the activities of superoxide dismutase(SOD)and glutathione peroxdase(GPX)in gills of juvenile O.fasciatus were downgraded,while the quantity of malonaldehyde(MDA)was upgraded in experimental trials.Under ozone exposure stress,the gill lamella of juvenile O.fasciatus was shown to be in irregular array and some necrosis phenomenon was detected.Shedding epithelial cells from gill lamella were also observed.The vessel of gill filaments was pycnosis or even became cavum.The vessel wall was found to be rough and shrunk,with pyknotic and necrotic blood cells attached.

Abstract:In this study,the alterations of some typical hematoimmunological parameters in the swimming crab Portunus trituberculatus infected with low dose Vibrio alginolyticus were investigated.Healthy crabs with an average weight of(162±26)g were divided randomly into injected and control groups.Each crab was injected with 200 μL(2.4×10⁷ CFU/mL)V.alginolyticus in injected group,and with 200 μL 0.85% sterile saline solution in control group.Then haemolymph samples were drawn from each crab at hours 0,24,48,72 and 96 post injection for testing hematoimmunological parameters including total hemocyte count(THC),proportion of large granular cells,total serum protein concentration,acid phosphatase(ACP),alkaline phosphatase(AKP),nitric oxide(NO)and inducible nitric oxide synthase(iNOS).THC of injected crabs was significantly 36% lower than in control group and touched the bottom post injection 24 h(P<0.05).Also,in injected groups,the proportion of large granular cells increased significantly at 24 h and 48 h(P<0.05),and returned to the same level at 72 h and 96 h.Noticeably,there was no significant difference in the injected and control groups in PC,although the numerical value of injected group waved during the test(lower at 24 h,48 h and higher at 72 h,96 h than control group).The ACP activity,after injection,increased very significantly at 24 h,48 h(P<0.01)and 72 h(P<0.05),then decreased to the control level at 96 h.The AKP activity increased gradually after injection,and noticeably,there was no significant difference with control group until at 48 h and 72 h(P<0.05),then decreased to the control level at 96 h.The NO concentration and iNOS activity of injected group shared the same pronounced increasing,there was no significant difference with control group until 72 h(P<0.01 for NO and P<0.05 for iNOS)and 96 h(P<0.01 for NO and iNOS),especially,the NO concentration in injected group was three times higher than that in control group at 96 h.All the results indicated hematoimmunological parameters of P.trituberculatus did play an important role in confronting the V.alginolyticus’s infection.

Abstract:A total of 76 different nucleotide acid sequences of MHC gene,which were classed as 20 alleles,were identified in 185 clones from 16 resistant and 21 susceptible “whole red” color patterns of Cyprinus carpio var.color individuals using the specific primer pair of DABF and DABR.The 624 bp-long nucleotide fragment consisted of the exon1,exon2,exon3 and exon4,encoding signal peptide,β1 domain,β2 domain and part transmembrane,respectively.There were 144 nucleotide(52.17%)and 70 amino acid(76.07%)variable sites in the 276 bp-long β1 domain,whereas the nucleotide and amino acid variable sites were 98(34.75%)and 50(53.19%)in the 282 bp-long β2 domain.It was obviously found that β1 domain had more variable sites than β2 domain.Meanwhile,23 variable sites were observed in total 24 peptide binding residues(PBR)of β1 domain.The ω-values(ω=d_N/d_S)were 1.367,0.886,and 0.754 for PBR and non-PBR of the β1 domain,and for β2 domain,respectively,implying positive selection pressure conducted on the MHC-DAB gene(especially for β1 domain)of C.carpio var.color.The percentage(13.75%)of Cyca-DAB3*15 was significantly higher in the resistant stock than that(3.81%)in the susceptible stock(P<0.05).Interestingly,the Cyca-DAB3*09 and CycaDAB3*10 were only found in the resistant stock,with percentage of 3.75%(P<0.05),whereas the Cyca-DAB3*02 and Cyca-DAB3*14 were only observed in the susceptible stock,with the percentage of 7.62%(P<0.05)and 8.57%(P<0.01),respectively.The present results would be useful to conduct the disease-resistant breeding program in the C.carpio var.color.

Abstract:In order to find out the characteristics and distribution of dominant fish assemblages in kelp beds of Gouqi Island,we sampled the fish assemblages in kelp beds and sandy beach every month from February 2009 to January 2010.The composition,biological characteristics and prey habits of dominant species were compared,separately.The results showed that the dominant fishes in kelp beds dominated by larger macroalgae Sargassum horueri or smaller algae,as Ulva pertusa were the same,i.e. Sebastiscus marmoratus, Agrammus agrammus and Nibea albiflora.The assemblages of S.marmoratus,with younger age and smaller size,have frequent prey activity along the coast and large variety in abundance.The strong recruitment of stock comes from the high reproduction of female,which were early sexual maturation and more than male in abundance.Prey variety of objects survived from the overfishing.The assemblages of both A.agrammus and N.albiflora were younger age and affected by the migration assemblages from open sea.The growth of above three species was different owing to the different feeding habits and prey objects.Meanwhile,due to the food conversion at the different stages of development,body variety and predation pressure from the top predator, S.marmoratus and N.albiflora will alter their choice in habitats for different utilization. A.agrammus doesn’t change into prey objects in its life,so the main activity habitats are affected by Caprellidea,the major feeding target.