Aquaculture Fisheries
To provide reference materials for the development of bacteria and algae synergistic aquaculture technology, this paper outlines the basic information of algae and bacteria in aquaculture and water environment, describes the main algae and bacteria and their use in aquaculture, conducts different experiments to understand the influence of algae and bacteria on the culture water environment and the growth performance of culture organisms, and analyzes the role of bacteria and algae synergistic system on the culture water environment and the growth performance of culture organisms. Finally, we made an outlook on the optimization of new and efficient bacteria and algae synergistic control technology for aquaculture environment.
To reveal the impact of meteorological factors on the vertical gradient of water temperature, daily and hourly meteorological observation data from the Honghu National Meteorological Station in the summer of 2022 was used, as well as minute by minute water temperature observation data from different depths at the Honghu Aquatic Base, mathematical statistics and correlation analysis were used to analyze the vertical variation of water temperature in pond aquaculture on sunny days in summer. The results showed that: (1) on clear days in summer, the single peak daily variation characteristics of water temperature in each layer were obvious, with the minimum value appearing before sunrise, the highest value of surface water temperature appearing around 16:00. The deeper the water layer, the later the highest and lowest values appear. The changes in water temperature in the upper and lower layers had a certain lag. (2) Light had a significant impact on water temperature, and there was a significant positive correlation between the two factors. The correlation coefficient reached its maximum at a depth of 60 cm; the average illumination at different levels was negatively correlated with the vertical gradient of water temperature, while the illumination gradient at different levels was significantly positively correlated with the vertical gradient of water temperature. (3) There was a significant negative correlation between the vertical gradient of water temperature and wind speed. The higher the wind speed, the smaller the vertical gradient of water temperature. When the wind speed ranges from 3 to 4, and the vertical gradient of water temperature was small, it was advisable to temporarily postpone or reduce the use of oxygen generators in a timely manner. (4) There was a significant positive correlation between the vertical gradient of water temperature and water vapor pressure. The higher the water vapor pressure, the greater the vertical gradient of water temperature. In hot and humid weather, it was necessary to strengthen the patrol of the pond and timely start the aerator. The paper revealed the mechanism of the influence of meteorological factors on the vertical gradient of water temperature, and provided technical support for healthy aquaculture.
With the rapid development of aquaculture in China, the environmental problems caused by the discharge of aquaculture tailwater are becoming more and more serious. The treatment of aquaculture tailwater has emerged as a crucial research area in recent years. At present, the main methods of aquaculture tailwater treatments include physical, chemical, and biological treatments, which are often combined in practical production. Based on the research status at home and abroad, the physical, chemical and biological technologies of aquaculture tail water treatment were summarized and analyzed, and the development trend of aquaculture tail water treatment technology in China was prospected, aiming to provide some references and directions for aquaculture tail water treatment.
To investigate the feasibility of the crossbreeding between Schizothorax chongi and Percocypris pingi pingi(Tchang), evaluate the growth advantage between hybrids and original progenies, and provided theoretical reference for crossbreeding between Schizothorax chongi and Percocypris pingi pingi(Tchang), laying a foundation for the development and utilization of Schizothorax chongi and Percocypris pingi pingi(Tchang), a crossbreeding experiment was conducted. Artificial breeding including spawning, fertilization and fry rearing were carried out by using Schizothorax chongi as maternity and Percocypris pingi pingi(Tchang)as paternity. We also measured morphological data of hybrids and Schizothorax chongicry. Finally, a total of 14300 hybrids were obtained with fertility and hatching rate was 82.8% and 73.4%, respectively. Morphological analysis showed that the significant growth advantage for hybrids was exhibited from one year old. In this study, we verified the possibility of the crossbreeding between chizothorax chongi(♀) and Percocypris pingi pingi(Tchang)(♂).
The environmental and ecological problems have been widely concerned in fishery waters. At present, it has been found that aquatic plants and their epiphytic microorganisms play a significant role in the removal of pollutants in fishery waters, which are sustainable and efficient water quality regulation measure, and are widely used in the regulation of fishery environment. In this paper, the relevant research progress in recent years is reviewed from the perspectives of aquatic plant restoration methods, the interaction between aquatic plants and epiphytic microorganisms, and the role of aquatic plants and their epiphytic microorganisms in typical pollutants in fishery waters. The aim is to clarify the important role of aquatic plants and their epiphytic microorganisms in water quality regulation. We also hope to identify the current limitation of aquatic plant-epiphytic microbial ecological regulation methods and demonstrate the direction of improving these control methods, providing a better scheme for the water quality regulation of fishery environment.
To study the evolution of the plankton community structure during the pond aquaculture of Chinese softshell turtle (Pelodiscus sinensis), water samples were collected at three stages: pre-aquaculture, mid-aquaculture stage and late-aquaculture stage for physicochemical and phytoplankton detection and analysis. The results showed that the NH4+-N reached 2.38 mg/L in the late-aquaculture stage, which was significantly higher than that of pre-aquaculture, mid-aquaculture stage. 62 species of phytoplankton in 5 phyla were detected, and the species composition was mainly Chlorophyta and Cyanophyta; 4 types and 39 species of zooplankton were detected, which were mainly protozoa and Rotifers. The abundance and biomass of phytoplankton were mainly Chlorophyta, and that of zooplankton were mainly copepods. The average abundance of phytoplankton and zooplankton reached the highest at the mid-aquaculture stage, with values of 4762600 ind/L and 1634 ind/L, respectively, and the biomass of phytoplankton and zooplankton reached the highest at the late-aquaculture stage, with 18.09 mg/L and 10.106 mg/L, respectively. The mean values of phytoplankton diversity index (H) and evenness index (J) were 0.1779 and 0.0604, respectively, which were significantly lower than those of pre-aquaculture. In the middle and late stage of aquaculture, Closterium gracile breb was the dominant algae. There was no significant difference in zooplankton diversity index (H) before and after aquaculture of P.sinensis. The results showed that the community structure of phytoplankton changed greatly while zooplankton changed little during the aquaculture of P.sinensis. The aquaculture water showed the trend of first getting worse and then gradually getting better, and the water stability was poor in the mid-aquaculture stage, so it was necessary to transfer water actively.
In order to solve the bottleneck problems of single variety of peach planting, short fruit picking period and large ditch area, a productive experiment of three-dimensional planting and aquiculture of peach and soft-shelled turtle was carried out, the planting and aquiculture system was constructed, the test area was 3.33 hectares, the ratio of planting area to aquiculture area was 9:1. The results showed that aquiculture water quality indexes such as TAN, NO2--N and NO3--N were stable and kept within an ideal range in the three-dimensional planting and aquiculture mode of peach and soft-shelled turtle. COD, TSS, TN and TP were all better, which met the discharge standards of freshwater aquaculture. The pH was slightly alkaline and remained between pH 8.2 and pH 9.5. The yield of peach was 15 t/hm2, and the SSC was 16.2%-19.8%. The survival rate of soft-shelled turtle was 88.83%, the yield of aquiculture area was 1.29 t/hm2, the yield of planting and aquiculture system was 129 kg/hm2, and the income increased by 17900-23000 yuan/hm2. The research indicated that this model of peach and soft-shelled turtle had better water quality indexes, remarkable economic and ecological benefits, which was a kind of model with the advantages of resource recycling, energy saving and environmental protection, high ecological efficiency and high product quality.
In order to evaluate the carbon sink capacity of mariculture shellfish in Guangdong Province, based on the output of mariculture shellfish in Guangdong Province in the China Fishery Statistical Yearbook, the quality and value of the carbon sink capacity of mariculture shellfish in Guangdong Province from 2016 to 2020 were evaluated with reference to tissue dry mass ratio and tissue carbon content. The results showed that the carbon sink capacity of mariculture shellfish in Guangdong Province was stable on the whole. The removal of carbon material by shellfish was 156300 tons per year, equivalent to the removal of 573500 tons of CO2, and the annual economic value was 86-343 million US dollars. The study shows that the environmental benefits and considerable economic benefits brought by shellfish carbon sink in Guangdong Province are helpful to accelerate the realization of the "double carbon" goal in our country, and we should pay more attention to the treatment of shells at the same time.
To investigate the anesthetic effect of eugenol on junvenile Schizothorax chongi and provide theoretical basis for artificial breeding of Schizothorax chongi, we measured the time of anesthesia and recovery under different concentration, different anesthetic time and different exposure time by hydrostatic method. The results showed that a negative correlation between the eugenol concentration and anesthesia time was identified with y1=286.63e-0.0135x, R2=0.9593; a positive correlation between the eugenol concentration and recovery time was found with y2=101.54e0.0134x, R2=0.9913; the anesthetic time and the recovery time differed significantly with different concentration of eugenol (P<0.05); the recovery time was positively correlated with the anesthetic time (y=64.647x0.2394, R2=0.9823) under concentration of eugenol was 40 mg/L; a significant negative correlation between recovery time and exposure time was identified with y=900.92x-0.4078, R2=0.8961. The conclusion of this study was that eugenol concentration of 40-80 mg/L was the best in the production, transportation and sampling; the medicinal bath time of young fish should not exceed 600 s and the exposure time of juveniles were permitted no more than 1200 s.
In order to understand the toxic effects of commonly used biopesticides or insecticides (zhongshengmycin, chlorantraniliprole-thiamethoxam, Zn thiazole and validamycin A) in rice field, semi-static acute toxicity test for aquatic organism was conducted on juvenile red claw crayfish (about 4 cm). The results showed that 96 h semi-lethal concentration of the four pesticides against juvenile red claw crayfish were 19.66 mg/L, 1.65 mg/L, 1132.83 mg/L and 2092.07 mg/L, respectively. The safe concentrations were 5.65 mg/L, 1.27 mg/L, 260.40 mg/L and 248.11 mg/L respectively. According to the results of behavior and tolerance, the toxicity of the four pesticides to the juvenile red claw crayfish were in the order of chlorantraniliprole-thiamethoxam> zhongshengmycin> validamycin A> Zn thiazole. Furthermore, in accordance with the national standard (GB/T16310.5-1996), Zn thiazole and validamycin A were non-toxic pesticides, zhongshengmycin was slightly toxic, and chlorantraniliprole-thiamethoxam was medium toxic pesticide for juvenile red claw crayfish. This research defined the tolerance of juvenile red claw crayfish to four major pesticides used in rice. It was expected to provide reference for disease control in the process of co-culture of rice and red claw crayfish.
In order to study the relationships between morphological traits and body weight of Sillago sinica, 107 samples in the offshore of Zhoushan were randomly selected, and their body weight (X0) and 11 morphological traits including snout length (X1), head length (X2), body length (X3), total length (X4), caudal peduncle length (X5), caudal peduncle height (X6), body thickness (X7), eye diameter (X8), interorbital diameter (X9), head length behind eyes (X10) and body height (X11) were measured and analyzed by correlation analysis, multiple regression analysis, path analysis and grey relational analysis. The correlation analysis results showed that all the morphological traits were significantly correlated with body weight (P<0.01), and the correlation coefficient between body length and body weight was the greatest of all. After eliminating the severe collinearity effects, two indexes (body length and caudal peduncle height) that significantly linearly correlated with body weight were considered as the independent variables, and body weight was regarded as the dependent variable. The optimal multiple linear regression equation was finally constructed as: Y=-87.734+6.174X3+24.398X6. The path analysis results revealed that body length had the largest direct effect on body weight, while caudal peduncle height had the largest indirect effect on it. The top five grey relational degrees between each morphological trait and body weight were body length, total length, caudal peduncle height, body height, and head length. Comprehensive findings indicated that during the process of Sillago sinica fishery resource development and management, body length and caudal peduncle height should be separately used as the priority measure index and auxiliary one to formulate the optimal catchable size and mesh size.
In order to investigate the current status of germplasm resources of the freshwater snail B. purificata in China and provide quality germplasm resource for selection breeding, 249 samples were collected from wild populations in Jiangsu, Anhui, Shanghai, Shandong, Hunan, Guangxi, Jiangxi, Guizhou, Hubei, Zhejiang and Guangdong Provinces, 24 landmark points were set clockwise from the top of the shell for each individual of different groups and 15 semi-landmark points were set at equal intervals between the 11th-12th, 12-13th, 13-14th, 14-15th, 15-11th, 15-16th landmarks. After all the landmarks and semi-landmarks setting finished, Procrustes fitting was performed and the outliers that exceeding upper quartile were removed. The missing value was checked by thin plate spline method. All the variations of the shape of all species were subjected to principal component analysis. Procrustes distance for different geographical groups were analysis by ANOVA and these distances were used for cluster analysis. The results showed that the main variation of shell morphology in the 11 geographic populations of the freshwater snail B. purificata was at the top of the shell and the upper edge of the aperture. The concentration of variation in morphological traits of different geographical populations was poor, and the 1st principal component and 2nd principal component could not significantly distinguish among different populations. The 11 populations could be divided into two major groups, the Yangtze River basin group and the south of Yangtze River group, and there were significant differences in the shape of the different populations, which may be related to the local habitats.
Pond culture is the main business model of aquaculture in China, which plays a significant role in the development of aquaculture in China. In the pond culture system, nitrogen and phosphorus are essential nutrients for plants in the water. Exploring their balance is an effective method to evaluate the utilization efficiency, conversion efficiency and aquaculture pollution level in the pond culture system. This paper summarized the nitrogen and phosphorus budget and the utilization rate of nitrogen and phosphorus by aquaculture organisms in the pond culture system. It analyzed the significance of the research on nitrogen and phosphorus budget in the pond culture system, and provided a reference for reducing nitrogen and phosphorus deposition in the water, improving the utilization rate of nitrogen and phosphorus by aquaculture organisms, further optimizing the aquaculture model, and reducing the pollution to the ecological environment.
This study was performed to investigate the body color and meat quality of crucian carp (Carasslius auratus) cultured under two modes. Experimental fishes of artificial culture mode (230.90±8.14) g and wild mode (179.43±13.01) g were randomly selected. The body parameters, color, muscle composition, amino acids contents and muscle texture of crucian carp of two modes were measured. The results showed that the condition factor, viscera index, crude lipid content of crucian carp under artificial culture mode were higher than those under wild mode (P<0.05), but no significant difference was observed in body height/ body length (P>0.05). L and B values of crucian carp under artificial culture mode were significantly lower than those under wild mode (P<0.05). No significant difference was observed in moisture, crude protein and ash (P>0.05). In addition, the hardness, adhesiveness, springiness, chewiness of the muscle of crucian carp under wild mode were significantly higher than those under artificial culture mode (P<0.05). For essential amino acid, threonine, valine, leucine contents in muscle of crucian carp under wild mode were significantly higher than those under artificial culture mode (P<0.05). For nonessential amino acid, glutamate content in muscle of crucian carp under artificial culture mode was significantly higher than those under wild mode (P<0.05). In conclusion, compared with pond culture mode, crucian carp in wild culture mode has the characteristics of higher texture and lower fat, but its physical indexes are weaker than those in artificial culture mode.
Shule River is one of the important inland rivers in Gansu Province. In order to develop the edible value of native fishes in Shule River, a comparative study was conducted on nutritional components, amino acid content, fatty acid content and nutritional quality of muscle in Gymnocypris chilianensis, Triplophysa (Hedinichthys) yarkandensis and Schizopygopsis pylzovi, and the muscle nutritional quality of G. chilianensis was compared with other fishes of Gymnocypris. The results showed that the contents of moisture, crude ash, crude protein and crude fat in muscle of the three native fishes were different. The types and quantities of amino acids were consistent, the total amount of amino acids, essential amino acids, flavor amino acids, and nonessential amino acids in S. pylzovi muscle were higher than that of G. chilianensis and T. yarkandensis. According to the amino acid and chemistry score, the first limiting amino acid in all muscle samples was valine. All three species of native fish were rich in fatty acids, the contents of saturated fatty acids, monounsaturated fatty acids, and polyunsaturated fatty acids in S. pylzovi muscle were significantly higher than that of G. chilianensis and T. yarkandensis (P<0.05). The comparison of muscle nutritional quality between G. chilianensis and other fishes of Gymnocypris showed that there were differences in general nutrients among the muscles, the types and quantities of amino acids of the three species of Gymnocypris were the same. The content of essential amino acids was the highest in the muscles of G. chilianensis, and more kinds of fatty acids were detected in the muscles of G. chilianensis. The results showed that the muscle of the three native fishes in Shule River was delicious, and they had higher edible value and nutritional value. G. chilianensis has the same nutritional value as G. eckloni and G. przewalskii, which has higher development value.
With the continuous development of China's aquaculture industry, the improvement of aquaculture tailwater treatment technology becomes more and more urgent. In recent years, with the continuous expansion of the scale of industrialized aquaculture, untreated aquaculture tailwater not only increases the mortality rate of aquatic organisms in the surrounding environment, but also leads to eutrophication of surrounding water bodies, thereby limiting the development of aquaculture industry and affecting industrial upgrading. The current research on tailwater treatment process, the technologies for screening of water purification materials and ozone disinfection, and the current situation of constructed wetland technology were summarized in this study, and on this basis, the prospects were put forward to provide reference for optimizing the water purification mode and realizing ecological priority and green development of the aquaculture industry.
In order to comprehensively understand the current status of major diseases in freshwater aquaculture across the country, and identify the existing drawbacks in disease prevention and control, we conducted a survey at the city level in freshwater aquaculture areas. By conducting a comprehensive analysis of disease data from different regions, the types of diseases (a total of 101 species, including 25 viral diseases, 25 bacterial diseases, 6 fungal and algal diseases, 32 parasitic diseases, and 13 other diseases), epidemiological patterns, severity of damage and control measures for aquaculture species across the country were clarified. By further analyzing the existing drawbacks in disease prevention and control, the targeted recommendations for guiding the future development of aquatic disease prevention and control are put forward.
The aim of this research was to investigate the molecular evolutionary characteristics of histone H2 and its role in the immune regulation in pearl oyster Pinctada fucata martensii, and to provide a theoretical basis for further elucidation of the physiological functions of histone H2 in Pinctada fucata martensii. Bioinformatics methods were used to identify histone H2A and H2B from nine species, such as Pinctada fucata martensii, Homo sapiens, and Crassostrea gigas, and their molecular evolution was analyzed. Using the data available in our previous research, the functions of histone H2A and H2B in the development, tissue and immunity of Pinctada fucata martensii were also analyzed. The main results showed that the human genome contained 27 histone H2A and 20 histone H2B, the C. gigas genome contained 12 histone H2A and 8 histone H2B, and the genome of Pinctada fucata martensii contained only two H2A (H2A-1 and H2A-2) and one H2B, which showed a contraction phenomenon compared with other species. Sequence analysis revealed that there were 6 H2A and 2 H2B variants in human genome, 3 H2A and 1 H2B variants in C. gigas, and 1 H2A variant (H2A-2) in Pinctada fucata martensii. The expression of H2A-1 and H2B were changed after transplantation in Pinctada fucata martensii, indicating that they were involved in the immunological regulation of the transplantation immune response. The expression level of H2A-1 gene was higher in the gastrula stage, H2A-2 was highly expressed in trochophore stage and type D larvae, and the expression level of H2B was higher in the egg and fertilized egg. H2A-1 was relatively high in pearl sac, the expression level of H2A-2 was relatively high in blood cell, foot, and mantle pallium, and H2B gene was relatively high in gonad and pearl sac. The genome of pearl oyster Pinctada fucata martensii contained only two H2 genes, and both of them involved and played a different role in the regulation of transplantation immune response in Pinctada fucata martensii.
To analyze the composition of microbial community in integrated rice-crayfish farming system at different time in spring, Illumina Miseq high-throughput sequencing technology was used to analyze the bacterial community composition in the intestinal tract and culture environment of Procambarus clarkii. The results showed that a total of 16966 operational taxonomic units (OTUs) were detected in all samples. The maximum OTUs of sediment samples in April were 3677, and the minimum OTUs of intestine were 757. Alpha diversity analysis showed that the abundance and diversity of the sediment microflora were high. The dominant bacteria groups in the integrated rice-crayfish farming system were Proteobacteria, Actinobacteria, Bacteroidetes and Firmicutes. Proteobacteria was the predominant group in all samples in April and May, and Firmicutes was the predominant group in P. clarkii intestinal tract in June. The proportion of Actinomycetes in water was higher than that in intestinal tract and sediment. Principal coordinates analysis (PCoA) and unweighted pair group method with arithmatic mean (UPGMA) analysis showed that, microbial communities of the sediment and water in different months were clustered together according to species, but the microbial community structure of intestines and the sediment in June were relatively similar. These results suggested that in spring integrated rice-crayfish farming system, the composition of intestinal microflora of P. clarkii was correlated with the external culture environment. The diversity and composition of microflora in each sample were different but relatively stable in different months.
The aim of this study was to explore the molecular mechanism of the response of Pacific oyster to ocean acidification through transcriptome analysis. In this study, the RNA-seq data (including pH 7.8, pH 7.4, pH 7.0 and pH 6.6 groups) of Pacific oyster under ocean acidification stress in NCBI were used to analyze the differential genes, GO and KEGG by Fastp, Hisat2, Samtools and R language analysis. The results showed that there were 61, 93 and 943 significantly differentially expressed genes in pH 7.4 vs pH 7.8, pH 7.0 vs pH 7.8 and pH 6.6 vs pH 7.8 groups. GO analysis of the significantly differentially expressed genes in pH 6.6 vs pH 7.8 group showed that these genes were significantly enriched in metabolism, genetic information processing, human disease and other molecular functions. KEGG enrichment analysis showed that these genes were significantly enriched in glucose metabolism, lipid metabolism and immune function. Expression analysis showed that with the decrease of pH, the amount of gene expression related to energy metabolism and immunity decreased significantly. For example, the expression of glycogen phosphorylase in saccharometabolism decreased from 41.5 to 0. The expression of arginine kinase 1 in amino acid metabolism decreased from 1438 to 0, and the expression of arginine kinase 2 decreased from 27 to 3. The expression of fatty acid synthetase in fat metabolism decreased from 28 to 2.5. The significant inhibition of these genes may lead to the disturbance of energy metabolism in oyster body. In addition, the expression of immune-related genes, such as CD151, decreased from 45 almost to 0, and was extremely significantly inhibited, which may alter osmotic pressure in oysters, lead to immune system disorders and reduce their ability to withstand changes in the external environment. In conclusion, ocean acidification is likely to lead to the disorder of metabolism and immune system of oyster body, and reduce the ability of Pacific oyster to resist environmental changes.
Aquaculture Fisheries
