Understan ding the mechanism of harmful algal bloom formation is vital for effectively preventing algal bloom outbreaks in coastal environments.Karenia spp.blooms in the East China Sea show a significant correlation w...Understan ding the mechanism of harmful algal bloom formation is vital for effectively preventing algal bloom outbreaks in coastal environments.Karenia spp.blooms in the East China Sea show a significant correlation with nutrient regimes.However,the impact of key components of nutrients,especially dissolved organic nitrogen(DON),on the blooms of Karenia spp.is not clear.Quantitative research is still lacking.In this study,the cruise observations,field mesocosm-flask culture experiments,and a multinitrogen-tri-phytoplankton-detritus model(NTPD) are combined to reveal the quantitative influence of nutrient regimes on the shift of Prorocentrum donghaiense and Karenia spp.in the East China Sea.It has a synchronism rhythm of diatom-P.donghaienseKarenia spp.-diatom loop in the field culture experiment,which is consistent with the results of the cruise observation.The results showed that the processes of terrigenous DON(TeDON) and dissolved inorganic nitrogen(DIN:NO_3~--N,NH_4~+-N) absorption promoted P.donghaiense to become the dominant algae in the community;whereas the processes of DON from P.donghaiense absorption promoted Karenia spp.to become the dominant algae in ambient DIN exhaustion.In addition,the three-dimensional fluorescence components of humus C,tyrosine and fulvic acid can indicate the processes of growth and extinction of P.donghaiense and Karenia spp.,respectively.This study infers that P.donghaiense and Karenia spp.regime shift mechanism associated with the nutrient regime in coastal waters,which provides a scientific basis for the environmental management of coastal eco system health.展开更多
The dinoflagellate Prorocentrum minimum is known to affect the normal physiological function of Exopalaemon carinicauda by inducing oxidative stress,apoptosis,and cellular injury.To study the effects of P.minimum on t...The dinoflagellate Prorocentrum minimum is known to affect the normal physiological function of Exopalaemon carinicauda by inducing oxidative stress,apoptosis,and cellular injury.To study the effects of P.minimum on the immune defense system of shrimp,E.carinicauda were exposed to 5×10^(3)cells mL^(-1)and 5×10^(4)cells mL^(-1)of P.minimum for 336 h in treatment groups,while E.carinicauda cultured in filtered seawater was employed as control.The total hemocyte counts(THC),hemocyanin concentration(HEM),and the activity of alkaline phosphatase(AKP)in hemolymph serum,as well as expressions of six immunity-related genes in hemocytes,hepatopancreases and gills were determined.The exposure of P.minimum significantly reduced the THC,HEM concentration and AKP activity in hemolymph serum.Immunity-related genes expressed differently in hemocytes,hepatopancreases and gills.Compared with the control group,the expressions of Crustin and pro PO in hemocytes were significantly up-regulated in the treatment groups,while the up-regulated expressions of LGBP,Lysozyme and Serpin were only found in the group exposed to 5×10^(4)cells mL^(-1)of P.minimum.In the gills of E.carinicauda exposed to P.minimum,the down-regulation of ALF,proPO and Serpin,up-regulation of LGBP and Lysozyme,as well as unaffected Crustin were observed.In hepatopancreases,the up-regulated expressions of LGBP,Crustin,Lysozyme,Serpin and proPO(only in 5×10^(3)cells mL^(-1)of P.minimum group)were found in the treatment groups.After exposure to P.minimum for 336 h,shrimps were injected with Vibrio parahaemolyticus and WSSV.The results showed that the mortality rates of shrimp in the treatment groups were significantly increased with a dose-dependent effect,which suggests that exposure to P.minimum may reduce the immunity of E.carinicauda.The research indicates that hemocytes and hepatopancreases play important roles in protecting the shrimp immune response to harmful algae,while the protection effect of hemolymph serum and gills may be suppressed.Since the exposure to P.minimum depressed the immunity of E.carinicauda,further studies are needed to confirm whether the presence of the algae will affect the susceptibility of shrimp to pathogens.展开更多
Laboratory culture experiments showed that 【 100μmol/L nitrate, amonium or mixture of aminoacids promote the growth of the red tide organism Prorocentrum micans Ehrenb, but that 】100μmol/Lof ammonium, or mixture o...Laboratory culture experiments showed that 【 100μmol/L nitrate, amonium or mixture of aminoacids promote the growth of the red tide organism Prorocentrum micans Ehrenb, but that 】100μmol/Lof ammonium, or mixture of glycine and glutamate was harmful to growth, and that orthophosphatewas P. micrns’main phosphorous soruce in the ocean. Presence of 80μmol/L EDTA, 0.5 to 1μmol/LFe<sup>3+</sup>, 1.0 to 20.0 μmol/L Mn<sup>2+</sup> 0.1 to 0.4 μmol/L Co<sup>2+</sup> in the culture medium could improvethe growth of P. micans. Vitamin B<sub>1</sub> promoted growth, but vitamin B<sub>12</sub> and biotin did not. Theestimated minimum cell quotaS （q<sub>ο</sub>） for nitrogen and phosphorus being 0.74 pmole/cell and 0.045pmole/cell show that phosphorus （more than nitrogen） limits the growth of P. micans in the study area.展开更多
The dinoflagellate Prorocentrum minimum,one of the most widespread red tide causing species,affects marine aquaculture and ecosystems worldwide.In this study,ridgetail white prawn Exopalaemon carinicauda were exposed ...The dinoflagellate Prorocentrum minimum,one of the most widespread red tide causing species,affects marine aquaculture and ecosystems worldwide.In this study,ridgetail white prawn Exopalaemon carinicauda were exposed to P.minimum cells(5 × 104 cells mL-1) to investigate its harmful effects on the shrimp.Antioxidant activities and histological changes were used as indicators of health status of the shrimp.In 72 hours,the mortality of E.carinicauda was not affected,but its antioxidant response and histology were statistically different from those of control.Elevated superoxide dismutase(SOD) and glutathione peroxidase(GPX) activities and depressed catalase(CAT) activity were observed in gill;while increased SOD,glutathione S-transferase(GST),CAT activities and modulated GPX activity were observed in hepatopancreas.Thus,antioxidant activities in gill and hepatopancreas seem to respond differentially to harmful alga exposure.Increased malondialdehyde(MDA) content in early a few hours indicates the damage of the antioxidant defense system.Although MDA content recovered to a low level thereafter,a series of histological abnormalities including accumulation or infiltration of hemocytes,tissue lesions and necrosis were discovered in gill and hepatopancreas.Exposure to P.minimum induced sublethal effects on E.carinicauda,including temporary oxidative damage and histological injury.展开更多
Prorocentrum donghaiense is one of the most common red tide causative dinoflagellates in the Changjiang （Yangtze） River Estuary and the adjacent area of the East China Sea. It causes large-scale blooms in late sprin...Prorocentrum donghaiense is one of the most common red tide causative dinoflagellates in the Changjiang （Yangtze） River Estuary and the adjacent area of the East China Sea. It causes large-scale blooms in late spring and early summer that lead to widespread ecologic and economic damage. A means for distinguish- ing dinoflagellate blooms from diatom （Skeletonema costatum） blooms is desired. On the basis of measure- ments of remote sensing refectance [Rrs（λ）] and inherent optical parameters, the potential of using a mul- tispectral approach is assessed for discriminating the algal blooms due to P. donghaiense from those due to S. costatum. The behavior of two reflectance ratios [R1 = Rrs（560）/Rrs（532） and Re = Rrs（708）/Rrs（665）], suggests that differentiation of P. donghaiense blooms from diatom bloom types is possible from the current band setup of ocean color sensors. It is found that there are two reflectance ratio regimes that indicate a bloom is dominated by P. donghaiense; （1） R1 〉 1.55 and R2 〈 1.0 or （2） R1 〉 1.75 and R2 ≥ 1.0. Various sensitivity analyses are conducted to investigate the effects of the variation in varying levels of chlorophyll concentration and colored dissolved organic matter （CDOM） as well as changes in the backscattering ratio （bbp/bp） on the efficacy of this muitispectral approach. Results indicate that the intensity and inherent op- tical properties of the algal species explain much of the behavior of the two ratios. Although backscattering influences the amplitude of Rrs（λ）, especially in the 530 and 560 nm bands, the discrimination between P. donghaiense and diatoms is not significantly affected by the variation of bbp/bp. Since aCDOM （440） in coastal areas of the ECS is typically lower than 1.0 m-1 in most situations, the presence of CDOM does not interfere with this discrimination, even as SCDOM varies from 0.01 to 0.026 nm-1. Despite all of these effects, the dis- crimination of P. donghaiense blooms from diatom blooms based on multispectral measurements of Rrs（λ） is feasible.展开更多
Prorocentrum minimum is a bloom-forming, planktonic mixotrophic dinoflagellate, and can cause stress in shrimp ponds. In this study, healthy Exopalaemon carinicauda were exposed to 5 × 10^4 cells mL^-1 P. minimum...Prorocentrum minimum is a bloom-forming, planktonic mixotrophic dinoflagellate, and can cause stress in shrimp ponds. In this study, healthy Exopalaemon carinicauda were exposed to 5 × 10^4 cells mL^-1 P. minimum for 72 hours to investigate the adverse effect of P. minimum on shrimps. Elevated superoxide dismutase(SOD) activity and malondialdehyde(MDA) content, reduced total antioxidant capacity(T-AOC) and catalase(CAT) activity, and regulatory glutathione peroxidase(GPX) activity were found in the hemolymph of E. carinicauda after exposure to P. minimum. In this study, P. minimum exposure induced oxidative stress and caused significant oxidative damage to E. carinicauda. P. minimum exposure increased the expression of HSP70 gene in the hemocyte, gills and hepatopancreas. Compared with the enhanced level of caspase-3 gene mR NA in the hemocyte and gills, the up-regulation of caspase-3 gene in the hepatopancreas was only observed from 3 to 6 h, and then the mRNA level of glutathione-S-transferase(GST) gene increased. These results indicated that GST might be involved in the shrimp hepatopancreas’ defense against P. minimum exposure. The present study demonstrates that exposure to P. minimum could induce oxidative stress and apoptosis in E. carinicauda. The SOD activity, HSP70 and GST(in the hepatopancreas) were evoked to protect cells from oxidative stress and apoptosis. This study will provide new insights into the toxic mechanism of P. minimum on shrimps.展开更多
基金The National Natural Science Foundation of China under contract No. 42130403the Fundamental Research Funds for the Central Universities under contract No. 202362003the National Key Research&Development Program of China under contract No. 2017YFC1404300。
文摘Understan ding the mechanism of harmful algal bloom formation is vital for effectively preventing algal bloom outbreaks in coastal environments.Karenia spp.blooms in the East China Sea show a significant correlation with nutrient regimes.However,the impact of key components of nutrients,especially dissolved organic nitrogen(DON),on the blooms of Karenia spp.is not clear.Quantitative research is still lacking.In this study,the cruise observations,field mesocosm-flask culture experiments,and a multinitrogen-tri-phytoplankton-detritus model(NTPD) are combined to reveal the quantitative influence of nutrient regimes on the shift of Prorocentrum donghaiense and Karenia spp.in the East China Sea.It has a synchronism rhythm of diatom-P.donghaienseKarenia spp.-diatom loop in the field culture experiment,which is consistent with the results of the cruise observation.The results showed that the processes of terrigenous DON(TeDON) and dissolved inorganic nitrogen(DIN:NO_3~--N,NH_4~+-N) absorption promoted P.donghaiense to become the dominant algae in the community;whereas the processes of DON from P.donghaiense absorption promoted Karenia spp.to become the dominant algae in ambient DIN exhaustion.In addition,the three-dimensional fluorescence components of humus C,tyrosine and fulvic acid can indicate the processes of growth and extinction of P.donghaiense and Karenia spp.,respectively.This study infers that P.donghaiense and Karenia spp.regime shift mechanism associated with the nutrient regime in coastal waters,which provides a scientific basis for the environmental management of coastal eco system health.
基金financially supported by the earmarked fund for National Key R&D Program of China(No.2019YFD0900403)the Modern Agro-Industry Technology Research System(No.CARS-48)+2 种基金the Program of Shandong Leading Talent(No.LNJY2015002)the Central Public-Interest Scientific Institution Basal Research Fund of CAFS(No.2020TD46)the Scientific Research Start-Up Funding of Shandong Agricultural University(No.72188)。
文摘The dinoflagellate Prorocentrum minimum is known to affect the normal physiological function of Exopalaemon carinicauda by inducing oxidative stress,apoptosis,and cellular injury.To study the effects of P.minimum on the immune defense system of shrimp,E.carinicauda were exposed to 5×10^(3)cells mL^(-1)and 5×10^(4)cells mL^(-1)of P.minimum for 336 h in treatment groups,while E.carinicauda cultured in filtered seawater was employed as control.The total hemocyte counts(THC),hemocyanin concentration(HEM),and the activity of alkaline phosphatase(AKP)in hemolymph serum,as well as expressions of six immunity-related genes in hemocytes,hepatopancreases and gills were determined.The exposure of P.minimum significantly reduced the THC,HEM concentration and AKP activity in hemolymph serum.Immunity-related genes expressed differently in hemocytes,hepatopancreases and gills.Compared with the control group,the expressions of Crustin and pro PO in hemocytes were significantly up-regulated in the treatment groups,while the up-regulated expressions of LGBP,Lysozyme and Serpin were only found in the group exposed to 5×10^(4)cells mL^(-1)of P.minimum.In the gills of E.carinicauda exposed to P.minimum,the down-regulation of ALF,proPO and Serpin,up-regulation of LGBP and Lysozyme,as well as unaffected Crustin were observed.In hepatopancreases,the up-regulated expressions of LGBP,Crustin,Lysozyme,Serpin and proPO(only in 5×10^(3)cells mL^(-1)of P.minimum group)were found in the treatment groups.After exposure to P.minimum for 336 h,shrimps were injected with Vibrio parahaemolyticus and WSSV.The results showed that the mortality rates of shrimp in the treatment groups were significantly increased with a dose-dependent effect,which suggests that exposure to P.minimum may reduce the immunity of E.carinicauda.The research indicates that hemocytes and hepatopancreases play important roles in protecting the shrimp immune response to harmful algae,while the protection effect of hemolymph serum and gills may be suppressed.Since the exposure to P.minimum depressed the immunity of E.carinicauda,further studies are needed to confirm whether the presence of the algae will affect the susceptibility of shrimp to pathogens.
基金This project was supported by the Natural Science Foundation of Zhejiang Province
文摘Laboratory culture experiments showed that 【 100μmol/L nitrate, amonium or mixture of aminoacids promote the growth of the red tide organism Prorocentrum micans Ehrenb, but that 】100μmol/Lof ammonium, or mixture of glycine and glutamate was harmful to growth, and that orthophosphatewas P. micrns’main phosphorous soruce in the ocean. Presence of 80μmol/L EDTA, 0.5 to 1μmol/LFe<sup>3+</sup>, 1.0 to 20.0 μmol/L Mn<sup>2+</sup> 0.1 to 0.4 μmol/L Co<sup>2+</sup> in the culture medium could improvethe growth of P. micans. Vitamin B<sub>1</sub> promoted growth, but vitamin B<sub>12</sub> and biotin did not. Theestimated minimum cell quotaS （q<sub>ο</sub>） for nitrogen and phosphorus being 0.74 pmole/cell and 0.045pmole/cell show that phosphorus （more than nitrogen） limits the growth of P. micans in the study area.
基金supported by the Special Fund for Agro-scientific Research in the Public Interest of China(No.2060302201515013)the Scientific and Technological Innovation Project Financially Supported by Qingdao National Laboratory for Marine Science and Technology(No.2015ASKJ02)
文摘The dinoflagellate Prorocentrum minimum,one of the most widespread red tide causing species,affects marine aquaculture and ecosystems worldwide.In this study,ridgetail white prawn Exopalaemon carinicauda were exposed to P.minimum cells(5 × 104 cells mL-1) to investigate its harmful effects on the shrimp.Antioxidant activities and histological changes were used as indicators of health status of the shrimp.In 72 hours,the mortality of E.carinicauda was not affected,but its antioxidant response and histology were statistically different from those of control.Elevated superoxide dismutase(SOD) and glutathione peroxidase(GPX) activities and depressed catalase(CAT) activity were observed in gill;while increased SOD,glutathione S-transferase(GST),CAT activities and modulated GPX activity were observed in hepatopancreas.Thus,antioxidant activities in gill and hepatopancreas seem to respond differentially to harmful alga exposure.Increased malondialdehyde(MDA) content in early a few hours indicates the damage of the antioxidant defense system.Although MDA content recovered to a low level thereafter,a series of histological abnormalities including accumulation or infiltration of hemocytes,tissue lesions and necrosis were discovered in gill and hepatopancreas.Exposure to P.minimum induced sublethal effects on E.carinicauda,including temporary oxidative damage and histological injury.
基金The National Basic Research Program of China (973 Program) under contract No.2013CB430302the National High Technology Research and Development Program of China (863 Program) under contract No.2007AA092002+2 种基金the National Natural Science Foundation of China under contract No.41206170the public science and technology research funds projects of the ocean under contract No.201005030scientific research fund of the Second Institute of Oceanography,SOA under contract No.JG1212
文摘Prorocentrum donghaiense is one of the most common red tide causative dinoflagellates in the Changjiang （Yangtze） River Estuary and the adjacent area of the East China Sea. It causes large-scale blooms in late spring and early summer that lead to widespread ecologic and economic damage. A means for distinguish- ing dinoflagellate blooms from diatom （Skeletonema costatum） blooms is desired. On the basis of measure- ments of remote sensing refectance [Rrs（λ）] and inherent optical parameters, the potential of using a mul- tispectral approach is assessed for discriminating the algal blooms due to P. donghaiense from those due to S. costatum. The behavior of two reflectance ratios [R1 = Rrs（560）/Rrs（532） and Re = Rrs（708）/Rrs（665）], suggests that differentiation of P. donghaiense blooms from diatom bloom types is possible from the current band setup of ocean color sensors. It is found that there are two reflectance ratio regimes that indicate a bloom is dominated by P. donghaiense; （1） R1 〉 1.55 and R2 〈 1.0 or （2） R1 〉 1.75 and R2 ≥ 1.0. Various sensitivity analyses are conducted to investigate the effects of the variation in varying levels of chlorophyll concentration and colored dissolved organic matter （CDOM） as well as changes in the backscattering ratio （bbp/bp） on the efficacy of this muitispectral approach. Results indicate that the intensity and inherent op- tical properties of the algal species explain much of the behavior of the two ratios. Although backscattering influences the amplitude of Rrs（λ）, especially in the 530 and 560 nm bands, the discrimination between P. donghaiense and diatoms is not significantly affected by the variation of bbp/bp. Since aCDOM （440） in coastal areas of the ECS is typically lower than 1.0 m-1 in most situations, the presence of CDOM does not interfere with this discrimination, even as SCDOM varies from 0.01 to 0.026 nm-1. Despite all of these effects, the dis- crimination of P. donghaiense blooms from diatom blooms based on multispectral measurements of Rrs（λ） is feasible.
基金supported by the Program of Shandong Leading Talent (No. LNJY2015002)the Scientific and Technological Innovation Project Financially Supported by Qingdao National Laboratory for Marine Science and Technology (No. 2015ASKJ02)the Qingdao Planned Projects for Postdoctoral Research Funds (No. ZQ 5120 1617013)
文摘Prorocentrum minimum is a bloom-forming, planktonic mixotrophic dinoflagellate, and can cause stress in shrimp ponds. In this study, healthy Exopalaemon carinicauda were exposed to 5 × 10^4 cells mL^-1 P. minimum for 72 hours to investigate the adverse effect of P. minimum on shrimps. Elevated superoxide dismutase(SOD) activity and malondialdehyde(MDA) content, reduced total antioxidant capacity(T-AOC) and catalase(CAT) activity, and regulatory glutathione peroxidase(GPX) activity were found in the hemolymph of E. carinicauda after exposure to P. minimum. In this study, P. minimum exposure induced oxidative stress and caused significant oxidative damage to E. carinicauda. P. minimum exposure increased the expression of HSP70 gene in the hemocyte, gills and hepatopancreas. Compared with the enhanced level of caspase-3 gene mR NA in the hemocyte and gills, the up-regulation of caspase-3 gene in the hepatopancreas was only observed from 3 to 6 h, and then the mRNA level of glutathione-S-transferase(GST) gene increased. These results indicated that GST might be involved in the shrimp hepatopancreas’ defense against P. minimum exposure. The present study demonstrates that exposure to P. minimum could induce oxidative stress and apoptosis in E. carinicauda. The SOD activity, HSP70 and GST(in the hepatopancreas) were evoked to protect cells from oxidative stress and apoptosis. This study will provide new insights into the toxic mechanism of P. minimum on shrimps.
