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Available online
, doi: 10.7541/2019.039
Abstract:
Pacific oysters (Crassostrea gigas), the most widely cultivated shellfish over the world with advantages of fast growth and strong environmental adaption, are suitable materials for selective breeding due to the characters of high fertility, short reproductive cycle and large genetic variation. Broodstocks from white shell strain of C. gigas that had undergone four-generation family selection and three-generation mass selection were used to establish 29 full-sib families and 12 half-sib families by nested design. Random selected individuals were utilized as parents to generate the control families. Phenotypic traits such as growth and survival rate of different periods in larval stage were analyzed. Results showed that the growth performance and average survival rates of white shell families were significantly higher than those of control group with the augmentation of 3.65% to 14.58% and 1.11% to 19.26% in a family dependent pattern, respectively. The G11, G15 and G35 families represented remarkable superiorities in shell height and survival rates. At the age of 19 days, the increased shell heights of G11, G15 and G35 families were bigger than the average values of white shell families by 11.87%, 17.03%, and 30.32%, respectively, and were greater than the average values of the control by 34.09%, 28.18%, and 49.31%, respectively. Besides, the survival rates of G11, G15 and G35 families at 19d were higher than the average values of both white shell by 38.35%, 33.41%, 51.07%, and control families by 65.00%, 59.11%, and 80.18% (G35), respectively. Results of genetic parameters of larvae shell height and shell length of white shell strain indicated that the variation of heritability was ranged from 0.28 to 0.81 in shell height and from 0.42 to 0.88 in shell length, representing the heritability at medium to high level. The genetic and phenotypic correlations were positive between the two growth traits with the correlation coefficients ranging from 0.35 to 0.81 and from 0.57 to 0.85, respectively. This study provides optimum breeding strategy for white shell strains ofC. gigas to improve performance in growth and survival.
Pacific oysters (Crassostrea gigas), the most widely cultivated shellfish over the world with advantages of fast growth and strong environmental adaption, are suitable materials for selective breeding due to the characters of high fertility, short reproductive cycle and large genetic variation. Broodstocks from white shell strain of C. gigas that had undergone four-generation family selection and three-generation mass selection were used to establish 29 full-sib families and 12 half-sib families by nested design. Random selected individuals were utilized as parents to generate the control families. Phenotypic traits such as growth and survival rate of different periods in larval stage were analyzed. Results showed that the growth performance and average survival rates of white shell families were significantly higher than those of control group with the augmentation of 3.65% to 14.58% and 1.11% to 19.26% in a family dependent pattern, respectively. The G11, G15 and G35 families represented remarkable superiorities in shell height and survival rates. At the age of 19 days, the increased shell heights of G11, G15 and G35 families were bigger than the average values of white shell families by 11.87%, 17.03%, and 30.32%, respectively, and were greater than the average values of the control by 34.09%, 28.18%, and 49.31%, respectively. Besides, the survival rates of G11, G15 and G35 families at 19d were higher than the average values of both white shell by 38.35%, 33.41%, 51.07%, and control families by 65.00%, 59.11%, and 80.18% (G35), respectively. Results of genetic parameters of larvae shell height and shell length of white shell strain indicated that the variation of heritability was ranged from 0.28 to 0.81 in shell height and from 0.42 to 0.88 in shell length, representing the heritability at medium to high level. The genetic and phenotypic correlations were positive between the two growth traits with the correlation coefficients ranging from 0.35 to 0.81 and from 0.57 to 0.85, respectively. This study provides optimum breeding strategy for white shell strains ofC. gigas to improve performance in growth and survival.
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Available online
, doi: 10.7541/2019.037
Abstract:
Relish and Dorsal, members of nuclear factor-κB (NF-κB) family protein, play crucial role in immune response in Arthropoda. In this study, the cDNA sequences of Relish and Dorsal were cloned by rapid amplification of cDNA ends (RACE). There are 3254 nucleotides in Pt-Rel with a putative open reading frame (ORF) of 2949 bp that encodes a polypeptide of 983 amino acid residues. The Pt-Dor cDNA was 2348 bp in length including an ORF encoding a polypeptide of 637 amino acid residues．Prediction of protein domains revealed that both Pt-Rel and Pt-Dor contained typical NF-κB family structures RHD (Rel homology domain) and IPT (Immunoglobulin-like fold, Plexins, Transcription factors). Alignment of amino acid sequences for Pt-Rel and Pt-Dor revealed high identities with other arthropodas orthologs. Phylogenetic tree analysis based on amino acid sequences showed that the Pt-Rel and Pt-Dor were distinctly clustered with crustaceans Relish and Dorsal, respectively, but separated from insect orthologs. Pt-Rel and Pt-Dor were expressed in all tested tissues with the highest level in hemocytes. Three different pathogenic microorganism significantly induced both Pt-Rel and Pt-Dor expression in primary cultured crab hemocytes at 2h by Candida lusitaniae infection and 4h by Staphylococcus aureus and Vibrio alginolyticus challenge. These data suggest that Pt-Rel and Pt-Dor might be involved in host defense against to microbial pathogens in Portunus trituberculatus.
Relish and Dorsal, members of nuclear factor-κB (NF-κB) family protein, play crucial role in immune response in Arthropoda. In this study, the cDNA sequences of Relish and Dorsal were cloned by rapid amplification of cDNA ends (RACE). There are 3254 nucleotides in Pt-Rel with a putative open reading frame (ORF) of 2949 bp that encodes a polypeptide of 983 amino acid residues. The Pt-Dor cDNA was 2348 bp in length including an ORF encoding a polypeptide of 637 amino acid residues．Prediction of protein domains revealed that both Pt-Rel and Pt-Dor contained typical NF-κB family structures RHD (Rel homology domain) and IPT (Immunoglobulin-like fold, Plexins, Transcription factors). Alignment of amino acid sequences for Pt-Rel and Pt-Dor revealed high identities with other arthropodas orthologs. Phylogenetic tree analysis based on amino acid sequences showed that the Pt-Rel and Pt-Dor were distinctly clustered with crustaceans Relish and Dorsal, respectively, but separated from insect orthologs. Pt-Rel and Pt-Dor were expressed in all tested tissues with the highest level in hemocytes. Three different pathogenic microorganism significantly induced both Pt-Rel and Pt-Dor expression in primary cultured crab hemocytes at 2h by Candida lusitaniae infection and 4h by Staphylococcus aureus and Vibrio alginolyticus challenge. These data suggest that Pt-Rel and Pt-Dor might be involved in host defense against to microbial pathogens in Portunus trituberculatus.
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Available online
, doi: 10.7541/2019.043
Abstract:
C-type lectin, a Ca2+-dependent protein, is a type of carbohydrate-recognition protein that plays an important role in innate immunity. ShLec21 and ShLec23 are two C-type lectins that respond to cadmium stress in the freshwater crab Sinopotamon henanense. In this paper, the ShLec21 and ShLec23 were cloned by RACE method, and the phylogenetic analysis was carried out. The tissues expression pattern of ShLec21 and ShLec23 and effects of the two C-type lectins in hepatopancreas and hemolymph after the treatment of cadmium followed by Aeromonas hydrophila infection were detected. The results showed that ShLec21 cDNA was 863bp in length that encoded 152 amino acid residues and ShLec23 cDNA was 681bp in length that encoded 164 amino acid residues. ShLec21 and ShLec23 clustered into two branches of invertebrates. Both of ShLec21 and ShLec23 were widely expressed in hemolymph, gill, hepatopancreas, intestine, muscle, ovary, and testis with highest level in hepatopancreas. Cadmium stress had no significant effect on the expression of ShLec21 and ShLec23 in hepatopancreas and hemolymph. Bacteria A. hydrophila infection significantly down-regulated the expression of ShLec21 (P<0.05) and ShLec23 (P<0.01) in the hepatopancreas, and significantly (P<0.05) reduced the expression ofShLec23 in hemolymph. However, in the course of infection with A. hydrophila after cadmium stress, the expression levels of ShLec21 (P<0.05) andShLec23 (P<0.01) were significantly up-regulated in hepatopancreas and hemolymph. The results suggest that cadmium stress could upregulate the expression ofShLec21 and ShLec23 in response to A. hydrophila infection in a certain extent.
C-type lectin, a Ca2+-dependent protein, is a type of carbohydrate-recognition protein that plays an important role in innate immunity. ShLec21 and ShLec23 are two C-type lectins that respond to cadmium stress in the freshwater crab Sinopotamon henanense. In this paper, the ShLec21 and ShLec23 were cloned by RACE method, and the phylogenetic analysis was carried out. The tissues expression pattern of ShLec21 and ShLec23 and effects of the two C-type lectins in hepatopancreas and hemolymph after the treatment of cadmium followed by Aeromonas hydrophila infection were detected. The results showed that ShLec21 cDNA was 863bp in length that encoded 152 amino acid residues and ShLec23 cDNA was 681bp in length that encoded 164 amino acid residues. ShLec21 and ShLec23 clustered into two branches of invertebrates. Both of ShLec21 and ShLec23 were widely expressed in hemolymph, gill, hepatopancreas, intestine, muscle, ovary, and testis with highest level in hepatopancreas. Cadmium stress had no significant effect on the expression of ShLec21 and ShLec23 in hepatopancreas and hemolymph. Bacteria A. hydrophila infection significantly down-regulated the expression of ShLec21 (P<0.05) and ShLec23 (P<0.01) in the hepatopancreas, and significantly (P<0.05) reduced the expression ofShLec23 in hemolymph. However, in the course of infection with A. hydrophila after cadmium stress, the expression levels of ShLec21 (P<0.05) andShLec23 (P<0.01) were significantly up-regulated in hepatopancreas and hemolymph. The results suggest that cadmium stress could upregulate the expression ofShLec21 and ShLec23 in response to A. hydrophila infection in a certain extent.
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Available online
, doi: 10.7541/2019.057
Abstract:
The structure and function of microbial communities in aquatic ecosystems have been widely reported. In eutrophic waters, bacteria play an important role in the occurrence, development, decline and degradation of Microcystis blooms. In this paper, we described the unique characteristics ofMicrocystisand bacterial communities in the water column and sediment, as well as the responses of the dynamics of Microcystis and bacterial communities to environmental factors. Furthermore, the interactions between Microcystis and bacteria were summarized from the following aspects: first, attached bacteria can mediate the growth of Microcystis in the microenvironment of algal cells. Second, bacteria are involved in the formation and maintenance of Microcystis colonies. Third, bacteria regulate the aggregation and degradation of Microcystis blooms. Fourth, the bacterial degradation of microcystins was introduced. Finally, the future research focus of the relationships betweenMicrocystisand bacteria and the available omics technology were prospected.
The structure and function of microbial communities in aquatic ecosystems have been widely reported. In eutrophic waters, bacteria play an important role in the occurrence, development, decline and degradation of Microcystis blooms. In this paper, we described the unique characteristics ofMicrocystisand bacterial communities in the water column and sediment, as well as the responses of the dynamics of Microcystis and bacterial communities to environmental factors. Furthermore, the interactions between Microcystis and bacteria were summarized from the following aspects: first, attached bacteria can mediate the growth of Microcystis in the microenvironment of algal cells. Second, bacteria are involved in the formation and maintenance of Microcystis colonies. Third, bacteria regulate the aggregation and degradation of Microcystis blooms. Fourth, the bacterial degradation of microcystins was introduced. Finally, the future research focus of the relationships betweenMicrocystisand bacteria and the available omics technology were prospected.
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Available online
, doi: 10.7541/2019.038
Abstract:
In order to explore the origin and physiological function of ascorbate peroxidase (APX) gene of Hydra sinensis, a full-length cDNA of APX gene of H. sinensis was isolated by rapid amplification of cDNA ends (RACE) technique. The full-length cDNA of APX gene was 1357 bp, containing 107 bp 5’UTR (Untranslated region), 146 bp 3’UTR and a 1104 bp open reading frame (ORF) which encodes a polypeptide of 367 amino-acid residues with a molecular weight of 40.79 kDa. BLAST (Basic Local Alignmen Search Tool) showed that most of homologous protein sequences of APX in H.sinensis belonged to the plant kingdom. Phylogenetic results by Maximum Likelihood (ML) method and Bayesian analyses revealed that homologous sequences of APX from plant and animal kingdom each formed a single cluster. The ORF of APX gene was subcloned into plasmid pET-GST and transferred into Escherichia coli BL21 (DE3). The recombinant GST-APX fusion protein mainly expressed in the form of soluble were immunized New Zealand rabbits get the polyclonal antibody against APX for Western blotting assay (WB). H. sinensis was cultured (0, 4, 8, 12, 16, 20 and 24 hours per day with illumination intensity 2000 Lux) for 30 days, which up-regulated APX expression under longer illumination time (more than 16 hours per day). Due to continuous photosynthetic activity, a large number of reactive oxygen species (ROS) accumulating in symbiotic green algae could spread to the host cell (hydra cell), and the upregulation of APX expression in H. sinensis may mediate the removal of intracellular ROS.
In order to explore the origin and physiological function of ascorbate peroxidase (APX) gene of Hydra sinensis, a full-length cDNA of APX gene of H. sinensis was isolated by rapid amplification of cDNA ends (RACE) technique. The full-length cDNA of APX gene was 1357 bp, containing 107 bp 5’UTR (Untranslated region), 146 bp 3’UTR and a 1104 bp open reading frame (ORF) which encodes a polypeptide of 367 amino-acid residues with a molecular weight of 40.79 kDa. BLAST (Basic Local Alignmen Search Tool) showed that most of homologous protein sequences of APX in H.sinensis belonged to the plant kingdom. Phylogenetic results by Maximum Likelihood (ML) method and Bayesian analyses revealed that homologous sequences of APX from plant and animal kingdom each formed a single cluster. The ORF of APX gene was subcloned into plasmid pET-GST and transferred into Escherichia coli BL21 (DE3). The recombinant GST-APX fusion protein mainly expressed in the form of soluble were immunized New Zealand rabbits get the polyclonal antibody against APX for Western blotting assay (WB). H. sinensis was cultured (0, 4, 8, 12, 16, 20 and 24 hours per day with illumination intensity 2000 Lux) for 30 days, which up-regulated APX expression under longer illumination time (more than 16 hours per day). Due to continuous photosynthetic activity, a large number of reactive oxygen species (ROS) accumulating in symbiotic green algae could spread to the host cell (hydra cell), and the upregulation of APX expression in H. sinensis may mediate the removal of intracellular ROS.
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Available online
, doi: 10.7541/2019.056
Abstract:
To optimize the cultivation condition of microalgae, single-factor design and orthogonal experiments were performed to assess the growth rate, total lipid content and fatty acid composition of STR01 by temperature, light intensity and salinity. The results showed that all these ecological factors exerted significant effects on the growth, total lipid content and fatty acid composition of STR01 (P< 0.05) with the appropriate temperature for growth at 15—35℃, the optimum temperature at 25—30℃(K-value 0.679—0.682) and the optimum temperature for total lipid content accumulation at 25℃ (17.23%). The highest PUFA content at 34.23% appeared at 20℃. The appropriate light intensity for growth was 40—120 μmol/(m2·s) and the optimum one was 60 μmol/(m2·s). The light intensity of 40 μmol/(m2·s) had the highest PUFA accumulation at 34.29%. The appropriate salinity for growth was 10—35 and the optimum salinity was 25. The orthogonal experiments showed that the optimum condition for growth was temperature 30℃, light intensity 60 μmol/(m2·s), and salinity 25, and that the optimum total lipid accumulation was temperature 30℃, light intensity 60 μmol/(m2·s) and salinity 20, and that the optimum PUFA content was temperature 25℃, light intensity 60 μmol/(m2·s), and salinity 20 at 37%. In conclusion, STR01 was promising prospect in future aquaculture with fast growth rate and high total lipid and PUFA contents.
To optimize the cultivation condition of microalgae, single-factor design and orthogonal experiments were performed to assess the growth rate, total lipid content and fatty acid composition of STR01 by temperature, light intensity and salinity. The results showed that all these ecological factors exerted significant effects on the growth, total lipid content and fatty acid composition of STR01 (P< 0.05) with the appropriate temperature for growth at 15—35℃, the optimum temperature at 25—30℃(K-value 0.679—0.682) and the optimum temperature for total lipid content accumulation at 25℃ (17.23%). The highest PUFA content at 34.23% appeared at 20℃. The appropriate light intensity for growth was 40—120 μmol/(m2·s) and the optimum one was 60 μmol/(m2·s). The light intensity of 40 μmol/(m2·s) had the highest PUFA accumulation at 34.29%. The appropriate salinity for growth was 10—35 and the optimum salinity was 25. The orthogonal experiments showed that the optimum condition for growth was temperature 30℃, light intensity 60 μmol/(m2·s), and salinity 25, and that the optimum total lipid accumulation was temperature 30℃, light intensity 60 μmol/(m2·s) and salinity 20, and that the optimum PUFA content was temperature 25℃, light intensity 60 μmol/(m2·s), and salinity 20 at 37%. In conclusion, STR01 was promising prospect in future aquaculture with fast growth rate and high total lipid and PUFA contents.
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Available online
, doi: 10.7541/2019.044
Abstract:
To assess the effects of PFOS pollution on burst swimming performance and metabolic recovery of fish, juvenile Spinibarbus sinensis were exposed to different PFOS concentrations (0, 0.32, 0.8, 2 and 5 mg/L) to measure the burst swimming speed (Uburst), relative Uburst (rUburst), resting metabolic rate (RMR) and metabolic recovery after exhaustive swimming. The results showed that PFOS had a profound effect on the Uburst and rUburst of fish (P<0.05). TheUburst and rUburst were reduced by 17.4% and 10.8%, respectively, upon exposure to 5 mg/L PFOS. A possible non-monotonic dose response was found in rUburst to PFOS. Moreover, PFOS significantly increased RMR (P<0.05), but did not have a marked effect on maximum metabolic rate (MMR), metabolic scope (MS), factorial metabolic scope (F-MS) and excess post-exercise oxygen consumption (EPOC) (P>0.05). The results indicated that PFOS had more dramatical effect on low metabolic level than high metabolic level of the experimental fish. Additionally, PFOS negatively impact survival-related activities such as capturing prey, avoiding predators, hunting for suitable habitats without significant ecotoxicological effects on metabolic recovery associated with anaerobic metabolism.
To assess the effects of PFOS pollution on burst swimming performance and metabolic recovery of fish, juvenile Spinibarbus sinensis were exposed to different PFOS concentrations (0, 0.32, 0.8, 2 and 5 mg/L) to measure the burst swimming speed (Uburst), relative Uburst (rUburst), resting metabolic rate (RMR) and metabolic recovery after exhaustive swimming. The results showed that PFOS had a profound effect on the Uburst and rUburst of fish (P<0.05). TheUburst and rUburst were reduced by 17.4% and 10.8%, respectively, upon exposure to 5 mg/L PFOS. A possible non-monotonic dose response was found in rUburst to PFOS. Moreover, PFOS significantly increased RMR (P<0.05), but did not have a marked effect on maximum metabolic rate (MMR), metabolic scope (MS), factorial metabolic scope (F-MS) and excess post-exercise oxygen consumption (EPOC) (P>0.05). The results indicated that PFOS had more dramatical effect on low metabolic level than high metabolic level of the experimental fish. Additionally, PFOS negatively impact survival-related activities such as capturing prey, avoiding predators, hunting for suitable habitats without significant ecotoxicological effects on metabolic recovery associated with anaerobic metabolism.
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Available online
, doi: 10.7541/2019.053
Abstract:
Gaoyou Lake is the sixth largest freshwater lake in China, it is located between Anhui Province and Jiangsu Province. It has been located in the eastern part of the South-to-North Water Diversion Project, playing an important role in the national water allocation strategy. Base on the investigation performed on the distribution of submerged plants in Gaoyou Lake in 2016, this paper analyzed the characteristics of distribution of submerged plants, and presented a relationship between submerged plants and key environmental factors with redundancy analysis. The results showed that there were few submerged plants in Gaoyou Lake. In addition, it was revealed that Potamogeton crispus was a dominant species and prevalent in the whole lake in late spring and summer seasons, which occupied all over the lake. Myriophyllum spicatum and Potamogeton pectinatus were only visible in few sampling points as well. Nitrogen (N) content of Gaoyou Lake maintained at Ⅲ level in different seasons, whereas phosphorus severely exceeded the limit. The correlation analysis revealed that the distribution of submerged plants was positively correlated with water transparency, while negatively correlated with total phosphorus (P) and ammonium. Results of Monte Carlo analysis also showed that both the total phosphorus and water transparency were the main environmental factors playing key roles in the distribution of submerged plants in Lake Gaoyou. These results have provided a strong basis for utilization and protection of submerged plant resources in Gaoyou Lake.
Gaoyou Lake is the sixth largest freshwater lake in China, it is located between Anhui Province and Jiangsu Province. It has been located in the eastern part of the South-to-North Water Diversion Project, playing an important role in the national water allocation strategy. Base on the investigation performed on the distribution of submerged plants in Gaoyou Lake in 2016, this paper analyzed the characteristics of distribution of submerged plants, and presented a relationship between submerged plants and key environmental factors with redundancy analysis. The results showed that there were few submerged plants in Gaoyou Lake. In addition, it was revealed that Potamogeton crispus was a dominant species and prevalent in the whole lake in late spring and summer seasons, which occupied all over the lake. Myriophyllum spicatum and Potamogeton pectinatus were only visible in few sampling points as well. Nitrogen (N) content of Gaoyou Lake maintained at Ⅲ level in different seasons, whereas phosphorus severely exceeded the limit. The correlation analysis revealed that the distribution of submerged plants was positively correlated with water transparency, while negatively correlated with total phosphorus (P) and ammonium. Results of Monte Carlo analysis also showed that both the total phosphorus and water transparency were the main environmental factors playing key roles in the distribution of submerged plants in Lake Gaoyou. These results have provided a strong basis for utilization and protection of submerged plant resources in Gaoyou Lake.
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Available online
, doi: 10.7541/2019.033
Abstract:
To guide breeding of Megalobrama terminalis, Megalobrama amblycephala and Erythroculter ilishaeformis, two hybrids Megalobrama amblycephala×Erythroculter ilishaeformis, Megalobrama terminalis×Erythroculter ilishaeformisand their parents were analyzed using sixteen microsatellite markers. The mean value of number of alleles (Na) were 3.56, 3.63, 3.44, 4.00 and 4.31, respectively. The mean value of observed heterozygosity (Ho) were 0.3510, 0.3757, 0.3175, 0.3818, and 0.4079, respectively. The mean value of expected heterozygosity (He) were 0.6182, 0.6290, 0.5921, 0.6490 and 0.6825, respectively. And the average value of polymorphism information content (PIC) were 0.5354, 0.5367, 0.5258, 0.5785, and 0.6067, respectively. The average value of polymorphism information content (PIC) of two hybrid population were higher than their parent Megalobrama amblycephala, Megalobrama terminalis and Erythroculter ilishaeformis, indicating a high genetic diversity. The unweighted pair-group method with arithmetic means (UPGMA) showed that populations of the Megalobrama amblycephalaand Megalobrama terminalisfirst grouped together, and that Megalobrama amblycephala♀×Erythroculter ilishaeformis♂ andMegalobrama terminalis♀×Erythroculter ilishaeformis♂ first grouped together, and then they clustered with the Erythroculter ilishaeformis. In addition, the farthest genetic distance (0.5204) was between Megalobrama amblycephala and Erythroculter ilishaeformis, and the nearest genetic distance (0.0853) was between Megalobrama amblycephalaand Megalobrama terminalis. According to the genetic identity analysis, two hybirds groups showed the maternal effect. The alleles of two hybirds were from their parents based on genetic analysis. Particularly, microsatellite primers TTF3, TTF4, TTF10, and Mam25 identified 5 groups. Our results provide important value in breeding, germplasm resources preservation, and germplasm identification of Megalobrama terminalis×Erythroculter ilishaeformis andMegalobrama amblycephala×Erythroculter ilishaeformis.
To guide breeding of Megalobrama terminalis, Megalobrama amblycephala and Erythroculter ilishaeformis, two hybrids Megalobrama amblycephala×Erythroculter ilishaeformis, Megalobrama terminalis×Erythroculter ilishaeformisand their parents were analyzed using sixteen microsatellite markers. The mean value of number of alleles (Na) were 3.56, 3.63, 3.44, 4.00 and 4.31, respectively. The mean value of observed heterozygosity (Ho) were 0.3510, 0.3757, 0.3175, 0.3818, and 0.4079, respectively. The mean value of expected heterozygosity (He) were 0.6182, 0.6290, 0.5921, 0.6490 and 0.6825, respectively. And the average value of polymorphism information content (PIC) were 0.5354, 0.5367, 0.5258, 0.5785, and 0.6067, respectively. The average value of polymorphism information content (PIC) of two hybrid population were higher than their parent Megalobrama amblycephala, Megalobrama terminalis and Erythroculter ilishaeformis, indicating a high genetic diversity. The unweighted pair-group method with arithmetic means (UPGMA) showed that populations of the Megalobrama amblycephalaand Megalobrama terminalisfirst grouped together, and that Megalobrama amblycephala♀×Erythroculter ilishaeformis♂ andMegalobrama terminalis♀×Erythroculter ilishaeformis♂ first grouped together, and then they clustered with the Erythroculter ilishaeformis. In addition, the farthest genetic distance (0.5204) was between Megalobrama amblycephala and Erythroculter ilishaeformis, and the nearest genetic distance (0.0853) was between Megalobrama amblycephalaand Megalobrama terminalis. According to the genetic identity analysis, two hybirds groups showed the maternal effect. The alleles of two hybirds were from their parents based on genetic analysis. Particularly, microsatellite primers TTF3, TTF4, TTF10, and Mam25 identified 5 groups. Our results provide important value in breeding, germplasm resources preservation, and germplasm identification of Megalobrama terminalis×Erythroculter ilishaeformis andMegalobrama amblycephala×Erythroculter ilishaeformis.
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Available online
, doi: 10.7541/2019.052
Abstract:
Jianghan Plain is an alluvial plain located in the middle and south of Hubei province, China. In order to explore the community structure of phytoplankton in an integrated rice-crayfish symbiosis farming (IRCSF) system, algal species, cell density, algal biomass, and physicochemical factors in four rice-crayfish symbiosis farming water bodies were monthly investigated in the Jianghan Plain from April 2016 to December 2016. There were 124 species belonged to 7 phylum, which observed in this integrated system; 78 species belonged to Chlorophyta; 16 species belonged to Cyanophyta; 15 species belonged to Bacillariophyta; 3 species belonged to Euglenophyta; 2 species belonged to Cryptophyta; 7 species belonged to Pyrrophyta; and 3 species belonged to Chrysophyta. The number of algal species, cell density value, and chlorophyll-a content all reached the maximum value from June to September, while the minimum value appeared in December. Algal cell density fluctuated in the range of 1.37×105 to 2.93×108 cells/L, and the content of chlorophyll-a varied from 0.15 to 208.60 μg/L. During the study period, 28 dominant species were totally identified. The dominant species were Oscillatoria, Dactyloccocpsis, Microcystis, Chlorella, and Cryptomonas. The annual variation of the Shannon-Wiener diversity index was from 0.64 to 6.3. The maximum value of diversity index achieved in October, while the minimum value was in August. The results showed that the community structure of phytoplankton in the IRCSF sytem was complex with an obvious spatio-temporal heterogeneity. Since algae plays an important role in water environment and crayfish cultivation, it is of great significance to pay attention to the change of community structure of phytoplankton in the IRCSF system.
Jianghan Plain is an alluvial plain located in the middle and south of Hubei province, China. In order to explore the community structure of phytoplankton in an integrated rice-crayfish symbiosis farming (IRCSF) system, algal species, cell density, algal biomass, and physicochemical factors in four rice-crayfish symbiosis farming water bodies were monthly investigated in the Jianghan Plain from April 2016 to December 2016. There were 124 species belonged to 7 phylum, which observed in this integrated system; 78 species belonged to Chlorophyta; 16 species belonged to Cyanophyta; 15 species belonged to Bacillariophyta; 3 species belonged to Euglenophyta; 2 species belonged to Cryptophyta; 7 species belonged to Pyrrophyta; and 3 species belonged to Chrysophyta. The number of algal species, cell density value, and chlorophyll-a content all reached the maximum value from June to September, while the minimum value appeared in December. Algal cell density fluctuated in the range of 1.37×105 to 2.93×108 cells/L, and the content of chlorophyll-a varied from 0.15 to 208.60 μg/L. During the study period, 28 dominant species were totally identified. The dominant species were Oscillatoria, Dactyloccocpsis, Microcystis, Chlorella, and Cryptomonas. The annual variation of the Shannon-Wiener diversity index was from 0.64 to 6.3. The maximum value of diversity index achieved in October, while the minimum value was in August. The results showed that the community structure of phytoplankton in the IRCSF sytem was complex with an obvious spatio-temporal heterogeneity. Since algae plays an important role in water environment and crayfish cultivation, it is of great significance to pay attention to the change of community structure of phytoplankton in the IRCSF system.
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Available online
, doi: 10.7541/2019.051
Abstract:
" Plate-shaped Lake Enclosed in Autumn” is a fishing method used by fishermen in the Poyang Lake. According to seasonal water level, fishermen use artificial gates to control sub-lake water level for fishing. This study analyzed the zooplankton community structure during the " Plate-shaped Lake Enclosed in Autumn” and discussed the impact of water level and other possible influencing factors on the zooplankton community structure. From 9th November, 2014 to 4th January, 2015, we conducted 8 times qualitative and quantitative zooplankton acquisitions from seven sampling sites in the open water area of Dahuchi Lake, a sub-lake located in the Poyang Lake National Nature Reserve. A total of 77 species of zooplankton were identified, which consisted of 53 species of Rotifera, 10 species of Cladocera and 14 species of Copepoda. During the " Plate-shaped Lake Enclosed in Autumn” fishing process, the specie richness of zooplankton gradually decreased with the decrease of water level. The diversity index of zooplankton also showed a decreasing tendency. Zooplankton density and biomass increased first and then decreased. However, the density variation of dominant species in zooplankton has obvious species differences. The density of Asplanchna priodonta and Limnoithona sinensis gradually increased during " Plate-shaped Lake Enclosed in Autumn”. The density of Polyarthra vulgaris, Mesocyclops leuckarti, Bosmina longirostris and Copepod nauplii continuously decreased. Redundancy analysis (RDA) showed that several environmental factors such as water level, conductivity, water temperature, dissolved oxygen and nutrient had significant effect on the zooplankton community structure with the strongest effect by dissolved oxygen. In addition, according to the information of fishing catch during " Plate-shaped Lake Enclosed in Autumn”, we propose that the decrease in planktonic fish caused by fishing activities can impact zooplankton density.
" Plate-shaped Lake Enclosed in Autumn” is a fishing method used by fishermen in the Poyang Lake. According to seasonal water level, fishermen use artificial gates to control sub-lake water level for fishing. This study analyzed the zooplankton community structure during the " Plate-shaped Lake Enclosed in Autumn” and discussed the impact of water level and other possible influencing factors on the zooplankton community structure. From 9th November, 2014 to 4th January, 2015, we conducted 8 times qualitative and quantitative zooplankton acquisitions from seven sampling sites in the open water area of Dahuchi Lake, a sub-lake located in the Poyang Lake National Nature Reserve. A total of 77 species of zooplankton were identified, which consisted of 53 species of Rotifera, 10 species of Cladocera and 14 species of Copepoda. During the " Plate-shaped Lake Enclosed in Autumn” fishing process, the specie richness of zooplankton gradually decreased with the decrease of water level. The diversity index of zooplankton also showed a decreasing tendency. Zooplankton density and biomass increased first and then decreased. However, the density variation of dominant species in zooplankton has obvious species differences. The density of Asplanchna priodonta and Limnoithona sinensis gradually increased during " Plate-shaped Lake Enclosed in Autumn”. The density of Polyarthra vulgaris, Mesocyclops leuckarti, Bosmina longirostris and Copepod nauplii continuously decreased. Redundancy analysis (RDA) showed that several environmental factors such as water level, conductivity, water temperature, dissolved oxygen and nutrient had significant effect on the zooplankton community structure with the strongest effect by dissolved oxygen. In addition, according to the information of fishing catch during " Plate-shaped Lake Enclosed in Autumn”, we propose that the decrease in planktonic fish caused by fishing activities can impact zooplankton density.
,
Available online
, doi: 10.7541/2019.050
Abstract:
To understand the structure and its driving factors of macroinvertebrate community, two surveys were conducted in the Anning River and its tributaries in wet season (July and August 2016) and dry season (January and February 2016). Furthermore, sampling was also performed monthly from July 2015 to June 2016 in the tributaries of the Anning River. As a result, a total of 122 species of macroinvertebrates were collected, which belonged to 115 genera of 5 phyla. Among them, aquatic insects (109 species) were dominant taxa. The densities and biomass of macroinvertebrate community were much higher in the tributaries than those in the mainstream both in the wet and dry seasons, and were much higher in the dry season than those in the wet season both in the mainstream and tributaries. All through the year, the dominant species in the tributaries were Baetis sp., Simulium sp., Epeorus sp., Baetiella sp., Peltoperlidae spp. and Ephemerella sp. Temporal variability of macroinvertebrates showed that the highest density was in December and the lowest one in July; while the highest biomass was in January and the lowest one in July. Canonical correspondences analysis (CCA) indicated that substrate type and altitude were key factors driving the macroinvertebrate distribution in the wet season, whereas flow velocity, altitude and water temperature were the significant driving factors in the dry season. In addition, monthly variations of macroinvertebrate structure in the tributaries were relative to the ecological factors such as water temperature and conductivity. Overall, this study provides a scientific basis for the studies and conservation of biodiversity in high altitude areas.
To understand the structure and its driving factors of macroinvertebrate community, two surveys were conducted in the Anning River and its tributaries in wet season (July and August 2016) and dry season (January and February 2016). Furthermore, sampling was also performed monthly from July 2015 to June 2016 in the tributaries of the Anning River. As a result, a total of 122 species of macroinvertebrates were collected, which belonged to 115 genera of 5 phyla. Among them, aquatic insects (109 species) were dominant taxa. The densities and biomass of macroinvertebrate community were much higher in the tributaries than those in the mainstream both in the wet and dry seasons, and were much higher in the dry season than those in the wet season both in the mainstream and tributaries. All through the year, the dominant species in the tributaries were Baetis sp., Simulium sp., Epeorus sp., Baetiella sp., Peltoperlidae spp. and Ephemerella sp. Temporal variability of macroinvertebrates showed that the highest density was in December and the lowest one in July; while the highest biomass was in January and the lowest one in July. Canonical correspondences analysis (CCA) indicated that substrate type and altitude were key factors driving the macroinvertebrate distribution in the wet season, whereas flow velocity, altitude and water temperature were the significant driving factors in the dry season. In addition, monthly variations of macroinvertebrate structure in the tributaries were relative to the ecological factors such as water temperature and conductivity. Overall, this study provides a scientific basis for the studies and conservation of biodiversity in high altitude areas.
,
Available online
, doi: 10.7541/2019.030
Abstract:
An 8-week feeding experiment was conducted to evaluate the effects of different monocalcium phosphate (MCP) levels added into high lipid (7.0%) diet on grass carp (Ctenopharyngodon idella) growth performance, lipid metabolism and antioxidant activity. Five levels of MCP (0, 1.0%, 2.0%, 3.0% and 4.0%) were added into high lipid diet, respectively, as basal diets to feed grass carp [initial body weight (47.51±0.52) g]. Each treatment contained three replicates with 15 fishes per replicate. The results showed that the addition of suitable MCP in high-fat diets could significantly increase the weight gain rate (WGR) and the whole-body phosphorus of grass carp, as well as reduce the Feed conversion ratio (FCR) and Viscerosomatic index (VSI). Taking WGR, FCR and whole-body phosphorus as the observational indicators, the analysis of broken-line model showed that the appropriate amount of dietary MCP was 3.26%, 2.96% and 2.63%, respectively. With the increase of MCP in the diet, the whole-body, viscera, muscle, and liver crude lipid content decreased first and then rose, but the whole-body and muscle crude protein had opposite trends. In the MCP3.0% group, grass carp intestinal amylase, lipase, trypsin, and serum alkaline phosphatase (AKP) had the highest activity, while serum triglyceride, hepatic malondialdehyde and acetyl-CoA carboxylase (ACC) were the lowest. Serum total cholesterol was significantly lower in the supplemented group than in the control group (P<0.05). Liver carnitine acyltransferase (CPT-I) activity increased with the increaseing dietary phosphorus. This study indicates that the optimal supplementation of MCP in grass carp high fat (7%) diets was 2.96%—3.26% (TP 1.43%—1.50%), and the appropriate level of MCP can promote the digestion and utilization of dietary nutrients, as well as reduce hepatic lipid accumulation. At the same time, it also increases protein and antioxidant capacity, and decreases lipid, which help promote growth.
An 8-week feeding experiment was conducted to evaluate the effects of different monocalcium phosphate (MCP) levels added into high lipid (7.0%) diet on grass carp (Ctenopharyngodon idella) growth performance, lipid metabolism and antioxidant activity. Five levels of MCP (0, 1.0%, 2.0%, 3.0% and 4.0%) were added into high lipid diet, respectively, as basal diets to feed grass carp [initial body weight (47.51±0.52) g]. Each treatment contained three replicates with 15 fishes per replicate. The results showed that the addition of suitable MCP in high-fat diets could significantly increase the weight gain rate (WGR) and the whole-body phosphorus of grass carp, as well as reduce the Feed conversion ratio (FCR) and Viscerosomatic index (VSI). Taking WGR, FCR and whole-body phosphorus as the observational indicators, the analysis of broken-line model showed that the appropriate amount of dietary MCP was 3.26%, 2.96% and 2.63%, respectively. With the increase of MCP in the diet, the whole-body, viscera, muscle, and liver crude lipid content decreased first and then rose, but the whole-body and muscle crude protein had opposite trends. In the MCP3.0% group, grass carp intestinal amylase, lipase, trypsin, and serum alkaline phosphatase (AKP) had the highest activity, while serum triglyceride, hepatic malondialdehyde and acetyl-CoA carboxylase (ACC) were the lowest. Serum total cholesterol was significantly lower in the supplemented group than in the control group (P<0.05). Liver carnitine acyltransferase (CPT-I) activity increased with the increaseing dietary phosphorus. This study indicates that the optimal supplementation of MCP in grass carp high fat (7%) diets was 2.96%—3.26% (TP 1.43%—1.50%), and the appropriate level of MCP can promote the digestion and utilization of dietary nutrients, as well as reduce hepatic lipid accumulation. At the same time, it also increases protein and antioxidant capacity, and decreases lipid, which help promote growth.
,
Available online
, doi: 10.7541/2019.029
Abstract:
The purpose of this study was to investigate dietary lipid requirement and the effect of different lipid levels on the body composition and plasma biochemical indices in cobia (Rachycentron canadum L) at two different body sizes (initial weight: 40 g vs. 500 g). Six isonitrogenous diets were formulated using fish meal, soybean meal and wheat meal as the protein source and fish oil as lipid source, with six different lipid contents of 5.27%, 8.22%, 10.81%, 14.26%, 17.32% and 20.94% (at a dry matter basis), respectively. Fish at two different growth stages were randomly distributed to seawater floating net cages (1.5 m×1.5 m×2.5 m) at a density of 25 and 10 fish per net cage, respectively. Each diet was fed to triplicate groups of fish twice daily to satiation for 10 weeks (40 g) and 8 weeks (500 g), respectively. Specific growth rate (SGR) and feed efficiency ratio (FER) significantly increased and then decreased with increasing dietary lipid levels at both developmental stages. The Viscerosomatic index (VSI) and Condition factor (CF) increased significantly with the increase of dietary lipid levels. Significantly higher Hepatosomatic index (HSI), whole-body, liver and muscle lipid contents and lower moisture and protein contents were observed in fish feed the diets containing higher lipid among small fish groups, but no significant difference was detected among large body size groups among above parameters. In addition, the contents of TC, TG, HDL-C, LDL-C and Glu increased significantly with the increasing lipid levels among small fish groups, there was no significant effect among large fish groups in these indices except TG. The overall results showed that based on SGR and FER, the diet containing 13.97—14.16% and 13.18%—13.47% lipid was most suitable for the cobia culture at the body size of 40 g and 500 g, respectively
The purpose of this study was to investigate dietary lipid requirement and the effect of different lipid levels on the body composition and plasma biochemical indices in cobia (Rachycentron canadum L) at two different body sizes (initial weight: 40 g vs. 500 g). Six isonitrogenous diets were formulated using fish meal, soybean meal and wheat meal as the protein source and fish oil as lipid source, with six different lipid contents of 5.27%, 8.22%, 10.81%, 14.26%, 17.32% and 20.94% (at a dry matter basis), respectively. Fish at two different growth stages were randomly distributed to seawater floating net cages (1.5 m×1.5 m×2.5 m) at a density of 25 and 10 fish per net cage, respectively. Each diet was fed to triplicate groups of fish twice daily to satiation for 10 weeks (40 g) and 8 weeks (500 g), respectively. Specific growth rate (SGR) and feed efficiency ratio (FER) significantly increased and then decreased with increasing dietary lipid levels at both developmental stages. The Viscerosomatic index (VSI) and Condition factor (CF) increased significantly with the increase of dietary lipid levels. Significantly higher Hepatosomatic index (HSI), whole-body, liver and muscle lipid contents and lower moisture and protein contents were observed in fish feed the diets containing higher lipid among small fish groups, but no significant difference was detected among large body size groups among above parameters. In addition, the contents of TC, TG, HDL-C, LDL-C and Glu increased significantly with the increasing lipid levels among small fish groups, there was no significant effect among large fish groups in these indices except TG. The overall results showed that based on SGR and FER, the diet containing 13.97—14.16% and 13.18%—13.47% lipid was most suitable for the cobia culture at the body size of 40 g and 500 g, respectively
,
Available online
, doi: 10.7541/2019.045
Abstract:
In order to explore activities of digestive enzymes fluctuation of common carp (Cyprinus carpio) larvae during growth stage, this study investigated the growth, soluble protein content and the activities of digestive enzymes of laboratory-reared common carp. The results indicated that total length and body weight of larvae at 40 days after hatching (DAH) increased greatly with a 14.81% growth rate. The activities of amylase, lipase, trypsin, chymotrypsin, alkaline phosphatase and aminopeptidase were detected at 1 DAH in common carp. During the development of larvae, soluble protein content of larvae decreased firstly, and then gradually increased. The activity of digestive enzymes in larvae increased before feeding. With the development of digestive systems and change of alimentation mode, activities of digestive enzymes of larvae changed continually from 3 to 25 DAH. After 25 DAH, activities of digestive enzymes of common crap were relatively stable, a sign of completed larval digestive function. In order to improve the ecological restoration effect of artificial fishnest and reduce starvation effect on the survival rate of larvae, organic materials could be used for artificial fishnest according to the digestive enzyme activity of common carp at different developmental stages.
In order to explore activities of digestive enzymes fluctuation of common carp (Cyprinus carpio) larvae during growth stage, this study investigated the growth, soluble protein content and the activities of digestive enzymes of laboratory-reared common carp. The results indicated that total length and body weight of larvae at 40 days after hatching (DAH) increased greatly with a 14.81% growth rate. The activities of amylase, lipase, trypsin, chymotrypsin, alkaline phosphatase and aminopeptidase were detected at 1 DAH in common carp. During the development of larvae, soluble protein content of larvae decreased firstly, and then gradually increased. The activity of digestive enzymes in larvae increased before feeding. With the development of digestive systems and change of alimentation mode, activities of digestive enzymes of larvae changed continually from 3 to 25 DAH. After 25 DAH, activities of digestive enzymes of common crap were relatively stable, a sign of completed larval digestive function. In order to improve the ecological restoration effect of artificial fishnest and reduce starvation effect on the survival rate of larvae, organic materials could be used for artificial fishnest according to the digestive enzyme activity of common carp at different developmental stages.
,
Available online
, doi: 10.7541/2019.041
Abstract:
To investigate whether Aeromonas hydrophila generally mediate liver protein expression, isobaric tags for relative and absolute quantitation (iTRAQ) combined with LC-MS/MS were used to screen liver proteins of black carp Mylopharyngodon piceus after infected with Aeromonas hydrophila (BCK0712) for 24 hours. Differentially expressed proteins were screened through identification and quantification analysis. As a result, a total of 4475 proteins were identified and 188 differentially expressed proteins were quantified upon bacterial infection, including 70 up-regulated and 118 down-regulated proteins. Bioinformatics analysis indicated that these differentially expressed proteins were mainly associated with complement and coagulation cascades, spliceosome, endocytosis, oxidative phosphorylation, carbon metabolism, arginine and proline metabolism, etc. Hispathological characteristics including unclear cell boundary, hemorrhage at different degrees and necrosis were observed on liver of black carp infected with A. hydrophila under microscope after hematoxylin-eosin staining. The potential mechanism of regulated proteins by A. hydrophila infection in liver pathology need further investigation.
To investigate whether Aeromonas hydrophila generally mediate liver protein expression, isobaric tags for relative and absolute quantitation (iTRAQ) combined with LC-MS/MS were used to screen liver proteins of black carp Mylopharyngodon piceus after infected with Aeromonas hydrophila (BCK0712) for 24 hours. Differentially expressed proteins were screened through identification and quantification analysis. As a result, a total of 4475 proteins were identified and 188 differentially expressed proteins were quantified upon bacterial infection, including 70 up-regulated and 118 down-regulated proteins. Bioinformatics analysis indicated that these differentially expressed proteins were mainly associated with complement and coagulation cascades, spliceosome, endocytosis, oxidative phosphorylation, carbon metabolism, arginine and proline metabolism, etc. Hispathological characteristics including unclear cell boundary, hemorrhage at different degrees and necrosis were observed on liver of black carp infected with A. hydrophila under microscope after hematoxylin-eosin staining. The potential mechanism of regulated proteins by A. hydrophila infection in liver pathology need further investigation.
,
Available online
, doi: 10.7541/2019.034
Abstract:
Insulin-like growth factor-Ⅰ (IGF-Ⅰ) plays an important role in regulating somatic growth in vertebrates via growth hormone. In order to study the effect of IGF-Ⅰ gene on growth traits of topmouth culter (Culter alburnus Basilewsky), IGF-Ⅰ gene was cloned from the genomic DNA of topmouth culter in this study. The gene spanned 14567 bp and comprised five exons and five introns. The five exons of IGF-Ⅰ in topmouth culter were 298, 160, 182, 36, and 1360 bp long, respectively. The hypothetical open reading frame of the IGF-Ⅰ cDNA precursor was 486 bp, encoding a putative protein of 161 amino acids. The precursor peptide comprisedincluded a signal peptide (44 amino acids), a mature peptide (70 amino acids), and an E peptide (47 amino acids). The mature peptide comprised four regions: B, C, A, and D. The A and B domains were conserved, and there werewith six cysteine residues in these two regions to that form three disulfide bonds. The B region also contained a conserved IGF Ⅰ receptor recognition sequence (PheB23-TyrB24-PheB25). Analysis of the E peptide showed that IGF-Ⅰ of the topmouth culter was an Ea-2 type. The IGF-Ⅰamino acid sequence of the topmouth culter had high sequence identity with IGF-Ⅰ proteins from Cyprinidae fish, ranging from 94 to 100%. Phylogenetic analysis of IGF- I amino acid sequences showed that IGF-Ⅰ from the topmouth culter does not cluster with the fish from subfamily Cultrinae. Quantitative real-time reverse transcription PCR analysis showed that the IGF-Ⅰ mRNA is expressed in all 10 tested tissues tested, with the highest mRNA expressionlevel in liver, modest level. IGF-Ⅰ was highly expressed in spleen, heart, testis, and brain, butand at a lowerlow level in kidney, gill, stomach, and ovary. The lengths of the four introns inof topmouth culter IGF-Ⅰ were 1170, 9364, 251, and 1746 bp, respectively. The variation in the sequence of the introns among species was greater than that of the exons with the, highest and the variation inof the third intron was the highest. Six microsatellite loci were found in the introns of IGF-Ⅰ with: (GATG)5AATAT (ATAG)11 was found in intron Ⅰ, and (CT)8, (TTA)5, (AC)13, (TG)12, and (ATT)5 were found in intron II. Four of the 6 microsatellite loci were polymorphic, and the genotypes of the four microsatellite loci had no significant correlation with the growth traits of 120 topmouth culter cultured in the same pond (P>0.05). These results provided molecular basis for studying the function and transcriptional regulation of theIGF-Ⅰ gene, as well as the temporal expression in different developmental stages and atunder various nutrition levels.
Insulin-like growth factor-Ⅰ (IGF-Ⅰ) plays an important role in regulating somatic growth in vertebrates via growth hormone. In order to study the effect of IGF-Ⅰ gene on growth traits of topmouth culter (Culter alburnus Basilewsky), IGF-Ⅰ gene was cloned from the genomic DNA of topmouth culter in this study. The gene spanned 14567 bp and comprised five exons and five introns. The five exons of IGF-Ⅰ in topmouth culter were 298, 160, 182, 36, and 1360 bp long, respectively. The hypothetical open reading frame of the IGF-Ⅰ cDNA precursor was 486 bp, encoding a putative protein of 161 amino acids. The precursor peptide comprisedincluded a signal peptide (44 amino acids), a mature peptide (70 amino acids), and an E peptide (47 amino acids). The mature peptide comprised four regions: B, C, A, and D. The A and B domains were conserved, and there werewith six cysteine residues in these two regions to that form three disulfide bonds. The B region also contained a conserved IGF Ⅰ receptor recognition sequence (PheB23-TyrB24-PheB25). Analysis of the E peptide showed that IGF-Ⅰ of the topmouth culter was an Ea-2 type. The IGF-Ⅰamino acid sequence of the topmouth culter had high sequence identity with IGF-Ⅰ proteins from Cyprinidae fish, ranging from 94 to 100%. Phylogenetic analysis of IGF- I amino acid sequences showed that IGF-Ⅰ from the topmouth culter does not cluster with the fish from subfamily Cultrinae. Quantitative real-time reverse transcription PCR analysis showed that the IGF-Ⅰ mRNA is expressed in all 10 tested tissues tested, with the highest mRNA expressionlevel in liver, modest level. IGF-Ⅰ was highly expressed in spleen, heart, testis, and brain, butand at a lowerlow level in kidney, gill, stomach, and ovary. The lengths of the four introns inof topmouth culter IGF-Ⅰ were 1170, 9364, 251, and 1746 bp, respectively. The variation in the sequence of the introns among species was greater than that of the exons with the, highest and the variation inof the third intron was the highest. Six microsatellite loci were found in the introns of IGF-Ⅰ with: (GATG)5AATAT (ATAG)11 was found in intron Ⅰ, and (CT)8, (TTA)5, (AC)13, (TG)12, and (ATT)5 were found in intron II. Four of the 6 microsatellite loci were polymorphic, and the genotypes of the four microsatellite loci had no significant correlation with the growth traits of 120 topmouth culter cultured in the same pond (P>0.05). These results provided molecular basis for studying the function and transcriptional regulation of theIGF-Ⅰ gene, as well as the temporal expression in different developmental stages and atunder various nutrition levels.
,
Available online
, doi: 10.7541/2019.046
Abstract:
To protect Schizothorax macropogon, belong to Schizothorax, Schizothorax, this study investigated the embryonic and larval development characteristics of Schizothorax macropogon to provide technical support for its scientific protection and rational development. The results indicated that the egg with the diameter 3.0—3.2 mm were slightly sticky when met with water and then take off the stick. The egg hatched about 460.67 hours at temperature 10℃. Based on external morphological characteristics, embryonic development was separated into 7 stages, including cleavage preparing stage, cleavage stage, blastula stage, gastrula stage, neural embryo stage, organ differentiation stage, and hatching stage. Newly hatching fry with body length 9.9—11.0 mm, heart rate 48—50 beats/min, operculum, underjaw primordial radial of tail fin primordia clearly appeared. 2-day fry after hatching, nose concave appeared. Hepatopancreas primordial observed from 3 day fry after hatching, and gill raker and shoulder strap primordium shown in 4 day fry after hatching. The upper and lower jaw began to open and close in 6 day fry after hatching, and vascular differentiation ended, turned into mixed vegetative phase at 7 day fry after hatching. 14 day fry after hatching, swim bladder one room and pigment zone formed. 26 day fry after hatching, rib primordia developed. 35 day fry after hatching, swim bladder two room formed and yolk sac depleted. 63 day fry after hatching, dorsal fin differentiation ended and lateral line developed. 83 day fry after hatching, anal fin differentiation ended. An unique development timing for the first blastopore to metameres existed in Schizothorax macropogon, which is the adaptation and evolution to plateau environment.
To protect Schizothorax macropogon, belong to Schizothorax, Schizothorax, this study investigated the embryonic and larval development characteristics of Schizothorax macropogon to provide technical support for its scientific protection and rational development. The results indicated that the egg with the diameter 3.0—3.2 mm were slightly sticky when met with water and then take off the stick. The egg hatched about 460.67 hours at temperature 10℃. Based on external morphological characteristics, embryonic development was separated into 7 stages, including cleavage preparing stage, cleavage stage, blastula stage, gastrula stage, neural embryo stage, organ differentiation stage, and hatching stage. Newly hatching fry with body length 9.9—11.0 mm, heart rate 48—50 beats/min, operculum, underjaw primordial radial of tail fin primordia clearly appeared. 2-day fry after hatching, nose concave appeared. Hepatopancreas primordial observed from 3 day fry after hatching, and gill raker and shoulder strap primordium shown in 4 day fry after hatching. The upper and lower jaw began to open and close in 6 day fry after hatching, and vascular differentiation ended, turned into mixed vegetative phase at 7 day fry after hatching. 14 day fry after hatching, swim bladder one room and pigment zone formed. 26 day fry after hatching, rib primordia developed. 35 day fry after hatching, swim bladder two room formed and yolk sac depleted. 63 day fry after hatching, dorsal fin differentiation ended and lateral line developed. 83 day fry after hatching, anal fin differentiation ended. An unique development timing for the first blastopore to metameres existed in Schizothorax macropogon, which is the adaptation and evolution to plateau environment.
,
Available online
, doi: 10.7541/2019.032
Abstract:
Leptin has been reported to play important roles in regulation of glucose homeostasis in mammals. However, the relationship between blood glucose and leptin gene expression in teleosts is largely unknown. In the present study, blood glucose and leptin-A gene expression in liver, intestine and visceral adipose tissue were characterized in Chinese perch (Siniperca chuatsi) after fasting or insulin treatment. In the fasting experiment, Chinese perch were fasted for 10 days, sampling at 0, 4h, 2d, 6d and 10d after fasting. Blood glucose was significantly decreased at 10d after fasting; leptin-A mRNA expression was significantly increased in liver at 6d after fasting, and significantly increased in intestine and visceral adipose tissue at 4h after fasting. In the insulin treatment experiment, Chinese perch were intraperitoneally injected with bovine insulin (80 IU/kg body weight) or 0.7% saline as control, sampling at 12h and 36h post treatment. Blood glucose decreased significantly at 12h after insulin treatment, and leptin-A mRNA expression in intestine increased significantly at 36h after insulin treatment, which suggesting that prolonged fasting and insulin treatment decreased blood glucose, and increased leptin-A gene expression in fat depot organ and digestive organ of fish.
Leptin has been reported to play important roles in regulation of glucose homeostasis in mammals. However, the relationship between blood glucose and leptin gene expression in teleosts is largely unknown. In the present study, blood glucose and leptin-A gene expression in liver, intestine and visceral adipose tissue were characterized in Chinese perch (Siniperca chuatsi) after fasting or insulin treatment. In the fasting experiment, Chinese perch were fasted for 10 days, sampling at 0, 4h, 2d, 6d and 10d after fasting. Blood glucose was significantly decreased at 10d after fasting; leptin-A mRNA expression was significantly increased in liver at 6d after fasting, and significantly increased in intestine and visceral adipose tissue at 4h after fasting. In the insulin treatment experiment, Chinese perch were intraperitoneally injected with bovine insulin (80 IU/kg body weight) or 0.7% saline as control, sampling at 12h and 36h post treatment. Blood glucose decreased significantly at 12h after insulin treatment, and leptin-A mRNA expression in intestine increased significantly at 36h after insulin treatment, which suggesting that prolonged fasting and insulin treatment decreased blood glucose, and increased leptin-A gene expression in fat depot organ and digestive organ of fish.
,
Available online
, doi: 10.7541/2019.055
Abstract:
To evaluate the impacts of nitrogen concentration on both biomanipulation and the competition between algae and water grass, Microcystis aeruginosa, Daphnia magna and Ceratophyllum demersum were selected for experiments to represent phytoplankton, zooplankton and submerged macrophyte, respectively. When two or three of them were cultured together, the changes of growth rate and removal rate of nitrogen and phosphorus were observed with the phosphorous concentration of 1.5 mg/L and 5 different nitrogen concentrations (0.5, 2, 4, 8 and 16 mg/L, prepared with KNO3 solution), under temperature of 25℃, illumination of 2600 lx, light dark ratio 14h﹕10h. The results indicated that whenM. aeruginosa was cultured separately, its growth rate effectively reduced with a nitrogen concentration less than 1.97 mg/L. When D. magna andM. aeruginosa were co-cultured, the nitrogen concentration which D. magna could effectively control algae was from 0.5 to 4 mg/L. However, the nitrogen concentration which C. demersum could effectively control algae was from 0.5 to 2 mg/L, when C. demersum and M. aeruginosa were co-cultured. When nitrogen concentrations were at 0.5 and 2 mg/L, the cell densities of M. aeruginosa were 23.89% and 21.51%, respectively, of that when D. magna and M. aeruginosa were co-cultured at the last of experiment. So the effect of algae control was better when C. demersum and M. aeruginosa were co-cultured. The algae could be effectively controlled with nitrogen concentration from 0.5 to 16 mg/L, when D. magna, C. demersum and M. aeruginosa were co-cultured, under which the effect of algae control was the best. Especially, the growth rate of M. aeruginosa was all negative and significantly lower than those of D. magna and C. demersum when nitrogen concentration was bewteen 0.5 and 4 mg/L. In the co-culture environment of D. magna and M. aeruginosa, with the addition of large submerged macrophyte, the effect of algae control could effectively enhance, and the nitrogen and phosphorus in the water could be decreased, which can effectively improve the water quality over the long term.
To evaluate the impacts of nitrogen concentration on both biomanipulation and the competition between algae and water grass, Microcystis aeruginosa, Daphnia magna and Ceratophyllum demersum were selected for experiments to represent phytoplankton, zooplankton and submerged macrophyte, respectively. When two or three of them were cultured together, the changes of growth rate and removal rate of nitrogen and phosphorus were observed with the phosphorous concentration of 1.5 mg/L and 5 different nitrogen concentrations (0.5, 2, 4, 8 and 16 mg/L, prepared with KNO3 solution), under temperature of 25℃, illumination of 2600 lx, light dark ratio 14h﹕10h. The results indicated that whenM. aeruginosa was cultured separately, its growth rate effectively reduced with a nitrogen concentration less than 1.97 mg/L. When D. magna andM. aeruginosa were co-cultured, the nitrogen concentration which D. magna could effectively control algae was from 0.5 to 4 mg/L. However, the nitrogen concentration which C. demersum could effectively control algae was from 0.5 to 2 mg/L, when C. demersum and M. aeruginosa were co-cultured. When nitrogen concentrations were at 0.5 and 2 mg/L, the cell densities of M. aeruginosa were 23.89% and 21.51%, respectively, of that when D. magna and M. aeruginosa were co-cultured at the last of experiment. So the effect of algae control was better when C. demersum and M. aeruginosa were co-cultured. The algae could be effectively controlled with nitrogen concentration from 0.5 to 16 mg/L, when D. magna, C. demersum and M. aeruginosa were co-cultured, under which the effect of algae control was the best. Especially, the growth rate of M. aeruginosa was all negative and significantly lower than those of D. magna and C. demersum when nitrogen concentration was bewteen 0.5 and 4 mg/L. In the co-culture environment of D. magna and M. aeruginosa, with the addition of large submerged macrophyte, the effect of algae control could effectively enhance, and the nitrogen and phosphorus in the water could be decreased, which can effectively improve the water quality over the long term.
,
Available online
, doi: 10.7541/2019.048
Abstract:
To evaluate muscle nutritive values of the hybrid F1 of female Culter alburnus × male Megalobrama terminalis (CA×MT), the proximate composition, amino acids levels, fatty acids profiles and mineral contents in muscle of Culter alburnus (CA), Megalobrama terminalis (MT), and CA×MT were measured. The results showed that muscle moisture of CA×MT were significantly lower than those of CA and MT (P<0.05), while the muscle crude protein of CA×MT was significantly higher than others (P<0.05). Muscle essential amino acids (EAA) of CA×MT was the highest one that was significantly higher than that of MT (P<0.05). According to amino acid score (AAS) and chemical score (CS), the first limiting amino acid was methionine+cysteine (Met+Cys) for all three kinds of fish. The percentage of unsaturated fatty acid (UFA) to total fatty acids of CA×MT in muscle was higher than those of CA and MT (P<0.05). The contents of iron (Fe), copper (Cu), manganese (Mn) and zinc (Zn) of three kinds of fish in muscle had no significant difference (P>0.05). In conclusion, the muscle of CA×MT has a higher nutritive value with higher protein contents, EAA and UFA.
To evaluate muscle nutritive values of the hybrid F1 of female Culter alburnus × male Megalobrama terminalis (CA×MT), the proximate composition, amino acids levels, fatty acids profiles and mineral contents in muscle of Culter alburnus (CA), Megalobrama terminalis (MT), and CA×MT were measured. The results showed that muscle moisture of CA×MT were significantly lower than those of CA and MT (P<0.05), while the muscle crude protein of CA×MT was significantly higher than others (P<0.05). Muscle essential amino acids (EAA) of CA×MT was the highest one that was significantly higher than that of MT (P<0.05). According to amino acid score (AAS) and chemical score (CS), the first limiting amino acid was methionine+cysteine (Met+Cys) for all three kinds of fish. The percentage of unsaturated fatty acid (UFA) to total fatty acids of CA×MT in muscle was higher than those of CA and MT (P<0.05). The contents of iron (Fe), copper (Cu), manganese (Mn) and zinc (Zn) of three kinds of fish in muscle had no significant difference (P>0.05). In conclusion, the muscle of CA×MT has a higher nutritive value with higher protein contents, EAA and UFA.
,
Available online
, doi: 10.7541/2019.047
Abstract:
Most Balitoridae fish with similar shapes separately distribute in different rivers or different sections of a river. Providing the morphological similarities, it’s interesting to find why Sinogastromyzon sichangensisandMetahomaloptera omeiensis coexist in the Zaodu River. To address this, the digestive systems of these two fish species were comparatively analyzed by morphological, histological and histochemical methods. The digestive systems of these two fish were nearly the same at morphology, which were consistent with characteristics of omnivorous fishes, however, the morphological difference of the digestive system was obvious. First, the intestine of S. sichangensis was circled into a" φ”shape, with hepatopancrease covered on the ventral part, however, that of M. omeiensis was organized in a complicated ways. Second, the gut index (GI) and digestive system index (DSI) of S. sichangensis were greater than those of M. omeiensis.Besides, the digestive tract of S. sichangensis had a significant higher mucosal fold and thicker muscular layer compared with M.oneiensis, however, there was no significant difference in hepatopancrease. The mucous secreting cells were similar in these two fishes based on AB (Alcian Blue) and PAS (Periodic Acid Schiff) staining, and most of these cells belong to type II and IV mucous cells that were similar to most teleosts. The characteristics of digestive system reflect the feeding habits and digestive ability of fish, in some degree. Thus, the morphological and histological differences in digestive system between S. sichangensis and M. omeiensis may suggest different diet and digestion, which maybe the reasons for the coexistence of these two morphologically similar species.
Most Balitoridae fish with similar shapes separately distribute in different rivers or different sections of a river. Providing the morphological similarities, it’s interesting to find why Sinogastromyzon sichangensisandMetahomaloptera omeiensis coexist in the Zaodu River. To address this, the digestive systems of these two fish species were comparatively analyzed by morphological, histological and histochemical methods. The digestive systems of these two fish were nearly the same at morphology, which were consistent with characteristics of omnivorous fishes, however, the morphological difference of the digestive system was obvious. First, the intestine of S. sichangensis was circled into a" φ”shape, with hepatopancrease covered on the ventral part, however, that of M. omeiensis was organized in a complicated ways. Second, the gut index (GI) and digestive system index (DSI) of S. sichangensis were greater than those of M. omeiensis.Besides, the digestive tract of S. sichangensis had a significant higher mucosal fold and thicker muscular layer compared with M.oneiensis, however, there was no significant difference in hepatopancrease. The mucous secreting cells were similar in these two fishes based on AB (Alcian Blue) and PAS (Periodic Acid Schiff) staining, and most of these cells belong to type II and IV mucous cells that were similar to most teleosts. The characteristics of digestive system reflect the feeding habits and digestive ability of fish, in some degree. Thus, the morphological and histological differences in digestive system between S. sichangensis and M. omeiensis may suggest different diet and digestion, which maybe the reasons for the coexistence of these two morphologically similar species.
CADMIUM EXPOSURE INDUCES HISTOLOGICAL DAMAGE, OXIDATIVE STRESS AND IMMUNE RESPONSE IN YELLOW CATFISH
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Available online
, doi: 10.7541/2019.042
Abstract:
To investigate the effect of different Cd (0 (control), 50, and 200 μg/L Cd2+) on Yellow catfish (Pelteobagrus fulvidraco), fish were exposed for 8 weeks before analyzing the histological structure, antioxidant status and immune-related gene expression in gills. The results showed that Cd2+ exposure induced significant Cd accumulation and histological changes in gill, such as aneurism, hyperplasia, curling of lamella and cell desquamation. Meanwhile, Cd2+ increased the activity of glutathione-S-transferase (GST), glutathione peroxidase (GPx) and anti-hydroxyl radical (AHR) as well as the content of hydrogen peroxide (H2O2), and it decreased catalase (CAT) activity and glutathione (GSH) content. However, Cd2+ had no significant effect on superoxide dismutase (SOD) activity. In addition, Cd exposure up-regulated tumor necrosis factor-a (tnf-a), major histocompatibility complex (mhc), interleukin-10 (il-10), transforming growth factor-β (tgf-β) and complement factor C3 (c3) expressions, but down-regulated interleukin-1β (il-1β), interleukin-8 (il-8) and lysozyme (lys) transcription levels. These results showed that Cd exposure resulted in the accumulation of Cd, and induced histological damage, oxidative stress and immune response of gill in yellow catfish.
To investigate the effect of different Cd (0 (control), 50, and 200 μg/L Cd2+) on Yellow catfish (Pelteobagrus fulvidraco), fish were exposed for 8 weeks before analyzing the histological structure, antioxidant status and immune-related gene expression in gills. The results showed that Cd2+ exposure induced significant Cd accumulation and histological changes in gill, such as aneurism, hyperplasia, curling of lamella and cell desquamation. Meanwhile, Cd2+ increased the activity of glutathione-S-transferase (GST), glutathione peroxidase (GPx) and anti-hydroxyl radical (AHR) as well as the content of hydrogen peroxide (H2O2), and it decreased catalase (CAT) activity and glutathione (GSH) content. However, Cd2+ had no significant effect on superoxide dismutase (SOD) activity. In addition, Cd exposure up-regulated tumor necrosis factor-a (tnf-a), major histocompatibility complex (mhc), interleukin-10 (il-10), transforming growth factor-β (tgf-β) and complement factor C3 (c3) expressions, but down-regulated interleukin-1β (il-1β), interleukin-8 (il-8) and lysozyme (lys) transcription levels. These results showed that Cd exposure resulted in the accumulation of Cd, and induced histological damage, oxidative stress and immune response of gill in yellow catfish.
,
Available online
, doi: 10.7541/2019.054
Abstract:
We studied the effects of different amount biostimulants supplement on the removal efficiency of nitrogen, phosphorus and COD in vertical flow constructed wetland. The mechanism was analyzed by determining the activities of substrate phosphatase and urease in the constructed wetland systems. The results showed that biostimulanta suppklement could improve nitrogen removal efficiency in the systems, and the removal rates of \begin{document}${\rm{NH}}_4^ + $\end{document} ![]()
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-N and TN reached up to 80%, increasing by 71.5% and 31.7% respectively when compared with the control group. The maximum removal rates of TP and COD reached up to 36.0% and 91.6%, increasing by 9.1% and 5.9%, respectively. Meanwhile, the biostimulants could improve the enzymatic activities of substrate phosphatase and urease in the system, and the biostimulants had a significant influence on substrate urease activity. Significant positive relationships were found between COD removal rate and the activities of substrate phosphatase and urease. The most suitable amount of biostimulant sipplement used in this system is 5 μL/L, which means 5 μL biostimulants was supplied to 1 L influent.
We studied the effects of different amount biostimulants supplement on the removal efficiency of nitrogen, phosphorus and COD in vertical flow constructed wetland. The mechanism was analyzed by determining the activities of substrate phosphatase and urease in the constructed wetland systems. The results showed that biostimulanta suppklement could improve nitrogen removal efficiency in the systems, and the removal rates of
,
Available online
, doi: 10.7541/2019.031
Abstract:
To investigate the effects of dietary carbohydrate on growth performance, body composition and digestive enzyme activities of juvenile crab, Scylla paramamosain, five isonitrogenous and isolipidic diets with varying carbohydrate contents of 20.34%, 25.59%, 30.17%, 35.30% and 39.95% were fed to juvenile crabs with an average body weight of (38.11±0.55) mg of triplicate groups, respectively, for a 3-week feeding trial. Results showed that the survival rate, weight gain ratio and specific growth rate of the juvenile crabs significantly increased firstly and then decreased under the increased dietary carbohydrate level (P<0.05) with the highest level at 30.17%. With the increasing dietary carbohydrate level, the body crude protein and body ash contents of the crabs were significantly increased firstly and then decreased (P<0.05) with the highest level at 35.30%. Dietary carbohydrate level significantly affected amylase activity (P<0.05) without any significant influence on protease and lipase activities (P>0.05). The amylase activity significantly induced by high carbohydrate level (P<0.05). These results indicate that the diet with 25.59%-35.30% carbohydrate could greatly support growth performance. The regression model analysis showed that the most suitable dietary carbohydrate level reach the highest weight gain ratio is 29.93%.
To investigate the effects of dietary carbohydrate on growth performance, body composition and digestive enzyme activities of juvenile crab, Scylla paramamosain, five isonitrogenous and isolipidic diets with varying carbohydrate contents of 20.34%, 25.59%, 30.17%, 35.30% and 39.95% were fed to juvenile crabs with an average body weight of (38.11±0.55) mg of triplicate groups, respectively, for a 3-week feeding trial. Results showed that the survival rate, weight gain ratio and specific growth rate of the juvenile crabs significantly increased firstly and then decreased under the increased dietary carbohydrate level (P<0.05) with the highest level at 30.17%. With the increasing dietary carbohydrate level, the body crude protein and body ash contents of the crabs were significantly increased firstly and then decreased (P<0.05) with the highest level at 35.30%. Dietary carbohydrate level significantly affected amylase activity (P<0.05) without any significant influence on protease and lipase activities (P>0.05). The amylase activity significantly induced by high carbohydrate level (P<0.05). These results indicate that the diet with 25.59%-35.30% carbohydrate could greatly support growth performance. The regression model analysis showed that the most suitable dietary carbohydrate level reach the highest weight gain ratio is 29.93%.
,
Available online
, doi: 10.7541/2019.040
Abstract:
Transgenic efficiency in mammal cell lines is usually higher but relatively lower in the fish cell lines. Therefore, establishment of any fish cell lines with high transfection efficiency is needed, ideally in the fish model such as medaka (Oryzias latipes). In the present study, we derived a new cell line from medaka muscle termed as OLM (Oryzias latipes muscle), which was maintained in DMEM/HEPES supplemented with 10% bovine serum at 28℃. Up to now, OLM cells have been subcultured over 88 passages and mainly exhibited a fibroblast-like morphology. By chromosomal analysis, OLM has a modal diploid chromosome number of 48. Moreover, transient transfection efficiency by liposome of OLM cell line was up to 40%, which is much higher than that of the common fish cell lines as tested. In addition, the stable OLMs expressing exogenic non-coding RNA or gene were established. Unexpectedly, the OLM was resistant to the fish virus such as Spring viraemia of carp viruses (SVCV), Grass carp reovirus (GCRV) and Singapore grouper iridovirus (SGIV). Taken together, we have established a stable muscle cell line from model fish medaka as an in vitro model for transgenic application.
Transgenic efficiency in mammal cell lines is usually higher but relatively lower in the fish cell lines. Therefore, establishment of any fish cell lines with high transfection efficiency is needed, ideally in the fish model such as medaka (Oryzias latipes). In the present study, we derived a new cell line from medaka muscle termed as OLM (Oryzias latipes muscle), which was maintained in DMEM/HEPES supplemented with 10% bovine serum at 28℃. Up to now, OLM cells have been subcultured over 88 passages and mainly exhibited a fibroblast-like morphology. By chromosomal analysis, OLM has a modal diploid chromosome number of 48. Moreover, transient transfection efficiency by liposome of OLM cell line was up to 40%, which is much higher than that of the common fish cell lines as tested. In addition, the stable OLMs expressing exogenic non-coding RNA or gene were established. Unexpectedly, the OLM was resistant to the fish virus such as Spring viraemia of carp viruses (SVCV), Grass carp reovirus (GCRV) and Singapore grouper iridovirus (SGIV). Taken together, we have established a stable muscle cell line from model fish medaka as an in vitro model for transgenic application.
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Available online
, doi: 10.7541/2019.
Abstract:
PAEs have been proved to be one of the major organic pollutants. The present study determined the level of PAEs using surface water samples from the upper reaches of the Yangtze River. The results showed that DEHP contributed the most to PAEs pollution, followed by DBP. Risk Quotients of PAEs were used for preliminary screening, and DEHP and BBP were identified as potential risk factors with RQ of 310 and 70.7. The MOS10 of DEHP and BBP were 1.40 and 1.32×105, respectively, indicating that BBP may pose little risk to aquatic organisms. The potential risk of DEHP was further analyzed with joint probabilistic curves. Among different biological groups, fish and zoobenthos were two major groups sensitive to DEHP-induced damage under current concentrations with 99.4% and 98.3% for 5% species of each group. While among the toxicity endpoints, reproduction may be more sensitive than others. The 5% and 10% aquatic species were suffered from reproductive damages by 100% and 97.8%, respectively. Overall, our results indicated that DEHP in the surface water of the upper Yangtze River may pose potential risk to aquatic organisms, especially on their reproduction. Therefore, more concerns should be paid in species protection and environmental management.
PAEs have been proved to be one of the major organic pollutants. The present study determined the level of PAEs using surface water samples from the upper reaches of the Yangtze River. The results showed that DEHP contributed the most to PAEs pollution, followed by DBP. Risk Quotients of PAEs were used for preliminary screening, and DEHP and BBP were identified as potential risk factors with RQ of 310 and 70.7. The MOS10 of DEHP and BBP were 1.40 and 1.32×105, respectively, indicating that BBP may pose little risk to aquatic organisms. The potential risk of DEHP was further analyzed with joint probabilistic curves. Among different biological groups, fish and zoobenthos were two major groups sensitive to DEHP-induced damage under current concentrations with 99.4% and 98.3% for 5% species of each group. While among the toxicity endpoints, reproduction may be more sensitive than others. The 5% and 10% aquatic species were suffered from reproductive damages by 100% and 97.8%, respectively. Overall, our results indicated that DEHP in the surface water of the upper Yangtze River may pose potential risk to aquatic organisms, especially on their reproduction. Therefore, more concerns should be paid in species protection and environmental management.
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Available online
, doi: 10.7541/2019.049
Abstract:
To increase feed intake and reduce feed loss in the production of Eriocher sinensis, this study screened the attractants for Chinese mitten crab by pigment indication method using crabs of (26.4+0.17) g that were equally divided into 20 concrete tankages. To explore color preference and the optimum supplement dosages of five attractants of squid extract (SE), yeast hydrolysate (YH), cottonseed meal protein hydrolysate (CPH), betaine, and allicin, these five attractants were added pigment of different colors. The results showed that color did not significantly impact on feeding of crab (P>0.05). The stimulant index of fed 0.3% SE, 0.6% YH, 0.6% CPH and 0.09% allicin diets were significantly (P<0.05) higher than that of the control diet. The highest stimulant index of betaine was 1%, but there was no significant difference among other groups (P>0.05). The highest stimulant index was observed in 0.6% CPH group, and the stimulant index of 0.6% CPH and 0.6% YH diet was significantly (P<0.05) higher than other groups. The stimulant index of 0.3% SE diet was higher than 0.09% allicin diet group and 1% betaine diet group (P<0.05). In conclusion, the optimum supplement dosages of SE, YH, CPH, betaine and allicin for crab were 0.3%, 0.6%, 0.6%, 1% and 0.09% orderly and diets preference were following: CPH>YH>SE>allicin>betaine. The 0.6% CPH or 0.6% YH had stronger attractive effect among the attractants, which can be used as attractants of crab.
To increase feed intake and reduce feed loss in the production of Eriocher sinensis, this study screened the attractants for Chinese mitten crab by pigment indication method using crabs of (26.4+0.17) g that were equally divided into 20 concrete tankages. To explore color preference and the optimum supplement dosages of five attractants of squid extract (SE), yeast hydrolysate (YH), cottonseed meal protein hydrolysate (CPH), betaine, and allicin, these five attractants were added pigment of different colors. The results showed that color did not significantly impact on feeding of crab (P>0.05). The stimulant index of fed 0.3% SE, 0.6% YH, 0.6% CPH and 0.09% allicin diets were significantly (P<0.05) higher than that of the control diet. The highest stimulant index of betaine was 1%, but there was no significant difference among other groups (P>0.05). The highest stimulant index was observed in 0.6% CPH group, and the stimulant index of 0.6% CPH and 0.6% YH diet was significantly (P<0.05) higher than other groups. The stimulant index of 0.3% SE diet was higher than 0.09% allicin diet group and 1% betaine diet group (P<0.05). In conclusion, the optimum supplement dosages of SE, YH, CPH, betaine and allicin for crab were 0.3%, 0.6%, 0.6%, 1% and 0.09% orderly and diets preference were following: CPH>YH>SE>allicin>betaine. The 0.6% CPH or 0.6% YH had stronger attractive effect among the attractants, which can be used as attractants of crab.
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Available online
, doi: 10.7541/2019.036
Abstract:
This study cloned the full-length cDNA of UHRF1 (PtUHRF1) from the swimming crab Portunus trituberculatus using rapid amplification of cDNA ends (RACE). The length of PtUHRF1 cDNA was 2849 bp, which contained a 2298 bp open reading frame to encode 765 amino acids. Structure analysis revealed that PtUHRF1 contained several conserved domains, including UBL, PHD, TTD, SRA and RING. Homology analysis revealed that PtUHRF1 exhibited high identity with other species. The expression of PtUHRF1 at mRNA level was detected in all tested tissues with the highest level in testes. PtUHRF1 showed stage-specific expression during embryonic and larval development with the highest expression in fertilized egg. There were significant differences in PtUHRF1 expression at different ovary and testis stages. In ovary, its expression reached the highest value at stage II, and then decreased gradually, while in testis, the highest expression was detected at stage I, and then decreased as testis developed. These results indicated that PtUHRF1 is important in regulating embryonic, larval and gonadal development in the swimming crab, and provided useful reference for further studies on the roles of this gene in growth and development of P. trituberculatus and crustaceans.
This study cloned the full-length cDNA of UHRF1 (PtUHRF1) from the swimming crab Portunus trituberculatus using rapid amplification of cDNA ends (RACE). The length of PtUHRF1 cDNA was 2849 bp, which contained a 2298 bp open reading frame to encode 765 amino acids. Structure analysis revealed that PtUHRF1 contained several conserved domains, including UBL, PHD, TTD, SRA and RING. Homology analysis revealed that PtUHRF1 exhibited high identity with other species. The expression of PtUHRF1 at mRNA level was detected in all tested tissues with the highest level in testes. PtUHRF1 showed stage-specific expression during embryonic and larval development with the highest expression in fertilized egg. There were significant differences in PtUHRF1 expression at different ovary and testis stages. In ovary, its expression reached the highest value at stage II, and then decreased gradually, while in testis, the highest expression was detected at stage I, and then decreased as testis developed. These results indicated that PtUHRF1 is important in regulating embryonic, larval and gonadal development in the swimming crab, and provided useful reference for further studies on the roles of this gene in growth and development of P. trituberculatus and crustaceans.
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Available online
, doi: 10.7541/2019.035
Abstract:
Asingle gene fragment and combined nucleotide sequences for two gene fragments of mitochondrial DNA (mtDNA), which were 16S ribosomal RNA (16S rRNA) and cytochrome oxidase c subunit 1 (COⅠ), were analyzed for three populations of Trichiurus lepturus (T. lepturus, designated by A, B, and C). The length of 16S rRNA gene of mtDNA and COⅠ was 1130 and 554 bp, respectively. These two gene fragments were combined together to form a gene fragment with the length of 1684 bp for the purpose of subsequent genetic diversity analysis. The average contents of nucleotides T, C, A, and G were 29.0%, 28.9%, 24.4%, and 17.7%, respectively in the mtDNA COⅠgene, while those mean contents were 22.7%, 27.6%, 28.0%, and 21.7%, respectively in 16S rRNA gene. In this study, 43, 8, and 49 haplotypes were defined in 72 individuals by using single and combined gene fragments, in which haplotypes were shared among the mentioned populations. The diversities of haplotypes varied between 0.9766 and 0.9992, indicating that the abundance of haplotypes was within different populations. The nucleotide differences and the nucleotide diversity in each population were in the ranges of 5.111—9.024, and 0.0045—0.0076, respectively. Genetic distances among the populations varied from 0.0048 to 0.00084. These results indicated that genetic diversity in three populations of T. lepturus was considerable. The construction of phylogenetic trees based on Neighbour-Joining (NJ) method showed that several individuals in the same population were aggregated. The achieved findings also indicated that high frequency of gene transfer among different populations resulted in low genetic differentiation. Population A contained richer genetic background than that of populations B and C. The difference within different populations was higher compared to among various populations. It could be concluded that the three mentioned populations of T. lepturus had low genetic diversity based on single and combined mtDNA genes.
Asingle gene fragment and combined nucleotide sequences for two gene fragments of mitochondrial DNA (mtDNA), which were 16S ribosomal RNA (16S rRNA) and cytochrome oxidase c subunit 1 (COⅠ), were analyzed for three populations of Trichiurus lepturus (T. lepturus, designated by A, B, and C). The length of 16S rRNA gene of mtDNA and COⅠ was 1130 and 554 bp, respectively. These two gene fragments were combined together to form a gene fragment with the length of 1684 bp for the purpose of subsequent genetic diversity analysis. The average contents of nucleotides T, C, A, and G were 29.0%, 28.9%, 24.4%, and 17.7%, respectively in the mtDNA COⅠgene, while those mean contents were 22.7%, 27.6%, 28.0%, and 21.7%, respectively in 16S rRNA gene. In this study, 43, 8, and 49 haplotypes were defined in 72 individuals by using single and combined gene fragments, in which haplotypes were shared among the mentioned populations. The diversities of haplotypes varied between 0.9766 and 0.9992, indicating that the abundance of haplotypes was within different populations. The nucleotide differences and the nucleotide diversity in each population were in the ranges of 5.111—9.024, and 0.0045—0.0076, respectively. Genetic distances among the populations varied from 0.0048 to 0.00084. These results indicated that genetic diversity in three populations of T. lepturus was considerable. The construction of phylogenetic trees based on Neighbour-Joining (NJ) method showed that several individuals in the same population were aggregated. The achieved findings also indicated that high frequency of gene transfer among different populations resulted in low genetic differentiation. Population A contained richer genetic background than that of populations B and C. The difference within different populations was higher compared to among various populations. It could be concluded that the three mentioned populations of T. lepturus had low genetic diversity based on single and combined mtDNA genes.
,
Available online
, doi: 10.7541/2019.
Abstract:
To explore the toxic effects of streptomycin, the growth and chlorophyll fluorescence were measured in Nostoc treated with different concentrations (0, 0.05, 0.10, 0.20, 0.50 and 1 mg/L) of streptomycin. The results indicated that the EC50 of streptomycin to Nostoc (96h−EC50) was (0.13±0.037) mg/L at the 96−hour. Streptomycin significantly decreased the content of chlorophyll a at all concentrations. In a concentration-dependent pattern, streptomycin significantly reduced the maximum photochemical efficiency (φP0), variable fluorescence (Fv), potential activity of PSⅡ (Fv/F0), active reaction center per unit area (RC/CS0), the performance index based on absorbed light energy (PIabs) and the quantum energy yield of the light energy absorbed by the reaction center for electron transfer (φE0). However, Streptomycin significantly increased the maximum fluorescence relative to chlorophyll a (Fm/Chl. a), the light energy absorbed by each active reaction center (ABS/RC) and heat dissipation (DI0/RC) in a concentration-dependent pattern. A K-point at chlorophyll a fluorescence transient curve was found when the concentration is greater than 0.1 mg/L. These results suggest that streptomycin might affect the growth of Nostoc by inhibiting the electron transport of photosynthetic system Ⅱ (PSⅡ) and reducing active reaction centers, and that high concentrations of streptomycin showed an inhibitory effect on the growth of algae.
To explore the toxic effects of streptomycin, the growth and chlorophyll fluorescence were measured in Nostoc treated with different concentrations (0, 0.05, 0.10, 0.20, 0.50 and 1 mg/L) of streptomycin. The results indicated that the EC50 of streptomycin to Nostoc (96h−EC50) was (0.13±0.037) mg/L at the 96−hour. Streptomycin significantly decreased the content of chlorophyll a at all concentrations. In a concentration-dependent pattern, streptomycin significantly reduced the maximum photochemical efficiency (φP0), variable fluorescence (Fv), potential activity of PSⅡ (Fv/F0), active reaction center per unit area (RC/CS0), the performance index based on absorbed light energy (PIabs) and the quantum energy yield of the light energy absorbed by the reaction center for electron transfer (φE0). However, Streptomycin significantly increased the maximum fluorescence relative to chlorophyll a (Fm/Chl. a), the light energy absorbed by each active reaction center (ABS/RC) and heat dissipation (DI0/RC) in a concentration-dependent pattern. A K-point at chlorophyll a fluorescence transient curve was found when the concentration is greater than 0.1 mg/L. These results suggest that streptomycin might affect the growth of Nostoc by inhibiting the electron transport of photosynthetic system Ⅱ (PSⅡ) and reducing active reaction centers, and that high concentrations of streptomycin showed an inhibitory effect on the growth of algae.
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Available online
, doi: 10.7541/2019.
Abstract:
The morphology and annulus characteristics ofPtychobarbus dipogon were described by eight aging materials in Tibet Autonomous Region, China, and then the suitable aging materials were determined in term of structures and annuli characteristics of eight aging materials. Hip scale was seriously specialized, annulus characteristics of chest scale, lateral-line scale, back scale were not obvious. Compared with the lapillus, the average percentage error was 41.63% for hip scale, 51.26% for chest scale, 50.50% for lateral-line scale, and 51.26% for back scale. The average percentage errors of asteriscus (12.28%), vertebrae (15.67%), and opercular bones (17.81%) were little different from lapillus. Below 23 years old fish, the average age of lapillus was 14.39 years that was similar with asteriscus (13.13 years) and vertebrae (13.20 years), but it was significantly higher than opercular bones and four scales (P<0.05). Above 23 years old fish, the average ages of seven aging materials were significantly lower than that of lapillus (P<0.05). The maximal age was 49 years for lapillus, 35 years for asteriscus, 34 years for vertebrae, 34 years for opercular bones, 22 years for hip scale, 19 years for chest scale, 16 years lateral-line for scale, and 17 years for back scale. The relationship between the age of lapillus and body length was logarithm function (P<0.01). Therefore, the lapillus was the suitable age determination material forPtychobarbus dipogon.
The morphology and annulus characteristics ofPtychobarbus dipogon were described by eight aging materials in Tibet Autonomous Region, China, and then the suitable aging materials were determined in term of structures and annuli characteristics of eight aging materials. Hip scale was seriously specialized, annulus characteristics of chest scale, lateral-line scale, back scale were not obvious. Compared with the lapillus, the average percentage error was 41.63% for hip scale, 51.26% for chest scale, 50.50% for lateral-line scale, and 51.26% for back scale. The average percentage errors of asteriscus (12.28%), vertebrae (15.67%), and opercular bones (17.81%) were little different from lapillus. Below 23 years old fish, the average age of lapillus was 14.39 years that was similar with asteriscus (13.13 years) and vertebrae (13.20 years), but it was significantly higher than opercular bones and four scales (P<0.05). Above 23 years old fish, the average ages of seven aging materials were significantly lower than that of lapillus (P<0.05). The maximal age was 49 years for lapillus, 35 years for asteriscus, 34 years for vertebrae, 34 years for opercular bones, 22 years for hip scale, 19 years for chest scale, 16 years lateral-line for scale, and 17 years for back scale. The relationship between the age of lapillus and body length was logarithm function (P<0.01). Therefore, the lapillus was the suitable age determination material forPtychobarbus dipogon.
,
Available online
, doi: 10.7541/2019.
Abstract:
Carbon and nitrogen stable isotopes of herbarium specimens have been used by ecologists to study long-history pollution and climate change. However, whether the preparation and preservation procedure impact isotopic signatures of herbarium specimens remain unclear. We tested the effect of herbarium on three submerged macrophyte species, and found the variations by both preparation and preservation processes. The press procedure significantly reduced carbon stable isotopes of submerged macrophytes for P. malaianusby 1.78‰, M. spicatumby 0.98‰ and C. demersumby 0.72‰. The press procedure reduced C. demersumnitrogen stable isotopes by 1.1‰. The soak procedure did not affect nitrogen stable isotopes of submerged macrophytes, but increased carbon stable isotopes of M. spicatumand P. malaianusby 1.00‰ and 0.52‰, separately. Carbon stable isotopes of C. demersum wereincreased less than 0.08‰. Preparing procedures had larger effect on carbon isotope than nitrogen isotope. These influences were highly variable between species and times. The results suggest that if the interested stable isotopic variations are within 3‰, herbarium specimens are not suitable samples for the relevant studies without the experimental corrections.
Carbon and nitrogen stable isotopes of herbarium specimens have been used by ecologists to study long-history pollution and climate change. However, whether the preparation and preservation procedure impact isotopic signatures of herbarium specimens remain unclear. We tested the effect of herbarium on three submerged macrophyte species, and found the variations by both preparation and preservation processes. The press procedure significantly reduced carbon stable isotopes of submerged macrophytes for P. malaianusby 1.78‰, M. spicatumby 0.98‰ and C. demersumby 0.72‰. The press procedure reduced C. demersumnitrogen stable isotopes by 1.1‰. The soak procedure did not affect nitrogen stable isotopes of submerged macrophytes, but increased carbon stable isotopes of M. spicatumand P. malaianusby 1.00‰ and 0.52‰, separately. Carbon stable isotopes of C. demersum wereincreased less than 0.08‰. Preparing procedures had larger effect on carbon isotope than nitrogen isotope. These influences were highly variable between species and times. The results suggest that if the interested stable isotopic variations are within 3‰, herbarium specimens are not suitable samples for the relevant studies without the experimental corrections.
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Available online
Abstract:
Three Gorges Reservoir (TGR) is the key project for the governance and development of the Yangtze River. TGR is an important region for the ecological and environmental protection in the Yangtze River economic belt. The hydrology and water environment have taken fundamental changes since the impoundment of TGR with some negative ecological and environmental problems. To address whether the aquatic ecosystem of TGR is healthy or not, the phytoplankton community index (PhyCoI) was used to assess the ecosystem health of TGR. Field survey was carried out on April 2015 in the whole region of TGR, including 23 tributary bays and 18 sections in the main channel of TGR with 174 sampling sites. A total of 61 phytoplankton taxa were identified, belonging to Cyanophyta, Chlorophyta, Bacillariophyta, Cryptophyta, Pyrrophyta, Euglenophyta, and Chrysophyta. Based on the scores of PhyCoI, the overall health status of TGR is good, with 68% sites in the status of very healthy (4≤PhyCoI<5) or healthy (3≤PhyCoI<4), 26% sites in sub-healthy (2≤PhyCoI<3), and 6% sites in general sick condition (1≤PhyCoI<2). Specifically, 96% sites in the main channel of TGR are healthy, and other 4% sites are in the status of sub-healthy. In the tributary bays, the ratios for the status of very healthy, healthy, sub-healthy, and general sick are 2%, 53%, 35%, and 9%, respectively. From the view of spatial distribution, overall health status of the main channel of TGR is good, and the health status of the main channel in Hubei Province is better than that in the Chongqing Province. In addition, the health status of sites in the Xiangxi Bay, Meixi Bay, and Xiaojiang Bay were highly variable. And in general, the health status of the bays near the dam of TGR is better than the bays far away from the dam. These results provide science and technology support for ecological and environmental protection of TGR.
Three Gorges Reservoir (TGR) is the key project for the governance and development of the Yangtze River. TGR is an important region for the ecological and environmental protection in the Yangtze River economic belt. The hydrology and water environment have taken fundamental changes since the impoundment of TGR with some negative ecological and environmental problems. To address whether the aquatic ecosystem of TGR is healthy or not, the phytoplankton community index (PhyCoI) was used to assess the ecosystem health of TGR. Field survey was carried out on April 2015 in the whole region of TGR, including 23 tributary bays and 18 sections in the main channel of TGR with 174 sampling sites. A total of 61 phytoplankton taxa were identified, belonging to Cyanophyta, Chlorophyta, Bacillariophyta, Cryptophyta, Pyrrophyta, Euglenophyta, and Chrysophyta. Based on the scores of PhyCoI, the overall health status of TGR is good, with 68% sites in the status of very healthy (4≤PhyCoI<5) or healthy (3≤PhyCoI<4), 26% sites in sub-healthy (2≤PhyCoI<3), and 6% sites in general sick condition (1≤PhyCoI<2). Specifically, 96% sites in the main channel of TGR are healthy, and other 4% sites are in the status of sub-healthy. In the tributary bays, the ratios for the status of very healthy, healthy, sub-healthy, and general sick are 2%, 53%, 35%, and 9%, respectively. From the view of spatial distribution, overall health status of the main channel of TGR is good, and the health status of the main channel in Hubei Province is better than that in the Chongqing Province. In addition, the health status of sites in the Xiangxi Bay, Meixi Bay, and Xiaojiang Bay were highly variable. And in general, the health status of the bays near the dam of TGR is better than the bays far away from the dam. These results provide science and technology support for ecological and environmental protection of TGR.
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Available online
Abstract:
The Yangtze River is the largest river in China. It is a priority conservation area for biodiversity of the world, with its main river, branches and wetlands. As an essential part of freshwater ecosystem, aquatic vegetation has been well studied by Chinese researchers since 1950s, but large-scaled analysis on the biodiversity pattern is lacked. Based on published studies, we analyzed spatial and temporal pattern of aquatic plant diversity in the Yangtze River Basin, and calculated the suitable habitat area and underlying influence of environmental factors using MaxEnt software. A total of 298 species are recognized, belonging to 121 genera in 52 families, which is 57.6% of the total aquatic vascular plants in China. The Yangtze River Basin is the key area for aquatic plant diversity of China, especially the subregions of middle reaches. The elevation and land use are the key environmental variables to the spatial pattern of aquatic plants. The separation among water systems have weak influence on the spatial pattern of diversity in aquatic vascular plants, but potamo-lacustrine habitats facilitated the species homogenization of the flora in a sub-basin scale. The network consists of Poyang Lake, Dongting Lake, Tai Lake, and the middle and lower mainstream is the suitable area for the aquatic plants based on the MaxEnt model. In the past half century, the decline or loss of aquatic vegetation occurred in plenty of lakes in the Yangtze River Basin. We suggested that the protection of aquatic vegetation should be incorporated into the integrated conservation of the middle and lower Yangtze River.
The Yangtze River is the largest river in China. It is a priority conservation area for biodiversity of the world, with its main river, branches and wetlands. As an essential part of freshwater ecosystem, aquatic vegetation has been well studied by Chinese researchers since 1950s, but large-scaled analysis on the biodiversity pattern is lacked. Based on published studies, we analyzed spatial and temporal pattern of aquatic plant diversity in the Yangtze River Basin, and calculated the suitable habitat area and underlying influence of environmental factors using MaxEnt software. A total of 298 species are recognized, belonging to 121 genera in 52 families, which is 57.6% of the total aquatic vascular plants in China. The Yangtze River Basin is the key area for aquatic plant diversity of China, especially the subregions of middle reaches. The elevation and land use are the key environmental variables to the spatial pattern of aquatic plants. The separation among water systems have weak influence on the spatial pattern of diversity in aquatic vascular plants, but potamo-lacustrine habitats facilitated the species homogenization of the flora in a sub-basin scale. The network consists of Poyang Lake, Dongting Lake, Tai Lake, and the middle and lower mainstream is the suitable area for the aquatic plants based on the MaxEnt model. In the past half century, the decline or loss of aquatic vegetation occurred in plenty of lakes in the Yangtze River Basin. We suggested that the protection of aquatic vegetation should be incorporated into the integrated conservation of the middle and lower Yangtze River.
Display Method: |
2019, 43(1): 1 -8
doi: 10.7541/2019.001
Abstract:
Through regulating the post-transcriptional maturation of UsnRNAs (U-rich small nuclear RNAs), integrator complex has an effect on the intron splicing of pre-mRNA. Therefore, integrator complex plays an important role in the production of mature mRNA. However, the regulation and developmental functions of integrator complex are poorly understood in vertebrates. In this study, zebrafish (Danio rerio) was used to generate the ints12 knockout model by CRISPR/Cas9, and two homozygous lines were generated with different frame-shifts. Observation on the misprocessing of UsnRNA 3′ ends in zygotic mutant of ints12 (Zints12) was conducted through real-time quantitative PCR analysis. When compared with the control fish, the overall growth of Zints12 was largely retarded, and the Zints12 population was all-male. Further studies showed that cell proliferation was significantly interfered, and the level of introns retention of ints12 transcripts was significantly increased in Zints12, suggesting an " auto-regulation loop” in the splicing regulation by ints12. Overall, we obtained homozygous mutants of zebrafish ints12 by gene knockout technology and revealed that zebrafish ints12 regulates UsnRNA 3′-box processing to exert various effects on early embryonic development and body growth.
Through regulating the post-transcriptional maturation of UsnRNAs (U-rich small nuclear RNAs), integrator complex has an effect on the intron splicing of pre-mRNA. Therefore, integrator complex plays an important role in the production of mature mRNA. However, the regulation and developmental functions of integrator complex are poorly understood in vertebrates. In this study, zebrafish (Danio rerio) was used to generate the ints12 knockout model by CRISPR/Cas9, and two homozygous lines were generated with different frame-shifts. Observation on the misprocessing of UsnRNA 3′ ends in zygotic mutant of ints12 (Zints12) was conducted through real-time quantitative PCR analysis. When compared with the control fish, the overall growth of Zints12 was largely retarded, and the Zints12 population was all-male. Further studies showed that cell proliferation was significantly interfered, and the level of introns retention of ints12 transcripts was significantly increased in Zints12, suggesting an " auto-regulation loop” in the splicing regulation by ints12. Overall, we obtained homozygous mutants of zebrafish ints12 by gene knockout technology and revealed that zebrafish ints12 regulates UsnRNA 3′-box processing to exert various effects on early embryonic development and body growth.
2019, 43(1): 9 -16
doi: 10.7541/2019.002
Abstract:
In order to investigate the role of TRAF6 in Lethenteron morii with signal pathway of TLR, the full-length cDNA of LmTRAF6 was cloned. The distribution of tissues (supraneural body, gill, intestine, kidney) and related gene expression in both juvenile and adult were studied with real-time quantitative PCR. Additionally, the change of gene expression in those tissues from adult L. morii was also examined after challenged by Pseudomonas aeruginosa. A recombinant plasmid pEGFP-TRAF6 was constructed by the double digestion method, and transformed into the HEK293T cells. Fluorescence observation was conducted after 48 hours, and the results were photographed. The results showed that the length of LmTRAF6 cDNA was 2751 bp, including 1785 bp open reading frame (ORF) and 594 amino acids. The structure of LmTRAF6 was highly similar to that in other mammal and fish species, containing one RING domain, one coiled-coil region, one MATH domain and two zinc fingers. Phylogenetic tree showed that LmTRAF6 was evolutionarily closer to that in mammals and fishes, but not to that in Drosophila melanogaster and Penaeus chinensis. LmTRAF6 was expressed in all tested tissues and their developmental stages. However, higher expression was detected in heart, skin, gill, liver of juvenile, as well as in kidney, gill, and muscle of adult. When adult L. morii was challenged by Pseudomonas aeruginosa, the expression of LmTRAF6 in gill, intestine and kidney reached to the peak after 24h. Subcellular localization showed that LmTRAF6 was expressed in both cytoplasm and nucleus.
In order to investigate the role of TRAF6 in Lethenteron morii with signal pathway of TLR, the full-length cDNA of LmTRAF6 was cloned. The distribution of tissues (supraneural body, gill, intestine, kidney) and related gene expression in both juvenile and adult were studied with real-time quantitative PCR. Additionally, the change of gene expression in those tissues from adult L. morii was also examined after challenged by Pseudomonas aeruginosa. A recombinant plasmid pEGFP-TRAF6 was constructed by the double digestion method, and transformed into the HEK293T cells. Fluorescence observation was conducted after 48 hours, and the results were photographed. The results showed that the length of LmTRAF6 cDNA was 2751 bp, including 1785 bp open reading frame (ORF) and 594 amino acids. The structure of LmTRAF6 was highly similar to that in other mammal and fish species, containing one RING domain, one coiled-coil region, one MATH domain and two zinc fingers. Phylogenetic tree showed that LmTRAF6 was evolutionarily closer to that in mammals and fishes, but not to that in Drosophila melanogaster and Penaeus chinensis. LmTRAF6 was expressed in all tested tissues and their developmental stages. However, higher expression was detected in heart, skin, gill, liver of juvenile, as well as in kidney, gill, and muscle of adult. When adult L. morii was challenged by Pseudomonas aeruginosa, the expression of LmTRAF6 in gill, intestine and kidney reached to the peak after 24h. Subcellular localization showed that LmTRAF6 was expressed in both cytoplasm and nucleus.
2019, 43(1): 17 -26
doi: 10.7541/2019.003
Abstract:
The next-generation sequencing technology was used to obtain the whole mitochondrial genome sequences of Gadus macrocephalus. The mitochondrial gene was annotated and its structure was analyzed. The results showed that the circular genome was 16569 bp in length with typical mtDNA components. The mitochondrial genome encodes 13 proteins and 22 tRNAs, 2 rRNAs and a D-Loop region. The base composition showed a tendency of high AT and AT weak negative skewness. There were five kinds of termination codon in the protein coding gene of G. macrocephalus mitochondria, including AGG and AGA which were commonly found in mammalian mitochondria. It was shown that most of the tRNA structures share the classical clover shape, but the tRNA-Ser(GCT) is unique because of a shortage of DHU. Two sequences with the functions of TAS and CSB, as well as 17 bp pyrimidine-rich sequences were found in D-Loop region. The non-coding region contains a conserved sequence controlling the initiation of light chain replication (OL) and a gene spacer with 74 bp. Based on the whole mitochondrial genome sequence and the Cytb gene, the phylogenetic trees were constructed separately with several cod fish that belong to Gadiformes. The results provide an important evidence to reveal the evolutionary status of the pacific cod.
The next-generation sequencing technology was used to obtain the whole mitochondrial genome sequences of Gadus macrocephalus. The mitochondrial gene was annotated and its structure was analyzed. The results showed that the circular genome was 16569 bp in length with typical mtDNA components. The mitochondrial genome encodes 13 proteins and 22 tRNAs, 2 rRNAs and a D-Loop region. The base composition showed a tendency of high AT and AT weak negative skewness. There were five kinds of termination codon in the protein coding gene of G. macrocephalus mitochondria, including AGG and AGA which were commonly found in mammalian mitochondria. It was shown that most of the tRNA structures share the classical clover shape, but the tRNA-Ser(GCT) is unique because of a shortage of DHU. Two sequences with the functions of TAS and CSB, as well as 17 bp pyrimidine-rich sequences were found in D-Loop region. The non-coding region contains a conserved sequence controlling the initiation of light chain replication (OL) and a gene spacer with 74 bp. Based on the whole mitochondrial genome sequence and the Cytb gene, the phylogenetic trees were constructed separately with several cod fish that belong to Gadiformes. The results provide an important evidence to reveal the evolutionary status of the pacific cod.
2019, 43(1): 27 -36
doi: 10.7541/2019.004
Abstract:
In this study, the cDNA sequences of FcγRα and FcRγ subunits of FcγR rainbow trout were cloned for the first time by RACE technique. The sequences of FcγRα and FcRγ were analyzed by using bioinformatics software. The expressions of the genes in different cell subpopulations and tissues, as well as in the head kidney after Poly (I鲶C) and lipopolysaccharide (LPS) stimulations were analyzed by real-time fluorescent quantitative polymerase chain reaction (PCR). The results showed that the full-length cDNA ofFcγRα is 1677 bp with an open reading frame (ORF) of 954 bp encoding 317 amino acids. The FcγRα is composed of a signal peptide and two Ig-like domains, however, without including transmembrane and intracellular regions. There are three kinds of FcγR subunit, involving FcRγ1, FcRγ2a, and FcRγ2b. FcRγ1 and FcRγ2 genes are located on different chromosomes, while FcRγ2a and FcRγ2b are two splicing isoforms of FcRγ2 gene. These subunits are composed of signal peptide, transmembrane domain, and immunoreceptor tyrosine-based activation motif (ITAM). Amino acid sequence similarity analysis showed that the highest identity (30%) of FcγRα is between rainbow trout and channel catfish (Ictalurus punctatus), and FcRγ1 and FcRγ2a/2b in rainbow trout have the maximum sequence identity (40%) with mammalian FcRγ. Tissue distribution analysis showed that the expression of FcγRα, FcRγ1, and FcRγ2a/2b was higher in head kidney, spleen, and blood cells, respectively. Analysis of cell subpopulations showed that the expression of FcγRα, FcRγ1, and FcRγ2a/2b was the highest in the myeloid cell population. In addition, the expression of FcγRα, FcRγ1, and FcRγ2a/2b in the head kidney was significantly up-regulated after LPS and Poly (I鲶C) stimulations, indicating that FcγR plays an important role in the antibacterial and antiviral immunity.
In this study, the cDNA sequences of FcγRα and FcRγ subunits of FcγR rainbow trout were cloned for the first time by RACE technique. The sequences of FcγRα and FcRγ were analyzed by using bioinformatics software. The expressions of the genes in different cell subpopulations and tissues, as well as in the head kidney after Poly (I鲶C) and lipopolysaccharide (LPS) stimulations were analyzed by real-time fluorescent quantitative polymerase chain reaction (PCR). The results showed that the full-length cDNA ofFcγRα is 1677 bp with an open reading frame (ORF) of 954 bp encoding 317 amino acids. The FcγRα is composed of a signal peptide and two Ig-like domains, however, without including transmembrane and intracellular regions. There are three kinds of FcγR subunit, involving FcRγ1, FcRγ2a, and FcRγ2b. FcRγ1 and FcRγ2 genes are located on different chromosomes, while FcRγ2a and FcRγ2b are two splicing isoforms of FcRγ2 gene. These subunits are composed of signal peptide, transmembrane domain, and immunoreceptor tyrosine-based activation motif (ITAM). Amino acid sequence similarity analysis showed that the highest identity (30%) of FcγRα is between rainbow trout and channel catfish (Ictalurus punctatus), and FcRγ1 and FcRγ2a/2b in rainbow trout have the maximum sequence identity (40%) with mammalian FcRγ. Tissue distribution analysis showed that the expression of FcγRα, FcRγ1, and FcRγ2a/2b was higher in head kidney, spleen, and blood cells, respectively. Analysis of cell subpopulations showed that the expression of FcγRα, FcRγ1, and FcRγ2a/2b was the highest in the myeloid cell population. In addition, the expression of FcγRα, FcRγ1, and FcRγ2a/2b in the head kidney was significantly up-regulated after LPS and Poly (I鲶C) stimulations, indicating that FcγR plays an important role in the antibacterial and antiviral immunity.
2019, 43(1): 37 -44
doi: 10.7541/2019.005
Abstract:
Two variants of EcHcL1 and 2 based on Exopalaemon carinicauda transcriptome library were obtained by using RACE technique. The total length of EcHcL1 and 2 were 2248 bp and 2121 bp, which encoded protein of 685 and 676 amino acids, respectively. EcHcL1 and 2 are relatively conservative in evolution, and has typical domains of hemocyanin, including copper ion binding region, conserved His site and Ig-like region. EcHcL1 may relate to pigment metabolism and phenoloxidase activity because of more than a tyrosinase domain. The results of tissue expression distribution showed that EcHcL1 and 2 were expressed in all the 10 tissues, and higher expressed in hepatopancreas and haemocytes. Different variants of E. carinicauda hemocyanin subunit may also have various immunological functions. The expression of the 2 variants of mRNA after pathogen stresses were investigated using the Real-time PCR strategy. The results showed that EcHcL1 had higher expression level during 12—48h after Staphylococcus aureus, Vibrio parahaemolyticus and WSSV challenges, and its among more 1.5—4 times higher than that in control group. The expression level of EcHcL2 reached the highest value among 24—48h after stress, which increased 2—9 times compared with the control group. Therefore, we speculated that the E. carinicauda hemocyanin subunit variants may related to immune defenses closely and might have antimicrobial resistance activity.
Two variants of EcHcL1 and 2 based on Exopalaemon carinicauda transcriptome library were obtained by using RACE technique. The total length of EcHcL1 and 2 were 2248 bp and 2121 bp, which encoded protein of 685 and 676 amino acids, respectively. EcHcL1 and 2 are relatively conservative in evolution, and has typical domains of hemocyanin, including copper ion binding region, conserved His site and Ig-like region. EcHcL1 may relate to pigment metabolism and phenoloxidase activity because of more than a tyrosinase domain. The results of tissue expression distribution showed that EcHcL1 and 2 were expressed in all the 10 tissues, and higher expressed in hepatopancreas and haemocytes. Different variants of E. carinicauda hemocyanin subunit may also have various immunological functions. The expression of the 2 variants of mRNA after pathogen stresses were investigated using the Real-time PCR strategy. The results showed that EcHcL1 had higher expression level during 12—48h after Staphylococcus aureus, Vibrio parahaemolyticus and WSSV challenges, and its among more 1.5—4 times higher than that in control group. The expression level of EcHcL2 reached the highest value among 24—48h after stress, which increased 2—9 times compared with the control group. Therefore, we speculated that the E. carinicauda hemocyanin subunit variants may related to immune defenses closely and might have antimicrobial resistance activity.
2019, 43(1): 45 -51
doi: 10.7541/2019.006
Abstract:
In order to provide biological information for research on sex-determination mechanism in Pelodiscus sinensis, we here first attempted to clone and analyze the partial-length of Foxl2 cDNA. In addition, to address the differential expression of Foxl2 at genetic and physiological levels, both male and female sexes of Pelodiscus sinensis were treated with 10 mg/kg E2 and 17α-methyltestosterone (MT), respectively; Foxl2 mRNA expression was quantitatively examined in the gonads after injection treatment at 6, 12, 24, and 48h, as well as 7 and 14d, respectively. Foxl2 (GenBank Accession No. KP734210) was achieved, belonging to Forkhead family of transcription factors that is involved in ovarian development and functional maintenance, as well as a 903 bp of open reading frame (ORF) encoding 300 amino acids. Multiple sequence alignment showed that Foxl2 contained typical FH-domain, and the most similar ortholog was Trachemys scripta, reaching up to 99%. Stability analysis of phylogenetic trees showed that Pelodiscus sinensis Foxl2 was clustered with reptile Foxl2 as a sub-branch, and was closely associated with Foxl2 from Chrysemys picta bellii. Results of quantitative reverse transcription PCR (RT-qPCR) indicated that, compared to the control group, E2 significantly up-regulated Foxl2 mRNA repression in ovary after 24h (P<0.001), which in testis was significantly increased after 7 and 14d (P<0.001). MT treatment strongly and equally up-regulated expression levels ofFoxl2 mRNA in ovary and testis at 24h (P<0.001). These results suggested that E2 and MT could up-regulate Foxl2 expression. Moreover, the sex differences in E2 promoting Foxl2 expression is more significant than MT. It can be concluded that the present research contributes to better understanding of the functional role of Foxl2 and provide basic data for further study on how exogenous hormone mediates Foxl2 in Pelodiscus sinensis.
In order to provide biological information for research on sex-determination mechanism in Pelodiscus sinensis, we here first attempted to clone and analyze the partial-length of Foxl2 cDNA. In addition, to address the differential expression of Foxl2 at genetic and physiological levels, both male and female sexes of Pelodiscus sinensis were treated with 10 mg/kg E2 and 17α-methyltestosterone (MT), respectively; Foxl2 mRNA expression was quantitatively examined in the gonads after injection treatment at 6, 12, 24, and 48h, as well as 7 and 14d, respectively. Foxl2 (GenBank Accession No. KP734210) was achieved, belonging to Forkhead family of transcription factors that is involved in ovarian development and functional maintenance, as well as a 903 bp of open reading frame (ORF) encoding 300 amino acids. Multiple sequence alignment showed that Foxl2 contained typical FH-domain, and the most similar ortholog was Trachemys scripta, reaching up to 99%. Stability analysis of phylogenetic trees showed that Pelodiscus sinensis Foxl2 was clustered with reptile Foxl2 as a sub-branch, and was closely associated with Foxl2 from Chrysemys picta bellii. Results of quantitative reverse transcription PCR (RT-qPCR) indicated that, compared to the control group, E2 significantly up-regulated Foxl2 mRNA repression in ovary after 24h (P<0.001), which in testis was significantly increased after 7 and 14d (P<0.001). MT treatment strongly and equally up-regulated expression levels ofFoxl2 mRNA in ovary and testis at 24h (P<0.001). These results suggested that E2 and MT could up-regulate Foxl2 expression. Moreover, the sex differences in E2 promoting Foxl2 expression is more significant than MT. It can be concluded that the present research contributes to better understanding of the functional role of Foxl2 and provide basic data for further study on how exogenous hormone mediates Foxl2 in Pelodiscus sinensis.
2019, 43(1): 52 -59
doi: 10.7541/2018.007
Abstract:
A 80-day feeding trial was conducted to assess the interactive effects of β-glucan (BG) and Heat-killed Lactobacillus plantarum (HK-LP) on growth performance, intestinal fatty acid composition, and immune function of juvenile loach Misgurnus anguillicaudatus. Fish [average initial weight of (0.17±0.01) g] were fed with six experimental formulated diets containing two levels of BG (0 and 1%) with three levels of HK-LP (0.025%, 0.05%, and 0.1%) in triplicate. Results showed that supplementation of BG and HK-LP increased the body weight gain, specific growth rate, while significantly reduced the feed conversion ratio of fish. However, interaction between BG and HK-LP showed no significant effect on those parameters. Supplementation of BG remarkably decreased the percentage of C16鲶1n-7 and C18鲶2n-6 in intestinal fatty acid composition. Meanwhile, the percentage of C22 鲶1n-11 was decreased by dietary HK-LP. Dietary BG, HK-LP and two-factor interactions significantly influenced the activities of alkaline phosphatase (AKP) from skin mucus. Increase of dietary BG and HK-LP levels enhanced the activities of lysozyme. Supplementation of dietary 1% BG and 0.05% HK-LP significantly increased the expression levels ofHsp70 and Hsp90α. Therefore, the addition of BG and HK-LP in the diets could improve the growth performance of juvenile loach, and in the experiment, the optimum level of BG and HK-LP in the loach diet was 1% and 0.1%, respectively.
A 80-day feeding trial was conducted to assess the interactive effects of β-glucan (BG) and Heat-killed Lactobacillus plantarum (HK-LP) on growth performance, intestinal fatty acid composition, and immune function of juvenile loach Misgurnus anguillicaudatus. Fish [average initial weight of (0.17±0.01) g] were fed with six experimental formulated diets containing two levels of BG (0 and 1%) with three levels of HK-LP (0.025%, 0.05%, and 0.1%) in triplicate. Results showed that supplementation of BG and HK-LP increased the body weight gain, specific growth rate, while significantly reduced the feed conversion ratio of fish. However, interaction between BG and HK-LP showed no significant effect on those parameters. Supplementation of BG remarkably decreased the percentage of C16鲶1n-7 and C18鲶2n-6 in intestinal fatty acid composition. Meanwhile, the percentage of C22 鲶1n-11 was decreased by dietary HK-LP. Dietary BG, HK-LP and two-factor interactions significantly influenced the activities of alkaline phosphatase (AKP) from skin mucus. Increase of dietary BG and HK-LP levels enhanced the activities of lysozyme. Supplementation of dietary 1% BG and 0.05% HK-LP significantly increased the expression levels ofHsp70 and Hsp90α. Therefore, the addition of BG and HK-LP in the diets could improve the growth performance of juvenile loach, and in the experiment, the optimum level of BG and HK-LP in the loach diet was 1% and 0.1%, respectively.
2019, 43(1): 60 -68
doi: 10.7541/2019.008
Abstract:
Oils are widely used in aquatic feed to supply essential fatty acids and energy for the fish. However, the abundance of unsaturated fatty acids makes oils susceptible to be oxidized, resulting in harmful effect on the health of fish. To investigate the effect of dietary oxidized oils on the growth performance, body color and antioxidant capacity in liver of channel catfish, Ictalurus punctatus, six isonitrogenous and isolipidic diets were prepared to feed channel catfish (150.5±4.2) g. The six diets were designed with 6% supplementation level of fish oil (FO-6), soybean oil (SO-6), mixed oil (3% fish oil + 3% soybean oil, MO-6), oxidized fish oil (OFO-6), oxidized soybean oil (OSO-6), oxidized mixed oil (3% oxidized fish oil + 3% oxidized soybean oil, OMO-6), respectively. After 8 weeks feeding, the fish fed FO-6, SO-6 or MO-6 diet showed no differences in weight gain (WG), feed conversion ratio (FCR), muscle composition, body color and antioxidant indicators in liver (P>0.05), which indicated that soybean oil could completely substitute the inclusion of fish oil in the diet of channel catfish. The WG and muscle lipid level of the three oxidized oil groups were significantly lower, andFCR, skin yellowness, liver malondialdehyde content, and total bilirubin, direct bilirubin, alanine aminotransferase, aspartate aminotransferase in serum were significantly higher (P<0.05) than that of the normal oil groups. The activities of catalase and superoxide dismutase, and the glutathione contents in liver were reduced by dietary oxidized oils (P<0.05), but the dorsal muscle color and moisture, crude protein, ash content in flesh were not affected (P>0.05). The above results showed that 6% oxidized oils (fish oil, soybean oil, or mixed oil) reduced the growth performance, increased the yellowness of skin and damaged the antioxidant capacity of liver of channel catfish. Soybean oil could completely replace the fish oil inclusion in the diet of channel catfish.
Oils are widely used in aquatic feed to supply essential fatty acids and energy for the fish. However, the abundance of unsaturated fatty acids makes oils susceptible to be oxidized, resulting in harmful effect on the health of fish. To investigate the effect of dietary oxidized oils on the growth performance, body color and antioxidant capacity in liver of channel catfish, Ictalurus punctatus, six isonitrogenous and isolipidic diets were prepared to feed channel catfish (150.5±4.2) g. The six diets were designed with 6% supplementation level of fish oil (FO-6), soybean oil (SO-6), mixed oil (3% fish oil + 3% soybean oil, MO-6), oxidized fish oil (OFO-6), oxidized soybean oil (OSO-6), oxidized mixed oil (3% oxidized fish oil + 3% oxidized soybean oil, OMO-6), respectively. After 8 weeks feeding, the fish fed FO-6, SO-6 or MO-6 diet showed no differences in weight gain (WG), feed conversion ratio (FCR), muscle composition, body color and antioxidant indicators in liver (P>0.05), which indicated that soybean oil could completely substitute the inclusion of fish oil in the diet of channel catfish. The WG and muscle lipid level of the three oxidized oil groups were significantly lower, andFCR, skin yellowness, liver malondialdehyde content, and total bilirubin, direct bilirubin, alanine aminotransferase, aspartate aminotransferase in serum were significantly higher (P<0.05) than that of the normal oil groups. The activities of catalase and superoxide dismutase, and the glutathione contents in liver were reduced by dietary oxidized oils (P<0.05), but the dorsal muscle color and moisture, crude protein, ash content in flesh were not affected (P>0.05). The above results showed that 6% oxidized oils (fish oil, soybean oil, or mixed oil) reduced the growth performance, increased the yellowness of skin and damaged the antioxidant capacity of liver of channel catfish. Soybean oil could completely replace the fish oil inclusion in the diet of channel catfish.
2019, 43(1): 69 -77
doi: 10.7541/2019.009
Abstract:
This study was conducted to investigate the effects of 4 kinds [24L﹕0D (D1), 16L﹕8D (D2), 8L﹕16D (D3), 0L﹕24D (D4)] of photoperiods on feed consumption, digestive enzyme activities and blood hormone of turbotScophthalmus maximus L. juveniles with initial body weight of (30.5±2.0) g in 20 hours (8:00am—4:00am). The results showed that the feed rate decreased with the shorten of illumination time, and feeding peak in D1 group appeared every 8h, meanwhile others appeared at 8:00am and 4:00pm. Activities of protease and amylase of former 3 groups were appeared spike at 12:00am and 8:00pm, and lipase was significantly higher than that of the D4 group. There were no difference of GH contents from 8:00am to 8:00pm among all groups, and D1 group at 4:00am was significantly higher than others, but D4 group was significantly lower than others from 0:00am to 4:00am. COR contents of D1, D2 and D3 groups were not significant difference in 8h after first feeding, and then increased firstly and decreased afterwards; D4 group reached the maximum level at 8:00pm. NE content of D1 and D2 groups were significantly higher than that of the others at 0:00am, meanwhile D4 group was significantly lower than others at 8:00pm. T3 content of D2 group was significantly higher than that of the other groups at 8:00am and 12:00am; D4 group was lower at 8:00pm, and higher at 0:00am than others; D2 and D3 group were lower than those of D1 and D4 group at 4:00am; The highest values of T3 of all groups were appeared at 8:00pm. These results demonstrated that feed intake, digestive enzyme activities and serum hormone contents of turbot juvenile were affected by photoperiod under current experimental conditions. 8—16 lighting period and feed twice daily would be recommended for turbot culture under this intensity of illumination.
This study was conducted to investigate the effects of 4 kinds [24L﹕0D (D1), 16L﹕8D (D2), 8L﹕16D (D3), 0L﹕24D (D4)] of photoperiods on feed consumption, digestive enzyme activities and blood hormone of turbotScophthalmus maximus L. juveniles with initial body weight of (30.5±2.0) g in 20 hours (8:00am—4:00am). The results showed that the feed rate decreased with the shorten of illumination time, and feeding peak in D1 group appeared every 8h, meanwhile others appeared at 8:00am and 4:00pm. Activities of protease and amylase of former 3 groups were appeared spike at 12:00am and 8:00pm, and lipase was significantly higher than that of the D4 group. There were no difference of GH contents from 8:00am to 8:00pm among all groups, and D1 group at 4:00am was significantly higher than others, but D4 group was significantly lower than others from 0:00am to 4:00am. COR contents of D1, D2 and D3 groups were not significant difference in 8h after first feeding, and then increased firstly and decreased afterwards; D4 group reached the maximum level at 8:00pm. NE content of D1 and D2 groups were significantly higher than that of the others at 0:00am, meanwhile D4 group was significantly lower than others at 8:00pm. T3 content of D2 group was significantly higher than that of the other groups at 8:00am and 12:00am; D4 group was lower at 8:00pm, and higher at 0:00am than others; D2 and D3 group were lower than those of D1 and D4 group at 4:00am; The highest values of T3 of all groups were appeared at 8:00pm. These results demonstrated that feed intake, digestive enzyme activities and serum hormone contents of turbot juvenile were affected by photoperiod under current experimental conditions. 8—16 lighting period and feed twice daily would be recommended for turbot culture under this intensity of illumination.
2019, 43(1): 78 -85
doi: 10.7541/2019.010
Abstract:
To investigate the effects of exhaustive chasing training on parameters of respiratory and circulatory system and excess post-exercise oxygen consumption (EPOC) in juvenile qingbo (Spinibarbus sinensis) and rock carp (Procypris rabaudi), sixty samples of S. sinensis (28.36±0.08) g and sixty samples of P. rabaudi (19.53±0.13) g were randomly divided (equally 30 fish in each group) into control group and training group, respectively. Then, these fish in the training group were analyzed under exhaustive chasing training once per day for 3 weeks at 25℃ to measure the heart index, gill index, hematological parameters, and EPOC. The results showed that there were no significant differences in the heart index, gill index, hemoglobin content, and number of red cells between the control group and training group of S. sinensis and Procypris rabaudi(P<0.05). The gill index in the control group ofP. rabaudi was significantly lower than that in the control group of S. sinensis(P>0.05), whereas the heart index, hemoglobin content, and number of red cells in the control group ofP. rabaudi were not significantly different than that in the control group of S. sinensis(P<0.05). No significant differences were found in pre-exercise metabolic rate, peak post-exercise metabolic rate, factorial metabolic scope, and recovery rate between the control group and training group (P>0.05), whereas duration of EPOC in the training group was significantly higher than that in the control group ofS. sinensis (P<0.05). The pre-exercise metabolic rate in the control group was significantly lower than that in the training group (P<0.05), whereas peak post-exercise metabolic rate and factorial metabolic scope, duration of EPOC, and recovery rate in the control group were not significantly different than that in the training group ofP. rabaudi(P>0.05). The pre-exercise metabolic rate, peak post-exercise metabolic rate, EPOC magnitude, and recovery rate in the control group ofP. rabaudi were significantly lower than that in the control group of S. sinensis(P<0.05), whereas factorial metabolic scope and duration of EPOC in the control group ofP. rabaudi were not significantly different than that in the control group of S. sinensis(P>0.05). Our results suggested that (1) exhaustive chasing training had no significant effects on the parameters of respiratory and circulatory system ofS. sinensisandP. rabaudi(P>0.05); (2) exhaustive chasing training significantly increased anaerobic capacity ofS. sinensis(P<0.05); and (3) the pre-exercise metabolic rate and peak post-exercise metabolic rate ofS. sinensis were significantly higher than those of P. rabaudi(P<0.05), which may be related to active habits ofS. sinensis.
To investigate the effects of exhaustive chasing training on parameters of respiratory and circulatory system and excess post-exercise oxygen consumption (EPOC) in juvenile qingbo (Spinibarbus sinensis) and rock carp (Procypris rabaudi), sixty samples of S. sinensis (28.36±0.08) g and sixty samples of P. rabaudi (19.53±0.13) g were randomly divided (equally 30 fish in each group) into control group and training group, respectively. Then, these fish in the training group were analyzed under exhaustive chasing training once per day for 3 weeks at 25℃ to measure the heart index, gill index, hematological parameters, and EPOC. The results showed that there were no significant differences in the heart index, gill index, hemoglobin content, and number of red cells between the control group and training group of S. sinensis and Procypris rabaudi(P<0.05). The gill index in the control group ofP. rabaudi was significantly lower than that in the control group of S. sinensis(P>0.05), whereas the heart index, hemoglobin content, and number of red cells in the control group ofP. rabaudi were not significantly different than that in the control group of S. sinensis(P<0.05). No significant differences were found in pre-exercise metabolic rate, peak post-exercise metabolic rate, factorial metabolic scope, and recovery rate between the control group and training group (P>0.05), whereas duration of EPOC in the training group was significantly higher than that in the control group ofS. sinensis (P<0.05). The pre-exercise metabolic rate in the control group was significantly lower than that in the training group (P<0.05), whereas peak post-exercise metabolic rate and factorial metabolic scope, duration of EPOC, and recovery rate in the control group were not significantly different than that in the training group ofP. rabaudi(P>0.05). The pre-exercise metabolic rate, peak post-exercise metabolic rate, EPOC magnitude, and recovery rate in the control group ofP. rabaudi were significantly lower than that in the control group of S. sinensis(P<0.05), whereas factorial metabolic scope and duration of EPOC in the control group ofP. rabaudi were not significantly different than that in the control group of S. sinensis(P>0.05). Our results suggested that (1) exhaustive chasing training had no significant effects on the parameters of respiratory and circulatory system ofS. sinensisandP. rabaudi(P>0.05); (2) exhaustive chasing training significantly increased anaerobic capacity ofS. sinensis(P<0.05); and (3) the pre-exercise metabolic rate and peak post-exercise metabolic rate ofS. sinensis were significantly higher than those of P. rabaudi(P<0.05), which may be related to active habits ofS. sinensis.
2019, 43(1): 86 -93
doi: 10.7541/2019.011
Abstract:
This study was conducted to investigate the effect of transportation stress on the plasma biochemical indices, body color, fish quality of gibel carp [Carassis gibelio var. CAS III, body weight of (116.46±2.09) g] and water quality. Transportation was simulated on an automobile vibration bench for 4h. After 4h simulative transportation, the ammonia concentration of water in bags increased significantly (P<0.01), and the dissolved oxygen of water in bags was increased (P<0.05), while the pH value decreased significantly (P<0.05). Fish plasma cortisol, glucose and MDA concentration increased significantly (P<0.01), while plasma lactic acid concentration decreased (P<0.01). Plasma GSH-PX significantly decreased after 4h simulative transportation (P<0.05), and plasma SOD and CAT had a low value after simulative transportation (P>0.05). Dorsal skin showed significantly decreasing L* values after 4h simulative transportation (P<0.01), and the abdomen and lateral line L* values also decreased with no significance (P>0.05). While a* (P>0.05) and b* (P<0.05) values declined in these three parts after 4h transportation. Cohesiveness, chewiness and resilience decreased significantly in fillet (P<0.05). The fillet gumminess, springiness and adhesiveness were slightly decreased (P>0.05), while its hardness increased (P>0.05). The results indicated that transportation could induce stress response of gibel carp and reduce fish quality.
This study was conducted to investigate the effect of transportation stress on the plasma biochemical indices, body color, fish quality of gibel carp [Carassis gibelio var. CAS III, body weight of (116.46±2.09) g] and water quality. Transportation was simulated on an automobile vibration bench for 4h. After 4h simulative transportation, the ammonia concentration of water in bags increased significantly (P<0.01), and the dissolved oxygen of water in bags was increased (P<0.05), while the pH value decreased significantly (P<0.05). Fish plasma cortisol, glucose and MDA concentration increased significantly (P<0.01), while plasma lactic acid concentration decreased (P<0.01). Plasma GSH-PX significantly decreased after 4h simulative transportation (P<0.05), and plasma SOD and CAT had a low value after simulative transportation (P>0.05). Dorsal skin showed significantly decreasing L* values after 4h simulative transportation (P<0.01), and the abdomen and lateral line L* values also decreased with no significance (P>0.05). While a* (P>0.05) and b* (P<0.05) values declined in these three parts after 4h transportation. Cohesiveness, chewiness and resilience decreased significantly in fillet (P<0.05). The fillet gumminess, springiness and adhesiveness were slightly decreased (P>0.05), while its hardness increased (P>0.05). The results indicated that transportation could induce stress response of gibel carp and reduce fish quality.
2019, 43(1): 94 -101
doi: 10.7541/2019.012
Abstract:
To investigate the effects of histamine and Lactobacillus reuteri on Pelteobagrus fulvidraco, three isonitrogenous diets, namely diet C (control, with a 147 mg/kg content of histamine), diet H (with a 479 mg/kg content of histamine) and diet H+B (histamine+ bacteria: a 496 mg/kg content of histamine and 1×105 CFU/g L. reuteri), were formulated for a 56-day trial of P. fulvidraco juveniles (14.23±0.65) g. Our data indicated that plasma alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activity were significantly lower in group H+B compared with those of group H (P<0.05), while there was no significant difference between group H+B and group C (P>0.05). Meanwhile, liver glutathione-s-transferase (GSH-ST) activity and malondialdehyde (MDA) content were dramatically reduced in group H+B compared with those of group H (P<0.05), while there was no significant difference between group H+B and group C (P>0.05). Furthermore, the HE staining showed that there were inflammatory cells infiltrating in the liver of fish fed with diet H, while no hepatocyte abnormality observed in group C and group H+B, and that the intestinal folds decreased significantly with shorter and edema in diet H group, while this is no marked difference in the length of intestinal folds between group C and H+B. Overall, our studies indicated the protective effect ofL. reuteri against histamine in cultured fish diet.
To investigate the effects of histamine and Lactobacillus reuteri on Pelteobagrus fulvidraco, three isonitrogenous diets, namely diet C (control, with a 147 mg/kg content of histamine), diet H (with a 479 mg/kg content of histamine) and diet H+B (histamine+ bacteria: a 496 mg/kg content of histamine and 1×105 CFU/g L. reuteri), were formulated for a 56-day trial of P. fulvidraco juveniles (14.23±0.65) g. Our data indicated that plasma alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activity were significantly lower in group H+B compared with those of group H (P<0.05), while there was no significant difference between group H+B and group C (P>0.05). Meanwhile, liver glutathione-s-transferase (GSH-ST) activity and malondialdehyde (MDA) content were dramatically reduced in group H+B compared with those of group H (P<0.05), while there was no significant difference between group H+B and group C (P>0.05). Furthermore, the HE staining showed that there were inflammatory cells infiltrating in the liver of fish fed with diet H, while no hepatocyte abnormality observed in group C and group H+B, and that the intestinal folds decreased significantly with shorter and edema in diet H group, while this is no marked difference in the length of intestinal folds between group C and H+B. Overall, our studies indicated the protective effect ofL. reuteri against histamine in cultured fish diet.
2019, 43(1): 102 -108
doi: 10.7541/2019.013
Abstract:
To investigate the effects of acute cold stress on the mucosal histology in different sections of the juvenile Pelodiscus sinensis, the activity of serum diamine oxidase (DAO) and histological features of intestinal mucosa in Chinese soft-shelled turtle in culture temperature and acute cold stress were conducted. The first acute cold stress reduced the DAO activity with the lowest level at 48h after cold stress. In the acute cold stress and rewarming experiment, the DAO activity decreased significantly after 3 days of cold stress and then restored to normal level with the recovery of temperature. Histopathological results showed no significant difference in the morphology of mucosal epithelium in the intestine (posterior segment of ileum and large intestine) between acute cold stress group and control group. There were no significant difference in the number of goblet cells, the length of villus and the ratio of villus length to crypt depth in the posterior segment of ileum between acute cold stress group and control group, while the mucosal thickness in the posterior segment of ileum significantly decreased in the acute cold stress group in comparison to control group. Acute cold stress significantly reduced the large intestine number of goblet cells. The structures of the intestinal mucosal mechanical barrier of Chinese soft-shelled turtle under acute cold stress are an intestinal segment dependent pattern. These results suggest that the various segments of the intestine of Chinese soft-shelled turtle have a special response style to acute cold stress.
To investigate the effects of acute cold stress on the mucosal histology in different sections of the juvenile Pelodiscus sinensis, the activity of serum diamine oxidase (DAO) and histological features of intestinal mucosa in Chinese soft-shelled turtle in culture temperature and acute cold stress were conducted. The first acute cold stress reduced the DAO activity with the lowest level at 48h after cold stress. In the acute cold stress and rewarming experiment, the DAO activity decreased significantly after 3 days of cold stress and then restored to normal level with the recovery of temperature. Histopathological results showed no significant difference in the morphology of mucosal epithelium in the intestine (posterior segment of ileum and large intestine) between acute cold stress group and control group. There were no significant difference in the number of goblet cells, the length of villus and the ratio of villus length to crypt depth in the posterior segment of ileum between acute cold stress group and control group, while the mucosal thickness in the posterior segment of ileum significantly decreased in the acute cold stress group in comparison to control group. Acute cold stress significantly reduced the large intestine number of goblet cells. The structures of the intestinal mucosal mechanical barrier of Chinese soft-shelled turtle under acute cold stress are an intestinal segment dependent pattern. These results suggest that the various segments of the intestine of Chinese soft-shelled turtle have a special response style to acute cold stress.
2019, 43(1): 109 -116
doi: 10.7541/2019.014
Abstract:
The grass carp (Ctenopharyngodon idellus) infected with the hemorrhage virus was used to analyze the intestinal microbiota by using high-throughput sequencing. The results showed that microbiota significantly differed between grass carp reovirus (GCRV)-infected and control grass carp (multiple response permutation procedure (MRPP), analysis of similarity (Anosim), and Adonis; P<0.01). When we compared alpha diversity, we found that Shannon-Wiener index, inverse of Simpson's original index and Pielou’s evenness index of intestinal microbiota were all significantly decreased after infecting with GCRV (independent samplest-test, P<0.05). Besides, we found that the individual difference within GCRV-infected group was significantly greater than those in the controls (Wilcoxon signed-rank test,P<0.05), suggesting that the intestinal microbiota in GCRV-infected grass carps became disorganized and lost their original balance. Proteobacteria, Firmicutes, Fusobacteriaceae, and Bacteroidetes were dominant phylum in both GCRV-infected group and controls. However, the relative abundance of operational taxonomic units (OTUs) between the two groups was different. For example, OTU_69 (Pasteurellaceae), OTU_504 (Comamonadaceae), and OTU_1898 (Cetobacterium) were all significantly lower than that of controls (t-test, P<0.05), confirming that GCRV could make intestinal microbiota of grass carps disorganized. The stability of intestinal microbiota is important for health of host. By detecting changes in the intestinal microbiota of GCRV-infected grass carp, we will be able to provide theoretical basis and data reference for the prevention and treatment of common disease of farmed fish, as well as providing a reference for healthy breeding.
The grass carp (Ctenopharyngodon idellus) infected with the hemorrhage virus was used to analyze the intestinal microbiota by using high-throughput sequencing. The results showed that microbiota significantly differed between grass carp reovirus (GCRV)-infected and control grass carp (multiple response permutation procedure (MRPP), analysis of similarity (Anosim), and Adonis; P<0.01). When we compared alpha diversity, we found that Shannon-Wiener index, inverse of Simpson's original index and Pielou’s evenness index of intestinal microbiota were all significantly decreased after infecting with GCRV (independent samplest-test, P<0.05). Besides, we found that the individual difference within GCRV-infected group was significantly greater than those in the controls (Wilcoxon signed-rank test,P<0.05), suggesting that the intestinal microbiota in GCRV-infected grass carps became disorganized and lost their original balance. Proteobacteria, Firmicutes, Fusobacteriaceae, and Bacteroidetes were dominant phylum in both GCRV-infected group and controls. However, the relative abundance of operational taxonomic units (OTUs) between the two groups was different. For example, OTU_69 (Pasteurellaceae), OTU_504 (Comamonadaceae), and OTU_1898 (Cetobacterium) were all significantly lower than that of controls (t-test, P<0.05), confirming that GCRV could make intestinal microbiota of grass carps disorganized. The stability of intestinal microbiota is important for health of host. By detecting changes in the intestinal microbiota of GCRV-infected grass carp, we will be able to provide theoretical basis and data reference for the prevention and treatment of common disease of farmed fish, as well as providing a reference for healthy breeding.
2019, 43(1): 117 -122
doi: 10.7541/2019.015
Abstract:
To investigate the structure characteristics of skeleton of Acipenser baeri, the conventional method was used to study the skeletal system of A. baeri Brandt mainly focusing on morphology and taxonomy. The results showed that the skeletal system ofA. baeri Brandt juvenile consists of two parts, axial skeleton and appendicular skeleton. The axial skeleton of A. baeri was composed of skull, vertebral column and ribs. The appendicular skeleton of A. baeri included fin-ray, pterygiophore and girdle. We found that the skeletal system ofA. baeri Brandt was more similar to Acipenser schrencki Brandt than other sturgeons, which probably explained by the long-term life adaptation to the high latitude and low temperature environment.
To investigate the structure characteristics of skeleton of Acipenser baeri, the conventional method was used to study the skeletal system of A. baeri Brandt mainly focusing on morphology and taxonomy. The results showed that the skeletal system ofA. baeri Brandt juvenile consists of two parts, axial skeleton and appendicular skeleton. The axial skeleton of A. baeri was composed of skull, vertebral column and ribs. The appendicular skeleton of A. baeri included fin-ray, pterygiophore and girdle. We found that the skeletal system ofA. baeri Brandt was more similar to Acipenser schrencki Brandt than other sturgeons, which probably explained by the long-term life adaptation to the high latitude and low temperature environment.
2019, 43(1): 123 -132
doi: 10.7541/2019.16
Abstract:
Different species of Rhodeinae have been wildly distributed across China. Different species have shown very similar morphological characteristics, making their distinguish to be indeed difficult. In order to compare the morphological differences among Rhodeus sinensis, Acheilongnathus tonkinensis, A. macropterus, A. chankaensis and A. taenianalis by the morphometric characteristics, and enrich the classification features, multivariate morphometrics were used to analyze the morphological variations of five Rhodeinae species in Huaihe River Basin (Henan province, China). The results showed that there were significant differences in the body’s width/body’s length, head’s length/body’s length, snout’s length/body’s length, caudal peduncle’s length/body’s length, dorsal fin base’s length/body’s length, pectoral fin’s length/body’s length, pelvic fin’s length/body’s length, and head’s length/snout’s length among the five species (P<0.01), and there were significant differences in the total length/body’s length and body’s height/body’s length (P<0.05). Therefore, these differences mainly focus on the head, tail, fin, and so on. Principal component analysis, discriminant analysis, and cluster analysis showed that the five species had obvious morphological differences, the most significant difference betweenA. taenianalis and A. tonkinensis was found, and the most insignificant difference was observed between A. taenianalis and A. macropterus. The discriminant accuracy rate of the five species varied from 82.35% to 100%, effectively realizing the distinguish of the five Rhodeinae species.
Different species of Rhodeinae have been wildly distributed across China. Different species have shown very similar morphological characteristics, making their distinguish to be indeed difficult. In order to compare the morphological differences among Rhodeus sinensis, Acheilongnathus tonkinensis, A. macropterus, A. chankaensis and A. taenianalis by the morphometric characteristics, and enrich the classification features, multivariate morphometrics were used to analyze the morphological variations of five Rhodeinae species in Huaihe River Basin (Henan province, China). The results showed that there were significant differences in the body’s width/body’s length, head’s length/body’s length, snout’s length/body’s length, caudal peduncle’s length/body’s length, dorsal fin base’s length/body’s length, pectoral fin’s length/body’s length, pelvic fin’s length/body’s length, and head’s length/snout’s length among the five species (P<0.01), and there were significant differences in the total length/body’s length and body’s height/body’s length (P<0.05). Therefore, these differences mainly focus on the head, tail, fin, and so on. Principal component analysis, discriminant analysis, and cluster analysis showed that the five species had obvious morphological differences, the most significant difference betweenA. taenianalis and A. tonkinensis was found, and the most insignificant difference was observed between A. taenianalis and A. macropterus. The discriminant accuracy rate of the five species varied from 82.35% to 100%, effectively realizing the distinguish of the five Rhodeinae species.
2019, 43(1): 133 -141
doi: 10.7541/2019.017
Abstract:
To establish a simple and reliable index for determining silvering stages of the Japanese eel, Anguilla japonica, we observed the colorations of various body parts and biological characteristics on the reproductive stock of the eels from the Yangtze River estuary before starting their oceanic migrations. The body color, and age, total length, body weight, and silvering index were analyzed in the silvering process of the Japanese eel. The two silvering stages are characterized by the colorations of trunk skin as follows: (1) Pre-silver stage: pigments deposited completely on the upper edge of pectoral fin on the lateral sides of trunk, (2) Silver stage: pigments deposited completely on the lower edge of pectoral fin on the lateral sides of trunk.The body size, eye diameter, pectoral fins length and gonad-somatic index were increased from pre-silver stage to silver stage, and digestive tract index were decreased in contrast. The principal component analysis demonstrated that the silver stage eels had larger eye and pectoralfins, higher sexual maturity and the degenerated digestive tract compared to pre-silver stage eels. Without feeding, the various modifications of the body and physiological changes indicated that silver eels developed various adaptations to prepare the long oceanic migration. The silver stage and pre-silver stage could be distinguished by canonical discriminant function analysis using five characters with a 95% reliability for correct classification. Our results revealed that an eye index of 5.0 is the cut off point for distinguishing the silver stage from the pre-silver stage of the Japanese eels for the field survey.
To establish a simple and reliable index for determining silvering stages of the Japanese eel, Anguilla japonica, we observed the colorations of various body parts and biological characteristics on the reproductive stock of the eels from the Yangtze River estuary before starting their oceanic migrations. The body color, and age, total length, body weight, and silvering index were analyzed in the silvering process of the Japanese eel. The two silvering stages are characterized by the colorations of trunk skin as follows: (1) Pre-silver stage: pigments deposited completely on the upper edge of pectoral fin on the lateral sides of trunk, (2) Silver stage: pigments deposited completely on the lower edge of pectoral fin on the lateral sides of trunk.The body size, eye diameter, pectoral fins length and gonad-somatic index were increased from pre-silver stage to silver stage, and digestive tract index were decreased in contrast. The principal component analysis demonstrated that the silver stage eels had larger eye and pectoralfins, higher sexual maturity and the degenerated digestive tract compared to pre-silver stage eels. Without feeding, the various modifications of the body and physiological changes indicated that silver eels developed various adaptations to prepare the long oceanic migration. The silver stage and pre-silver stage could be distinguished by canonical discriminant function analysis using five characters with a 95% reliability for correct classification. Our results revealed that an eye index of 5.0 is the cut off point for distinguishing the silver stage from the pre-silver stage of the Japanese eels for the field survey.
2019, 43(1): 142 -154
doi: 10.7541/2019.018
Abstract:
Hukou section, the connection between the Yangtze River and Poyang Lake for the migration route of many fish species, plays a vital role in the proliferation of fish. A systematic investigation on larval and juvenile fish resources were conducted during the fish breeding period in the Hukou section from May to August 2016. The community structure, dominant species, fish density, time-space distribution and their relationships with environmental factors in Hukou section were studied during the continuous 88-day investigation. A total of 39 larvae and juvenile taxonomic groups including 7 orders and 12 families were identified. Among them, 37 were identified to species level, one was identified to subfamily, and one was identified to family. Hemiculter bleekeri is the first dominant species and other dominant species are Gobiidae, Parabramis pekinensis, Pseudolaubuca sinensis. The larval and juvenile fish density reached its peak level on July 1 with 1230.77 ind./100 m3. The overall fish density showed a trend of decreasing volatility from July 1 to August 15. The cluster analysis divided 6 periods into 2 groups: Late May to early July in group Ⅰand late July to early August in group Ⅱ. Hemiculter bleekeri, Culter alburnus, Coilia nasus, etc. peaked in late June and Parabramis pekinensis, four famous domestic fishes, Siniperca chuatsi, etc. peaked in early July. The density of larval and juvenile fish on the south and north sides of the section were higher than that of the center section. Redundancy analysis (RDA) found that water temperature, transparency, and flow are the main environmental factors affecting the community structure of larval and juvenile fish. Correlation analysis showed highly significant correlation between water level and larval and juvenile fish density (P<0.01). This study indicates a large amount of fishes of early life history in Hukou section. The community structure of larval and juvenile fish is dominated by middle and small-sized fishes, and the proportion of river-lake migratory fishes are relatively high. Larval and juvenile fish have different adaptation characteristics to various environmental conditions. The species showed different degrees of positive and negative correlations with water temperature, transparency and flow. The results provide the scientific basis for the protection strategy of fisheries resource in the middle-lower reaches of the Yangtze River.
Hukou section, the connection between the Yangtze River and Poyang Lake for the migration route of many fish species, plays a vital role in the proliferation of fish. A systematic investigation on larval and juvenile fish resources were conducted during the fish breeding period in the Hukou section from May to August 2016. The community structure, dominant species, fish density, time-space distribution and their relationships with environmental factors in Hukou section were studied during the continuous 88-day investigation. A total of 39 larvae and juvenile taxonomic groups including 7 orders and 12 families were identified. Among them, 37 were identified to species level, one was identified to subfamily, and one was identified to family. Hemiculter bleekeri is the first dominant species and other dominant species are Gobiidae, Parabramis pekinensis, Pseudolaubuca sinensis. The larval and juvenile fish density reached its peak level on July 1 with 1230.77 ind./100 m3. The overall fish density showed a trend of decreasing volatility from July 1 to August 15. The cluster analysis divided 6 periods into 2 groups: Late May to early July in group Ⅰand late July to early August in group Ⅱ. Hemiculter bleekeri, Culter alburnus, Coilia nasus, etc. peaked in late June and Parabramis pekinensis, four famous domestic fishes, Siniperca chuatsi, etc. peaked in early July. The density of larval and juvenile fish on the south and north sides of the section were higher than that of the center section. Redundancy analysis (RDA) found that water temperature, transparency, and flow are the main environmental factors affecting the community structure of larval and juvenile fish. Correlation analysis showed highly significant correlation between water level and larval and juvenile fish density (P<0.01). This study indicates a large amount of fishes of early life history in Hukou section. The community structure of larval and juvenile fish is dominated by middle and small-sized fishes, and the proportion of river-lake migratory fishes are relatively high. Larval and juvenile fish have different adaptation characteristics to various environmental conditions. The species showed different degrees of positive and negative correlations with water temperature, transparency and flow. The results provide the scientific basis for the protection strategy of fisheries resource in the middle-lower reaches of the Yangtze River.
2019, 43(1): 155 -164
doi: 10.7541/2019.019
Abstract:
In order to provide basic information for protecting and rational utilizing resources of the Yangtze Estuary, feeding types, trophic level, energy flow, and food web, 43 aquatic animals were studied by using stomach content analysis. The species were classified into four groups according to their feeding habit: plankton feeding, benthic feeding, nekton feeding, and mixed feeding (benthic and nekton feeding). Among the samples collected in this study, the plankton predators were dominant accountings for 39.53%, and the nekton predators had the minimum dominancy, accounting for 11.63%. The results of trophic level showed that according to the dietary habits, these aquatic animals can be also divided into 3 different groups, which herbivorous consumers were dominant, and accounted for 76.75%, while intermediate carnivorous fish had the minimum dominancy, accounting for 4.65%. Through the overfishing and environmental degradation, the trophic levels of the 12 common fish in the Yangtze Estuar were generally lower than those of the 1990s, the average trophic level dropped from 3.80 to 2.87. According to each consumer’s stomach content, this study determined the benthic algae and phytoplankton, and organic detritus, including particulate organic matter (POM), as the main producers of the Yangtze Estuary aquatic food web, and drew their own energy flow. Eventually, based on the nutritional relationship among different aquatic animals, this study proposed a simplified model for the Yangtze Estuary aquatic animals’ food web.
In order to provide basic information for protecting and rational utilizing resources of the Yangtze Estuary, feeding types, trophic level, energy flow, and food web, 43 aquatic animals were studied by using stomach content analysis. The species were classified into four groups according to their feeding habit: plankton feeding, benthic feeding, nekton feeding, and mixed feeding (benthic and nekton feeding). Among the samples collected in this study, the plankton predators were dominant accountings for 39.53%, and the nekton predators had the minimum dominancy, accounting for 11.63%. The results of trophic level showed that according to the dietary habits, these aquatic animals can be also divided into 3 different groups, which herbivorous consumers were dominant, and accounted for 76.75%, while intermediate carnivorous fish had the minimum dominancy, accounting for 4.65%. Through the overfishing and environmental degradation, the trophic levels of the 12 common fish in the Yangtze Estuar were generally lower than those of the 1990s, the average trophic level dropped from 3.80 to 2.87. According to each consumer’s stomach content, this study determined the benthic algae and phytoplankton, and organic detritus, including particulate organic matter (POM), as the main producers of the Yangtze Estuary aquatic food web, and drew their own energy flow. Eventually, based on the nutritional relationship among different aquatic animals, this study proposed a simplified model for the Yangtze Estuary aquatic animals’ food web.
2019, 43(1): 165 -172
doi: 10.7541/2019.020
Abstract:
In order to understand the community characteristics of zooplankton and relationships with environmental factors, and aimed to use zooplankton community parameters monitoring the water quality of water source reservoirs, a seasonal investigation was conducted on the water quality parameters, abundance and biomass of zooplankton in water source reservoirs (K1— K10) from January, 2014 to October, 2016 in Zhejiang Province. The relationships and action mechanism between water environment factors and zooplankton abundance and biomass were studied by the method of multiple stepwise regression and path analysis. The results showed that the average abundance of zooplankton in the reservoirs was 97.5 ind./L from 2014 to 2016, mainly composed of copepods nauplii (36.3%), Rotifer (28.4%) and Cyclops (20.0%). The average biomass was 289.3 μg/L, which was mainly composed of Cladocera (39.3%), Cyclops (29.0%) and Cyclops (14.5%). Chl. a content was the decisive factor of zooplankton abundance in spring and summer, and TP content was the limiting factor for fluctuation of community abundance in autumn and winter, and the community abundance was affected by TN through N﹕P ratio in spring. DO content was a decisive factor in the development of zooplankton biomass in winter and summer, and the community biomass was promoted by DO through reducing N﹕P ratio in winter. The present zooplankton stock in the reservoirs was affected by the fluctuation of TP content, the change of N﹕P ratio and the Chl.a content of the water body ultimately reflected.
In order to understand the community characteristics of zooplankton and relationships with environmental factors, and aimed to use zooplankton community parameters monitoring the water quality of water source reservoirs, a seasonal investigation was conducted on the water quality parameters, abundance and biomass of zooplankton in water source reservoirs (K1— K10) from January, 2014 to October, 2016 in Zhejiang Province. The relationships and action mechanism between water environment factors and zooplankton abundance and biomass were studied by the method of multiple stepwise regression and path analysis. The results showed that the average abundance of zooplankton in the reservoirs was 97.5 ind./L from 2014 to 2016, mainly composed of copepods nauplii (36.3%), Rotifer (28.4%) and Cyclops (20.0%). The average biomass was 289.3 μg/L, which was mainly composed of Cladocera (39.3%), Cyclops (29.0%) and Cyclops (14.5%). Chl. a content was the decisive factor of zooplankton abundance in spring and summer, and TP content was the limiting factor for fluctuation of community abundance in autumn and winter, and the community abundance was affected by TN through N﹕P ratio in spring. DO content was a decisive factor in the development of zooplankton biomass in winter and summer, and the community biomass was promoted by DO through reducing N﹕P ratio in winter. The present zooplankton stock in the reservoirs was affected by the fluctuation of TP content, the change of N﹕P ratio and the Chl.a content of the water body ultimately reflected.
2019, 43(1): 173 -180
doi: 10.7541/2019.021
Abstract:
In this study, the method of irradiation breeding was applied to wetland plants in order to improve its cold resistance. Herein, 25, 45, 60 and 80 Gy doses of gamma ray were used to irradiate Canna indica Linn (CIL) seeds, and the dose rate was 6 Gy/min. After CIL seeds were grown up, they were exposed to a low temperature stage, and their cold hardiness was accordingly evaluated. The results showed that the activity of superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) in irradiated CIL seeds were higher than that of the control group. Malondialdehyde (MDA) in control group accumulated in large quantities under low temperature, which was higher than that of the irradiation treatment group. Besides, at low temperature, the content of proline, the total soluble sugar, and protein of irradiated seedlings were totally higher than that of the control group. The score of cold resistance in irradiated group was also higher than that of the control group, and the 45 Gy dose of gamma ray group showed the highest score. Moreover, CIL with the strongest cold resistance was planted in the constructed wetland to evaluate its purification effect in winter, and evaluation indexes were total phosphorus (TP), total nitrogen (TN), and chemical oxygen demand (COD). Results revealed that the removal rate of TP in the group of CIL in constructed wetland by using 45 Gy dose of gamma ray was significantly higher than that of the control group (P<0.05). It can be concluded that irradiation treatment can effectively improve the cold resistance of CIL and enhance the effect of artificial wetland purification in winter.
In this study, the method of irradiation breeding was applied to wetland plants in order to improve its cold resistance. Herein, 25, 45, 60 and 80 Gy doses of gamma ray were used to irradiate Canna indica Linn (CIL) seeds, and the dose rate was 6 Gy/min. After CIL seeds were grown up, they were exposed to a low temperature stage, and their cold hardiness was accordingly evaluated. The results showed that the activity of superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) in irradiated CIL seeds were higher than that of the control group. Malondialdehyde (MDA) in control group accumulated in large quantities under low temperature, which was higher than that of the irradiation treatment group. Besides, at low temperature, the content of proline, the total soluble sugar, and protein of irradiated seedlings were totally higher than that of the control group. The score of cold resistance in irradiated group was also higher than that of the control group, and the 45 Gy dose of gamma ray group showed the highest score. Moreover, CIL with the strongest cold resistance was planted in the constructed wetland to evaluate its purification effect in winter, and evaluation indexes were total phosphorus (TP), total nitrogen (TN), and chemical oxygen demand (COD). Results revealed that the removal rate of TP in the group of CIL in constructed wetland by using 45 Gy dose of gamma ray was significantly higher than that of the control group (P<0.05). It can be concluded that irradiation treatment can effectively improve the cold resistance of CIL and enhance the effect of artificial wetland purification in winter.
2019, 43(1): 181 -188
doi: 10.7541/2019.022
Abstract:
To explore the cause of Potamogeton lucens’s decline, a dominant plant inhabiting the shallow water of Nansi Lake, the physiological and biochemical changes of P. lucens were examined under a group of constant temperatures at 25℃, 30℃, 35℃, and 40℃, respectively, for 3h. The results showed that the contents of protein, soluble sugar and chlorophyll decreased significantly, while the content of malondialdehyde (MDA) increased significantly at a high temperature above 35℃. The results indicated that high temperature above 35℃ had significant damage to P. lucens. The photosystem of P. lucens was more sensitive to heat stress. The characteristics of standardized chlorophyll fluorescence kinetics curves under heat stress were as follows. Peaks at J and K phases were observed, but no L-band was found on the normalized chlorophyll fluorescence kinetics curves. The chlorophyll fluorescence parameters were calculated from the OJIP curves of the heat-treated leaves. The results showed that the initial closing speed of the reaction center (dVG/dto, dV/dto) slowed down with the increase of temperature under heat stress, but it took a shorter time to reach the maximal fluorescence (Tfm). The maximum quantum yield of PSII (Photosystem II) photochemistry (Fv/Fm) decreased. However, the non-photochemical constants (Kn), relative variable fluorescence at the J-step (Vj), and dissipated energy flux (DIo/RC, DIo/CSo, Fo/Fm) increased under heat stress. Although the turn-over number of QA (N), average redox state of QA (Sm/Tfm), and relative variable fluorescence at the I-step (Vi) barely changed, the plastoquinone pool (Sm) decreased significantly at high temperature. Absorption and trapped energy flux per RC (ABS/RC, TRo/RC; reaction center, RC) increased, whereas the electron transport efficiency per RC (ETo/RC) decreased when temperature increased. Heat stress also decreased the trapped energy flux, electron transport flux and density of RCs per CS (TRo/CSo, ETo/CSo, RC/CSo; cross section, CS). These effects of heat stress on photosystem eventually led to a significant reduction in the structure and function index (SFIabs), performance index (PIabs), and drive force for photosynthesis (DF) of the P. lucens leaves. These results demonstrated that heat stress mainly caused inactivation of oxygen-evolving complex of PSII, reduction of the density of RCs, and decrease of photochemical efficiency of RC in P. lucens plants, and these led to the production of reactive oxygen species, and thus caused remarkable damage to cells. Therefore, P. lucens is a sensitive aquatic plant to high temperature in summer.
To explore the cause of Potamogeton lucens’s decline, a dominant plant inhabiting the shallow water of Nansi Lake, the physiological and biochemical changes of P. lucens were examined under a group of constant temperatures at 25℃, 30℃, 35℃, and 40℃, respectively, for 3h. The results showed that the contents of protein, soluble sugar and chlorophyll decreased significantly, while the content of malondialdehyde (MDA) increased significantly at a high temperature above 35℃. The results indicated that high temperature above 35℃ had significant damage to P. lucens. The photosystem of P. lucens was more sensitive to heat stress. The characteristics of standardized chlorophyll fluorescence kinetics curves under heat stress were as follows. Peaks at J and K phases were observed, but no L-band was found on the normalized chlorophyll fluorescence kinetics curves. The chlorophyll fluorescence parameters were calculated from the OJIP curves of the heat-treated leaves. The results showed that the initial closing speed of the reaction center (dVG/dto, dV/dto) slowed down with the increase of temperature under heat stress, but it took a shorter time to reach the maximal fluorescence (Tfm). The maximum quantum yield of PSII (Photosystem II) photochemistry (Fv/Fm) decreased. However, the non-photochemical constants (Kn), relative variable fluorescence at the J-step (Vj), and dissipated energy flux (DIo/RC, DIo/CSo, Fo/Fm) increased under heat stress. Although the turn-over number of QA (N), average redox state of QA (Sm/Tfm), and relative variable fluorescence at the I-step (Vi) barely changed, the plastoquinone pool (Sm) decreased significantly at high temperature. Absorption and trapped energy flux per RC (ABS/RC, TRo/RC; reaction center, RC) increased, whereas the electron transport efficiency per RC (ETo/RC) decreased when temperature increased. Heat stress also decreased the trapped energy flux, electron transport flux and density of RCs per CS (TRo/CSo, ETo/CSo, RC/CSo; cross section, CS). These effects of heat stress on photosystem eventually led to a significant reduction in the structure and function index (SFIabs), performance index (PIabs), and drive force for photosynthesis (DF) of the P. lucens leaves. These results demonstrated that heat stress mainly caused inactivation of oxygen-evolving complex of PSII, reduction of the density of RCs, and decrease of photochemical efficiency of RC in P. lucens plants, and these led to the production of reactive oxygen species, and thus caused remarkable damage to cells. Therefore, P. lucens is a sensitive aquatic plant to high temperature in summer.
2019, 43(1): 189 -195
doi: 10.7541/2019.023
Abstract:
There is increasing evidence that different light intensities or ocean acidification (OA) induced by elevated atmospheric CO2 concentration can affect the photosynthetic capacity of marine diatom to different degrees, respectively however, little attention had been paid to their interaction on diatom. In this study, the growth rate, net photosynthetic rate (Pn), biochemical composition, extracellular carbonic anhydrase (eCA) activity, and Ribulose-1,5-bisphosphate carboxylase/oxygenase (RubiscO) activity were investigated when Phaeodactylum tricornutum was grown under different light intensities and CO2 concentrations. The results showed that the specific growth rates and Pn in P. tricornutum were not significantly affected by CO2 concentration under low light intensity (LL), whereas in presence of the high light intensity (HL), elevated CO2 concentration was beneficial to promote the increase of the rate of Pn. The eCA activity, chlorophyll content, and soluble protein content decreased with increase of CO2 concentration, regardless of the high or low light. Under LL, RubiscO activity of HC-grown algae was 2.42 and 1.39 times higher than that of LC- or Medium-CO2 (MC)-grown ones. However, RubiscO activity of HC-grown algae was 6.72 and 3.45 times greater than that of LC- or MC-grown ones under high light. These results indicate that the algae can adapt to changes of light intensity and CO2 concentrations in the environment by adjusting the allocation of energy during the operation of the CO2-concentrating mechanism and photosynthesis.
There is increasing evidence that different light intensities or ocean acidification (OA) induced by elevated atmospheric CO2 concentration can affect the photosynthetic capacity of marine diatom to different degrees, respectively however, little attention had been paid to their interaction on diatom. In this study, the growth rate, net photosynthetic rate (Pn), biochemical composition, extracellular carbonic anhydrase (eCA) activity, and Ribulose-1,5-bisphosphate carboxylase/oxygenase (RubiscO) activity were investigated when Phaeodactylum tricornutum was grown under different light intensities and CO2 concentrations. The results showed that the specific growth rates and Pn in P. tricornutum were not significantly affected by CO2 concentration under low light intensity (LL), whereas in presence of the high light intensity (HL), elevated CO2 concentration was beneficial to promote the increase of the rate of Pn. The eCA activity, chlorophyll content, and soluble protein content decreased with increase of CO2 concentration, regardless of the high or low light. Under LL, RubiscO activity of HC-grown algae was 2.42 and 1.39 times higher than that of LC- or Medium-CO2 (MC)-grown ones. However, RubiscO activity of HC-grown algae was 6.72 and 3.45 times greater than that of LC- or MC-grown ones under high light. These results indicate that the algae can adapt to changes of light intensity and CO2 concentrations in the environment by adjusting the allocation of energy during the operation of the CO2-concentrating mechanism and photosynthesis.
2019, 43(1): 196 -204
doi: 10.7541/2019.024
Abstract:
A newly isolated spontaneously flocculating microalgae Parachlorella kessleri F01 was used as the material, and the algae sample in autotrophic cultivation of one-step culture method was used as the control group. A two-step culture method was designed in which glucose was supplemented for mixotrophic cultivation at stage Ⅰ, and nutritional limitation treatments were done at stage Ⅱ, and we studied their effects on the lipid accumulation and flocculation performance of the algae. The algae cell number was determined by a hemocytometer. Biomass was measured via dry weight, and the total lipid was quantified with staining method. The extracellular polymeric substances (EPS) components of algae were analyzed by three-dimensional fluorescence spectroscopy. The results showed that: (1) The optimum glucose concentration was 10 g/L at stage Ⅰ. The alga lipid productivity reached to 204.25 mg/L/d on the 10th harvesting day, which was 16.20 times of that in the control group, and the self-flocculation rate of alga cell was 96.1% after sitting for 12h, which has no significant difference with that in the control group. (2) On the basis of stage Ⅰ, alga cells were cultured for 1 day in stage Ⅱ with different elemental treatments. The alga lipid productivity were 242.64 mg/L/d and 227.61 mg/L/d in the low-glucose group and the low-glucose coupled with low-nitrogen group, respectively, increasing by 18.8% and 11.4% of those at stage Ⅰ. After 4 days cultivation, the alga lipid productions of the four treatment groups including low-glucose, no-glucose, low-nitrogen and the low-glucose coupled with low-nitrogen significantly increased compared with those in the control group and stage Ⅰ. The highest production reached to 3.08 g/L in the low-glucose and low-nitrogen co-treatment group, which was 23.69 times of that in the control group, and increased by 51.0% compared with that in stage Ⅰ. The self-flocculation rates in four treatment groups at stage Ⅱ were nearly above 85.0%, which could satisfy the harvesting requirements. (3) The content of protein tryptophan in alga EPS was positively related to the self-flocculation rate. Different culture treatments could change the protein tryptophan content in EPS of algae cells, and thus affect their flocculation performance. Self-flocculation Parachlorella kessleri F01 is an excellent potential alga for biodiesel production. The two-step culture method can greatly enhance its lipid production. The advantage of self-flocculation combined with two-step culture method is expected to be the key breakthrough to solve the bottleneck of biodiesel production technology of microalgae.
A newly isolated spontaneously flocculating microalgae Parachlorella kessleri F01 was used as the material, and the algae sample in autotrophic cultivation of one-step culture method was used as the control group. A two-step culture method was designed in which glucose was supplemented for mixotrophic cultivation at stage Ⅰ, and nutritional limitation treatments were done at stage Ⅱ, and we studied their effects on the lipid accumulation and flocculation performance of the algae. The algae cell number was determined by a hemocytometer. Biomass was measured via dry weight, and the total lipid was quantified with staining method. The extracellular polymeric substances (EPS) components of algae were analyzed by three-dimensional fluorescence spectroscopy. The results showed that: (1) The optimum glucose concentration was 10 g/L at stage Ⅰ. The alga lipid productivity reached to 204.25 mg/L/d on the 10th harvesting day, which was 16.20 times of that in the control group, and the self-flocculation rate of alga cell was 96.1% after sitting for 12h, which has no significant difference with that in the control group. (2) On the basis of stage Ⅰ, alga cells were cultured for 1 day in stage Ⅱ with different elemental treatments. The alga lipid productivity were 242.64 mg/L/d and 227.61 mg/L/d in the low-glucose group and the low-glucose coupled with low-nitrogen group, respectively, increasing by 18.8% and 11.4% of those at stage Ⅰ. After 4 days cultivation, the alga lipid productions of the four treatment groups including low-glucose, no-glucose, low-nitrogen and the low-glucose coupled with low-nitrogen significantly increased compared with those in the control group and stage Ⅰ. The highest production reached to 3.08 g/L in the low-glucose and low-nitrogen co-treatment group, which was 23.69 times of that in the control group, and increased by 51.0% compared with that in stage Ⅰ. The self-flocculation rates in four treatment groups at stage Ⅱ were nearly above 85.0%, which could satisfy the harvesting requirements. (3) The content of protein tryptophan in alga EPS was positively related to the self-flocculation rate. Different culture treatments could change the protein tryptophan content in EPS of algae cells, and thus affect their flocculation performance. Self-flocculation Parachlorella kessleri F01 is an excellent potential alga for biodiesel production. The two-step culture method can greatly enhance its lipid production. The advantage of self-flocculation combined with two-step culture method is expected to be the key breakthrough to solve the bottleneck of biodiesel production technology of microalgae.
2019, 43(1): 205 -212
doi: 10.7541/2019.025
Abstract:
In this study, we explored the ability to remove nitrate and phosphorus of two strains of Stigeoclonium spp. (SHY-370 and HB1617) by setting different initial concentrations of ammonia nitrogen and nitrogen/ phosphorus (N/P) ratios in synthetic wastewater. The results indicated that different initial concentrations of ammonia nitrogen in synthetic wastewater could affect the biomass concentration and the ability to remove N and P of SHY-370 and HB1617. The maximum ammonia nitrogen concentration in synthetic wastewater that SHY-370 can tolerate was 10 mg/L, while that was 5 mg/L for HB1617. The ammonia-nitrogen removal rate of SHY-370 and HB1617 was above 97% and the maximum daily ammonia-nitrogen removal rate was 3.98 mg/L/d, while the initial concentration of ammonia nitrogen in synthetic wastewater varied between 1-10 mg/L. N/P ratios had a slight impact on the biomass concentration of the SHY-370, however, the biomass concentration of HB1617 was reduced when the corresponding rate was over 20 mg/L. The concentration of total phosphorus (TP) in synthetic wastewater was 10 mg/L. When the N/P ratio was 2, the content of TP in synthetic wastewater was higher than 10 mg/L, which led to a low TP removal rate. According to the results of our study, we can conclude that SHY-370 and HB1617 are appropriate for the treatment of urban sewage in which the concentration of ammonia nitrogen is relatively low, whereas the concentration of TP and NO3-N is relatively high.
In this study, we explored the ability to remove nitrate and phosphorus of two strains of Stigeoclonium spp. (SHY-370 and HB1617) by setting different initial concentrations of ammonia nitrogen and nitrogen/ phosphorus (N/P) ratios in synthetic wastewater. The results indicated that different initial concentrations of ammonia nitrogen in synthetic wastewater could affect the biomass concentration and the ability to remove N and P of SHY-370 and HB1617. The maximum ammonia nitrogen concentration in synthetic wastewater that SHY-370 can tolerate was 10 mg/L, while that was 5 mg/L for HB1617. The ammonia-nitrogen removal rate of SHY-370 and HB1617 was above 97% and the maximum daily ammonia-nitrogen removal rate was 3.98 mg/L/d, while the initial concentration of ammonia nitrogen in synthetic wastewater varied between 1-10 mg/L. N/P ratios had a slight impact on the biomass concentration of the SHY-370, however, the biomass concentration of HB1617 was reduced when the corresponding rate was over 20 mg/L. The concentration of total phosphorus (TP) in synthetic wastewater was 10 mg/L. When the N/P ratio was 2, the content of TP in synthetic wastewater was higher than 10 mg/L, which led to a low TP removal rate. According to the results of our study, we can conclude that SHY-370 and HB1617 are appropriate for the treatment of urban sewage in which the concentration of ammonia nitrogen is relatively low, whereas the concentration of TP and NO3-N is relatively high.
2019, 43(1): 213 -218
doi: 10.7541/2019.026
Abstract:
Microcystis bloom has caused many environmental problems, and its mechanism of bloom-formation and adaptation has been noticed wildly. To examine the possible information transfer by chemicals between both algae, the effect of Ochromonas and its culture media filtrate on the growth and physiological traits of Microcystis aeruginosa was investigated in this study. The results indicated that the cell density in Microcystis decreased significantly, while the cell density in Ochromonas increased markedly when Microcystis and Ochromonas were co-cultured at three initial cell density (1﹕4, 1﹕1 and 4﹕1). Moreover, the culture media filtrate ofOchromonas sp. could inhibit the growth, and resulted in an increase of malondialdehyde (MDA) content and catalase (CAT) activity. Additionally, the content of extracellular polysaccharides (EPS) increased markedly in Microcystis when it was inoculated into the culture media filtrate of Ochromonas sp. These results indicated that Ochromonas not only could prey on Microcystis, but also might release some of the chemicals to inhibit the growth and physiological parameters of Microcystis. This suggested that Ochromonas might be used to inhibit the early proliferation of algae as a potential control of algae blooms.
Microcystis bloom has caused many environmental problems, and its mechanism of bloom-formation and adaptation has been noticed wildly. To examine the possible information transfer by chemicals between both algae, the effect of Ochromonas and its culture media filtrate on the growth and physiological traits of Microcystis aeruginosa was investigated in this study. The results indicated that the cell density in Microcystis decreased significantly, while the cell density in Ochromonas increased markedly when Microcystis and Ochromonas were co-cultured at three initial cell density (1﹕4, 1﹕1 and 4﹕1). Moreover, the culture media filtrate ofOchromonas sp. could inhibit the growth, and resulted in an increase of malondialdehyde (MDA) content and catalase (CAT) activity. Additionally, the content of extracellular polysaccharides (EPS) increased markedly in Microcystis when it was inoculated into the culture media filtrate of Ochromonas sp. These results indicated that Ochromonas not only could prey on Microcystis, but also might release some of the chemicals to inhibit the growth and physiological parameters of Microcystis. This suggested that Ochromonas might be used to inhibit the early proliferation of algae as a potential control of algae blooms.
2019, 43(1): 219 -225
doi: 10.7541/2019.027
Abstract:
We discovered for the first time that Grateloupia turuturu filaments, developed from discoid crusts, had the ability to form spores under laboratory condition,which defined as " disc-filamentospore”. We investigated the formation of disc-filamentospores and the effects of various temperatures (6, 12, 16, 20, 24, 30℃) and light intensities (10, 30, 45, 60, 90, 120 μmol/(m2.s)) on the release of disc-filamentospores. The results indicated that carpospores that formed and released from cystocarps of female gametophyte of G. turuturu, first developed into discoid crusts. The discoid crusts were induced to form filaments of monolayer cells, which formed massive plurilocular sporangiums and released large amounts of disc-filamentospores.Temperature and light intensity significantly affected the releasing efficiency of disc-filamentospores with the maximum level at 16℃ and 60 μmol/(m2·s). The releasing number of disc-filamentospores reduced when the temperature was lower than 12℃ or higher than 24℃. The light intensity with less than 30 μmol/(m2·s) or more than 90 μmol/(m2·s) significantly inhibited the releasing efficiency of disc-filamentospores. Our results improved the asexual reproduction process of Grateloupia turuturu and provided more abundant theoretical basis for its germplasm preservation, artificial breeding and aquaculture. Finally, we suggest a plausible solution to investigate the origin and evolution of Grateloupia turuturu.
We discovered for the first time that Grateloupia turuturu filaments, developed from discoid crusts, had the ability to form spores under laboratory condition,which defined as " disc-filamentospore”. We investigated the formation of disc-filamentospores and the effects of various temperatures (6, 12, 16, 20, 24, 30℃) and light intensities (10, 30, 45, 60, 90, 120 μmol/(m2.s)) on the release of disc-filamentospores. The results indicated that carpospores that formed and released from cystocarps of female gametophyte of G. turuturu, first developed into discoid crusts. The discoid crusts were induced to form filaments of monolayer cells, which formed massive plurilocular sporangiums and released large amounts of disc-filamentospores.Temperature and light intensity significantly affected the releasing efficiency of disc-filamentospores with the maximum level at 16℃ and 60 μmol/(m2·s). The releasing number of disc-filamentospores reduced when the temperature was lower than 12℃ or higher than 24℃. The light intensity with less than 30 μmol/(m2·s) or more than 90 μmol/(m2·s) significantly inhibited the releasing efficiency of disc-filamentospores. Our results improved the asexual reproduction process of Grateloupia turuturu and provided more abundant theoretical basis for its germplasm preservation, artificial breeding and aquaculture. Finally, we suggest a plausible solution to investigate the origin and evolution of Grateloupia turuturu.
2019, 43(1): 226 -232
doi: 10.7541/2019.028
Abstract:
Growth rate, feeding, development of organs, disease resistance, adaptability, and self-regulation to the change of environment are all associated with fish health assessment. With the rapid development of aquaculture, the assessment of fish health condition is increasingly important. The present manuscript reviewed the evaluation procedures and indices related to fish health condition and available shortcomings, and also discussed the possibility of developing new methods to assess fish health condition using computer technology and biotechnology, which are expected to provide new insights for fish health assessment.
Growth rate, feeding, development of organs, disease resistance, adaptability, and self-regulation to the change of environment are all associated with fish health assessment. With the rapid development of aquaculture, the assessment of fish health condition is increasingly important. The present manuscript reviewed the evaluation procedures and indices related to fish health condition and available shortcomings, and also discussed the possibility of developing new methods to assess fish health condition using computer technology and biotechnology, which are expected to provide new insights for fish health assessment.
Journal Introduction
- Establishment Time：1955 Bimonthly
- Competent unit：Chinese Academy of Sciences
- Host unit：Institute of Hydrobiology, Chinese Academy of Sciences ; Chinese Society for Oceanology and Limnology
- Editor-in-Chief：GUI Jian-Fang
- ISSN 1000-3207
- CN 42-1230/Q
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