Most read articles
ZHANG Hua-wei
,
MA Jia-hai
,
HU Xiang
,
YANG Jian-qiang
,
ZHANG Tian-fu
,
CHEN Bin-bin
,
XU Ren
,
YE Shu-feng
2011, 20(4):600-606.
Abstract:
In the last three years, vast green tides occurred repeatedly in the Yellow Sea area every summer. The biomass of floating green tide algae increased fast in a few months, moreover, the area covered by floating green tide algae expanded sharply. The material of this study is the dominant species Ulva prolifera in green tide. The reproductive characteristics study of the floating green algae showed that every square centimeter of the thalli produced about 5.35×106 spores or 1.07×107 gametes; during May to August, 25% surface area of the mature thalli produced about 1.15×107 spores or 2.31×107gametes. Parthenogenesis and asexual reproduction are the main reproductive modes of the floating green algae. Gametes showed intensive positive phototaxis, after syngamy, motile zygotes showed negative phototaxis. The spores and gametes could grow to new thalli independently, and the same to motile zygotes. As a result, the strong reproductive capacity of floating green tide algae Ulva prolifera might be the main reason of green tide occurrence.
In the last three years, vast green tides occurred repeatedly in the Yellow Sea area every summer. The biomass of floating green tide algae increased fast in a few months, moreover, the area covered by floating green tide algae expanded sharply. The material of this study is the dominant species Ulva prolifera in green tide. The reproductive characteristics study of the floating green algae showed that every square centimeter of the thalli produced about 5.35×106 spores or 1.07×107 gametes; during May to August, 25% surface area of the mature thalli produced about 1.15×107 spores or 2.31×107gametes. Parthenogenesis and asexual reproduction are the main reproductive modes of the floating green algae. Gametes showed intensive positive phototaxis, after syngamy, motile zygotes showed negative phototaxis. The spores and gametes could grow to new thalli independently, and the same to motile zygotes. As a result, the strong reproductive capacity of floating green tide algae Ulva prolifera might be the main reason of green tide occurrence.
2011, 20(6):902-909.
Abstract:
Geographic information system (GIS), as a powerful spatiotemporal analysis tool, has been applied to marine fisheries since the late 1980s, and which is widely used in the fields of data processing and analysis of fishery conditions, relationship between fishery resources and environment, aquaculture selection, fishery resources assessment, tagging, marine ecosystem and fishing ground forecasting. But GIS in the marine fisheries still faces with great challenges. The information of fishery resources includes not only fishery data and environmental data, but also socialeconomic data which are closely related with fishermen. That is, in the future GIS in marine fishery should be a set of natural resources and environment systems, human systems, social systems and economic systems. Fisheries management and sustainability based marine ecosystem has been a common concern of community and international organizations, and GIS has greater advantages than traditional methods and will further enhances fishery decisionmaking. The applications of GIS in fisheries will focus on: （1） the establishment of the database and data standardization; （2） the design of key essential fish habitat; （3） the definition of marine protected areas; （4） longterm monitoring and management of resources; （5） distribution and migratory of fish specis and 3D analysis of marine environment. Finally, the establishment of GISbased framework for ocean fisheries information system in our country is proposed.
Geographic information system (GIS), as a powerful spatiotemporal analysis tool, has been applied to marine fisheries since the late 1980s, and which is widely used in the fields of data processing and analysis of fishery conditions, relationship between fishery resources and environment, aquaculture selection, fishery resources assessment, tagging, marine ecosystem and fishing ground forecasting. But GIS in the marine fisheries still faces with great challenges. The information of fishery resources includes not only fishery data and environmental data, but also socialeconomic data which are closely related with fishermen. That is, in the future GIS in marine fishery should be a set of natural resources and environment systems, human systems, social systems and economic systems. Fisheries management and sustainability based marine ecosystem has been a common concern of community and international organizations, and GIS has greater advantages than traditional methods and will further enhances fishery decisionmaking. The applications of GIS in fisheries will focus on: （1） the establishment of the database and data standardization; （2） the design of key essential fish habitat; （3） the definition of marine protected areas; （4） longterm monitoring and management of resources; （5） distribution and migratory of fish specis and 3D analysis of marine environment. Finally, the establishment of GISbased framework for ocean fisheries information system in our country is proposed.
2011, 20(2):275-283.
Abstract:
Generalized Linear Models (GLM) and Generalized Additive Models (GAM) were used to standardize catch per unit fishing effort (CPUE) of Chinese bigeye tuna (Thunnus obesus) fishery in the Indian Ocean. In CPUE standardization, nominal CPUE was treated as the dependent variable and three groups of affected variables were considered: spatial variables (longitude and latitude), temporal variables (year and month) and environmental variables (temperature at various depths, salinity at various depths and Sea Level Height). The results indicated that the standardized and nominal CPUEs were similar and showed the same trends in spatiotemporal distribution. The CPUE increased with year and high CPUE usually occurred in 42°E-60°E, 85°E -90°E, 15°S-5°S and 10°N-15°N. Both the results of GLM and GAM showed that the longitude was the most important variable affecting CPUE, which could explain 17.3% and 23.81% of the deviance，respectively. The effects of latitude, the interaction terms of longitude and latitude, year, temperature at 317 m depth and temperature at 381 m depth on CPUE were also apparent. GLM tended to be more appropriate than GAM in the analysis of CPUE standardization in this study.
Generalized Linear Models (GLM) and Generalized Additive Models (GAM) were used to standardize catch per unit fishing effort (CPUE) of Chinese bigeye tuna (Thunnus obesus) fishery in the Indian Ocean. In CPUE standardization, nominal CPUE was treated as the dependent variable and three groups of affected variables were considered: spatial variables (longitude and latitude), temporal variables (year and month) and environmental variables (temperature at various depths, salinity at various depths and Sea Level Height). The results indicated that the standardized and nominal CPUEs were similar and showed the same trends in spatiotemporal distribution. The CPUE increased with year and high CPUE usually occurred in 42°E-60°E, 85°E -90°E, 15°S-5°S and 10°N-15°N. Both the results of GLM and GAM showed that the longitude was the most important variable affecting CPUE, which could explain 17.3% and 23.81% of the deviance，respectively. The effects of latitude, the interaction terms of longitude and latitude, year, temperature at 317 m depth and temperature at 381 m depth on CPUE were also apparent. GLM tended to be more appropriate than GAM in the analysis of CPUE standardization in this study.
2011, 20(1):44-49.
Abstract:
The complete cDNA (GenBank accession number DQ678929) and its corresponding gene (EF468349) of chitin deacetylase CDA2 from Mucor racemosus mycelium had been cloned by rapid amplification cDNA end (RACE) with specific degenerate primers. In contrast to previously obtained gene cda1, cda2 contained no intron sequence. It consisted of 1 378 bp nucleotides, comprising 23-bp 5’ untranslated region (UTR), 1 254bp open reading frame (ORF) and 101-bp 3’ UTR. The ORF encoded 418 amino acid (a.a.) residues including a 21 a.a. N-terminal signal peptide and a conserved polysaccharide deacetylase domain were located in an area of 150-272 a.a. residues. The results from subsequent construction of expressional vector pET28a-cda2 and prokaryotic expression revealed that molecular weight of recombinant protein CDA2 was about 46 ku and it was mainly found in inclusion bodies. The purified CDA2 showed chitin deacetylating activities. This work is necessary for further structural and functional exploration in chitin deacetylase CDA2 from M. racemosus.
The complete cDNA (GenBank accession number DQ678929) and its corresponding gene (EF468349) of chitin deacetylase CDA2 from Mucor racemosus mycelium had been cloned by rapid amplification cDNA end (RACE) with specific degenerate primers. In contrast to previously obtained gene cda1, cda2 contained no intron sequence. It consisted of 1 378 bp nucleotides, comprising 23-bp 5’ untranslated region (UTR), 1 254bp open reading frame (ORF) and 101-bp 3’ UTR. The ORF encoded 418 amino acid (a.a.) residues including a 21 a.a. N-terminal signal peptide and a conserved polysaccharide deacetylase domain were located in an area of 150-272 a.a. residues. The results from subsequent construction of expressional vector pET28a-cda2 and prokaryotic expression revealed that molecular weight of recombinant protein CDA2 was about 46 ku and it was mainly found in inclusion bodies. The purified CDA2 showed chitin deacetylating activities. This work is necessary for further structural and functional exploration in chitin deacetylase CDA2 from M. racemosus.
2020, 29(2):295-304.
DOI: 10.12024/jsou.20190502686
Abstract:
The development of recreational fishery is an important part of promoting modern fishery construction, and an important measure to implement the rural revitalization strategy and the marine economy construction. Based on the literature sample data of the world’s leisure fisheries related research topics in the Web of Science database from 1966 to 2018, this paper uses CiteSpace measurement software to systematically sort out the international leisure fishery through literature citation analysis, keyword co-occurrence and sudden word detection. Research frontiers and hotspots show that: (1) The knowledge structure of international leisure fishery research is based on biology, resource science and environmental science. At the same time, the research frontier of international leisure fishery has gradually turned to the integrity of society-ecosystem and sustainable development in the past 10 years; (2) Recreational fishery is a typical composite interdisciplinary subject. Interdisciplinary comprehensive research is an important guarantee for its disciplinary development. The development of international recreational fisheries has formed a relatively complete research relying on multidisciplinary integration; (3) New technical methods such as big data technology, 3S technology, simulation technology and complex system models are widely used in the recreational fisheries, which will provide efficient and accurate technical support to solve comprehensive, dynamic and systematic problems. Finally, the study suggests that the domestic research on recreational fisheries should focus on the multi-scale nature of the research area, the integration of interdisciplinary disciplines and the attention to environmental issues in the development process of recreational fisheries in the future.
The development of recreational fishery is an important part of promoting modern fishery construction, and an important measure to implement the rural revitalization strategy and the marine economy construction. Based on the literature sample data of the world’s leisure fisheries related research topics in the Web of Science database from 1966 to 2018, this paper uses CiteSpace measurement software to systematically sort out the international leisure fishery through literature citation analysis, keyword co-occurrence and sudden word detection. Research frontiers and hotspots show that: (1) The knowledge structure of international leisure fishery research is based on biology, resource science and environmental science. At the same time, the research frontier of international leisure fishery has gradually turned to the integrity of society-ecosystem and sustainable development in the past 10 years; (2) Recreational fishery is a typical composite interdisciplinary subject. Interdisciplinary comprehensive research is an important guarantee for its disciplinary development. The development of international recreational fisheries has formed a relatively complete research relying on multidisciplinary integration; (3) New technical methods such as big data technology, 3S technology, simulation technology and complex system models are widely used in the recreational fisheries, which will provide efficient and accurate technical support to solve comprehensive, dynamic and systematic problems. Finally, the study suggests that the domestic research on recreational fisheries should focus on the multi-scale nature of the research area, the integration of interdisciplinary disciplines and the attention to environmental issues in the development process of recreational fisheries in the future.
6 The variations of digestive enzyme activities during the development of Oplegnathus fasciatus larvae
YIN Yan-qiang
,
FU Rong-bing
,
HUANG Xu-xiong
,
WEN Wen
,
SHI Zhao-hong
,
LUO Hai-zhong
,
YAN Jia-qi
2011, 20(1):56-62.
Abstract:
This paper investigated the trypsinase, acid protease, amylase and lipase activities of the Oplegnathus fasciatus larvae cultured in indoor pond from hatching to post hatching day (phd) 33rd. The results indicated that trypsinase, acid protease, amylase and lipase could be detected in newly hatched larvae, although the activities of trypsinase, acid protease and amylase were very low. The total activity of trypsinase (U/larva) of the larvae increased significantly on phd 9th and increased gradually with the development. The total activities of acid prolease and lipase of the larvae increased significantly on phd 28th. The total activities of acid prolease and lipase of the larvae on phd 33rd were significant higher than those on phd 28th respectively. The total activity of amylase of the larvae increased significantly on phd 9th and also increased gradually with the development. While the larvae developed at juvenile stage (>phd 22nd), the total activity of amylase decreased significantly with the development. It is suggested that the activities of digestive enzyme of the Oplegnathus fasciatus larvae closely correspond to the development stage and feeding habit. The trypsinase and amylase were the very important endogenous enzymes at the early stage of the larva development.
This paper investigated the trypsinase, acid protease, amylase and lipase activities of the Oplegnathus fasciatus larvae cultured in indoor pond from hatching to post hatching day (phd) 33rd. The results indicated that trypsinase, acid protease, amylase and lipase could be detected in newly hatched larvae, although the activities of trypsinase, acid protease and amylase were very low. The total activity of trypsinase (U/larva) of the larvae increased significantly on phd 9th and increased gradually with the development. The total activities of acid prolease and lipase of the larvae increased significantly on phd 28th. The total activities of acid prolease and lipase of the larvae on phd 33rd were significant higher than those on phd 28th respectively. The total activity of amylase of the larvae increased significantly on phd 9th and also increased gradually with the development. While the larvae developed at juvenile stage (>phd 22nd), the total activity of amylase decreased significantly with the development. It is suggested that the activities of digestive enzyme of the Oplegnathus fasciatus larvae closely correspond to the development stage and feeding habit. The trypsinase and amylase were the very important endogenous enzymes at the early stage of the larva development.
7 Comparative analysis on the countershading between several marine pelagic fishes and demersal fishes
2020, 29(2):199-208.
DOI: 10.12024/jsou.20190302552
Abstract:
The countershading formed by deep body color of dorsal surface and shallow body color of venteral surface is beneficial to avoid enemies and prey, and is more common in marine fishes. In order to understand the ecological adaptation of the marine bony fishes and the formation of pigment cells in the dorsal and venter surface, six kinds of marine pelagic fishes and five kinds of demersal fishes were collected, respectively. The results show that no matter the marine pelagic fishes (including Megalaspis cordyla, Hemiramphus far, Seriola quinqueradiata, Trachurus japonicus, Decapterus maruadsi, Scomberomorus niphonius) or marine demersal fishes (Muraenesox cinereus, Synechogobius ommaturus, Trichiurus japonicus, Aluterus monoceros, Harpadon nehereus). Both melanocytes and xanthophores are more in dorsal than in venter, and the difference between dorsal and venter is significant. Compared to the offshore demersal fishes, the countershading in these offshore pelagic fishes is more obvious. The iridocystes are present in both the skins of dorsal and venter, in the venter of marine demersal fishes most of pigments are iridocystes. There are few of the erythrophores in the demersal fishes, but more erythrophores can be seen in marine pelagic fishes. In summary, the investigation shows that the countershading mainly depends on the amounts of both melanocytes and xanthophores in the dorsal skin, and the venter color is related to iridocystes in marine bony fishes.
The countershading formed by deep body color of dorsal surface and shallow body color of venteral surface is beneficial to avoid enemies and prey, and is more common in marine fishes. In order to understand the ecological adaptation of the marine bony fishes and the formation of pigment cells in the dorsal and venter surface, six kinds of marine pelagic fishes and five kinds of demersal fishes were collected, respectively. The results show that no matter the marine pelagic fishes (including Megalaspis cordyla, Hemiramphus far, Seriola quinqueradiata, Trachurus japonicus, Decapterus maruadsi, Scomberomorus niphonius) or marine demersal fishes (Muraenesox cinereus, Synechogobius ommaturus, Trichiurus japonicus, Aluterus monoceros, Harpadon nehereus). Both melanocytes and xanthophores are more in dorsal than in venter, and the difference between dorsal and venter is significant. Compared to the offshore demersal fishes, the countershading in these offshore pelagic fishes is more obvious. The iridocystes are present in both the skins of dorsal and venter, in the venter of marine demersal fishes most of pigments are iridocystes. There are few of the erythrophores in the demersal fishes, but more erythrophores can be seen in marine pelagic fishes. In summary, the investigation shows that the countershading mainly depends on the amounts of both melanocytes and xanthophores in the dorsal skin, and the venter color is related to iridocystes in marine bony fishes.
2011, 20(1):108-113.
Abstract:
Sea water temperature (SST) is one of the important factors that impact growth, reproduction and recruitment of chub mackerel. According to the catch and standardized CPUE data of purse seine fishery with lights (PSFL) and monthly sea surface temperature of the spawning ground in February from 1998 to 2006, the author developed a surplus production model for chub mackerel based on SST, and analyzed the impact of SST on the chub mackerel stock and its sustainable yield. The result indicates the relationship between sustainable yield and SST, can be expressed as Yt=1 080.97 ft-0.006f2t+114.51SSTt ft-2.91SST2tft. Variations of chub mackerel stock biomass and sustainable yield are controlled mainly by SST in the spawning ground and fishing effort. The optimal SST range for chub mackerel spawning is 18.5- 20.6℃. It is suggested that the maximum sustainable yield may be estimated based on the annual different environmental conditions, and the fishery management measures should be adjusted in realtime.
Sea water temperature (SST) is one of the important factors that impact growth, reproduction and recruitment of chub mackerel. According to the catch and standardized CPUE data of purse seine fishery with lights (PSFL) and monthly sea surface temperature of the spawning ground in February from 1998 to 2006, the author developed a surplus production model for chub mackerel based on SST, and analyzed the impact of SST on the chub mackerel stock and its sustainable yield. The result indicates the relationship between sustainable yield and SST, can be expressed as Yt=1 080.97 ft-0.006f2t+114.51SSTt ft-2.91SST2tft. Variations of chub mackerel stock biomass and sustainable yield are controlled mainly by SST in the spawning ground and fishing effort. The optimal SST range for chub mackerel spawning is 18.5- 20.6℃. It is suggested that the maximum sustainable yield may be estimated based on the annual different environmental conditions, and the fishery management measures should be adjusted in realtime.
2011, 20(3):417-423.
Abstract:
The growth relationship between statolith and individual of the jumbo flying squid (Dosidicus gigas) sampled in waters off Costa Rica from July to August in 2009 was studied with multiple statistical methods. It was found that the growth relationship between statolith and mantle length (ML) was significant (P<0.01), and the biggest coefficient were ventral dorsal dome length (DDL) and total statolith length (TSL). Statolith growth contained two phases, rapid growth of statolith before ML was smaller than 26-30 cm, and after that there has a slow growth of statolith. The dorsal length (DL), rostrum inside length (RIL) and DDL grew faster than the TSL, but the ventral dorsal dome angle (DDA), rostrum lateral dome angle (RDA) and rostrum angle (RA) were reduced during the growth process. So the morphology of lateral dome and rostrum were changed significantly (P<0.05). Although the significant changes of statolith morphology preceded the growth changes and the significant changes of various parts in morphology were not synchronized, the morphological changes mainly occurred in individuals with 23-29 cm ML, after that the morphology kept stabilized. The significant changes of growth and morphology were associated with habitat changed of water layer, and the jumbo flying squid statolith was coincided with the characteristics of pelagic cephalopods.
The growth relationship between statolith and individual of the jumbo flying squid (Dosidicus gigas) sampled in waters off Costa Rica from July to August in 2009 was studied with multiple statistical methods. It was found that the growth relationship between statolith and mantle length (ML) was significant (P<0.01), and the biggest coefficient were ventral dorsal dome length (DDL) and total statolith length (TSL). Statolith growth contained two phases, rapid growth of statolith before ML was smaller than 26-30 cm, and after that there has a slow growth of statolith. The dorsal length (DL), rostrum inside length (RIL) and DDL grew faster than the TSL, but the ventral dorsal dome angle (DDA), rostrum lateral dome angle (RDA) and rostrum angle (RA) were reduced during the growth process. So the morphology of lateral dome and rostrum were changed significantly (P<0.05). Although the significant changes of statolith morphology preceded the growth changes and the significant changes of various parts in morphology were not synchronized, the morphological changes mainly occurred in individuals with 23-29 cm ML, after that the morphology kept stabilized. The significant changes of growth and morphology were associated with habitat changed of water layer, and the jumbo flying squid statolith was coincided with the characteristics of pelagic cephalopods.
2011, 20(1):71-75.
Abstract:
Ultrastructure of spermatozoa of E. septemfasciatus was investigated using transmission electron microscopes. The spermatozoa consists of two parts: the head and the tail (flagellum), no midpiece. The spermatozoa of E. septemfasciatus has no acrosome. A large spherical nucleus, covered with nuclear membrane, is located at the front part of the head and about its 1/3. The high electron density chromatin is the main components of nucleus, with several low electron density vesicles in it. There is little space between the plasma membrane and nuclear membrane at the front part of head. The implantation fossa is located in the posterior end of the nucleus. Proximal centriole and intercentriolar body are located in implantation fossa. The posterior end of the head is a large sleeve, which is about 2/3 of the head. The sleeve contains centriolar complex, several mitochondria and vesicles. At the midpart of the sleeve, there is a sleeve carve, out of which the thin and long tail stretches. The tail with only a little cytoplasm is thin and long. The axoneme between the end of the base body and the head of the tail is “9+0”. The 9 doublet of the axoneme, the central structure of the tail, is connected to the 9 strips of the posterior end of the basal body. The flagellar tail is the conventional “9+2”axoneme.
Ultrastructure of spermatozoa of E. septemfasciatus was investigated using transmission electron microscopes. The spermatozoa consists of two parts: the head and the tail (flagellum), no midpiece. The spermatozoa of E. septemfasciatus has no acrosome. A large spherical nucleus, covered with nuclear membrane, is located at the front part of the head and about its 1/3. The high electron density chromatin is the main components of nucleus, with several low electron density vesicles in it. There is little space between the plasma membrane and nuclear membrane at the front part of head. The implantation fossa is located in the posterior end of the nucleus. Proximal centriole and intercentriolar body are located in implantation fossa. The posterior end of the head is a large sleeve, which is about 2/3 of the head. The sleeve contains centriolar complex, several mitochondria and vesicles. At the midpart of the sleeve, there is a sleeve carve, out of which the thin and long tail stretches. The tail with only a little cytoplasm is thin and long. The axoneme between the end of the base body and the head of the tail is “9+0”. The 9 doublet of the axoneme, the central structure of the tail, is connected to the 9 strips of the posterior end of the basal body. The flagellar tail is the conventional “9+2”axoneme.
2011, 20(2):296-302.
Abstract:
Chitosanase (EC3.2.1.132) catalyses the hydrolysis of the β-1,4 glycosidic bonds in chitosan to produce physiologically active chitooligosaccharides, polyglucosamines with 2 to 10 degrees of polymerization. It has been found in many microorganisms including bacteria and fungi. 51 chitosanaseproducing strains were screened and isolated from 11 soilsamples rich in shrimp and crab shells by transparent circles in the culture media containing chitosan as sole carbon source. After screening of flatpanel, flaskshaking cultivation and enzyme kinetics in fermentation, a strain (H2) with higher chitosanlytic activity was acquired. According to its morphological, cultural, biochemical and physiological characteristics and phylogenetic analysis of 16S rDNA, the strain was identified and named as Streptomyces roseolus DH. Further studies of fermentation conditions showed that the optimum temperature and initial pH of medium were 30 ℃ and 7.2, respectively. Moreover, the colloid chitosan (1.0%) and peptone (0.5%) were chosen as the best carbon and nitrogen sources among the tested ones. Under these conditions, the activity of chitosanase in media reached 6.10±0.12 U/mL after 60hour fermentation. This strain with higher yield of chitosanase and shorter fermentation period displayed good potential for future applications.
Chitosanase (EC3.2.1.132) catalyses the hydrolysis of the β-1,4 glycosidic bonds in chitosan to produce physiologically active chitooligosaccharides, polyglucosamines with 2 to 10 degrees of polymerization. It has been found in many microorganisms including bacteria and fungi. 51 chitosanaseproducing strains were screened and isolated from 11 soilsamples rich in shrimp and crab shells by transparent circles in the culture media containing chitosan as sole carbon source. After screening of flatpanel, flaskshaking cultivation and enzyme kinetics in fermentation, a strain (H2) with higher chitosanlytic activity was acquired. According to its morphological, cultural, biochemical and physiological characteristics and phylogenetic analysis of 16S rDNA, the strain was identified and named as Streptomyces roseolus DH. Further studies of fermentation conditions showed that the optimum temperature and initial pH of medium were 30 ℃ and 7.2, respectively. Moreover, the colloid chitosan (1.0%) and peptone (0.5%) were chosen as the best carbon and nitrogen sources among the tested ones. Under these conditions, the activity of chitosanase in media reached 6.10±0.12 U/mL after 60hour fermentation. This strain with higher yield of chitosanase and shorter fermentation period displayed good potential for future applications.
2020, 29(2):180-188.
DOI: 10.12024/jsou.20190502654
Abstract:
Vibrio parahaemolyticus is a zoonotic pathogen that poses a serious threat to animal, fish and human health. In order to study the dynamic process of host neutrophils and bacteria infection, we established a model of local infection of the 48 hours post fertilization (hpf) zebrafish larvae otic vesicle infected with the V. parahaemolyticus strain labelled with red florescent protein (Vp57RFP) in this study, and the Escherichia coli Ec01 strain was used as a control to systematically compare the median lethal dose (LD50) and survival curves, infection process and dynamic process of interaction with neutrophils of V.parahaemolyticus and E. coli, respectively. RT-qPCR verified the expression levels of the inflammation-related genes il1b and il10. The results showed that the LD50 of E. coli and V.parahaemolyticus infected zebrafish larvae were 1.14×1011 CFU/mL and 7.90×107 CFU/mL, respectively. Compared to E. coli, V. parahaemolyticus recruited faster and more numerous neutrophils during dynamic infection imaging, and induced more il1b and il10 genes expression level that caused strong inflammatory response in zebra fish larvae at the same time point. Based on the above research, we successfully established the model of V.parahaemolyticus-otic vesicle zebrafish larvae infection, which provides a basis for further study of the dynamic process of neutrophil clearance of Vibrio parahaemolyticus infection and the in-depth revealing of the innate immune response mechanism.
Vibrio parahaemolyticus is a zoonotic pathogen that poses a serious threat to animal, fish and human health. In order to study the dynamic process of host neutrophils and bacteria infection, we established a model of local infection of the 48 hours post fertilization (hpf) zebrafish larvae otic vesicle infected with the V. parahaemolyticus strain labelled with red florescent protein (Vp57RFP) in this study, and the Escherichia coli Ec01 strain was used as a control to systematically compare the median lethal dose (LD50) and survival curves, infection process and dynamic process of interaction with neutrophils of V.parahaemolyticus and E. coli, respectively. RT-qPCR verified the expression levels of the inflammation-related genes il1b and il10. The results showed that the LD50 of E. coli and V.parahaemolyticus infected zebrafish larvae were 1.14×1011 CFU/mL and 7.90×107 CFU/mL, respectively. Compared to E. coli, V. parahaemolyticus recruited faster and more numerous neutrophils during dynamic infection imaging, and induced more il1b and il10 genes expression level that caused strong inflammatory response in zebra fish larvae at the same time point. Based on the above research, we successfully established the model of V.parahaemolyticus-otic vesicle zebrafish larvae infection, which provides a basis for further study of the dynamic process of neutrophil clearance of Vibrio parahaemolyticus infection and the in-depth revealing of the innate immune response mechanism.
2011, 20(1):22-26.
Abstract:
According to the Chile jack mackerel (Trachurus murphyi) samples in the southeast Pacific Ocean (34°S ~37°S,90°W-110°W) collected by Chinese trawler fishing vessel during July and December 2009, 146 muscle samples collected from17 sites were used for population genetic structure identification by Random Amplified Polymorphic DNA (RAPD) analysis. 52 loci were detected and 51 of these loci were polymorphic, which accounted for 98.08% of the total loci. The Shannon’s index was 0.5202±0.1813, the Nei’s genetic diversity index was 0.3500±0.1440, and the GSTvalues was 0.0311. The results indicated that the genetic diversity of the Trachurus murphyi was comparably high, and genetic differentiation was not significant among populations.
According to the Chile jack mackerel (Trachurus murphyi) samples in the southeast Pacific Ocean (34°S ~37°S,90°W-110°W) collected by Chinese trawler fishing vessel during July and December 2009, 146 muscle samples collected from17 sites were used for population genetic structure identification by Random Amplified Polymorphic DNA (RAPD) analysis. 52 loci were detected and 51 of these loci were polymorphic, which accounted for 98.08% of the total loci. The Shannon’s index was 0.5202±0.1813, the Nei’s genetic diversity index was 0.3500±0.1440, and the GSTvalues was 0.0311. The results indicated that the genetic diversity of the Trachurus murphyi was comparably high, and genetic differentiation was not significant among populations.
2016, 25(5):726-734.
DOI: 10.12024/jsou.20151201627
Abstract:
To study the influence of three common water plants decomposition on water quality in crab eco-culture pond, a 60-day interior simulation experiment was carried out in barrels. The results indicated that decomposition rates of three kinds of plants have the same characteristics, it was rapid in the early but slow in the middle and later periods. But they were different, the decomposition rate of Hydrilla verticillata and Elodea nuttallii were approximated and faster than Ceratophyllum demersum. At the end of experiment, the mass loss rate of Hydrilla verticillata, Elodea nuttalliiare and Ceratophyllum demersum were 72.3%±2.1%,71.7%±1.5% and 58.3%±0.6% . Water quality factors changed obviously in the early of decomposition and water was from neutral to acid. COD increased by about 4.5 times than start in the water of three kinds of water plants and the water was yellow and smelly. DO was greatly consumed, the water was in a hypoxic or anaerobic environment. Denitrification was promoted, so NO3--N decreased rapidly but NO2--N and NH4+-N increased rapidly, which NH4+-N was six times than initial concentration. TN and TP increased significantly and TP was the biggest change in all the water factors. The TP increased about 123,124 and 66 times in the water of Hydrilla verticillata、Elodea nuttallii and Ceratophyllum demersum on the third day. Along with the experiment, part of nitrogen and phosphorus in the water deposited into the sediment. So, the large biomass residues of submerged plants should be controlled avoid secondary pollution caused by excessive decomposition of submerged plants.
To study the influence of three common water plants decomposition on water quality in crab eco-culture pond, a 60-day interior simulation experiment was carried out in barrels. The results indicated that decomposition rates of three kinds of plants have the same characteristics, it was rapid in the early but slow in the middle and later periods. But they were different, the decomposition rate of Hydrilla verticillata and Elodea nuttallii were approximated and faster than Ceratophyllum demersum. At the end of experiment, the mass loss rate of Hydrilla verticillata, Elodea nuttalliiare and Ceratophyllum demersum were 72.3%±2.1%,71.7%±1.5% and 58.3%±0.6% . Water quality factors changed obviously in the early of decomposition and water was from neutral to acid. COD increased by about 4.5 times than start in the water of three kinds of water plants and the water was yellow and smelly. DO was greatly consumed, the water was in a hypoxic or anaerobic environment. Denitrification was promoted, so NO3--N decreased rapidly but NO2--N and NH4+-N increased rapidly, which NH4+-N was six times than initial concentration. TN and TP increased significantly and TP was the biggest change in all the water factors. The TP increased about 123,124 and 66 times in the water of Hydrilla verticillata、Elodea nuttallii and Ceratophyllum demersum on the third day. Along with the experiment, part of nitrogen and phosphorus in the water deposited into the sediment. So, the large biomass residues of submerged plants should be controlled avoid secondary pollution caused by excessive decomposition of submerged plants.
2011, 20(1):155-159.
Abstract:
Deng Xiaoping advocated three criteria. Practice is the only criterion to test truth. There are two criteria:public ownership is the main part and common prosperity to judge socialism.He also put forward ‘three favors ’criterion. Practice criterion is the basis for quality criterion and value criterion, quality criterion and value criterion turn into one unity in practice. We must deal with their relations. There exist some phenomena sometimes in some places, for example, to substitute quality criterion for value criterion, to dissimilate value criterion and distort quality criterion,to emphasize quality criterion affecting value criterion, to substitute value criterion for quality criterion. All these phenomena deal with the practice criterion. To sum up the experience, we must realize and handle the relations among them. We must stick to practice criterion, deepen the knowledge about value criterion and quality criterion, try to find rule for development, and enhance socialism with Chinese characteristics.
Deng Xiaoping advocated three criteria. Practice is the only criterion to test truth. There are two criteria:public ownership is the main part and common prosperity to judge socialism.He also put forward ‘three favors ’criterion. Practice criterion is the basis for quality criterion and value criterion, quality criterion and value criterion turn into one unity in practice. We must deal with their relations. There exist some phenomena sometimes in some places, for example, to substitute quality criterion for value criterion, to dissimilate value criterion and distort quality criterion,to emphasize quality criterion affecting value criterion, to substitute value criterion for quality criterion. All these phenomena deal with the practice criterion. To sum up the experience, we must realize and handle the relations among them. We must stick to practice criterion, deepen the knowledge about value criterion and quality criterion, try to find rule for development, and enhance socialism with Chinese characteristics.
2020, 29(2):313-320.
DOI: 10.12024/jsou.20190302564
Abstract:
An intracellular endo-cellulase was isolated and purified from the fermentation of Aspergillus niveus MA35 in the gut of Megalobrama amblycephala. The enzyme was purified sequentially by Q-Sepharose Fast Flow chromatography and Sephadex G-100 gel chromatography. The specific activity of the purified endoglucanase increased to 30.6 U/mg from 22.3 U/mg of the crude endoglucanase. The molecular masses of the enzyme was determined by SDS-PAGE to be about 45 ku. The optimum temperature is 45 ℃ and the optimum pH is 4.5. The enzyme has good stability between pH 4.0-8.0 and 30-55 ℃. Zn2+ and Mn2+ have an activation effect on enzymes. Mg2+, Cu2+, Fe2+, Cd2+ and Co2+ have inhibitory effects on enzyme activities, among which Mg2+, Cu2+ and Fe2+ have strong inhibitory effects, and Na+, K+ and Ca2+ have little effect on enzymes.
An intracellular endo-cellulase was isolated and purified from the fermentation of Aspergillus niveus MA35 in the gut of Megalobrama amblycephala. The enzyme was purified sequentially by Q-Sepharose Fast Flow chromatography and Sephadex G-100 gel chromatography. The specific activity of the purified endoglucanase increased to 30.6 U/mg from 22.3 U/mg of the crude endoglucanase. The molecular masses of the enzyme was determined by SDS-PAGE to be about 45 ku. The optimum temperature is 45 ℃ and the optimum pH is 4.5. The enzyme has good stability between pH 4.0-8.0 and 30-55 ℃. Zn2+ and Mn2+ have an activation effect on enzymes. Mg2+, Cu2+, Fe2+, Cd2+ and Co2+ have inhibitory effects on enzyme activities, among which Mg2+, Cu2+ and Fe2+ have strong inhibitory effects, and Na+, K+ and Ca2+ have little effect on enzymes.
2011, 20(4):636-640.
Abstract:
The graduation thesis of English majors is of considerable importance. And the graduation thesis of English majors can be the yardstick to have the comprehensive measurement of the integrated language abilities as well as the analytical abilities and research abilities of English major graduates .The quality of the graduation thesis of English majors is the actual reflection of the teaching result of English majors. In order to have the overall understanding of the present situation of the graduation thesis of English majors, the survey was conducted to get the information about the situation of graduation theses of English majors from 132 universities and colleges of different kinds. The findings of the questionnaire show there exist common problems in graduation theses of English majors such as plagiarism,grammatical mistakes, colloquial expressions, loose organization, lack of original ideas and so on. The exploration of the causes of the problems shows there are two major causes: objective and subjective. To tackle these problems, countermeasures are suggested in the paper: Reformation and innovation of teaching concept and teaching means. Strong emphasis on the teaching of English writing. Strict requirement on the selection the thesis title. Scientific use of research literature. Emphasis on the supervision of the whole process of student’s thesis writing. It is intended to improve the quality of graduation theses of English majors in a comprehensive way after having some reflections and taking some measures.
The graduation thesis of English majors is of considerable importance. And the graduation thesis of English majors can be the yardstick to have the comprehensive measurement of the integrated language abilities as well as the analytical abilities and research abilities of English major graduates .The quality of the graduation thesis of English majors is the actual reflection of the teaching result of English majors. In order to have the overall understanding of the present situation of the graduation thesis of English majors, the survey was conducted to get the information about the situation of graduation theses of English majors from 132 universities and colleges of different kinds. The findings of the questionnaire show there exist common problems in graduation theses of English majors such as plagiarism,grammatical mistakes, colloquial expressions, loose organization, lack of original ideas and so on. The exploration of the causes of the problems shows there are two major causes: objective and subjective. To tackle these problems, countermeasures are suggested in the paper: Reformation and innovation of teaching concept and teaching means. Strong emphasis on the teaching of English writing. Strict requirement on the selection the thesis title. Scientific use of research literature. Emphasis on the supervision of the whole process of student’s thesis writing. It is intended to improve the quality of graduation theses of English majors in a comprehensive way after having some reflections and taking some measures.
2017, 26(1):8-16.
DOI: 10.12024/jsou.20160401724
Abstract:
Single nucleotide polymorphism(SNP) markers coupled with the next-generation sequencing technology are powerful tools for studying population genetics, as well as for species delimitation. The popular ways of obtaining SNP data include RNA sequencing and restriction site associated DNA(RAD) sequencing. However, both methods have limitations. For example, RNA sequencing requires fresh tissue samples, whereas RAD sequencing targets anonymous loci usually not transferable across species. In comparison with these methods, target gene capture could be used to enrich homologous fragments across divergent species and even from degraded DNA. We showed that by targeting a set of universal single-copy nuclear gene markers of vertebrates, we could retrieve thousands of SNPs from the Japanese grenadier anchovy(Coilia nasus) sampled from three locations:coastal region close to the estuary of the Yangtze River, the mainstream of the river and Lake Dongting, a lake connected to the middle reaches of the Yangtze River. We analyzed hundreds of representative SNPs from the data using STRUCTURE and Bayes factor delimitation(*with genomic data; BFD*), a new Bayesian species delimitation tool. We found that the fish from Lake Dongting are genetically different from the fish of other sample locations. We also observed marginal difference between fish collected from the coastal region and the mainstream of the Yangtze River(Bayes factor=11.3). Our study demonstrated that gene capture could be used to generate SNP data for species delimitation applying new analytic tools such as BFD*.
Single nucleotide polymorphism(SNP) markers coupled with the next-generation sequencing technology are powerful tools for studying population genetics, as well as for species delimitation. The popular ways of obtaining SNP data include RNA sequencing and restriction site associated DNA(RAD) sequencing. However, both methods have limitations. For example, RNA sequencing requires fresh tissue samples, whereas RAD sequencing targets anonymous loci usually not transferable across species. In comparison with these methods, target gene capture could be used to enrich homologous fragments across divergent species and even from degraded DNA. We showed that by targeting a set of universal single-copy nuclear gene markers of vertebrates, we could retrieve thousands of SNPs from the Japanese grenadier anchovy(Coilia nasus) sampled from three locations:coastal region close to the estuary of the Yangtze River, the mainstream of the river and Lake Dongting, a lake connected to the middle reaches of the Yangtze River. We analyzed hundreds of representative SNPs from the data using STRUCTURE and Bayes factor delimitation(*with genomic data; BFD*), a new Bayesian species delimitation tool. We found that the fish from Lake Dongting are genetically different from the fish of other sample locations. We also observed marginal difference between fish collected from the coastal region and the mainstream of the Yangtze River(Bayes factor=11.3). Our study demonstrated that gene capture could be used to generate SNP data for species delimitation applying new analytic tools such as BFD*.
2017, 26(4):490-500.
DOI: 10.12024/jsou.20161101909
Abstract:
This study tries to gradually reduce the addition of carbon source to zero,and to explore the effect of domesticating nitrifying bio-flocs on water quality,bacterial community dynamics of bio-floc and the growth performance of shrimp in high-intensive culture system. Experiment was carried out in three runway aquaculture systems at stocking density of 685 shrimp/m3.Water quality results showed that daily addition of glucose at 100%-150% of feed,which can decrease the concentration of TAN,but the concentration of NO2--N was not decreased obviously.When the addition of glucose dropped to zero,TAN can be maintained at lower level,and the NO2--N concentration decreased significantly.The bacterial community structure was analyzed by using high throughput sequencing technology.At the phylum level,experiment results showed that both the main advantage microflora of heterotrophic bioflocs and nitrifying bioflocs are Proteobacteria and Bacteroidetes.At the class level,dominant microflora of heterotrophic biofloc is Alphaproteobacteria,and dominant microflora of nitrifying bioflocs are Alphaproteobacteria,Flavobacteria and Gammaproteobacteria.After 65 d,study found that without adding carbon source,nitrifying bio-flocs can limit the abundance of heterotrophic bacteria,nitrospira was rising,and developing into dominant bacteria.At the end of the experiment, glucose which is 41.03%±7.86% of feed was added throughout the culture period.The survival rate and harvest of Litopenaeus vannamei respectively were 43.35%±7.57% and (3.03±0.59) kg/m3.The domestication of nitrifying bio-flocs not only saved cost, but also effectively optimized the structure of bacterial communities, and contributed to better water environment which results in the higher growth and survival of shrimp.
This study tries to gradually reduce the addition of carbon source to zero,and to explore the effect of domesticating nitrifying bio-flocs on water quality,bacterial community dynamics of bio-floc and the growth performance of shrimp in high-intensive culture system. Experiment was carried out in three runway aquaculture systems at stocking density of 685 shrimp/m3.Water quality results showed that daily addition of glucose at 100%-150% of feed,which can decrease the concentration of TAN,but the concentration of NO2--N was not decreased obviously.When the addition of glucose dropped to zero,TAN can be maintained at lower level,and the NO2--N concentration decreased significantly.The bacterial community structure was analyzed by using high throughput sequencing technology.At the phylum level,experiment results showed that both the main advantage microflora of heterotrophic bioflocs and nitrifying bioflocs are Proteobacteria and Bacteroidetes.At the class level,dominant microflora of heterotrophic biofloc is Alphaproteobacteria,and dominant microflora of nitrifying bioflocs are Alphaproteobacteria,Flavobacteria and Gammaproteobacteria.After 65 d,study found that without adding carbon source,nitrifying bio-flocs can limit the abundance of heterotrophic bacteria,nitrospira was rising,and developing into dominant bacteria.At the end of the experiment, glucose which is 41.03%±7.86% of feed was added throughout the culture period.The survival rate and harvest of Litopenaeus vannamei respectively were 43.35%±7.57% and (3.03±0.59) kg/m3.The domestication of nitrifying bio-flocs not only saved cost, but also effectively optimized the structure of bacterial communities, and contributed to better water environment which results in the higher growth and survival of shrimp.
2015, 24(4):560-569.
Abstract:
The article explained that inhibitory components from Myriophyllum spicatum with the ultrasonic-cellulase method and water extraction method caused inhibition of M.aeruginosa. Based on one-way and orthogonal test, and regarding growth inhibition rate of extraction on M. aeruginosa as index of evaluation, an optimal extraction process of Myriophyllum spicatum was obtained as follows: enzymatic hydrolysis time was 4 h, pH was 3.0, optimal temperature was 30 ℃, cellulase dosage(mass of cellulase to Myriophyllum spicatum powder) was 21%, ultrasonic power was 120 W and ultrasonic time was 1h. The inhibition rate of extraction obtained with water extraction method and ultrasonic-cellulase method indicated that the latter showed better effect and had obvious difference with the water extraction (P<0.05). With the increasing of reaction time, the growth inhibition rate of the ultrasonic-cellulase extraction on M. aeruginosa continued to decrease, which was 271.74% at concentration of 40 g/L and reaction time for 24 h and the inhibition rate was more than 20% by the reaction time for 13d with the obvious difference with the other concentration groups (P<0.05).
The article explained that inhibitory components from Myriophyllum spicatum with the ultrasonic-cellulase method and water extraction method caused inhibition of M.aeruginosa. Based on one-way and orthogonal test, and regarding growth inhibition rate of extraction on M. aeruginosa as index of evaluation, an optimal extraction process of Myriophyllum spicatum was obtained as follows: enzymatic hydrolysis time was 4 h, pH was 3.0, optimal temperature was 30 ℃, cellulase dosage(mass of cellulase to Myriophyllum spicatum powder) was 21%, ultrasonic power was 120 W and ultrasonic time was 1h. The inhibition rate of extraction obtained with water extraction method and ultrasonic-cellulase method indicated that the latter showed better effect and had obvious difference with the water extraction (P<0.05). With the increasing of reaction time, the growth inhibition rate of the ultrasonic-cellulase extraction on M. aeruginosa continued to decrease, which was 271.74% at concentration of 40 g/L and reaction time for 24 h and the inhibition rate was more than 20% by the reaction time for 13d with the obvious difference with the other concentration groups (P<0.05).
