2010 Vol. 32, No. 5
Display Method:
2010, 32(5): 1-8.
Abstract:
Diatoms have different morphologies, structure complex and beautiful silica cell wall. They are one of the largest groups of silicifying organisms in the ocean. The genetic control and mechanism of this silica structure formation are a very complicated process, including silica acid transportation across biological membranes to cells, silica acid transformation inside cells, silica polymerization within silica deposition vesicle(SDV), and formation of species-specific cell wall and complex silica structure. An overview of current knowledge about the diatom silica structure formation in recent years was provided. It is focused on the detailed structure and function of silica acid transporters(SITs), three proteins associated with biomineralization-frustulins, silaffins and pleuralins, and the mode of the frustule formation inside SDV.
Diatoms have different morphologies, structure complex and beautiful silica cell wall. They are one of the largest groups of silicifying organisms in the ocean. The genetic control and mechanism of this silica structure formation are a very complicated process, including silica acid transportation across biological membranes to cells, silica acid transformation inside cells, silica polymerization within silica deposition vesicle(SDV), and formation of species-specific cell wall and complex silica structure. An overview of current knowledge about the diatom silica structure formation in recent years was provided. It is focused on the detailed structure and function of silica acid transporters(SITs), three proteins associated with biomineralization-frustulins, silaffins and pleuralins, and the mode of the frustule formation inside SDV.
2010, 32(5): 9-16.
Abstract:
The measurement principle of a space-borne real aperture radar spectrometer and the error analysis model are introdued. The analysis of the wavelength resolution and directional resolution is presented, based on the SWIM instrument, which is proposed by Hauser D et al. To reduce the fluctuation of retrieved spectra, it is proposed to average ten adjacent independent samples in the time domain and eight in the wavenumber domain, respectively, during the data processing. And for achieving the directional resolution better than 20°, the largest number of integrated subperiod is three, seven and ten for the instrument operated in three different modes, respectively. Two methods, namely, analytical process and simulation process, are adopted to analyze the energy error of retrieved wave spectra by SWIM operated at Mode 2. The results of the two methods are in agreement, which shows that the energy error is less than 20% for certain wave conditions.
The measurement principle of a space-borne real aperture radar spectrometer and the error analysis model are introdued. The analysis of the wavelength resolution and directional resolution is presented, based on the SWIM instrument, which is proposed by Hauser D et al. To reduce the fluctuation of retrieved spectra, it is proposed to average ten adjacent independent samples in the time domain and eight in the wavenumber domain, respectively, during the data processing. And for achieving the directional resolution better than 20°, the largest number of integrated subperiod is three, seven and ten for the instrument operated in three different modes, respectively. Two methods, namely, analytical process and simulation process, are adopted to analyze the energy error of retrieved wave spectra by SWIM operated at Mode 2. The results of the two methods are in agreement, which shows that the energy error is less than 20% for certain wave conditions.
2010, 32(5): 17-24.
Abstract:
High-resolution bathymetry and subbottom profile data have been acquired in the northern Luzon Trough, a landslide extended on an area of 500 km2, more than 20 m thick has been found in the middle trough. According to the analysis of landslide source and its sedimentary environment, the landslide is divided into two parts: an end area and a front area. From the relationship between the landslide area and the surrounding stratum and the history of the volcano eruption, it is suggested that the submarine landslide is triggered by the earthquake. Most submarine landslides occur in the depth range of 2 000 m, while the average depth of the study area is more than 3 000 m, thus the discovery of the submarine landslide is significant in deepening the research of the deepwater landslide.
High-resolution bathymetry and subbottom profile data have been acquired in the northern Luzon Trough, a landslide extended on an area of 500 km2, more than 20 m thick has been found in the middle trough. According to the analysis of landslide source and its sedimentary environment, the landslide is divided into two parts: an end area and a front area. From the relationship between the landslide area and the surrounding stratum and the history of the volcano eruption, it is suggested that the submarine landslide is triggered by the earthquake. Most submarine landslides occur in the depth range of 2 000 m, while the average depth of the study area is more than 3 000 m, thus the discovery of the submarine landslide is significant in deepening the research of the deepwater landslide.
2010, 32(5): 25-33.
Abstract:
Seventeen samples were collected from hydrothermal black smoker chimneys in the Endeavour segment of the Juan de Fuca Ridge, and were analyzed for sulfur isotope compositions.The ore-forming matter sources of hydrothermal black smoker chimneys were discussed, and the sulfur isotope data were coupled with the published data of hydrothermal fluid and sulfide.Summaries and /or conclusions are as follows.(1) Sulfide from the Endeavour segment has similar sulfur isotope range as that of other sediment-starving mid-ocean ridges, and heavy isotope is depleted when comparing with that of SJDFR (southern Juan de Fuca Ridge). Together with the previous results, it is considered that if sulfur in sulfide of SJDFR wholly comes from the leaching of basal basalts and sulfate in seawater,1%～3% sediment should contribute to sulfide in the Endeavour segment. Therefore, the sulfur sources for sulfide in the Endeavour segment are mainly from the leaching of basal basalts and minor from seawater and sediment. (2) Coupling the sulfur isotope data with the published data of hydrothermal fluid and sulfide, it is suggested that the sources for the sediment signal in hydrothermal fluid and sulfur in sulfide may be different, and it is proposed that the sediment end-member should be located in the recharge zone.
Seventeen samples were collected from hydrothermal black smoker chimneys in the Endeavour segment of the Juan de Fuca Ridge, and were analyzed for sulfur isotope compositions.The ore-forming matter sources of hydrothermal black smoker chimneys were discussed, and the sulfur isotope data were coupled with the published data of hydrothermal fluid and sulfide.Summaries and /or conclusions are as follows.(1) Sulfide from the Endeavour segment has similar sulfur isotope range as that of other sediment-starving mid-ocean ridges, and heavy isotope is depleted when comparing with that of SJDFR (southern Juan de Fuca Ridge). Together with the previous results, it is considered that if sulfur in sulfide of SJDFR wholly comes from the leaching of basal basalts and sulfate in seawater,1%～3% sediment should contribute to sulfide in the Endeavour segment. Therefore, the sulfur sources for sulfide in the Endeavour segment are mainly from the leaching of basal basalts and minor from seawater and sediment. (2) Coupling the sulfur isotope data with the published data of hydrothermal fluid and sulfide, it is suggested that the sources for the sediment signal in hydrothermal fluid and sulfur in sulfide may be different, and it is proposed that the sediment end-member should be located in the recharge zone.
2010, 32(5): 34-40.
Abstract:
The abandoned lobes of the modern Huanghe River Delta since 1855 have reached 15 m in thickness if not compacted. And the sedimentary compaction subsidence in the abandoned delta lobe varied between 2.28 and 3.87 m after passing 30 a, and the average compactional degree reached about 20.5%. The compactional subsidence of clayey silt is about 1.7 times than that of the silt.The compactional proportion of clayey silt is about 25.8% and silt is about 15.2%. which indicates that the compaction processes have been basically completed. On the other hand, the compaction subsidence of the underlying layer was quite limited. Theoretically, the compactional subsidence of the layer differed insignificantly with each other. For example, in the depth range of 20～30 m, the compaction subsidence varied between 0.2 and 0.28 m, namely, for the 24.4 m thickness underlying sedimentary layer, the compaction subsidence was 0.24 m and the average annual compaction subsidence was only 0.008 m. The average compaction ratio of clayey silt was 0.91%, while that of silt was 1.19%, and hence the average compaction ratio of the whole sedimentary layer was about 1%. During the process of compaction in both of types, there was a negative exponential function relationship between the porosity and depth of sedimentary layer, and the higher the clay content, the harder the pore water was drained or discharged. The sediments on the underlying sedimentary layer contributed more value to the compactional subsidence.
The abandoned lobes of the modern Huanghe River Delta since 1855 have reached 15 m in thickness if not compacted. And the sedimentary compaction subsidence in the abandoned delta lobe varied between 2.28 and 3.87 m after passing 30 a, and the average compactional degree reached about 20.5%. The compactional subsidence of clayey silt is about 1.7 times than that of the silt.The compactional proportion of clayey silt is about 25.8% and silt is about 15.2%. which indicates that the compaction processes have been basically completed. On the other hand, the compaction subsidence of the underlying layer was quite limited. Theoretically, the compactional subsidence of the layer differed insignificantly with each other. For example, in the depth range of 20～30 m, the compaction subsidence varied between 0.2 and 0.28 m, namely, for the 24.4 m thickness underlying sedimentary layer, the compaction subsidence was 0.24 m and the average annual compaction subsidence was only 0.008 m. The average compaction ratio of clayey silt was 0.91%, while that of silt was 1.19%, and hence the average compaction ratio of the whole sedimentary layer was about 1%. During the process of compaction in both of types, there was a negative exponential function relationship between the porosity and depth of sedimentary layer, and the higher the clay content, the harder the pore water was drained or discharged. The sediments on the underlying sedimentary layer contributed more value to the compactional subsidence.
2010, 32(5): 41-51.
Abstract:
Nanhui muddy bank shows its cyclic geomorphic evolution at different time scales.The nearly-a-centennial alternations of serious erosion and deposition are obvious from the bathymetrical data analyses of the longest time series (1842—2004) of charts available in the Changjiang Estuary.The erosion phase is characterized by "accretion on the northern and eastern flats,and erosion on the southern flat and the transition belt",while the deposition/erosion pattern is generally reversal during the deposition phase.The changing phases from erosion to deposition are inferred to highly relate to the shifting of the Changjiang main channel from the South Channel to the North Channel.There are much more and stronger storms in the erosion phases than the deposition phases.It is presumed that the pattern of"the higher flat erosion and the lower flat accretion" results from the iterative recording of bank erosion profiles by larger storms in the erosion phases; while the pattern of "the higher flat deposition and the lower flat erosion" is ascribed to the enhanced preservation of normal bank accretion landforms under weak wave conditions in the deposition phases.Net accretion/erosion regimes of the river delta are highly related to sediment discharge,but the morphodynamics is far from unification with the different delta sections undergoing dynamic erosion/deposition cycles at different tempo-spatial scales,which is jointly controlled by tides,waves,and river distributary processes through diverting riverine sediment toward/away from the study sections.There are at least three scenarios having been proposed for the critical sediment discharge (CSD) turning the delta from net accretion into net erosion.The higher and medium CSD values are considered to overestimate due to their deduction from segments instead of the entirety.The average annual sediment discharge has declined to 154 Mt/a since 2003 when the Three-Gorges Dam started its first phase operation,much lower than the lower CSD value of 184 Mt/a,but the Changjiang Delta is not observed to undergo the presumed change from net accretion into net erosion till now.Recent hydrologic data did not show the decrease of suspended sediment content in the estuary,either.It is partially due to the Changjiang Delta of tidal dominated type where tides play an important role in redistributing sediment within the estuary,resulting in lag response of delta to the sediment decrease.Synthetical studies are therefore proposed to improve complex processes in tide-dominated estuaries,and to elevate the accuracy for CSD scenario construction and the adaptability to potential disasters related to coastal erosion.
Nanhui muddy bank shows its cyclic geomorphic evolution at different time scales.The nearly-a-centennial alternations of serious erosion and deposition are obvious from the bathymetrical data analyses of the longest time series (1842—2004) of charts available in the Changjiang Estuary.The erosion phase is characterized by "accretion on the northern and eastern flats,and erosion on the southern flat and the transition belt",while the deposition/erosion pattern is generally reversal during the deposition phase.The changing phases from erosion to deposition are inferred to highly relate to the shifting of the Changjiang main channel from the South Channel to the North Channel.There are much more and stronger storms in the erosion phases than the deposition phases.It is presumed that the pattern of"the higher flat erosion and the lower flat accretion" results from the iterative recording of bank erosion profiles by larger storms in the erosion phases; while the pattern of "the higher flat deposition and the lower flat erosion" is ascribed to the enhanced preservation of normal bank accretion landforms under weak wave conditions in the deposition phases.Net accretion/erosion regimes of the river delta are highly related to sediment discharge,but the morphodynamics is far from unification with the different delta sections undergoing dynamic erosion/deposition cycles at different tempo-spatial scales,which is jointly controlled by tides,waves,and river distributary processes through diverting riverine sediment toward/away from the study sections.There are at least three scenarios having been proposed for the critical sediment discharge (CSD) turning the delta from net accretion into net erosion.The higher and medium CSD values are considered to overestimate due to their deduction from segments instead of the entirety.The average annual sediment discharge has declined to 154 Mt/a since 2003 when the Three-Gorges Dam started its first phase operation,much lower than the lower CSD value of 184 Mt/a,but the Changjiang Delta is not observed to undergo the presumed change from net accretion into net erosion till now.Recent hydrologic data did not show the decrease of suspended sediment content in the estuary,either.It is partially due to the Changjiang Delta of tidal dominated type where tides play an important role in redistributing sediment within the estuary,resulting in lag response of delta to the sediment decrease.Synthetical studies are therefore proposed to improve complex processes in tide-dominated estuaries,and to elevate the accuracy for CSD scenario construction and the adaptability to potential disasters related to coastal erosion.
2010, 32(5): 52-59.
Abstract:
By using 5 000 km long shallow penetrated seismic data collected in recent years in the Bohai Sea, many active faults and folds were found in Late Pleistocene—Holocene unconsolidated sediments. The distribution map of active faults is plotted. Further, their distribution, shallow structures, kinematics and activities are discussed in detail. The research results show that strikes of active faults express three predominant directions: NNE, E-W and NW. The quantity of faults with an E-W-trending is the most. Fault forming is controlled by regional tectonic stress and the former faults. Most of folds are anticlines and develop along the former faults.The distribution density of active faults in the Liaodong Gulf is smaller than in other sea area. In a same structural unit, more faults developed in the boundary zone than in its inner zone. The inherited fault is usually characterized by complex fracture zone where sedimentary sequences are deformed. Fracture zones usually exhibit rake-shaped or Y-shaped on the section. The formation age of sedimentary sequences offset by faults shows that the latest tectonic movement event of most faults occurs during the middle or the end of the Late Pleistocene and parts of faults are active during the Holocene. Most of faults are dominated by the normal component, but subfaults in the Tan-Lu fault zone and the Zhangjiakou—Penglai fault zone may be with some strike-slip component besides the normal component. Activities of shallow faults in the Bohai Sea have a good correlation with the earthquake epicenter, which is valuable for seismic risk assessment.
By using 5 000 km long shallow penetrated seismic data collected in recent years in the Bohai Sea, many active faults and folds were found in Late Pleistocene—Holocene unconsolidated sediments. The distribution map of active faults is plotted. Further, their distribution, shallow structures, kinematics and activities are discussed in detail. The research results show that strikes of active faults express three predominant directions: NNE, E-W and NW. The quantity of faults with an E-W-trending is the most. Fault forming is controlled by regional tectonic stress and the former faults. Most of folds are anticlines and develop along the former faults.The distribution density of active faults in the Liaodong Gulf is smaller than in other sea area. In a same structural unit, more faults developed in the boundary zone than in its inner zone. The inherited fault is usually characterized by complex fracture zone where sedimentary sequences are deformed. Fracture zones usually exhibit rake-shaped or Y-shaped on the section. The formation age of sedimentary sequences offset by faults shows that the latest tectonic movement event of most faults occurs during the middle or the end of the Late Pleistocene and parts of faults are active during the Holocene. Most of faults are dominated by the normal component, but subfaults in the Tan-Lu fault zone and the Zhangjiakou—Penglai fault zone may be with some strike-slip component besides the normal component. Activities of shallow faults in the Bohai Sea have a good correlation with the earthquake epicenter, which is valuable for seismic risk assessment.
2010, 32(5): 60-66.
Abstract:
The dose response, time-course induction and rehabilitation of hepatic microsomal EROD activity from Sparus macrocephalus、Sparus latus and Sebastiscus marmoratus were studied by crude oil water soluble fraction (WSF). The results show that in the dose-response experiments for 5 d, the hepatic EROD activity is significantly induced at the dose of 50 μg/dm3 WSF for Sebastiscus marmoratus and at the dose of 75 μg/dm3 WSF for both Sparus macrocephalus and Sparus latus; the induction of the hepatic EROD activity is the highest in Sebastiscus marmoratus, but has a wider concentration range in Sparus macrocephalus. In the time-course experiments exposure to 40 μg/dm3 WSF, the hepatic EROD activity of Sparus latus is significantly induced after 2 d of exposure; three species of fish hepatic EROD activities are significantly induced and reach a maximal level after the exposure of 4 d, then decreased and close to the control levels after 6 d of exposure. In the rehabilitation experiment, three species of fish hepatic EROD activities decrease and return to the control levels after 4 or 8 d of exposure. In general, the hepatic EROD activity from the above three species of fish can all be used for monitoring the oil pollution; However, for the comparison of the three species of fish, Sebastiscus marmoratus is more sensitive to the crude oil WSF and more suitable for monitoring marine environmental oil pollution and its biochemical effect, especially low-dose biochemical effect.
The dose response, time-course induction and rehabilitation of hepatic microsomal EROD activity from Sparus macrocephalus、Sparus latus and Sebastiscus marmoratus were studied by crude oil water soluble fraction (WSF). The results show that in the dose-response experiments for 5 d, the hepatic EROD activity is significantly induced at the dose of 50 μg/dm3 WSF for Sebastiscus marmoratus and at the dose of 75 μg/dm3 WSF for both Sparus macrocephalus and Sparus latus; the induction of the hepatic EROD activity is the highest in Sebastiscus marmoratus, but has a wider concentration range in Sparus macrocephalus. In the time-course experiments exposure to 40 μg/dm3 WSF, the hepatic EROD activity of Sparus latus is significantly induced after 2 d of exposure; three species of fish hepatic EROD activities are significantly induced and reach a maximal level after the exposure of 4 d, then decreased and close to the control levels after 6 d of exposure. In the rehabilitation experiment, three species of fish hepatic EROD activities decrease and return to the control levels after 4 or 8 d of exposure. In general, the hepatic EROD activity from the above three species of fish can all be used for monitoring the oil pollution; However, for the comparison of the three species of fish, Sebastiscus marmoratus is more sensitive to the crude oil WSF and more suitable for monitoring marine environmental oil pollution and its biochemical effect, especially low-dose biochemical effect.
2010, 32(5): 67-75.
Abstract:
According to the catch data of Dosidicus gigas and the marine environmental data, i.e.,sea surface temperature (SST), sea surface temperature horizontal gradient (SSTHG), sea surface salinity (SSS), sea surface height (SSH), chlorophyll (Chl-a) concentration in the fishing ground outside EEZ of Peru during 2003 to 2007, the method of principal component analysis was used to determine the weight of environmental factors, the weighted sum method and the geometric mean method were used to model habitat suitability index (HSI), and the optimal model was selected for an empirical analysis. The results show that the highest weight with the environmental factors for SST, the smallest for the Chl-a concentration. The high value of HSI estimated from the weighted sum method and the geometric mean method is generally distributed in the waters outside the 200 n mile exclusive economic zone. Based on the statistical comparison, the weighted sum method is better than the geometric mean method in the HSI calculation.The empirical analysis also shows that the weighted sum for estimating HSI is better suited to speculate fishing ground in 2008 since the average yield increase with the higher HSI values, which suggests that weighted sum method for estimating HSI can be used to predict the real-time dynamic fishing ground of Dosidicus gigas. The results also reveal that the putative HSI is closely related with marine environment, and the area with the HSI value above 0.8 is located at the mixture water.
According to the catch data of Dosidicus gigas and the marine environmental data, i.e.,sea surface temperature (SST), sea surface temperature horizontal gradient (SSTHG), sea surface salinity (SSS), sea surface height (SSH), chlorophyll (Chl-a) concentration in the fishing ground outside EEZ of Peru during 2003 to 2007, the method of principal component analysis was used to determine the weight of environmental factors, the weighted sum method and the geometric mean method were used to model habitat suitability index (HSI), and the optimal model was selected for an empirical analysis. The results show that the highest weight with the environmental factors for SST, the smallest for the Chl-a concentration. The high value of HSI estimated from the weighted sum method and the geometric mean method is generally distributed in the waters outside the 200 n mile exclusive economic zone. Based on the statistical comparison, the weighted sum method is better than the geometric mean method in the HSI calculation.The empirical analysis also shows that the weighted sum for estimating HSI is better suited to speculate fishing ground in 2008 since the average yield increase with the higher HSI values, which suggests that weighted sum method for estimating HSI can be used to predict the real-time dynamic fishing ground of Dosidicus gigas. The results also reveal that the putative HSI is closely related with marine environment, and the area with the HSI value above 0.8 is located at the mixture water.
2010, 32(5): 76-86.
Abstract:
Fritillarians, known as an important group of tunicates, played a crucial role in marine food web.A total of 8 species of fritillarians were collected (Fritillaria aberrens, F.abjornseni, F.formica, F.haplostoma, F.megachile, F.pacifica, F.pellucida, F.tenella) based on the data obtained from three cruises carried out in the summer and winter of 2006 and the spring of 2007 using planktonic net (mesh size: 169 μm).Fritillaria aberrens, F.abjornseni and F.pacifica were first records for waters of the South China Sea.7, 3 and 4 species occurred in summer, winter and spring and their abundance were(2.62±4.68),(0.23±0.52) and(1.72±5.43) ind/m3, respectively.The most frequent and abundant species was F.formica, accounting for 43.88%, 80.18% and 84.29% of total abundance in summer, winter and spring, followed by F.pellucida and F.haplostoma.Coastal upwelling and cyclonic circulation might push the fritillarians into coastal waters and enhanced their abundance.
Fritillarians, known as an important group of tunicates, played a crucial role in marine food web.A total of 8 species of fritillarians were collected (Fritillaria aberrens, F.abjornseni, F.formica, F.haplostoma, F.megachile, F.pacifica, F.pellucida, F.tenella) based on the data obtained from three cruises carried out in the summer and winter of 2006 and the spring of 2007 using planktonic net (mesh size: 169 μm).Fritillaria aberrens, F.abjornseni and F.pacifica were first records for waters of the South China Sea.7, 3 and 4 species occurred in summer, winter and spring and their abundance were(2.62±4.68),(0.23±0.52) and(1.72±5.43) ind/m3, respectively.The most frequent and abundant species was F.formica, accounting for 43.88%, 80.18% and 84.29% of total abundance in summer, winter and spring, followed by F.pellucida and F.haplostoma.Coastal upwelling and cyclonic circulation might push the fritillarians into coastal waters and enhanced their abundance.
2010, 32(5): 87-92.
Abstract:
Based on 105 specimens collected in the coastal waters of China, morphological characteristics of the sagittal otoliths were analyzed for the eight species of the genus Apogon (Apogon lineatus, A. siriatus, A. ellioti A. arafurae A. cathetogramma, A. semilineatus A. quadrifaosciatus and A. carinatus)inhabiting China’s seas.Results show that the sagittae of the eight species is similar in shape, all have narrow anterior part, wide posterior part, zigzag dorsal side and arcuate ventral side with a notch in the middle of the dorsal side, and the sulcus is wide. Otoliths have aspect ratio of 1.35 to 1.63, rectangularity of 0.67 to 0.77 and circularity of 14.77 to 24.99 for eight fishes. The cluster analysis is done based on the above-mentioned three kinds of morphological parameters, and results indicte that eight kinds of fishes were divided into three groups: Apogon lineatus, A. siriatus, A. ellioti and A. arafurae as a group; A. cathetogramma, A. semilineatus and A. quadrifaosciatus as a group; A. carinatus as a group alone. Sagittal shape differs among species, a systemic taxonomy is designed for eight fishes according to the sulcus acusticus shape and otolith form, and results of systemic taxonomy and cluster analysis have shown greater consistency in characteristics of the interspecific relationships. Results indicte that the trend and width of the sulcus acusticus, as well as the smoothness and other characteristics of outer contour are important characteristics of otoliths morphological classification for the genus Apogon, otoliths morphology has a good prospect of application in fish systematics.
Based on 105 specimens collected in the coastal waters of China, morphological characteristics of the sagittal otoliths were analyzed for the eight species of the genus Apogon (Apogon lineatus, A. siriatus, A. ellioti A. arafurae A. cathetogramma, A. semilineatus A. quadrifaosciatus and A. carinatus)inhabiting China’s seas.Results show that the sagittae of the eight species is similar in shape, all have narrow anterior part, wide posterior part, zigzag dorsal side and arcuate ventral side with a notch in the middle of the dorsal side, and the sulcus is wide. Otoliths have aspect ratio of 1.35 to 1.63, rectangularity of 0.67 to 0.77 and circularity of 14.77 to 24.99 for eight fishes. The cluster analysis is done based on the above-mentioned three kinds of morphological parameters, and results indicte that eight kinds of fishes were divided into three groups: Apogon lineatus, A. siriatus, A. ellioti and A. arafurae as a group; A. cathetogramma, A. semilineatus and A. quadrifaosciatus as a group; A. carinatus as a group alone. Sagittal shape differs among species, a systemic taxonomy is designed for eight fishes according to the sulcus acusticus shape and otolith form, and results of systemic taxonomy and cluster analysis have shown greater consistency in characteristics of the interspecific relationships. Results indicte that the trend and width of the sulcus acusticus, as well as the smoothness and other characteristics of outer contour are important characteristics of otoliths morphological classification for the genus Apogon, otoliths morphology has a good prospect of application in fish systematics.
2010, 32(5): 93-99.
Abstract:
The morphology and structure of sperm from the crab Charybdis japonica were observed in detail with a light and electron microscope,and the ultrastructural comparison of the spermatozoa collected from male seminal receptacle and female spermatheca has been summarized. Meanwhile the physiological density and pH of sperm were measured. The influence of pH and salinity on the sperm viability rates were also studied.The mature sperm of Charybdis japonica has not any flagella, and is consists of an acrosome,nuclear cup,membrane complex and 10～20 radial arms. The spherical acrosome is comprised of apical cap,acrosomal vesicle and acrosomal tubule. The acrosome is surrounded with nuclear cup which contains filamentous or grainular chromatin. The radial arms which extend from sperm surface were filled with karyoplasem and have no capable of movement. The sperm in male seminal receptacle forms many spheroidal spermatophore,but the sperm in female spermatheca is dispersed. Several ultrastructural differences exist in two sources sperm: the sperm from female spermatheca has vesicle-like structure in acrosomal tubule,the centrosome moves forward and cytoplasmic pellucid area becomes larger than the sperm from male seminal receptacle.The pH value of testis surface in Charybdis japonica is 6.5±0.2,while the pH value of semen is 7.0±0.2.The density of sperm is 3.47×109 ±0.42×109 /mL-1. For sperm viability,the optimum pH is 7～9,and the best is 8, the optimum salinity is 20～30,and the best is 25.
The morphology and structure of sperm from the crab Charybdis japonica were observed in detail with a light and electron microscope,and the ultrastructural comparison of the spermatozoa collected from male seminal receptacle and female spermatheca has been summarized. Meanwhile the physiological density and pH of sperm were measured. The influence of pH and salinity on the sperm viability rates were also studied.The mature sperm of Charybdis japonica has not any flagella, and is consists of an acrosome,nuclear cup,membrane complex and 10～20 radial arms. The spherical acrosome is comprised of apical cap,acrosomal vesicle and acrosomal tubule. The acrosome is surrounded with nuclear cup which contains filamentous or grainular chromatin. The radial arms which extend from sperm surface were filled with karyoplasem and have no capable of movement. The sperm in male seminal receptacle forms many spheroidal spermatophore,but the sperm in female spermatheca is dispersed. Several ultrastructural differences exist in two sources sperm: the sperm from female spermatheca has vesicle-like structure in acrosomal tubule,the centrosome moves forward and cytoplasmic pellucid area becomes larger than the sperm from male seminal receptacle.The pH value of testis surface in Charybdis japonica is 6.5±0.2,while the pH value of semen is 7.0±0.2.The density of sperm is 3.47×109 ±0.42×109 /mL-1. For sperm viability,the optimum pH is 7～9,and the best is 8, the optimum salinity is 20～30,and the best is 25.
2010, 32(5): 100-109.
Abstract:
Species composition and abundance distribution of chaetognaths were studied based on the data obtained from three separate cruises carried out in November 1997, April and July 1999 around the Nansha Islands. A total of 18 species were identified and the number of species did not show obvious seasonal variation.The abundance of chaetognaths ranged from 1.60 to 16.40 ind/m3 with the average of (6.86±3.08) ind/m3 in autumn,(9.95±3.50)ind/m3 in spring and (7.11±3.34)ind/m3 in summer. Flaccisagitta enflata dominanted, Pterosagitta draco and Serratosagitta pacifica followed during three seasons.Chaetognaths could be classified into three ecological groups, i.e.,the widespread warm-water species, the oceanic warm-water species and the nearshore warm-water species, in which the first two groups played a decisive role in the quantity distribution of chaetognaths. The seasonal distributions of chaetognaths were related to the southern South China Sea circulation driven by East Asian monsoon. During NE monsoon in autumn, the distribution of chaetognaths density showed decreasing tendency from the west to the east, and the high value spots were at oceanic fronts in southwestern survey area. In summer, the high density of chaetognaths was found in the northwest, where the upwelling and the oceanic fronts were induced by SW monsoon.
Species composition and abundance distribution of chaetognaths were studied based on the data obtained from three separate cruises carried out in November 1997, April and July 1999 around the Nansha Islands. A total of 18 species were identified and the number of species did not show obvious seasonal variation.The abundance of chaetognaths ranged from 1.60 to 16.40 ind/m3 with the average of (6.86±3.08) ind/m3 in autumn,(9.95±3.50)ind/m3 in spring and (7.11±3.34)ind/m3 in summer. Flaccisagitta enflata dominanted, Pterosagitta draco and Serratosagitta pacifica followed during three seasons.Chaetognaths could be classified into three ecological groups, i.e.,the widespread warm-water species, the oceanic warm-water species and the nearshore warm-water species, in which the first two groups played a decisive role in the quantity distribution of chaetognaths. The seasonal distributions of chaetognaths were related to the southern South China Sea circulation driven by East Asian monsoon. During NE monsoon in autumn, the distribution of chaetognaths density showed decreasing tendency from the west to the east, and the high value spots were at oceanic fronts in southwestern survey area. In summer, the high density of chaetognaths was found in the northwest, where the upwelling and the oceanic fronts were induced by SW monsoon.
2010, 32(5): 110-116.
Abstract:
Biofilm formation of 12 strains of Vibrio were determinated using the method of modified microtiter-plate test,and V. parahaemolyticus strain ND-02 was chosen for the further study on the influence of different environmental factors on bacterial biofilm formation .The results show that V. parahaemolyticus strain ND-02 forms mature biofilm in 24～36 h,V. parahaemolyticus with original bacterial concentrations of 107 and 108CFU/mL shows the largest biofilm quantity; the OD590 value of bacterial biofilm increases with the incubation temperature from 10 ℃ to 30 ℃ and peaks at 30 ℃;the OD590 value of bacterial biofilm fluctuates with different NaCl concentrations optimized at 3% to 5%,and OD590 values are remarkably higher at pH 7～10,and peak at pH 7.Addition of Ca2+ obviously promoted the bacterial biofilm formation while Mg2+ played as an opposite role. V. parahaemolyticus strain ND-02 showed better biofilm formation on the wells coated with liver extract,skin mucus and intestinal mucus of Pseudosciaena crocea,the less biofilm was found on the wells coated with muscle extract. The results indicate that V. parahaemolyticus strain ND-02 develops stable and evident biofilm,the biofilm formation is remarkably affected by environmental factors, such as temperature, pH, NaCl concentration,Ca2+ ,Mg2+ . The results also indicate that the bacterial biofilm formation of V. parahaemolyticus is governable,which will be useful for the epidemic control in fish culture.
Biofilm formation of 12 strains of Vibrio were determinated using the method of modified microtiter-plate test,and V. parahaemolyticus strain ND-02 was chosen for the further study on the influence of different environmental factors on bacterial biofilm formation .The results show that V. parahaemolyticus strain ND-02 forms mature biofilm in 24～36 h,V. parahaemolyticus with original bacterial concentrations of 107 and 108CFU/mL shows the largest biofilm quantity; the OD590 value of bacterial biofilm increases with the incubation temperature from 10 ℃ to 30 ℃ and peaks at 30 ℃;the OD590 value of bacterial biofilm fluctuates with different NaCl concentrations optimized at 3% to 5%,and OD590 values are remarkably higher at pH 7～10,and peak at pH 7.Addition of Ca2+ obviously promoted the bacterial biofilm formation while Mg2+ played as an opposite role. V. parahaemolyticus strain ND-02 showed better biofilm formation on the wells coated with liver extract,skin mucus and intestinal mucus of Pseudosciaena crocea,the less biofilm was found on the wells coated with muscle extract. The results indicate that V. parahaemolyticus strain ND-02 develops stable and evident biofilm,the biofilm formation is remarkably affected by environmental factors, such as temperature, pH, NaCl concentration,Ca2+ ,Mg2+ . The results also indicate that the bacterial biofilm formation of V. parahaemolyticus is governable,which will be useful for the epidemic control in fish culture.
2010, 32(5): 117-126.
Abstract:
The diversity and distribution of vibrios in Shenzhen coastal waters were studied, and the relationships between environmental factors and vibrio quantity were investigated. Results showed that the seasonal variations of culturable vibrios in Shenzhen coastal sea seemed to be obvious. In the east costal sea, the number of marine vibrios in April(with an average value of 1.50×104 CFU/cm3) was higher than that in September(with an average value of 8.89×102 CFU/cm3), while in the west costal sea, the number of marine vibrios in September(with an average value of 5.09×102 CFU/cm3) was higher than that in April(with an average value of 2.66×102 CFU/cm3). The highest number was detected in the Daya Bay. The seasonal variations of each dominant Vibrio sp. in the coastal waters indicate that V. gigantis-like species and V. splendidus-like species were dominant in April with lower temperature, while V. natriegens-like species were dominant in September with higher temperature; V. alginolyticus-like species were the dominant group in both seasons, the average number of it in April are higher than that in September. The vibrios density showed certain relationship between temperature, salinity, pH, level of fecal coliforms, level of total bacteria and culturable bacteria, and the salinity controls the distribution of vibrios obviously.
The diversity and distribution of vibrios in Shenzhen coastal waters were studied, and the relationships between environmental factors and vibrio quantity were investigated. Results showed that the seasonal variations of culturable vibrios in Shenzhen coastal sea seemed to be obvious. In the east costal sea, the number of marine vibrios in April(with an average value of 1.50×104 CFU/cm3) was higher than that in September(with an average value of 8.89×102 CFU/cm3), while in the west costal sea, the number of marine vibrios in September(with an average value of 5.09×102 CFU/cm3) was higher than that in April(with an average value of 2.66×102 CFU/cm3). The highest number was detected in the Daya Bay. The seasonal variations of each dominant Vibrio sp. in the coastal waters indicate that V. gigantis-like species and V. splendidus-like species were dominant in April with lower temperature, while V. natriegens-like species were dominant in September with higher temperature; V. alginolyticus-like species were the dominant group in both seasons, the average number of it in April are higher than that in September. The vibrios density showed certain relationship between temperature, salinity, pH, level of fecal coliforms, level of total bacteria and culturable bacteria, and the salinity controls the distribution of vibrios obviously.
2010, 32(5): 127-134.
Abstract:
A strain sensitive to heave metals was isolated from contaminated sediments of the Jiaozhow Bay coast and identified as Penicillium griseofulvum. The biological features and enzyme active reaction of the strain under heavy metal action were investigated. Results show that certain amounts of Cu2+ and Zn2+ exerted obvious influence on this strain’s morphology and pigment. The spore germination was totally restrained and the mycelium varied severely when Cu2+ and Zn2+ concentration reached 125 and 800 mg/dm3 respectively in mediums. The pigments presented from celadon to shallow yellow with the increase of Cu2+ concentration and from celadon to white with the increase of Zn2+ concentration. Within the growth concentration range, a small quantity of Cu2+ would enhance activities of CAT, GOD and MT and reached climax when Cu2+ concentration was 25 mg/dm3. When the Cu2+ concentration changed from 25 to 75 mg/dm3, the activities decreased gradually and the strain stopped growing when the concentration reached 100 mg/dm3. When the Zn2+ concentration changed from 100 to 400 mg/dm3, activities of CAT , GOD and MT increased gradually and reached climax at 400 mg/dm3 but stopped growing at 600 mg/L ,because the strain could not survive in this concentration.
A strain sensitive to heave metals was isolated from contaminated sediments of the Jiaozhow Bay coast and identified as Penicillium griseofulvum. The biological features and enzyme active reaction of the strain under heavy metal action were investigated. Results show that certain amounts of Cu2+ and Zn2+ exerted obvious influence on this strain’s morphology and pigment. The spore germination was totally restrained and the mycelium varied severely when Cu2+ and Zn2+ concentration reached 125 and 800 mg/dm3 respectively in mediums. The pigments presented from celadon to shallow yellow with the increase of Cu2+ concentration and from celadon to white with the increase of Zn2+ concentration. Within the growth concentration range, a small quantity of Cu2+ would enhance activities of CAT, GOD and MT and reached climax when Cu2+ concentration was 25 mg/dm3. When the Cu2+ concentration changed from 25 to 75 mg/dm3, the activities decreased gradually and the strain stopped growing when the concentration reached 100 mg/dm3. When the Zn2+ concentration changed from 100 to 400 mg/dm3, activities of CAT , GOD and MT increased gradually and reached climax at 400 mg/dm3 but stopped growing at 600 mg/L ,because the strain could not survive in this concentration.
2010, 32(5): 135-143.
Abstract:
Sponge-associated bacteria were isolated from marine organism sponge by dilution-plate method,and the antibacterial activities were screened for Bacillus subtilis, Staphylococcus aureus, Escherichia coli and Saccharomyces cerevisia by an agar diffusion method.And the occurrence of quorum-sensing signal molecule acylhomoserine lactones (AHLs) was investigated in the extracts of active strains by a gas chromatography-mass spectrometry.At the same time, taxonomy was studied based on the phylogenetic analysis of 16S rDNA sequences.The results show that 18 strains (accounting for 19.1%) among total 94 isolated marine bacteria have antimicrobial activity.The N-octanoyl-homoserine lactone and N-tetradecanoyl-homoserine lactone were detected from the majority of active strains, showing that the some relationship between the antimicrobial activity and the quorum sensing.The most active sponge-associated bacteria were identified to be the genus Bacillus.
Sponge-associated bacteria were isolated from marine organism sponge by dilution-plate method,and the antibacterial activities were screened for Bacillus subtilis, Staphylococcus aureus, Escherichia coli and Saccharomyces cerevisia by an agar diffusion method.And the occurrence of quorum-sensing signal molecule acylhomoserine lactones (AHLs) was investigated in the extracts of active strains by a gas chromatography-mass spectrometry.At the same time, taxonomy was studied based on the phylogenetic analysis of 16S rDNA sequences.The results show that 18 strains (accounting for 19.1%) among total 94 isolated marine bacteria have antimicrobial activity.The N-octanoyl-homoserine lactone and N-tetradecanoyl-homoserine lactone were detected from the majority of active strains, showing that the some relationship between the antimicrobial activity and the quorum sensing.The most active sponge-associated bacteria were identified to be the genus Bacillus.
2010, 32(5): 144-151.
Abstract:
The economic red macroalga Gracilaria lemaneiformis was selected to study the co-effects of CO2 and solar UVR (280～400 nm) on its growth, photosynthesis, pigments and UVAC contents.Two CO2 concentration levels (380×10-6 and 800×10-6) and three solar radiation treatments (PAB treatment, the thalli receiving full solar radiation; PA treatment, UV-B was cut off, P treatment, all UV radiation were cut off).Results show that the relative growth rate of the thalli increases when the thalli is cultured in high concentration CO2 condition (800×10-6) and it decreases in the presence of UVR, but the co-effects of CO2 and solar UVR are not significant.UVR significantly increase the content of UV-absorbing compounds ofGracilaria lemaneiformis, and further increase of the content of UVACs in PAB treatment is found under CO2 enriched condition.The positive effects on photosynthesis ofGracilaria lemaneiformis is found in the presence of UV-A when photosynthesis is limited by low PAR.the negative effects are found when the thalli is cultured under CO2 enriched condition.UVR significantly decreases the photosynthetic rate of theGracilaria lemaneiformis when the thalli is cultured under normal CO2 level condition, while no effects of UVR is found when the thalli is cultured under CO2-enriched condition.UVR significantly decreases the content of phycoerythrin, and high concentration CO2 also decreases the content of phycoerythrin under P and PA treatment, but the opposite result is found in PAB treatment.In conclusion,it is shown thatGracilaria lemaneiformis grown under CO2-enriched condition can eliminate the deleterious influence of UVR on photosynthesis by increasing UVAC contents and keeping the high content of phycoerythrin in thalli.
The economic red macroalga Gracilaria lemaneiformis was selected to study the co-effects of CO2 and solar UVR (280～400 nm) on its growth, photosynthesis, pigments and UVAC contents.Two CO2 concentration levels (380×10-6 and 800×10-6) and three solar radiation treatments (PAB treatment, the thalli receiving full solar radiation; PA treatment, UV-B was cut off, P treatment, all UV radiation were cut off).Results show that the relative growth rate of the thalli increases when the thalli is cultured in high concentration CO2 condition (800×10-6) and it decreases in the presence of UVR, but the co-effects of CO2 and solar UVR are not significant.UVR significantly increase the content of UV-absorbing compounds ofGracilaria lemaneiformis, and further increase of the content of UVACs in PAB treatment is found under CO2 enriched condition.The positive effects on photosynthesis ofGracilaria lemaneiformis is found in the presence of UV-A when photosynthesis is limited by low PAR.the negative effects are found when the thalli is cultured under CO2 enriched condition.UVR significantly decreases the photosynthetic rate of theGracilaria lemaneiformis when the thalli is cultured under normal CO2 level condition, while no effects of UVR is found when the thalli is cultured under CO2-enriched condition.UVR significantly decreases the content of phycoerythrin, and high concentration CO2 also decreases the content of phycoerythrin under P and PA treatment, but the opposite result is found in PAB treatment.In conclusion,it is shown thatGracilaria lemaneiformis grown under CO2-enriched condition can eliminate the deleterious influence of UVR on photosynthesis by increasing UVAC contents and keeping the high content of phycoerythrin in thalli.
2010, 32(5): 152-159.
Abstract:
2010, 32(5): 160-164.
Abstract:
2010, 32(5): 165-174.
Abstract:
2010, 32(5): 175-179.
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