Abstract:To investigate bacterial communities and diversity in the shrimp(Penaeus penicillatus)intestinal and culture-associated environment,16S rRNA clone library analysis was performed.The results demonstrated that there were obvious differences in the bacterial compositions of the outside seawater,culture system and the shrimp intestine.The comparison analysis revealed that the bacterial community had high diversity among the samples.The results also showed that the intestinal microbial community of shrimp had lower diversity than those from the culture-associated environments.Cyanobacteria(53.97%),Alpha-proteobacteria(13.76%)and Gamma-proteobacteria(10.58%)constituted the dominant components of the outside seawater samples.Cyanobacteria(33.55%),Gamma-proteobacteria(14.84%),Firmicutes(14.19%),Bacteriodietes(12.26%)and Alpha-proteobacteria(9.68%)were the dominant bacteria groups in culture water.Culture sediments were mainly dominated by Firmicutes(79.12%).Firmicutes(75.79%),Fusobacteria(13.68%)and Gamma-proteobacteria(10.53%)were dominant in the shrimp intestine.The order of Bacillales occupied a higher proportion of bacterial community in culture sediments(69.78%),culture water(13.55%)and the shrimp intestinal tract(72.63%),which may play an important role in the maintenance of healthy culture system.An important bacteria group,Rhodobacterales was also dominant in outside water(10.05%)and culture water samples(9.68%).In addition,outside seawater and culture water harbored higher diversity of bacterial community than the shrimp intestine and culture sediments,and had more potential pathogens,such as Flavobacteria(10.32%)and Fusobacteriales(13.68%).This study will increase our understanding about the effects of culture environment on bacterial community composition in the shrimp intestine and provide valuable data for the development of prevention mechanisms for shrimp cultivation.

Abstract:Tilapia is one of the important species in aquaculture in the world.In recent years,tilapia aquaculture has been badly damaged by streptococcusis.Streptococcus agalactiae is one of the major causative agents,which has caused severe economic losses in many species of freshwater,marine and estuarine fish worldwide.Vaccine is one of the main development future strategies to prevent fish streptococcusis.Some surface proteins of S.agalactiae have been documented and proved to be the ideal antigen candidates of protein vaccines,which included LrrG protein.The LrrG protein is one of the conserved surface proteins of S.agalactiae,which exists in all kinds of serotype of S.agalactiae strains.The LrrG protein of S.agalactiae isolated from human has been verified to protect mice from S.agalactiae infection.However,it has not been reported whether the LrrG protein from fish S.agalactiae isolates possessed the similar effect.In order to obtain plenty of LrrG protein and explore its immune protection in tilapia,in this study we designed the specific primers and cloned the LrrG gene sequence from tilapia virulent S.agalactiae strain according to the reported LrrG gene in GenBank of human S.agalactiae.The sequencing results showed that the ORF of the cloned LrrG was 2 361 bp in length and encoded 786 amino acids and contained 3 conserved LRR(Leucine-rich repeat)domains.The colis accounted for 68.83% in its secondary structure.NCBI Blast indicated that the homology of LrrG gene sequences of S.agalactiae from tilapia and human was 98.48%.The LrrG protein could form antigenic epitope based on the analysis of three indexes,i.e.hydrophilicity,surface probability and antigenic index.This suggests that the LrrG protein may have potential immunogenicity.The LrrG fragment was subcloned into pET-32a(+)vector and expressed in E.coli BL21(DE3)by IPTG induction at 22 ℃.SDS-PAGE showed the molecular weight of expressed protein was 108.9 ku,which is equal to the expected protein size.The recombinant protein existed as soluble protein and inclusion bodies.The soluble protein was highly purified by Ni-chelating affinity chromatography and the concentration could reach 3.40 mg/mL by ultrafiltration.Preliminary experiment showed that the relative percent survival of tilapia immunized with LrrG protein against tilapia streptococcicosis was 69.28%.ELISA analysis indicated the serum antibody titer of post-immuned tilapia for 4 weeks was 1:800.These findings provide the useful information for further investigation to evaluate the potential value of the LrrG protein as tilapia genetic engineering vaccine.

Abstract:The pathological changes present in tilapia(Oreochromis niloticus)naturally infected by Streptococcus iniae were described under optical and transmission electron microscope.Gram positive and sphere-shaped bacteria were isolated from the liver,spleen,kidney and brain.The diameter of the sphere-shaped bacteria was approximately 0.6-1.0 μm.Most were arranged in chains.Histopathological examination showed edema,hemorrhage,degeneration,necrosis and the inflammatory response in many organs,especially in liver,spleen,kidney and brain.Further,hepatitis,splenitis,interstitial nephritis,and meningitis with numerous lymphocytes or macrophages infiltrates were evident.Ultrastructural pathology examination confirmed extensive systemic infection.Cytopathological changes showed that ultrastructure damages in visceral organ cells.Cells containing aberrant nuclei appeared singly or in clusters,which seemed to be apoptotic(morphologically became pyknotic,karorrhexis and karyolysis).The main alterations concerned the endoplasmic reticulum and the mitochondria:a high development of both rough and smooth endoplasmic reticulum(RER and SER),degranulation of RER,dilatation and vesiculation of reticulum cisternae were common.The mitochondria were swelling,with disappearance of cristae and vacuolization.These observations indicated that S.iniae could cause simultaneous development of multiple-organ lesions with an acute systemic inflammation in the host,and the fish were dead in the end.

Abstract:In this study,the purpose is to excavate the main effect of quantitative trait loci related to head length,head length and body length ratio in mirror carp(Cyprinus carpio L.).A group of F₁ hybrids common carp including 68 individuals was used to construct a linkage map using 535 markers,which were arranged to 50 groups covering 2 244.66 cM genetic distance with an average space of 4.63 cM.MapQTL5.0 software was conducted to detect the quantitative trait loci(QTL)for HL and HBR using interval mapping(IM).Results showed that two QTLs were identified for head length on the linkage groups of LG21(SNP1392-HLJ643),LG42(SNP0562-SNP0109),which explained 14.9% to 32.6% of the total variation of the head length;six QTLs were responsible for head length and body length ratio associated with the linkage groups of LG8(HLJ423),LG15(SNP0002),LG18(HLJ1042-SNP0046),LG21(SNP1392-SNP0818),LG39(HLJ322),LG40(SNP0026),which explained 16.4% to 49.3% of the phenotypic variations.Seven QTLs explaining above 20%,HL-21 and HL-42 were major QTLs associated to the head length of common carp;HBR-8,HBR-15,HBR-21,HBR-39 and HBR-40 were major QTLs associated to the head length and body length ratio.These results indicated that it was highly probable that these QTLs were the main regions of the head length,head length and body length ratio development.SPSS general linear model(GLM)verified another group,and results showed that the HLJ692 was significant correlation for mirror carp head length and body length ratio(P<0.05).

Abstract:Vibrio mimicus is the causative agent of ascites disease in aquatic animals.It was found that there was an adhesion motif at amino-terminal of OmpU protein,and OmpU-specific antibody exhibited significant inhibition effects on the adhesion of V.mimicus to cells in our previous studies,but adhesion function of OmpU protein is still unclear.To investigate the role of OmpU protein from V.mimicus in cell adhesion and virulence,the OmpU gene deletion mutant of V.mimicus 04-14 strain was constructed by the homologous recombination.A recovery mutant was obtained by introducing a low-copy plasmid strain.PCR and sequence analysis confirmed that OmpU gene was successfully deleted in the mutant and restored in the complementary strain.We compared the differences of genetic stability,growth and biochemical characteristics,adhesion ability and virulence between the gene deletion mutant and wild strains,as well as the complemented strain.The results showed that the mutant strain stabilized genetically and grew slower than the wild strain.There was no significant difference between them in morphology,culture and biochemical characteristics.Compared with wild strain,deletion of OmpU gene significantly reduced bacterial adhesion to EPC cells monolayers by 66.6%,but the adhesion ability was restored in the complementary strain.Furthemore,the 50% lethal doses(LD₅₀)of the mutant strain was four times lower than those of the wild strain and complementary strain.These data indicate that the OmpU protein is involved in both adhesion and virulence in V.mimicus.The adhesion function of OmpU protein from V.mimicus and its role in virulence were comfirmed for the first time.

Abstract:The sizes of genome and chromosomes were respectively estimated with flow cytometry and image analysis in large yellow croaker(Larimichthys crocea).Genome size of large yellow croaker was estimated at 725.25±14.65 Mb.The relative area of chromosome ranged from 2.26%±0.08% to 4.83%±0.08%;the relative integrated optical density(IOD)ranged from 1.80%±0.32% to 5.04%±0.15%.Based on the relative IOD,the shortest physical length was estimated at 13.1±3.37 Mb for the 24th chromosome,while the physical length of the other chromosomes ranged from 24.4±6.21 Mb to 36.6±1.62 Mb.Linear correlation between the physical length and the relative area was observed,as well as linear correlation between the physical length and the relative length.The correlation coefficient for the physical length and the relative area was higher than that for the physical length and the relative length.The image of metaphase chromosome also showed that the optical density of chromosomes was not completely uniform with propidium iodide(PI)staining.The variation existed among non-homologous chromosomes,between sister chromatids,and among different regions of a chromosome.Above all,new parameters of chromosomes present in this paper will facilitate chromosome identification and pairing,as well as studies on genomics,in large yellow croaker.

Abstract:In order to understand the mechanism of development of IgM gene expression and its antibody transfer between generations in yellow catfish,Pelteobagrus fulvidraco,IgM gene transcription change and its antibody level in ovary,eggs,embryos,and larvas of P.fulvidraco were investigated by using the Real-time PCR and ELISA techniques.Results were as follows:IgM mRNA not detected in 3-7 d larvae was found in 14 d larvae.Immuning mother fish by bacteria did not influence IgM mRNA expression level in their larvae.IgM antibody in P.fulvidraco exsited in eggs,embryos,and all early phases of larvae.These antibody expression level continued to decline and reached the lowest level in 9 d larvae(which is 0.31 times of eggs'),and began to increase in 14 d larvae(which is 1.6 times of 9 d larvae's).Immuning mother fish by bacteria was able to significantly improve IgM antibody expression levels,which respectively increased to 2,3 times and 1.8 times in eggs and 9 d larvae of P.fulvidraco.These studies indicate that IgM gene expression of P.fulvidraco between generations is discontinuity,while its antibody expression is continous.The IgM antibody in early phases of larvae is from their mother fish.Immunizing may significantly improve antibody level of embryo and larvae.

Abstract:Fish schools present perfect order in dimension,which has attracted interest and attention of scientists.For observation of the structure characteristics of fish school,two video cameras were set up in lab to record the position of fish(Pseudorasbora parva)from up and side directions of aquarium simultaneously.Three-dimensional location data of each individual can be abstracted from the record in time series.The characteristic parameters data,nearest neighbor distance(NND),vision angle(VA),turning angle as well as individual swimming speed,have been analyzed for presenting the structure characteristics of fish school.The results show that NNDs of individuals have kept in a range of 0.5-2 BL mostly,and the preferred nearest neighbour distances(PNND)are 0.6-0.8 BL.To avoid a collision,the individual fish always keeps the neighbour fish located its visual field in range 80° and the variation of turning angle keeps the range from 0° to 30°(95.83%).Under natural conditions without any stimulus or disturbance,the fish swims at around 0.75 BL/s to match the others maintaining in schooling.The results of our study confirm that visual ability plays an important role in the schooling performance of P.parva,and the group structure is also affected by individual status(satiation and hunger).

Abstract:The purple strain F₄ of Hyriopsis cumingii was produced using intraspecific hybridization assisted by populations breeding for four generations with the breeding indexes of the inner shell color and body weight.In this paper,six polymorphic microsatellite markers were employed to identify the male parents of offspring from 15 female parents of the purple strain F₄.Parentage assignment showed that 42 full-sib families from 12 male parents and 15 female parents were obtained.Heritabilities,genetic correlations and phenotype correlations for inner shell color and growth traits were estimated using AS REML method during one year old stage.The heritability estimates of the color parameters L^*,a^*,b^*,dE^* were 0.31±0.22,0.11±0.08,0.36±0.18,0.29±0.19,respectively.The genetic correlations and phenotypic correlations of L^*,a^*,b^* were low,with the ranges of 0.08-0.47 and 0.04-0.32,but the correlations between L^* and dE^* were very high(r_g=-0.94±0.06,r_p=-0.96±0.01).The heritability estimates for shell length(0.24±0.19),shell height(0.37±0.27),shell width(0.26±0.16),wet weight(0.26±0.17),and shell weight(0.31±0.19)were moderate and high.A positive and high genetic correlation and phenotypic correlation were found among growth traits(r_g=0.71-0.92,r_p=0.66-0.94).The genetic correlations and phenotypic correlations between the color parameters and growth traits were very low,ranging from 0.02 to 0.18.The results showed that most of the heritabilities of color parameters and growth traits were moderate and high,which suggested that this strain should respond rapidly to selective breeding.Mutual selection couldn't be achieved due to the low correlations between inner shell color and growth traits,and the body weight should respond to targeted selection with the high phenotype correlations and genetic correlations with other growth traits.Therefore,selective breeding for inner shell color and body weight was a reasonable method to improve inner shell color and growth traits at the same time.

Abstract:There are abundant fisheries resources in South China Sea which accounts for important strategy position in China.Associated with Beidou Positioning System,ARM advanced processor and NR flushbonading operating system,South China Sea fisheries information dynamic collection and automatic analysis system was established based on GPS,GIS and RS integration technology.It is a distributed system including four independent subsystems such as ship-borne fishing information realtime collection,South China Sea data integrated center,marine fisheries information system and deep sea fishing ground forecast subsystems.We invented ship-borne fishing data realtime collection terminal with the Beidou communication function.The on-spot message interplay was realized between the fishing vessels and land data center by Beidou short message channel.Moreover,the safe and stable data sharing between data center and the data analysis application system by VPN channel also came into being.Therefore,it resulted that the establishment of whole connection visualization network between the fishing vessels and the land data center.Based on this network,the fishing data were sent to the South China Sea GIS by the fishing vessels and the data analysis themes of the catch by fishing zones,vessels or species were analyzed and displayed immediately.Through several years' collection and analysis of the fishing,fisheries biology and fishing ground data,the purpleback flying squid fishing ground of South China Sea deep sea can be preliminarily forecast and be sent to the fishing vessels to improve their fishing efficiency.The 3S integration platform technology put forward the fast synthesis process of the South China Sea fisheries data and created a new circulation model between fishing vessels operations and the data research and digestion.It can be deduced that this 3S integration technology will play a more and more important role in the future sustainable fisheries development in South China Sea.

Abstract:To study the regulatory role of ecdysteroid receptor(EcR)in molting and ovarian development of Chinese mitten crab,the full-length EcR gene of Eriocheir sinensis was cloned by using reverse transcriptase polymerase chain reaction(RT-PCR)and rapid-amplification of cDNA ends(RACE).The full-length cDNA sequence of EcR was 2 156 bp,and included a 1269bp ORF which encoded 422 amino acid residues.The alignment of EcR amino acid sequence of Eriocheir sinensis shared 89% identity with Uca pugilator.Quantitative real-time PCR(qRT-PCR)was used to quantify the relative expression level of EcR in different tissues,molting process,ovarian process and regulation of MF on ovarian EcR in E.sinensis The result showed the EcR mRNA were expressed in all tissues examined and highly in Y-organ,with small amount in ovary and muscle,and trace in hepatopancreas,gill,heart,stomach,intestine,thoracic ganglion and cerebral ganglion.During the molting process,the expression levels of EcR mRNA of Y-organ remained low from AB period to C period,then significantly increased in D period and E period.(P<0.05);the amount of EcR expression in hepatopancreas was rising from AB period to D period,and decreased in E period;EcR expression in muscle was highest in AB period(P<0.05);EcR expression in gill was highest in D period(P<0.05).In the process of Eriocheir sinensis ovarian development,the levels of EcR expression in ovary gradually increased to the maximum from stage Ⅰ to Ⅳ,low in stage Ⅴ.In injection experiment,EcR expression of the MF1(1 μg/crab)group had no significant difference with the control group and physiological saline group,MF2(2 μg/crab)group(P<0.05)had a marked increase;In vitro experiment,EcR expression was significantly increased in MF1(10^-8 mol/L)group and MF2(10^-7 mol/L)group(P<0.05).The results indicated that EcR might play an important role during molting process and ovarian development in Eriocheir sinensis,and MF could regulate EcR gene expression in ovarian.However,further studies are required to explore the underlying molecular mechanisms and clarify the function of EcR mRNA.

Abstract:The deep sea is increasingly recognized as a major global reservoir of the earth's biodiversity.The deep sea bottom fisheries represented by bottom trawl and their impact on the vulnerable deep sea ecosystems,including seamounts,hydrothermal vents and cold water corals,are fervently concerned by international community in the past ten years.General Assembly of the United Nations has approved a series of resolutions about biodiversity protection of the vulnerable marine ecosystems since 2002,and called upon all countries since 2004,individually or through regional fisheries management organizations or arrangements,to take actions immediately,and to be consistent with the precautionary approach and ecosystem approaches,to assess whether individual bottom fishing activities would have significant adverse impacts on vulnerable marine ecosystems,and to ensure that these activities which would have significant adverse impacts,are managed to prevent such impacts,or not to be authorized to proceed.The Food and Agriculture Organization of the United Nations provided international technical management standards and policy framework to regulate deep sea bottom fisheries and to protect the vulnerable marine ecosystems in high seas in 2008 International Guidelines for the Management of Deep-sea Fisheries in the high seas.Regional fisheries management organizations or arrangements are implementing and enforcing the rules as above to manage the bottom fishing activities.New regional fisheries management organizations or arrangements with the competence to regulate bottom fisheries and the impacts of fishing on vulnerable marine ecosystems are being established.In North Atlantic,Mediterranean,South Pacific and Antarctic,measures such as the interim prohibition of bottom trawling in some waters,fisheries and ecosystem data collection for assessment of vulnerable deep sea ecosystems and the impact by deep sea bottom fisheries,have been taken by the relevant fisheries management organizations.In North Pacific,a group of nations have agreed to a treaty that establishes conservation strategies for the most vulnerable ecosystems in international waters of the North Pacific Ocean.The NGOs such as the Deep Sea Conservation Coalition and some scientist are calling on a ban on the deep sea bottom trawl fishing in high seas,while various countries take different positions on that and the commercial fishing industry opposes to closing of the bottom trawl fishing.In the opinion of this paper,the deep sea bottom fisheries would not be closed completely in high seas in the short run,but would be closed in more and more waters in high seas.In the future development of China's oceanic fisheries,the status of the management of bottom trawling should be concerned closely to support decision-making,and for prevention of significant adverse impacts on vulnerable marine ecosystems,selective fishing gear and ecologically sound fishing methods should be developed and used.

Abstract:Anodonta woodiana belongs to the Unionidae that consists of freshwater bivalve mollusks and it is the main freshwater mussel in China.Theromaicn is an antimicrobial peptide that is an important component of the natural defenses of freshwater mussel.In this study,a theromacin gene from A.woodiana was identified and characterized.The full-length cDNA sequence of theromacin gene of A.woodiana was cloned by rapid amplification of cDNA ends(RACE).A 870 bp cDNA sequence contained a 306 bp open reading frame(ORF)encoding 101 amino acids,a 104 bp 5'untranslated region(5' UTR),and a 460 bp 3' untranslated region(3' UTR).The molecular weight of this mature peptide was estimated to be 11 1 66.9 u.Homology analysis indicated that amino acid sequence showed the highest similarity with theromacin in Hyriopsis cumingii(73%),and lower similarity with defensins,mytilins,myticins and mytimycins in mussels.It belongs to the macin family.Real-time quantitative PCR showed that theromacin gene expressed in a wide range of tissues including the mantle,blood,gill,foot,liver and intestine,with the highest level of transcripts in mantle,followed by foot,while in other tissues it was lowly expressed.After being challenged with Aeromonas hydrophila,the expression of theromacin gene was increased significantly in 6 tissues compared with the control mussel.The results suggested that theromacin gene might play an important role in the immune reaction of A.woodiana.

Abstract:In order to detect the DNA damage in digestive glands cells of Ruditapes philippinarum exposed to different concentrations of fenvalerate for 25 days respectively,R.philippinarum were divided into six groups and evaluated with comet assay method.The DNA damage parameters such as the comet rate,the tail length,the percentage of tail DNA,the tail moment and the olive moment were statistically analyzed by Comet Score 1.5.On the basis of one-dimensional regression equation we selected greater influenced fly parameters after comparing with SPSS 16.0 and constructed the multiple-dimensional regression equation.The results showed that DNA damages in digestive glands cells of all exposed groups were observed and the parameters of each exposed group were significantly different from the control group(P<0.01).The DNA damage in digestive glands cells of control group was minimal.The tail rate of control group was 8.06%±1.94%,the percentage of tail DNA,tail moment and olive moment were nearly 0.The value of each parameter of all experimental groups with exposure concentration from 0.067 5 mg/L to 1.080 0 mg/L was significantly increased.Our research indicated that there was a dose-effect relationship between fenvalerate and DNA damage in digestive glands cells,which increased regularly with the exposure concentrations.All DNA damage parameters were highly relevant to the exposure concentrations.The one-dimensional regression equation(P<0.05)and multiple-dimensional regression equation(P<0.02)had significant statistic meaning,which might be an effective way to estimate the exposure concentration and time of fenvalerate.Our research provided new methods and clues to analyze the genotoxicity of aquatic species caused by the pollutant of pyrethroid pesticides in the coastal sea of China,which could be broadly applied.

Abstract:Molting is an essential stage during the growth of crustacean,which is coordinated by ecdysone secreted by Y-organ,chitinase synthesized by the epidermis;while negatively regulated by molting-inhibiting hormone secreted by X-organ sinus-gland complex at the bottom of eyestalk.However,the specific mechanisms of the molting triggered by eyestalk ablation are still unknown.In this study,two eyestalks were ablated and the ecdysone level in Sinopotamon henanense haemolymph and chitinase level in the epidermis were measured by ELISA,and N-acetyl-β-D-glocosaminidase(β-NAGase)activity in the epidermis was measured by colormetry.Crabs were divided into one control group and seven eyestalk ablation groups respectively(from 24 hours to 168 hours).Our results showed that the level of ecdysone in haemolymph showed an increase at first and then decrease,with the maximum value at 96 h.[♂:(23.25±4.56) ng/L;♀:(35.75±7.15) ng/L,P<0.01].This tendency was accompanied by similar changes as that of chitinase levels in the epidermis.After the two eyestalks were ablated for 48 h to 120 h,chitinase level increased significantly(compared with the control group,P<0.05).Activity of β-NAGase increased continuously by the eyestalk ablation and reached the maximum value at 144 h[♂:(400.44±21.00) U/g;♀:(216.94±23.97) U/g,P<0.05].Then the activity of β-NAGase decreased gradually,but still higher than that of control group.The results imply that eyestalk ablation may affect the molting process by increasing the levels of ecdysone in the haemolymph,chitinase in the epidermis and the activity of β-NAGase.This study will provide the theoretical basis for the further study on the physiological regulation of crustacean molting and growth.

Abstract:In order to study the immune mechanism of coelomic fluid of Strongylocentrotus intermedius,we researched the phagocytosis activity in different media and different treatments of yeast cell.Then we analysed the non-cell coelomic fluid and ingredient which was isolated from regulating yeast cells and non-regulating yeast cells with SDS-PAGE,and the non-cell coelomic fluid was dialysed,SephadexG-200 gel chromatography,and SDS-PAGE;In isotonic buffer and cell-free coelomic fluid by yeast cell adsorption,we determined the phagocytosis effected by opsonin-like molecule of different concentration and different time.The result showed that isotonic buffer,cell-free coelomic fluid by yeast cell adsorption and non-cell coelomic fluid all can regulate phagocytosis,and the ratio was 1.00:1.11:1.94,and the phagocytosis rate of regulating yeast cells was 1.61 times of non-regulating yeast cells in isotonic buffer;There was a new opsonin-like molecular band from ingredient which was isolated from regulating yeast cells,and the molecular weight is 250.62 ku.We also found the molecular weight is 250.62 ku after dialysis,SephadexG-200 gel chromatography;In tested concentration range,the greater the opsonin-like concentration,the higher the phagocytosis and 5.0 and 10.0 μg/mL groups were higher than control group in each test time.In isotonic buffer,10.0 and 5.0 μg/mL groups had very significant difference(P<0.01)compared to control group in 30 min after reaction.In cell-free coelomic fluid by yeast cell adsorption,10.0 μg/mL group had significant difference compared to control group(P<0.05)in 30 min after reaction.These results indicate that there is a kind of new opsonin-like molecule in coelomic fluid of S.intermedius and the molecular weight is 250.62 ku which can promote phagocytosis.

Abstract:To compare the difference between Ulva prolifera cultured in different reproductive modes,we got the thalli grown from the spores(ST)and that from vegetative multiplication(VT)by using enclosure experiment in situ and then estimated the difference of photosynthetic performance between ST and VT by comparing the growth,photosynthesis and fluorescence parameter of VT and ST.Our results showed that the growth rate of ST was significantly higher than VT by 61.27% and the maximum photosynthetic rate Pmax,photosynthetic efficiency α and P/R of ST were significantly higher than those of VT by 25.33%,14.93%,134.69%,respectively.While the respiration rate and light compensation point for photosynthesis of ST were lower than those of VT by 45.7% and 52.2%,respectively.It showed that ST possessed better growth advantage compared with VT.Relative electron transport rates(rETR)and non-photochemical quenching(NPQ)of VT were significantly higher than those of ST,and had a higher non-photochemical quenching in the high light.These results implied that compared with the thalli grown from the spores,the thalli grown through vegetative multiplication had stronger high light adaptation ability.

Abstract:Tangshan Bay has been significantly affected by human activities.In order to research the situation and diversity of fishery resources community in Tangshan Bay,the species composition,spatial distribution,biodiversity,dominant species and ABC curves of the fishery resources were analyzed based on the bottom trawl survey data in May,August and November,2012.The results showed that 59 species were collected in the investigations,including 27 species of fishes,17 species of crustaceans,7 species of shell-fish,4 species of echinodermata,3 species of cephalopoda and 1 species of polychaetes;there were 35 species of the catch in spring,36 species in summer and 37 species in autumn;the catch rates(mass)in spring,summer and autumn were 3.50,13.68 and 16.99 kg/h,respectively.The study showed:(1)The catch rates and compositions in different seasons were obviously different.The biomass of cephalopods occupied the first place and the biomass of fish and crustaceans was slightly lower than cephalopods in spring;the biomass of crustaceans occupied the first place and the biomass of fish became the second in summer;the biomass of fish occupied first place and the biomass of crustaceans became second in autumn.(2)The spatial distribution of the catch rate showed significantly seasonal variation,the catch rate of the shallower waters was higher than that of the deepwater area in spring,while the deepwater area was higher than the shallower waters in summer.(3)The seasonal succession of dominant species was not obvious.(4)The biodiversity indices revealed that the biodiversity indices in spring were higher compared with those in summer and autumn,and the biodiversity indices in the shallow waters were higher compared with those in deepwater area.(5)The ABC curves indicated that the present community in Tangshan Bay was disturbed.