The resource of Fenneropenaeus chinensis has declined sharply due to excessive fishing intensity,ecological changes and diseases.In order to supplement the fishing yield and restore resources of F.chinensis,the releva...The resource of Fenneropenaeus chinensis has declined sharply due to excessive fishing intensity,ecological changes and diseases.In order to supplement the fishing yield and restore resources of F.chinensis,the relevant authorities have carried out the activities of stock enhancement and releasing.It can increase biomass and recover resources.However,compared with increasing biomass,there were still few reports on its effect on the recovery of resources.Resource recovery is a process related to whether the released individuals can form a reproductive population.Up to now,there has been a lack of evidence whether the released F.chinensis can complete the entire life history,and form reproduction population.In this study,gravid female shrimp after spawning migration were captured from coastal waters of Haiyang,Qingdao,and Yellow Sea.After identifying parentage relationships using simple sequence repeat(SSR)and mtDNA haplotype,it was finally confirmed that there were eight released individuals in the recapture samples.It was confirmed for the first time that at least part of the released F.chinensis can complete overwintering and reproductive migration,and maintain the migration habits as their wild counterparts.Therefore,we infered that the released shrimp can reproduce under natural conditions,these F.chinensis can form reproductive populations theoretically if without human intervention.These results indicated that enhancenment and release activities have a positive effect on resource recovery.展开更多
On the basis of computational fluid dynamics,the flow field characteristics of multi-trophic artificial reefs,including the flow field distribution features of a single reef under three different velocities and the ef...On the basis of computational fluid dynamics,the flow field characteristics of multi-trophic artificial reefs,including the flow field distribution features of a single reef under three different velocities and the effect of spacing between reefs on flow scale and the flow state,were analyzed.Results indicate upwelling,slow flow,and eddy around a single reef.Maximum velocity,height,and volume of upwelling in front of a single reef were positively correlated with inflow velocity.The length and volume of slow flow increased with the increase in inflow velocity.Eddies were present both inside and backward,and vorticity was positively correlated with inflow velocity.Space between reefs had a minor influence on the maximum velocity and height of upwelling.With the increase in space from 0.5 L to 1.5 L(L is the reef lehgth),the length of slow flow in the front and back of the combined reefs increased slightly.When the space was 2.0 L,the length of the slow flow decreased.In four different spaces,eddies were present inside and at the back of each reef.The maximum vorticity was negatively correlated with space from 0.5 L to 1.5 L,but under 2.0 L space,the maximum vorticity was close to the vorticity of a single reef under the same inflow velocity.展开更多
China(herein referred as China’s mainland,and excluding Hong Kong,Macao and Taiwan)ranks as the world’s leading fishing nation,with approximately 11.1 million tons of domestic marine catch acquired in 2017.Marine fi...China(herein referred as China’s mainland,and excluding Hong Kong,Macao and Taiwan)ranks as the world’s leading fishing nation,with approximately 11.1 million tons of domestic marine catch acquired in 2017.Marine fisheries resources in China are mainly exploited by its 11 coastal provinces and municipalities,and the development of fishing industry varies among them.However,few studies have examined the exploitation history of the 11 coastal provinces and municipalities.In this paper,we systematically quantified the exploitation history of marine fishery resources in China and then measured the vulnerability of the 11 coastal provinces and municipalities of China to a reduction in marine catches.Our analysis suggested that Chinese marine fisheries experienced rapid growth from the mid-1980 s to the end of the 20 th century,and this rapid increase in marine catches were mainly promoted by increased fishing effort.The total primary production required level amounted to approximately 80%of the average primary productivity in 2017,and Zhejiang,Fujian,Shandong,Hainan and Guangdong provinces were the main fishing provinces in China.By assessing three dimensions of vulnerability(exposure,sensitivity and adaptive capacity)to the impacts of a reduction in marine catches in the 11 coastal provinces and municipalities,we found that Hainan,Guangxi,Zhejiang and Fujian provinces had high or very high vulnerability,while the municipalities of Shanghai and Tianjin had low vulnerability.Identifying suitable adaptation policies and management plans based on the differences in vulnerability among coastal provinces is important in sustainable fisheries management.展开更多
In order to elucidate the genetic mechanism of growth traits in turbot during ontogeny, developmental genetic analysis of the body weights, total lengths, standard lengths and body heights of turbots was conducted by ...In order to elucidate the genetic mechanism of growth traits in turbot during ontogeny, developmental genetic analysis of the body weights, total lengths, standard lengths and body heights of turbots was conducted by mixed genetic models with additive-dominance effects, based on complete diallel crosses with four different strains of Scophthalmus maximus from Denmark, Norway, Britain, and France. Unconditional genetic analysis revealed that the unconditional additive effects for the four traits were more significant than unconditional dominance effects, meanwhile, the alternative expressions were also observed between the additive and dominant effects for body weights, total lengths and standard lengths. Conditional analysis showed that the developmental periods with active gene expression for body weights, total lengths, standard lengths and body heights were 15–18, 15 and 21–24, 15 and 24, and 21 and 27 months of age, respectively. The proportions of unconditional/conditional variances indicated that the narrow-sense heritabilities of body weights, total lengths and standard lengths were all increased systematically. The accumulative effects of genes controlling the four quantitative traits were mainly additive effects, suggesting that the selection is more efficient for the genetic improvement of turbots. The conditional genetic procedure is a useful tool to understand the expression of genes controlling developmental quantitative traits at a specific developmental period(t-1→t) during ontogeny. It is also important to determine the appropriate developmental period(t-1→t) for trait measurement in developmental quantitative genetic analysis in fish.展开更多
A new cell line,CSEC,has been successfully established from embryos at gastrula stage of a cultured marine fish,half smooth tongue sole(Cynoglossus semilaevis).CSEC cells grow actively and stably more than 50 passages...A new cell line,CSEC,has been successfully established from embryos at gastrula stage of a cultured marine fish,half smooth tongue sole(Cynoglossus semilaevis).CSEC cells grow actively and stably more than 50 passages for over 200 d in DMEM medium supplemented with 15% FBS(fetal bovine serum),2.5 ng/cm 3 bFGF(basic fibroblast growth factor),1 ng/cm 3 LIF(leukemia inhibitory factor) and 50 mmol/dm 3 2-ME(2-mecaptoethanol).The cells grew well in the temperature range of 24-30 ℃ and the optimal growth temperature was 24℃.FBS and bFGF concentrations are the two key components for CSEC cells proliferation.Chromosome analysis reveals that CSEC cells have a normal diploid karyotype with 2n=42t.The significant fluorescent signals were observed in CSEC after transfection with the GFP reporter gene,suggesting that the CSEC cell line can be used as a useful tool for transgenic and genetic manipulation studies.CSEC cells showed the cytopathic effect(CPE) after infection with lymphosystis disease virus(LCDV) in 2 d.Moreover,the LCDV particles can be observed in the cytoplasm of virus-infected cells by electron microscopy.It suggests that CSEC could be potentially used for the study of aquatic virus.展开更多
Differential expression of genes is crucial to growth and development of fish.To select the appropriate genes for gene normalization during Cynoglossus semilaevis early developmental process,eight candidate reference ...Differential expression of genes is crucial to growth and development of fish.To select the appropriate genes for gene normalization during Cynoglossus semilaevis early developmental process,eight candidate reference genes(ACTB,B2 M,EF1 A,GADPH,RPL7,TUBA,UBCE and 18S) were tested for their adequacy by using quantitative real-time PCR.The results showed that the expression of all the examined genes exhibited tissue dependent variations in the mature C.semilaevis.EF1 A was listed as the most stable reference among the 14 tissues by Ref Finder.Furthermore,the recommended comprehensive ranking of the stability determined by Ref Finder showed that 18 S was the most stable gene during the early developmental stages(from oosphere to 90 days old) in this study.However,when divided the Ct value data of the above mentioned early developmental stages into two separate periods(embryo and post-hatching periods),TUBA and 18 S represented the most stable references of these two developmental periods,respectively.Consequently,the reference gene should be carefully and accurately chosen even for studies of the same species at various developmental processes.The relevant data may help in selecting appropriate reference genes for m RNA expression analysis,and is of great value in the studies of fish growth and development.展开更多
Saccharina japonica gametophytes can survive a long period under unfavorable environmental conditions,while they also delay in growth and/or reproduction.Although the reproduction in delayed gametophyte of S.japonica ...Saccharina japonica gametophytes can survive a long period under unfavorable environmental conditions,while they also delay in growth and/or reproduction.Although the reproduction in delayed gametophyte of S.japonica was known to be strongly influenced by light intensity,light quality,and photoperiod,no previous studies have evaluated their interactive effects on gametogenesis.To evaluate these effects,we used an orthogonal experiment to expose delayed gametophytes of S.japonica to different light intensities,light qualities,and photoperiods for 12 days.The results showed that changes in light intensity rather than light quality and photoperiod significantly affected the relative growth rates of the delayed gametophytes.Blue light had the greatest promotion on reproduction rate.The optimal light conditions in the early vegetative growth phase in gametogenesis induction for the delayed gametophytes were at 60–80μmol photons m^(−2) s^(−1) with daylength of 12 or 16 hours under white or blue light.When the delayed gametophytes were maintained in a constant light condition from delayed state to gametogenesis,the beneficial photoperiods for vegetative growth and reproductive rate were both 16L(16 hours of light):8D(8 hours of dark).However,when the delayed S.japonica gametophytes achieve the optimal growth state during the first 6 days and then they were cultured at different light conditions for the following 6 days,the reproduction rate increased as the daylength decreased and attained a peak value in group of 8L:16D photoperiod,indicating that photoperiod adjustment at the transition period is crucial in the gametogenesis induction process of delayed gametophyte of S.japonica.展开更多
The Western Subarctic Gyre(WSG)is one of the two gyre-systems in the subarctic North Pacific known for high nutrient and low-chlorophyll waters.However,the bacterioplankton in marine water of this area,either in terms...The Western Subarctic Gyre(WSG)is one of the two gyre-systems in the subarctic North Pacific known for high nutrient and low-chlorophyll waters.However,the bacterioplankton in marine water of this area,either in terms of the taxonomic composition or functional structure,remains relatively unexplored.A total of 22 sampling sites from two water layers(surface water,SW and 50-m layer water,FW)were collected in this area.The physiochemical parameters of waters,Synechococcus,and bacterial density,as well as the bacterioplankton community composition and distribution pattern,were analyzed.The nutrient concentrations of DIN,DIP,and DSi,Chl-a concentration,and the average abundance of heterobacteria in FW were higher than those in SW.However,temperature and the average abundance of Synechococcus and pico-eukaryotes were higher in SW.A total of 3269 OTUs were assigned,and 2123OTUs were commonly shared;moreover,similar alpha diversity patterns were observed in both SW and FW.The bacterioplankton community showed significantly obvious correlation with salinity,DIP,DIN,and Chl a in both SW and FW.Proteobacteria,Cyanobacteria,Bacteroidota,Actinobacteriota,and Firmicutes were the main phyla while Synechococcus_CC9902,Psychrobacter,and Sulfitobacter were the dominant genera in each sampling site.Most correlations that happened between the OTUs in the cooccurrence network were positive and inter-module.Higher edges and graph density were found in SW,indicating that more correlations occurred,and the community was more complex in SW.This study provided novel knowledge on the bacterioplankton community structure and the correlation characteristics in WSG.展开更多
Stomatopods are better known as mantis shrimp with considerable ecological importance in wide coastal waters globally. Some stomatopod species are exploited commercially, including Oratosquilla oratoria in the Northwe...Stomatopods are better known as mantis shrimp with considerable ecological importance in wide coastal waters globally. Some stomatopod species are exploited commercially, including Oratosquilla oratoria in the Northwest Pacific. Yet, few studies have published to promote accurate habitat identification of stomatopods, obstructing scientific management and conservation of these valuable organisms. This study provides an ensemble modeling framework for habitat suitability modeling of stomatopods, utilizing the O. oratoria stock in the Bohai Sea as an example. Two modeling techniques(i.e., generalized additive model(GAM) and geographical weighted regression(GWR)) were applied to select environmental predictors(especially the selection between two types of sediment metrics) that better characterize O. oratoria distribution and build separate habitat suitability models(HSM). The performance of the individual HSMs were compared on interpolation accuracy and transferability.Then, they were integrated to check whether the ensemble model outperforms either individual model, according to fishers’ knowledge and scientific survey data. As a result, grain-size metrics of sediment outperformed sediment content metrics in modeling O. oratoria habitat, possibly because grain-size metrics not only reflect the effect of substrates on burrow development, but also link to sediment heat capacity which influences individual thermoregulation. Moreover, the GWR-based HSM outperformed the GAM-based HSM in interpolation accuracy,while the latter one displayed better transferability. On balance, the ensemble HSM appeared to improve the predictive performance overall, as it could avoid dependence on a single model type and successfully identified fisher-recognized and survey-indicated suitable habitats in either sparsely sampled or well investigated areas.展开更多
Western Subarctic Gyre(WSG),which possesses distinctive differences in oceanographic and biogeochemical processes,is situated in the northwest subarctic Pacific.The WSG is characterized by high nutrient and low chloro...Western Subarctic Gyre(WSG),which possesses distinctive differences in oceanographic and biogeochemical processes,is situated in the northwest subarctic Pacific.The WSG is characterized by high nutrient and low chlorophyll.We carried out a field investigation in this area in summer 2020 and performed microscopic observation,cytometric counting,and RuBisCO large subunit(rbc L)gene analysis to understand the community structure and spatial distribution of chromophytic phytoplankton better.Microscopic method revealed that total phytoplankton(>10μm,including Bacillariophyta,Dinoflagellata,Ochrophyta,and Chlorophyta)abundances ranged(0.6×10^(3))-(167.4×10^(3))cells/L with an increasing trend from south to north.Dinoflagellates and Pennatae diatoms dominated the phytoplankton assemblages in the southern and northern stations,respectively.Major chromophytic phytoplankton groups derived from rbc L genes included Haptophyta,Ochrophyta,Bacillariophyta,as well as rarely occurring groups,such as Xanthophyta,Cyanobacteria,Dinoflagellata,Rhodophyta,and Cryptophyta.At the phylum level,Haptophyta was the most abundant phylum,accounting for approximately 30.80%of the total obtained operational taxonomic units in all samples.Ochrophyta and Bacillariophyta were the second and third most abundant phylum,and their relative abundance was 20.26% and 19.60%,respectively.Further,redundancy analysis showed that high proportion of diatoms(e.g.,microscopic and rbc L methods)was positively correlated with nutrients(e.g.,dissolved inorganic nitrogen(DIN),dissolved inorganic phosphorous,and dissolved silicate(DSi))and negatively correlated with temperature and salinity.The proportion of Ochrophyta,Rhodophyta,and Cyanobateria identified by rbc L genes was positively correlated with salinity and temperature and showed negative correlation to nutrients.This work is the first molecular study of phytoplankton accomplished in the WSG,and our results show some discrepancies between morphological observation and rbc L gene sequences,which highlight the necessity of combining the microscopic and molecular methods to reveal the diversity of phytoplankton in marine environment.展开更多
Though the larval development of bivalves has been extensively studied for commercial purposes,the dynamic development of larval muscle system remains largely unknown.In this study,we characterized the larval muscle s...Though the larval development of bivalves has been extensively studied for commercial purposes,the dynamic development of larval muscle system remains largely unknown.In this study,we characterized the larval muscle system at different developmental stages(D-shaped veligers,umbo veligers and spats)in the bay scallop(Argopecten irradians)by phalloidin staining and under a confocal microscopy.The functional muscles are initially established at the early stage of veligers,which have four pairs of velar retractors and one anterior adductor.At the veliger stage,the velum and posterior retractor muscles are functionally important for velar contractility but undergo an irreversible shrink until they disappear at the end of the larval stage.During metamorphosis,three crucial modifications take place in the larval muscle system.The metamorphosis process involves the gradual degeneration of velum retractors,mantle margin development from an unfolded to a three-fold state,and remodeling of the adductor muscle system from dimyarian(two adductors)to monomyarian condition(one adductor)as in juveniles/adults.All retractor muscles are composed of striated muscle,but both anterior and posterior adductors have smooth and striated components.These findings highlight that the morphological changes at different stages are typical features of myogenesis in scallops.The present knowledge on the developmental dynamics of myogenesis in the bay scallop will not only improve our understanding of phenotypic diversity of larval myoanatomy in bivalves,but also provide useful information on the larval culture in hatcheries.展开更多
To characterize environmental factors controlling decadal-scale variations in the buried flux of marine organic carbon(BFC_(m))in the eastern shelf sea areas of China(ECSS),four well preserved sediment cores collected...To characterize environmental factors controlling decadal-scale variations in the buried flux of marine organic carbon(BFC_(m))in the eastern shelf sea areas of China(ECSS),four well preserved sediment cores collected from the central Yellow Sea mud(CYSM)area,the Yellow Sea Coastal Current(YSCC)area and the Changjiang River Estuary(CRE)were investigated in this study.In the CYSM,variations in BFC_(m) were found to be dependent on variations in primary productivity and to exhibit a cyclical trend possibly related to fluctuations in the Pacific Decadal Oscillation(PDO)and the East Asian winter monsoon index(EAWM).In the YSCC,BFC_(m) likewise depends on primary productivity.Prior to the 1950s,variations in BFC_(m) were similar to that of the EAWM.After the 1950s,BFC_(m) increased rapidly and exhibited maximum values in the surface layer,consistent with an increase in primary productivity caused by the input of terrestrial nutrients associated with China’s economic development.In the CRE,variations in BFC_(m) were affected by several competing factors making it difficult to identify clear relationships between variations in BFC_(m) and primary productivity.In contrast,long-term variability in BFC_(m) is more similar to changes in the Changjiang River sediment load.Thus,it is speculated that the construction of dams along the Changjiang River may be the main cause of variations in BFC_(m) in this area.Given the disproportionate effects of human activities on marine environments and decadal variations in BFC_(m) in the ECSS,careful attention should be paid to regional differences in organic carbon preservation and environmental changes lest estimates of these values be made imprecise or inaccurate.展开更多
Myogenic Regulatory Factors(MRFs)is involved in the muscle growth and differentiation.In this study,the cDNA sequence of yellowtail kingfish MRFs genes were cloned by rapid amplification of cDNA ends(RACE)method;then,...Myogenic Regulatory Factors(MRFs)is involved in the muscle growth and differentiation.In this study,the cDNA sequence of yellowtail kingfish MRFs genes were cloned by rapid amplification of cDNA ends(RACE)method;then,the character-istics of these genes and the predicted protein sequences were analyzed by bioinformatics methods,the tissue and embryonic stages differential expression pattern were detected by the quantitative real-time PCR.Our results showed that the yellowtail kingfish(YTK)Myf5 cDNA has a full length of 951 bp,encoding 266 amino acids.The yellowtail kingfish Myf6 cDNA has a full length of 1105bp,encoding 250 amino acids.The proteins containα-helix,β-strand,and loops.The Neighbour-joining tree revealed that YTK Myf5 and Myf6 are closely related to Seriola dumerili.The yellowtail kingfish Myf5 and Myf6 gene expressed significantly higher in mus-cle than in other tissues(P<0.05).In addition,Myf5 and Myf6 in muscle was significantly expressed in 400g and 500 g fish but not in 50 g,suggesting that myogenic regulatory factors expression had a great relationship with the fish size.Our results also indicated that Myf5 and Myf6 have different functions during embryonic development,because Myf5 showed highest expression level at the neuroembryo period,but Myf6 had the highest expression level at embryo coverage yolk 70%stage.Myf5 gene showed highest ex-pression at 30 d of age,suggesting it played key roles in myogenic period.However,the Myf6 gene was significantly highly ex-pressed at 60 d,revealing this gene functioned in the later muscle formation period.展开更多
In the present study, Fenneropenaeus chinensis individuals were assigned into six groups, and fed with a diet supplemented with 0(Con-trol), 0.5%(Group E0.5), 1.0%(Group E1.0), 2.0%(Group E2.0), 3.0%(Group E3.0) or 5....In the present study, Fenneropenaeus chinensis individuals were assigned into six groups, and fed with a diet supplemented with 0(Con-trol), 0.5%(Group E0.5), 1.0%(Group E1.0), 2.0%(Group E2.0), 3.0%(Group E3.0) or 5.0%(Group E5.0) of poly-β-hydroxybutyrate(PHB) during their growth and spawning periods, to explore the effect of PHB on the reproductive performance of parents and the development of larvae. The experi-ment was lasted for 192 d to measure the mortality rate, relative percentage of survival(RPS), weight gain rate(WGR), specific growth rate(SGR) and cycle of gonadal development of parental shrimps, number of eggs, number of nauplii, stages of larval development and metamorphosis. The results indicated that PHB had an obvious effect on the fecundity of parental shrimps and growth performance of larva. Compared with control group, the mortality rate of broodstock in experimental groups decreased initially and increased subsequently with the increase of PHB concentration, while RPS showed an opposite pattern. The mortality rate of group E2.0 was the lowest among all groups, showing significant difference from that of other groups(P﹤0.05) except group E1.0(P﹥0.05). WGR of all experimental groups was higher than that of the control group, among which, group E2.0 and group E5.0 had significantly higher WGR than the control(P<0.05). However, there was no significant difference in the cycle of gonadal development between the experimental groups and the control group(P ﹥ 0.05). The numbers of eggs and nauplii in the experimental groups were higher than those of the control group. And the numbers of eggs and nauplii in group E2.0 were significantly higher than those of the control(P ﹤ 0.05), bud showed no significant difference from those of other groups(P﹥0.05). However, there was no significant difference in the duration of larval devel-opment and metamorphosis among all the groups. In summary, PHB is capable of improving the reproductive performance of parents and the survival and development of larva in F. chinensis, and 2.0% is the optimal concentration of PHB supplemented to the diet.展开更多
Turbot Scophthalmus maximus, an important aquaculture species in China, currently suffers from epizootic diseases because of high density aquaculture. Enrofloxacin has been used to treat various systemic bacterial fis...Turbot Scophthalmus maximus, an important aquaculture species in China, currently suffers from epizootic diseases because of high density aquaculture. Enrofloxacin has been used to treat various systemic bacterial fish infections. However, studies concerning the pharmacokinetics of enrofloxacin in turbot are limited. In this study, the pharmacokinetics of enrofloxacin and its metabolite ciprofloxacin, were investigated in the turbot following intravenous and oral administration at 10 mg enrofloxacin/kg body weight, at 16°C and 10°C water temperatures. The concentrations of enrofloxacin and ciprofloxacin in the main tissues (plasma, muscle, liver and kidney) were detected by HPLC. The results show that the plasma concentration-time data for enrofloxacin were best described as a two-compartment open model after intravenous and oral administration. Three pharmacokinetic equations were established between the concentrations and temperatures. The kinetic profile of enrofloxacin was temperature dependent. The absorption half-life of enrofloxacin was 1.99 h and 2.17 h after oral administration, whereas the elimination half-life of the drug was 98.63 h and 136.59 h at 16°C and 10°C, respectively. The peak concentration of enrofloxacin in plasma and tissues was higher at 16°C than that at 10°C, and the peak plasma concentration time in the liver was the shortest at both temperatures among those of other tissues. The plasma C max /MIC ratio varied between 11.08 and 5 540.00 at 16°C; and between 7.92 and 3 960.00 at 10°C. The AUC/MIC ratio was 467.82-280 690.00 at 16°C, and 359.48-215 690.00 at 10°C. These ratios indicate that it is possible to obtain therapeutic efficacy. Very low levels of ciprofloxacin were detected. The AUC ratios of ciprofloxacin and enrofloxacin in plasma suggest that plasma ciprofloxacin might play a minor role in enrofloxacin treatment for turbot.展开更多
Catalase(CAT) and selenium-dependent glutathione peroxidase(Se-GPx) play a vital role in protecting organisms against various oxidative stresses by eliminating H2O2. The objective of this paper is to evaluate the role...Catalase(CAT) and selenium-dependent glutathione peroxidase(Se-GPx) play a vital role in protecting organisms against various oxidative stresses by eliminating H2O2. The objective of this paper is to evaluate the roles of these antioxidant molecules in the ridgetail white prawn Exopalaemon carinicauda in response to low salinity stress. A complementary DNA(cDNA) containing the complete coding sequence of CAT was cloned from the hepatopancreas using reverse-transcription polymerase chain reaction(RT-PCR) and rapid amplification of cDNA ends. The full-length cDNA of CAT(2 649 bp) contains a 5'-untranslated region(UTR) of 78 bp, a 3'- UTR of1 017 bp, with a poly(A) tail, and an open reading frame of 1 554 bp encoding a 517-amino-acid polypeptide with predicted molecular mass of 58.46 kDa and estimated isoelectric point of 6.64. This CAT sequence contained the proximal active site signature(60FDRERIPERVVHAKGAG76), proximal heme-ligand signature sequence(350RLFSYPDTH358) and three catalytic amino acid residues(His71, Asn144 and Tyr354). Sequence comparison showed that the CAT deduced amino acid sequence of E. carinicauda shared 68%-92% of identities with those of other species. Quantitative real-time PCR analysis revealed that CAT m RNA was widely expressed in the hepatopancreas(highest), hemocyte, eyestalk, heart, gill, muscle, ovary and stomach. Under low salinity stress,CAT and GPx m RNA expression levels both in the gill and hepatopancreas increased significantly at the first 48 h and 6 h respectively, indicating a tissue- and time-dependent antioxidant response in E. carinicauda. All these results indicate that E. carinicauda CAT is a member of the CAT family and might be involved in the acute response against low salinity stress.展开更多
Three surveys were carried out in Pearl River Estuary and adjacent coastal area in May, August, and November, 2013, to investigate the temporal and spatial variations of abundance of phycoerythrin-rich Synechococcus(P...Three surveys were carried out in Pearl River Estuary and adjacent coastal area in May, August, and November, 2013, to investigate the temporal and spatial variations of abundance of phycoerythrin-rich Synechococcus(PE-rich SYN) and phycocyanin-rich Synechococcus(PC-rich SYN). The effects of environmental factors on the alternation of the different Synechococcus groups were also elucidated. PE-rich SYN was detected in three surveys, whereas PC-rich SYN was detected in May and August, but not in November. The highest abundances of PE-rich SYN and PC-rich SYN were recorded in August and May, with mean values of 74.17×103 and 189.92×103 cells m L-1, respectively. From May to November, the relative abundance of PE-rich SYN increased, whereas that of PC-rich SYN declined. PE-rich and PC-rich SYN presented similar horizontal distributions with high abundance in the southern estuary in May, and in the western estuary in August. The abundances of PE-rich and PC-rich SYN were high at 27–32℃and salinity of 10–20. PC-rich SYN was not detected at < 24℃, and PC:PE-rich SYN decreased in abundance with salinity increase. When less than 20 mg L-1, suspended particulate matter(SPM) was helpful for Synechococcus growth. PE-rich SYN decreased in abundance when the concentration of dissolved inorganic nitrogen increased in May and November, and the concentration of phosphate increased in November. However, PC-rich SYN abundance and nutrients showed no correlation. Principal component analysis and regression analysis indicated that PE-rich SYN significantly correlated with the principal components that were affected by environmental factors.展开更多
Spatial interpolation is a common tool used in the study of fishery ecology, especially for the construction of ecosystem models. To develop an appropriate interpolation method of determining fishery resources density...Spatial interpolation is a common tool used in the study of fishery ecology, especially for the construction of ecosystem models. To develop an appropriate interpolation method of determining fishery resources density in the Yellow Sea, we tested four frequently used methods, including inverse distance weighted interpolation(IDW), global polynomial interpolation(GPI), local polynomial interpolation(LPI) and ordinary kriging(OK).A cross-validation diagnostic was used to analyze the efficacy of interpolation, and a visual examination was conducted to evaluate the spatial performance of the different methods. The results showed that the original data were not normally distributed. A log transformation was then used to make the data fit a normal distribution. During four survey periods, an exponential model was shown to be the best semivariogram model in August and October 2014, while data from January and May 2015 exhibited the pure nugget effect.Using a paired-samples t test, no significant differences(P>0.05) between predicted and observed data were found in all four of the interpolation methods during the four survey periods. Results of the cross-validation diagnostic demonstrated that OK performed the best in August 2014, while IDW performed better during the other three survey periods. The GPI and LPI methods had relatively poor interpolation results compared to IDW and OK. With respect to the spatial distribution, OK was balanced and was not as disconnected as IDW nor as overly smooth as GPI and LPI, although OK still produced a few "bull's-eye" patterns in some areas.However, the degree of autocorrelation sometimes limits the application of OK. Thus, OK is highly recommended if data are spatially autocorrelated. With respect to feasibility and accuracy, we recommend IDW to be used as a routine interpolation method. IDW is more accurate than GPI and LPI and has a combination of desirable properties, such as easy accessibility and rapid processing.展开更多
The dinoflagellate genus K arenia is known for recurrent harmful blooms worldwide. However, species diversity of the genus is generally overlooked owing to the difficulty of identifying small unarmored dinoflagellates...The dinoflagellate genus K arenia is known for recurrent harmful blooms worldwide. However, species diversity of the genus is generally overlooked owing to the difficulty of identifying small unarmored dinoflagellates. We have established four clonal cultures of K arenia longicanalis isolated from the type locality, Hong Kong harbor(strain HK01) and other three locations along the Chinese coasts(strains YB01, DT01, and NJ01). The morphology of the strain was studied by light and scanning electron microscopy(LM and SEM) and the pigment composition analyzed by high-performance liquid chromatography. We provide the first molecular data of K. longicanalis based on the large subunit(LSU) rRNA gene sequence and internal transcribed spacer(ITS). The four strains showed identical LSU rDNA sequences with a similarity of 99.4% to the holotype of K arenia umbella(strain KUTN05) from Australia. In the ITS phylogeny, the sequence of K. umbella branched between the Chinese strains of K. longicanalis. A careful comparison of the morphology of K. longicanalis and K. umbella reveals the similarity in the diagnostic characters. Diff erences may appear due to the sample treatment for SEM. We conclude that K. umbella is a junior synonym of K. longicanalis.展开更多
Intensive use of sulfamethazine(SM_2) in aquaculture has resulted in some detrimental effects to non-targeted organisms. In order to assess its potential ecological risk, it is crucial to have a good understanding on ...Intensive use of sulfamethazine(SM_2) in aquaculture has resulted in some detrimental effects to non-targeted organisms. In order to assess its potential ecological risk, it is crucial to have a good understanding on the bioaccumulation and biodegradation of SM_2 in Chlorella pyrenoidosa. The microalgae were treated with 2, 4, and 8 mg L^(-1) of sulfamethazine for 13 days, respectively, showing that the inhibition effects of sulfamethazine on the growth of Chlorella pyrenoidosa increased progressively as the concentrations of sulfamethazine increasing from 2 to 8 mg L^(-1). The peak concentrations of sulfamethazine accumulated in C. pyrenoidosa were 0.225, 0.325, and 0.596 ng per mg FW on day 13 for three treatment groups, respectively, showing a great ability to deplete sulfamethazine from the culture media. On day 13, the percentages of biotic degradation were 48.45%, 60.21% and 69.93%, respectively. The EC_(50) of 10.05 mg L^(-1) was derived which showed no significant risk for C. pyrenoidosa with a calculated risk quotient < 1. The activities of superoxide dismutase and catalase increased progressively in response to sulfamethazine and showed a positive correlation to the treatment concentrations. The highest superoxide dismutase activity was achieved at the concentration of 8 mg L^(-1) after 2 d of exposure, which was 1.89 folds higher than that of the control. The activity of catalase has a similar pattern to that of superoxide dismutase with the maximum activity achieved at day 2, which was 3.11 folds higher compared to that of the control. In contrast to superoxide dismutase and catalase, the maximum glutathione S-transferase activity was observed at day 6, showing 2.2 folds higher than that of the control.展开更多
基金Laoshan Laboratory under contract No.LSKJ202203803。
文摘The resource of Fenneropenaeus chinensis has declined sharply due to excessive fishing intensity,ecological changes and diseases.In order to supplement the fishing yield and restore resources of F.chinensis,the relevant authorities have carried out the activities of stock enhancement and releasing.It can increase biomass and recover resources.However,compared with increasing biomass,there were still few reports on its effect on the recovery of resources.Resource recovery is a process related to whether the released individuals can form a reproductive population.Up to now,there has been a lack of evidence whether the released F.chinensis can complete the entire life history,and form reproduction population.In this study,gravid female shrimp after spawning migration were captured from coastal waters of Haiyang,Qingdao,and Yellow Sea.After identifying parentage relationships using simple sequence repeat(SSR)and mtDNA haplotype,it was finally confirmed that there were eight released individuals in the recapture samples.It was confirmed for the first time that at least part of the released F.chinensis can complete overwintering and reproductive migration,and maintain the migration habits as their wild counterparts.Therefore,we infered that the released shrimp can reproduce under natural conditions,these F.chinensis can form reproductive populations theoretically if without human intervention.These results indicated that enhancenment and release activities have a positive effect on resource recovery.
基金supported by the National Natural Science Foundation of China(No.32002442)the National Key R&D Program(No.2019YFD0902101).
文摘On the basis of computational fluid dynamics,the flow field characteristics of multi-trophic artificial reefs,including the flow field distribution features of a single reef under three different velocities and the effect of spacing between reefs on flow scale and the flow state,were analyzed.Results indicate upwelling,slow flow,and eddy around a single reef.Maximum velocity,height,and volume of upwelling in front of a single reef were positively correlated with inflow velocity.The length and volume of slow flow increased with the increase in inflow velocity.Eddies were present both inside and backward,and vorticity was positively correlated with inflow velocity.Space between reefs had a minor influence on the maximum velocity and height of upwelling.With the increase in space from 0.5 L to 1.5 L(L is the reef lehgth),the length of slow flow in the front and back of the combined reefs increased slightly.When the space was 2.0 L,the length of the slow flow decreased.In four different spaces,eddies were present inside and at the back of each reef.The maximum vorticity was negatively correlated with space from 0.5 L to 1.5 L,but under 2.0 L space,the maximum vorticity was close to the vorticity of a single reef under the same inflow velocity.
基金The National Key R&D Program of China under contract No.2017YFE0104400the National Basic Research Program of China under contract No.2015CB453303+2 种基金the Special Funds for Taishan Scholars Project of Shandong Provincethe AoShan Talents Cultivation Program supported by Qingdao National Laboratory for Marine Science and Technology under contract No.2017ASTCPES07the Central Public-interest Scientific Institution Basal Research Fund,CAFS under contract No.2018GH20
文摘China(herein referred as China’s mainland,and excluding Hong Kong,Macao and Taiwan)ranks as the world’s leading fishing nation,with approximately 11.1 million tons of domestic marine catch acquired in 2017.Marine fisheries resources in China are mainly exploited by its 11 coastal provinces and municipalities,and the development of fishing industry varies among them.However,few studies have examined the exploitation history of the 11 coastal provinces and municipalities.In this paper,we systematically quantified the exploitation history of marine fishery resources in China and then measured the vulnerability of the 11 coastal provinces and municipalities of China to a reduction in marine catches.Our analysis suggested that Chinese marine fisheries experienced rapid growth from the mid-1980 s to the end of the 20 th century,and this rapid increase in marine catches were mainly promoted by increased fishing effort.The total primary production required level amounted to approximately 80%of the average primary productivity in 2017,and Zhejiang,Fujian,Shandong,Hainan and Guangdong provinces were the main fishing provinces in China.By assessing three dimensions of vulnerability(exposure,sensitivity and adaptive capacity)to the impacts of a reduction in marine catches in the 11 coastal provinces and municipalities,we found that Hainan,Guangxi,Zhejiang and Fujian provinces had high or very high vulnerability,while the municipalities of Shanghai and Tianjin had low vulnerability.Identifying suitable adaptation policies and management plans based on the differences in vulnerability among coastal provinces is important in sustainable fisheries management.
基金The Earmarked Fund for Modern Agro-Industry Technology Research System under contract No.CARS-50-G01
文摘In order to elucidate the genetic mechanism of growth traits in turbot during ontogeny, developmental genetic analysis of the body weights, total lengths, standard lengths and body heights of turbots was conducted by mixed genetic models with additive-dominance effects, based on complete diallel crosses with four different strains of Scophthalmus maximus from Denmark, Norway, Britain, and France. Unconditional genetic analysis revealed that the unconditional additive effects for the four traits were more significant than unconditional dominance effects, meanwhile, the alternative expressions were also observed between the additive and dominant effects for body weights, total lengths and standard lengths. Conditional analysis showed that the developmental periods with active gene expression for body weights, total lengths, standard lengths and body heights were 15–18, 15 and 21–24, 15 and 24, and 21 and 27 months of age, respectively. The proportions of unconditional/conditional variances indicated that the narrow-sense heritabilities of body weights, total lengths and standard lengths were all increased systematically. The accumulative effects of genes controlling the four quantitative traits were mainly additive effects, suggesting that the selection is more efficient for the genetic improvement of turbots. The conditional genetic procedure is a useful tool to understand the expression of genes controlling developmental quantitative traits at a specific developmental period(t-1→t) during ontogeny. It is also important to determine the appropriate developmental period(t-1→t) for trait measurement in developmental quantitative genetic analysis in fish.
基金The State "863" High-Technology Research and Development Project of China under contract Nos 2006AA09Z406 and 2006AA10A401the National Natural Science Foundation of China under contract No. 40376047the Taishan Scholar Project of Shandong Province and MOA for returned scientists from abroad
文摘A new cell line,CSEC,has been successfully established from embryos at gastrula stage of a cultured marine fish,half smooth tongue sole(Cynoglossus semilaevis).CSEC cells grow actively and stably more than 50 passages for over 200 d in DMEM medium supplemented with 15% FBS(fetal bovine serum),2.5 ng/cm 3 bFGF(basic fibroblast growth factor),1 ng/cm 3 LIF(leukemia inhibitory factor) and 50 mmol/dm 3 2-ME(2-mecaptoethanol).The cells grew well in the temperature range of 24-30 ℃ and the optimal growth temperature was 24℃.FBS and bFGF concentrations are the two key components for CSEC cells proliferation.Chromosome analysis reveals that CSEC cells have a normal diploid karyotype with 2n=42t.The significant fluorescent signals were observed in CSEC after transfection with the GFP reporter gene,suggesting that the CSEC cell line can be used as a useful tool for transgenic and genetic manipulation studies.CSEC cells showed the cytopathic effect(CPE) after infection with lymphosystis disease virus(LCDV) in 2 d.Moreover,the LCDV particles can be observed in the cytoplasm of virus-infected cells by electron microscopy.It suggests that CSEC could be potentially used for the study of aquatic virus.
基金The National Natural Science Foundation of China under contract No.31201981China Postdoctoral Science Foundation under contract No.2013M531658the Special Scientific Research Funds for Central Non-profit Institutes,Yellow Sea Fisheries Research Institutes under contract No.20603022012032
文摘Differential expression of genes is crucial to growth and development of fish.To select the appropriate genes for gene normalization during Cynoglossus semilaevis early developmental process,eight candidate reference genes(ACTB,B2 M,EF1 A,GADPH,RPL7,TUBA,UBCE and 18S) were tested for their adequacy by using quantitative real-time PCR.The results showed that the expression of all the examined genes exhibited tissue dependent variations in the mature C.semilaevis.EF1 A was listed as the most stable reference among the 14 tissues by Ref Finder.Furthermore,the recommended comprehensive ranking of the stability determined by Ref Finder showed that 18 S was the most stable gene during the early developmental stages(from oosphere to 90 days old) in this study.However,when divided the Ct value data of the above mentioned early developmental stages into two separate periods(embryo and post-hatching periods),TUBA and 18 S represented the most stable references of these two developmental periods,respectively.Consequently,the reference gene should be carefully and accurately chosen even for studies of the same species at various developmental processes.The relevant data may help in selecting appropriate reference genes for m RNA expression analysis,and is of great value in the studies of fish growth and development.
基金financially supported by the National Key R&D Program of China(Nos.2018YFD0900305,2018YFD 0901500)the China Agriculture Research System of MOF and MARA,Central Public-interest Scientific Institution Basal Research Fund CAFS(No.2020TD27)the‘Young Talent of Fishery Sciences’project from Laboratory for Marine Fisheries and Aquaculture(No.2018-MFS-T12).
文摘Saccharina japonica gametophytes can survive a long period under unfavorable environmental conditions,while they also delay in growth and/or reproduction.Although the reproduction in delayed gametophyte of S.japonica was known to be strongly influenced by light intensity,light quality,and photoperiod,no previous studies have evaluated their interactive effects on gametogenesis.To evaluate these effects,we used an orthogonal experiment to expose delayed gametophytes of S.japonica to different light intensities,light qualities,and photoperiods for 12 days.The results showed that changes in light intensity rather than light quality and photoperiod significantly affected the relative growth rates of the delayed gametophytes.Blue light had the greatest promotion on reproduction rate.The optimal light conditions in the early vegetative growth phase in gametogenesis induction for the delayed gametophytes were at 60–80μmol photons m^(−2) s^(−1) with daylength of 12 or 16 hours under white or blue light.When the delayed gametophytes were maintained in a constant light condition from delayed state to gametogenesis,the beneficial photoperiods for vegetative growth and reproductive rate were both 16L(16 hours of light):8D(8 hours of dark).However,when the delayed S.japonica gametophytes achieve the optimal growth state during the first 6 days and then they were cultured at different light conditions for the following 6 days,the reproduction rate increased as the daylength decreased and attained a peak value in group of 8L:16D photoperiod,indicating that photoperiod adjustment at the transition period is crucial in the gametogenesis induction process of delayed gametophyte of S.japonica.
基金Supported by the National Key Research and Development Program of China(No.2019YFD0901401)the Natural Science Foundation of Shandong Province(No.ZR202102280248)+1 种基金the National Natural Science Foundation of China(No.81900630)the Outstanding Youth Project of Yunnan Provincial Department of Science and Technology(No.2019F1019)。
文摘The Western Subarctic Gyre(WSG)is one of the two gyre-systems in the subarctic North Pacific known for high nutrient and low-chlorophyll waters.However,the bacterioplankton in marine water of this area,either in terms of the taxonomic composition or functional structure,remains relatively unexplored.A total of 22 sampling sites from two water layers(surface water,SW and 50-m layer water,FW)were collected in this area.The physiochemical parameters of waters,Synechococcus,and bacterial density,as well as the bacterioplankton community composition and distribution pattern,were analyzed.The nutrient concentrations of DIN,DIP,and DSi,Chl-a concentration,and the average abundance of heterobacteria in FW were higher than those in SW.However,temperature and the average abundance of Synechococcus and pico-eukaryotes were higher in SW.A total of 3269 OTUs were assigned,and 2123OTUs were commonly shared;moreover,similar alpha diversity patterns were observed in both SW and FW.The bacterioplankton community showed significantly obvious correlation with salinity,DIP,DIN,and Chl a in both SW and FW.Proteobacteria,Cyanobacteria,Bacteroidota,Actinobacteriota,and Firmicutes were the main phyla while Synechococcus_CC9902,Psychrobacter,and Sulfitobacter were the dominant genera in each sampling site.Most correlations that happened between the OTUs in the cooccurrence network were positive and inter-module.Higher edges and graph density were found in SW,indicating that more correlations occurred,and the community was more complex in SW.This study provided novel knowledge on the bacterioplankton community structure and the correlation characteristics in WSG.
基金The National Natural Science Foundation of China under contract No.31902375the David and Lucile Packard Foundation+1 种基金the Innovation Team of Fishery Resources and Ecology in the Yellow Sea and Bohai Sea under contract No.2020TD01the Special Funds for Taishan Scholars Project of Shandong Province。
文摘Stomatopods are better known as mantis shrimp with considerable ecological importance in wide coastal waters globally. Some stomatopod species are exploited commercially, including Oratosquilla oratoria in the Northwest Pacific. Yet, few studies have published to promote accurate habitat identification of stomatopods, obstructing scientific management and conservation of these valuable organisms. This study provides an ensemble modeling framework for habitat suitability modeling of stomatopods, utilizing the O. oratoria stock in the Bohai Sea as an example. Two modeling techniques(i.e., generalized additive model(GAM) and geographical weighted regression(GWR)) were applied to select environmental predictors(especially the selection between two types of sediment metrics) that better characterize O. oratoria distribution and build separate habitat suitability models(HSM). The performance of the individual HSMs were compared on interpolation accuracy and transferability.Then, they were integrated to check whether the ensemble model outperforms either individual model, according to fishers’ knowledge and scientific survey data. As a result, grain-size metrics of sediment outperformed sediment content metrics in modeling O. oratoria habitat, possibly because grain-size metrics not only reflect the effect of substrates on burrow development, but also link to sediment heat capacity which influences individual thermoregulation. Moreover, the GWR-based HSM outperformed the GAM-based HSM in interpolation accuracy,while the latter one displayed better transferability. On balance, the ensemble HSM appeared to improve the predictive performance overall, as it could avoid dependence on a single model type and successfully identified fisher-recognized and survey-indicated suitable habitats in either sparsely sampled or well investigated areas.
基金Supported by the National Key Research and Development Program of China(No.2019YFD0901401)the National Natural Science Foundation of China(Nos.42176206,81900630)+2 种基金the Natural Science Foundation of Shandong Province(No.ZR2021MD071)the“One Hundred Talents”Project of Guangxi(No.6020303891251)the Outstanding Youth Project of Yunnan Provincial Department of Science and Technology(No.2019F1019)。
文摘Western Subarctic Gyre(WSG),which possesses distinctive differences in oceanographic and biogeochemical processes,is situated in the northwest subarctic Pacific.The WSG is characterized by high nutrient and low chlorophyll.We carried out a field investigation in this area in summer 2020 and performed microscopic observation,cytometric counting,and RuBisCO large subunit(rbc L)gene analysis to understand the community structure and spatial distribution of chromophytic phytoplankton better.Microscopic method revealed that total phytoplankton(>10μm,including Bacillariophyta,Dinoflagellata,Ochrophyta,and Chlorophyta)abundances ranged(0.6×10^(3))-(167.4×10^(3))cells/L with an increasing trend from south to north.Dinoflagellates and Pennatae diatoms dominated the phytoplankton assemblages in the southern and northern stations,respectively.Major chromophytic phytoplankton groups derived from rbc L genes included Haptophyta,Ochrophyta,Bacillariophyta,as well as rarely occurring groups,such as Xanthophyta,Cyanobacteria,Dinoflagellata,Rhodophyta,and Cryptophyta.At the phylum level,Haptophyta was the most abundant phylum,accounting for approximately 30.80%of the total obtained operational taxonomic units in all samples.Ochrophyta and Bacillariophyta were the second and third most abundant phylum,and their relative abundance was 20.26% and 19.60%,respectively.Further,redundancy analysis showed that high proportion of diatoms(e.g.,microscopic and rbc L methods)was positively correlated with nutrients(e.g.,dissolved inorganic nitrogen(DIN),dissolved inorganic phosphorous,and dissolved silicate(DSi))and negatively correlated with temperature and salinity.The proportion of Ochrophyta,Rhodophyta,and Cyanobateria identified by rbc L genes was positively correlated with salinity and temperature and showed negative correlation to nutrients.This work is the first molecular study of phytoplankton accomplished in the WSG,and our results show some discrepancies between morphological observation and rbc L gene sequences,which highlight the necessity of combining the microscopic and molecular methods to reveal the diversity of phytoplankton in marine environment.
基金supported by research grants from the National Key R&D Program of China(No.2018YFD0900104)the Na-tional Natural Science Foundation of China(No.3160 2153)+1 种基金the Central Public-Interest Scientific Institution Basal Research Fund,YSFRI,CAFS(No.20603022019 005)Qingdao People’s Livelihood Science and Tech-nology Project(No.18-6-1-110-nsh)
文摘Though the larval development of bivalves has been extensively studied for commercial purposes,the dynamic development of larval muscle system remains largely unknown.In this study,we characterized the larval muscle system at different developmental stages(D-shaped veligers,umbo veligers and spats)in the bay scallop(Argopecten irradians)by phalloidin staining and under a confocal microscopy.The functional muscles are initially established at the early stage of veligers,which have four pairs of velar retractors and one anterior adductor.At the veliger stage,the velum and posterior retractor muscles are functionally important for velar contractility but undergo an irreversible shrink until they disappear at the end of the larval stage.During metamorphosis,three crucial modifications take place in the larval muscle system.The metamorphosis process involves the gradual degeneration of velum retractors,mantle margin development from an unfolded to a three-fold state,and remodeling of the adductor muscle system from dimyarian(two adductors)to monomyarian condition(one adductor)as in juveniles/adults.All retractor muscles are composed of striated muscle,but both anterior and posterior adductors have smooth and striated components.These findings highlight that the morphological changes at different stages are typical features of myogenesis in scallops.The present knowledge on the developmental dynamics of myogenesis in the bay scallop will not only improve our understanding of phenotypic diversity of larval myoanatomy in bivalves,but also provide useful information on the larval culture in hatcheries.
基金The Fund of Key Laboratory of Control of Quality and Safety for Aquatic Products,Ministry of Agriculture and Rural Affairs,P.R.China under contract No.2021C001the National Key Research and Development Program of China under contract No.2018YFD0900703the Major Scientific and Technological Innovation Project of Shandong Provincial Key Research and Development Program under contract No.2019JZZY020706。
文摘To characterize environmental factors controlling decadal-scale variations in the buried flux of marine organic carbon(BFC_(m))in the eastern shelf sea areas of China(ECSS),four well preserved sediment cores collected from the central Yellow Sea mud(CYSM)area,the Yellow Sea Coastal Current(YSCC)area and the Changjiang River Estuary(CRE)were investigated in this study.In the CYSM,variations in BFC_(m) were found to be dependent on variations in primary productivity and to exhibit a cyclical trend possibly related to fluctuations in the Pacific Decadal Oscillation(PDO)and the East Asian winter monsoon index(EAWM).In the YSCC,BFC_(m) likewise depends on primary productivity.Prior to the 1950s,variations in BFC_(m) were similar to that of the EAWM.After the 1950s,BFC_(m) increased rapidly and exhibited maximum values in the surface layer,consistent with an increase in primary productivity caused by the input of terrestrial nutrients associated with China’s economic development.In the CRE,variations in BFC_(m) were affected by several competing factors making it difficult to identify clear relationships between variations in BFC_(m) and primary productivity.In contrast,long-term variability in BFC_(m) is more similar to changes in the Changjiang River sediment load.Thus,it is speculated that the construction of dams along the Changjiang River may be the main cause of variations in BFC_(m) in this area.Given the disproportionate effects of human activities on marine environments and decadal variations in BFC_(m) in the ECSS,careful attention should be paid to regional differences in organic carbon preservation and environmental changes lest estimates of these values be made imprecise or inaccurate.
基金the National Key Research and Development Program(Nos.2018YFD0901204 and 2019YFD0900503)the National Natural Science Foun-dation of China(No.31772829)+4 种基金the Laboratory for Ma-rine Fisheries Science and Food Production Processes,Qingdao National Laboratory for Marine Science and Technology,P.R.China(No.2017-3A01)Central Pub-lic-interest Scientific Institution Basal Research,CAFS&Key Laboratory of Sustainable Development of Marine Fisheries,Ministry of Agriculture and Rural Affairs,P.R.China(No.2019HY-XKQ01)the Central Public-interest Scientific Institution Basal Research Fund,YSFRI,CAFS(No.20603022021004)the Central Public-interest Scien-tific Institution Basal Research fund,CAFS(No.47)the China Agriculture Research System(No.CARS-47).
文摘Myogenic Regulatory Factors(MRFs)is involved in the muscle growth and differentiation.In this study,the cDNA sequence of yellowtail kingfish MRFs genes were cloned by rapid amplification of cDNA ends(RACE)method;then,the character-istics of these genes and the predicted protein sequences were analyzed by bioinformatics methods,the tissue and embryonic stages differential expression pattern were detected by the quantitative real-time PCR.Our results showed that the yellowtail kingfish(YTK)Myf5 cDNA has a full length of 951 bp,encoding 266 amino acids.The yellowtail kingfish Myf6 cDNA has a full length of 1105bp,encoding 250 amino acids.The proteins containα-helix,β-strand,and loops.The Neighbour-joining tree revealed that YTK Myf5 and Myf6 are closely related to Seriola dumerili.The yellowtail kingfish Myf5 and Myf6 gene expressed significantly higher in mus-cle than in other tissues(P<0.05).In addition,Myf5 and Myf6 in muscle was significantly expressed in 400g and 500 g fish but not in 50 g,suggesting that myogenic regulatory factors expression had a great relationship with the fish size.Our results also indicated that Myf5 and Myf6 have different functions during embryonic development,because Myf5 showed highest expression level at the neuroembryo period,but Myf6 had the highest expression level at embryo coverage yolk 70%stage.Myf5 gene showed highest ex-pression at 30 d of age,suggesting it played key roles in myogenic period.However,the Myf6 gene was significantly highly ex-pressed at 60 d,revealing this gene functioned in the later muscle formation period.
基金Supported by Central Public-interest Scientific Institution Basal Research Fund,Yellow Sea Fisheries Research Institute,CAFS(20603022017001)National Natural Science Foundation of China(41676148)Taishan Scholar Program for Seed Industry and China Agriculture Research System(CARS-48)
文摘In the present study, Fenneropenaeus chinensis individuals were assigned into six groups, and fed with a diet supplemented with 0(Con-trol), 0.5%(Group E0.5), 1.0%(Group E1.0), 2.0%(Group E2.0), 3.0%(Group E3.0) or 5.0%(Group E5.0) of poly-β-hydroxybutyrate(PHB) during their growth and spawning periods, to explore the effect of PHB on the reproductive performance of parents and the development of larvae. The experi-ment was lasted for 192 d to measure the mortality rate, relative percentage of survival(RPS), weight gain rate(WGR), specific growth rate(SGR) and cycle of gonadal development of parental shrimps, number of eggs, number of nauplii, stages of larval development and metamorphosis. The results indicated that PHB had an obvious effect on the fecundity of parental shrimps and growth performance of larva. Compared with control group, the mortality rate of broodstock in experimental groups decreased initially and increased subsequently with the increase of PHB concentration, while RPS showed an opposite pattern. The mortality rate of group E2.0 was the lowest among all groups, showing significant difference from that of other groups(P﹤0.05) except group E1.0(P﹥0.05). WGR of all experimental groups was higher than that of the control group, among which, group E2.0 and group E5.0 had significantly higher WGR than the control(P<0.05). However, there was no significant difference in the cycle of gonadal development between the experimental groups and the control group(P ﹥ 0.05). The numbers of eggs and nauplii in the experimental groups were higher than those of the control group. And the numbers of eggs and nauplii in group E2.0 were significantly higher than those of the control(P ﹤ 0.05), bud showed no significant difference from those of other groups(P﹥0.05). However, there was no significant difference in the duration of larval devel-opment and metamorphosis among all the groups. In summary, PHB is capable of improving the reproductive performance of parents and the survival and development of larva in F. chinensis, and 2.0% is the optimal concentration of PHB supplemented to the diet.
基金Supported by the National Natural Science Foundation of China(Nos.30700617,31101298)the National Special Research Fund for NonProfit Sector(No.nyhyzx07-046)
文摘Turbot Scophthalmus maximus, an important aquaculture species in China, currently suffers from epizootic diseases because of high density aquaculture. Enrofloxacin has been used to treat various systemic bacterial fish infections. However, studies concerning the pharmacokinetics of enrofloxacin in turbot are limited. In this study, the pharmacokinetics of enrofloxacin and its metabolite ciprofloxacin, were investigated in the turbot following intravenous and oral administration at 10 mg enrofloxacin/kg body weight, at 16°C and 10°C water temperatures. The concentrations of enrofloxacin and ciprofloxacin in the main tissues (plasma, muscle, liver and kidney) were detected by HPLC. The results show that the plasma concentration-time data for enrofloxacin were best described as a two-compartment open model after intravenous and oral administration. Three pharmacokinetic equations were established between the concentrations and temperatures. The kinetic profile of enrofloxacin was temperature dependent. The absorption half-life of enrofloxacin was 1.99 h and 2.17 h after oral administration, whereas the elimination half-life of the drug was 98.63 h and 136.59 h at 16°C and 10°C, respectively. The peak concentration of enrofloxacin in plasma and tissues was higher at 16°C than that at 10°C, and the peak plasma concentration time in the liver was the shortest at both temperatures among those of other tissues. The plasma C max /MIC ratio varied between 11.08 and 5 540.00 at 16°C; and between 7.92 and 3 960.00 at 10°C. The AUC/MIC ratio was 467.82-280 690.00 at 16°C, and 359.48-215 690.00 at 10°C. These ratios indicate that it is possible to obtain therapeutic efficacy. Very low levels of ciprofloxacin were detected. The AUC ratios of ciprofloxacin and enrofloxacin in plasma suggest that plasma ciprofloxacin might play a minor role in enrofloxacin treatment for turbot.
基金The Modern Agro-industry Technology Research System under contract No.CARS-47the National High-tech R&D Program(863 Program) of China under contract No.2012AA10A409+1 种基金the Special Fund for Independent Innovation of Shandong Province under contract No.2013CX80202the Special Fund for Agro-scientific Research in the Public Interest under contract No.201103034
文摘Catalase(CAT) and selenium-dependent glutathione peroxidase(Se-GPx) play a vital role in protecting organisms against various oxidative stresses by eliminating H2O2. The objective of this paper is to evaluate the roles of these antioxidant molecules in the ridgetail white prawn Exopalaemon carinicauda in response to low salinity stress. A complementary DNA(cDNA) containing the complete coding sequence of CAT was cloned from the hepatopancreas using reverse-transcription polymerase chain reaction(RT-PCR) and rapid amplification of cDNA ends. The full-length cDNA of CAT(2 649 bp) contains a 5'-untranslated region(UTR) of 78 bp, a 3'- UTR of1 017 bp, with a poly(A) tail, and an open reading frame of 1 554 bp encoding a 517-amino-acid polypeptide with predicted molecular mass of 58.46 kDa and estimated isoelectric point of 6.64. This CAT sequence contained the proximal active site signature(60FDRERIPERVVHAKGAG76), proximal heme-ligand signature sequence(350RLFSYPDTH358) and three catalytic amino acid residues(His71, Asn144 and Tyr354). Sequence comparison showed that the CAT deduced amino acid sequence of E. carinicauda shared 68%-92% of identities with those of other species. Quantitative real-time PCR analysis revealed that CAT m RNA was widely expressed in the hepatopancreas(highest), hemocyte, eyestalk, heart, gill, muscle, ovary and stomach. Under low salinity stress,CAT and GPx m RNA expression levels both in the gill and hepatopancreas increased significantly at the first 48 h and 6 h respectively, indicating a tissue- and time-dependent antioxidant response in E. carinicauda. All these results indicate that E. carinicauda CAT is a member of the CAT family and might be involved in the acute response against low salinity stress.
基金supported by the National Natural Science Foundation of China (Nos. 41476098, 41276154)Special Scientific Research Funds for Central Non-profit Institutes of Yellow Sea Fisheries Research Institutes (2060302201502)
文摘Three surveys were carried out in Pearl River Estuary and adjacent coastal area in May, August, and November, 2013, to investigate the temporal and spatial variations of abundance of phycoerythrin-rich Synechococcus(PE-rich SYN) and phycocyanin-rich Synechococcus(PC-rich SYN). The effects of environmental factors on the alternation of the different Synechococcus groups were also elucidated. PE-rich SYN was detected in three surveys, whereas PC-rich SYN was detected in May and August, but not in November. The highest abundances of PE-rich SYN and PC-rich SYN were recorded in August and May, with mean values of 74.17×103 and 189.92×103 cells m L-1, respectively. From May to November, the relative abundance of PE-rich SYN increased, whereas that of PC-rich SYN declined. PE-rich and PC-rich SYN presented similar horizontal distributions with high abundance in the southern estuary in May, and in the western estuary in August. The abundances of PE-rich and PC-rich SYN were high at 27–32℃and salinity of 10–20. PC-rich SYN was not detected at < 24℃, and PC:PE-rich SYN decreased in abundance with salinity increase. When less than 20 mg L-1, suspended particulate matter(SPM) was helpful for Synechococcus growth. PE-rich SYN decreased in abundance when the concentration of dissolved inorganic nitrogen increased in May and November, and the concentration of phosphate increased in November. However, PC-rich SYN abundance and nutrients showed no correlation. Principal component analysis and regression analysis indicated that PE-rich SYN significantly correlated with the principal components that were affected by environmental factors.
基金The National Basic Research Program of China under contract No.2015CB453303the National Natural Science Foundation of China under contract No.U1405234+1 种基金the Aoshan Science&Technology Innovation Program under contract No.2015ASKJ02-05the Special Fund of the Taishan Scholar Project
文摘Spatial interpolation is a common tool used in the study of fishery ecology, especially for the construction of ecosystem models. To develop an appropriate interpolation method of determining fishery resources density in the Yellow Sea, we tested four frequently used methods, including inverse distance weighted interpolation(IDW), global polynomial interpolation(GPI), local polynomial interpolation(LPI) and ordinary kriging(OK).A cross-validation diagnostic was used to analyze the efficacy of interpolation, and a visual examination was conducted to evaluate the spatial performance of the different methods. The results showed that the original data were not normally distributed. A log transformation was then used to make the data fit a normal distribution. During four survey periods, an exponential model was shown to be the best semivariogram model in August and October 2014, while data from January and May 2015 exhibited the pure nugget effect.Using a paired-samples t test, no significant differences(P>0.05) between predicted and observed data were found in all four of the interpolation methods during the four survey periods. Results of the cross-validation diagnostic demonstrated that OK performed the best in August 2014, while IDW performed better during the other three survey periods. The GPI and LPI methods had relatively poor interpolation results compared to IDW and OK. With respect to the spatial distribution, OK was balanced and was not as disconnected as IDW nor as overly smooth as GPI and LPI, although OK still produced a few "bull's-eye" patterns in some areas.However, the degree of autocorrelation sometimes limits the application of OK. Thus, OK is highly recommended if data are spatially autocorrelated. With respect to feasibility and accuracy, we recommend IDW to be used as a routine interpolation method. IDW is more accurate than GPI and LPI and has a combination of desirable properties, such as easy accessibility and rapid processing.
基金Supported by the Youth Backbone Training Plan of the Beijing Academy of Science and Technology(No.201602)the National Nature Science Foundation of China(No.41606175,41576162)+1 种基金the National Key R&D Program of China(No.2017YFC1404301)the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDA1102030401)
文摘The dinoflagellate genus K arenia is known for recurrent harmful blooms worldwide. However, species diversity of the genus is generally overlooked owing to the difficulty of identifying small unarmored dinoflagellates. We have established four clonal cultures of K arenia longicanalis isolated from the type locality, Hong Kong harbor(strain HK01) and other three locations along the Chinese coasts(strains YB01, DT01, and NJ01). The morphology of the strain was studied by light and scanning electron microscopy(LM and SEM) and the pigment composition analyzed by high-performance liquid chromatography. We provide the first molecular data of K. longicanalis based on the large subunit(LSU) rRNA gene sequence and internal transcribed spacer(ITS). The four strains showed identical LSU rDNA sequences with a similarity of 99.4% to the holotype of K arenia umbella(strain KUTN05) from Australia. In the ITS phylogeny, the sequence of K. umbella branched between the Chinese strains of K. longicanalis. A careful comparison of the morphology of K. longicanalis and K. umbella reveals the similarity in the diagnostic characters. Diff erences may appear due to the sample treatment for SEM. We conclude that K. umbella is a junior synonym of K. longicanalis.
基金supported by the earmarked fund for the Modern Agro-Industry Technology Research System (CARS-47)the Program of Shandong Leading Talent (No.LJNY2015002)the AoShan Scientific and Technological Innovation Project which was financially backed by Qingdao National Laboratory for Marine Science and Technology (No.2015ASKJ02)
文摘Intensive use of sulfamethazine(SM_2) in aquaculture has resulted in some detrimental effects to non-targeted organisms. In order to assess its potential ecological risk, it is crucial to have a good understanding on the bioaccumulation and biodegradation of SM_2 in Chlorella pyrenoidosa. The microalgae were treated with 2, 4, and 8 mg L^(-1) of sulfamethazine for 13 days, respectively, showing that the inhibition effects of sulfamethazine on the growth of Chlorella pyrenoidosa increased progressively as the concentrations of sulfamethazine increasing from 2 to 8 mg L^(-1). The peak concentrations of sulfamethazine accumulated in C. pyrenoidosa were 0.225, 0.325, and 0.596 ng per mg FW on day 13 for three treatment groups, respectively, showing a great ability to deplete sulfamethazine from the culture media. On day 13, the percentages of biotic degradation were 48.45%, 60.21% and 69.93%, respectively. The EC_(50) of 10.05 mg L^(-1) was derived which showed no significant risk for C. pyrenoidosa with a calculated risk quotient < 1. The activities of superoxide dismutase and catalase increased progressively in response to sulfamethazine and showed a positive correlation to the treatment concentrations. The highest superoxide dismutase activity was achieved at the concentration of 8 mg L^(-1) after 2 d of exposure, which was 1.89 folds higher than that of the control. The activity of catalase has a similar pattern to that of superoxide dismutase with the maximum activity achieved at day 2, which was 3.11 folds higher compared to that of the control. In contrast to superoxide dismutase and catalase, the maximum glutathione S-transferase activity was observed at day 6, showing 2.2 folds higher than that of the control.
