Wastewater from aquaculture has attracted wide attention as one of the sources of agricultural non-point source pollution, and the management of aquaculture wastewater has become a current research hotspot. In order to understand the mechanism of aquaculture wastewater purification and enhance the purification technology efficiency, this paper introduces the current status, hazards, and related control policies of aquaculture pollution in China, and reviews the aquaculture wastewater purification technologies developed in the past two decades. Finally, the research direction of aquaculture wastewater is discussed to put forward the possibility of strengthening the sedimentation unit, and using new materials and microorganisms to intensify the purification system.

In order to grasp the water flow conditions suitable for fish growth, a systematic review was conducted on the behavioral characteristics and physiological metabolism of fish at home and abroad under different water flow conditions. The effects of water flow on water quality and the behavioral differences of different fish stimulated by water flow were analyzed and compared, and the effects of water flow on fish from the perspective of fish physiological metabolism was explored. The results show that the maximum water velocity that fish could withstand is generally related to body length (BL), and lower water velocity (<0.5 bl/s) has no significant effect on fish, higher water velocity (>2 bl/s) has more negative effects on fish behavior, survival rate and physiological metabolism, while medium water velocity (0.5-2 bl/s) is suitable for fish growth, which can improve fish immunity and enhance antioxidant level of fish. The current research on fish tolerance to water velocity was discussed and optimized from an experimental perspective in the study, in order to obtain a more accurate growth-flow velocity curve.

To provide scientific reference for illuminating the pollution status of aquaculture in China, based on the existed pollution discharging coefficients and breeding yield of 2014, we calculated and analyzed the total discharge amount of major aquacultural pollutants.Due to the lack of correlation data, this paper chooses the year of 2014 as the year of measurement. The results showed that the main pollution discharge amount of total nitrogen, ammonia nitrogen (NH3-N), total phosphorus, chemical oxygen demand (COD), copper and zinc in aquaculture in 2014 was 68.342 × 104, 16.660 × 104, 13.769 × 104, 164.154 × 104, 253.746 and 729.842 t, respectively. COD and NH3- N accounted for about 7% of the total wastewater amount in China.. Due to differences in yield, breeding way and variety, pollutant discharge amount from freshwater aquaculture was much higher than that of marine aquaculture. In addition, to promote the sustainable development of aquaculture in China, we put forward suggestions such as controlling freshwater aquaculture production, adjusting breeding way, developing healthy and ecological breeding technology and promoting research on related systems.

In this paper, the regional structure, market structure and market price of sturgeon caviar export of China are analyzed. The main exporting countries of sturgeon caviar in the world are estimated by using three indicators: international market share, dominant comparative advantage index and trade advantage index. It is found that the export areas and export structures of sturgeon caviar of China are relatively concentrated and have strong international competitiveness. The export price is declining year by year, and the overall competitiveness still has a lot of room to rise. On the basis of the previous analysis, suggestions on enhancing the competitiveness are put forward, such as accelerating the construction of aquatic products processing and export base, strengthening brand building and developing diversified export market.

To improve the water quality, the fishery multiplication and the restoration of ecological environment, the application of EM bacteria has attracted extensive attention and become a research hotspot in recent years. This study systematically reviewed the definition and source of EM bacteria, the effect and mechanism of EM bacteria in aquaculture in recent decades, and elaborated the factors affecting the effect of EM bacteria. It is found that: EM bacteria have significant effects on regulating microbial ecological structure, reducing harmful substances in water environment, improving immunity, gaining weight and increasing yield; however, the basic theoretical research of EM bacteria technology is still relatively weak, and there are still deficiencies in the production technology and application process. Therefore, in the future, it is necessary to improve production technology, establish and improve screening system, and develop new fields of research and application of EM bacteria in aquaculture, so as to create greater economic value for aquaculture and provide the possibility for sustainable aquaculture.

To study the effects of different feeding rates on the growth, water physicochemical indexes and microbial community metabolic diversity of cultured tilapia, 16±0.20 g Oreochromis niloticus was used as the research object, the effects of different feed rates on tilapia growth and water quality indicators were explored. Biolog-ECO method was used to detect the utilization of 31 carbon sources by microorganisms in culture water samples, to study the differences of microbial metabolic diversity under different feeding rates. The results showed that the tilapia with 4% feeding rate had the lowest feed coefficient and relatively high feed utilization rate; high feeding rate had a relatively great impact on water quality, and different feeding rates had an impact on microbial metabolic diversity in aquaculture water; the Shannon index of 4% feeding rate was relatively high, and there were more kinds of microorganisms in water; Pearson correlation analysis showed that COD, TN, TP, NH₃-N had strong positive correlations (P<0.05) with water microbial metabolic diversity metabolism of β-methyl-D-glucoside, glucose-1-phosphate, glycyl-L-glutamic acid. In the process of tilapia culture, considering both ecological and economic benefits, we should feed the tilapia with proper feeding rates, the feeding rate with the initial tilapia size of about 16g is around 4%.

China has a remarkably long history of aquaculture. At present, aquatic products have become a main way of protein intake for human body under the rapid economic growth, but there are some restricting factors for the sustainable development of aquaculture industry, including the industrialized and high-density breeding mode, unscientific breeding technologies and other external pollution, so the quality of aquatic products cannot be effectively guaranteed. This paper introduced current pollution status of aquaculture, analyzed the source of pollution in detail, and put forward effective countermeasures for achieving the sustainable development of aquaculture and ecology.

The Yalu River flows through Jilin and Liaoning Province. Because of its special geographical condition, climate environment and fish fauna composition, there are many special economic fish species. In recent years, in order to meet the needs of aquaculture farmers and consumers, a lot of research work has been done on the development and utilization of fish resources in the Yalu River, which has played an important role in promoting the freshwater fishery in Liaoning Province and increasing aquaculture farmers’ income. The paper summarized the characteristics of fish resources in the Yalu River, the development and utilization of the main economic fish resources such as Hypomesus transpacificus, Plecoglossus altivelis, Siniperca scherzeri, Hemibarbus labeo and Odontobutis yaluensis, and the present situation of fish breeding. Some suggestions were put forward, including the investigation of fish resources in the Yalu River, the management of cage culture, the selection of fine species and the development of feed.

In this paper, we optimized the determination method for geosmin (GSM) and 2-mathylisoborneol (2-MIB) in aquaculture water and aquatic products by using the method of microwave distillation - solid-phase microextraction - gas chromatographic-mass spectrometry (MD-SPME-GC-MS). We optimized the four pre-treatment processing parameters, including carrier gas rate, microwave power, distillation time and collection method, and determined the experimental conditions as follows: carrier gas rate of 60 mL/min, microwave power of 400 W, distillation time of 6 min, and constant of 250 mL. In aquaculture water, the detection limit of GSM and 2-MIB reached 1 ng/L and 10 ng/L, respectively. In aquatic products, the detection limit of GSM and 2-MIB reached 0.025 μg/kg and 0.25 μg/kg, respectively. The standard curve of this method had good liner relation in the range of 1-200 ng/L and 10-200 ng/L (R² was 0.9997 and 0.9982, respectively). The average recovery rate of GSM and 2-MIB at different concentrations (1, 5, 7, 10, and 20 μg/kg) was 45.28%-49.92% and 82.15%-87.36%, respectively. In this experiment, the water samples and aquatic product samples from Wuxi were detected by this method. The result showed that the average concentration of GSM and 2-MIB in the water samples was 19.58 ng /L and 58.29 ng /L, respectively. In aquatic products, only GSM was detected, and the average concentration was 0.61 μg/kg. This method can be widely used to detect fishy substances in aquaculture water and aquatic products.

Feeding habit is one of the important traits affect the growth of fish, it is also an important content in the study of genetic improvement. Diets is regulated by many factors, not only with the intrinsic genetic and physiological factors such as appetite, the structure of the digestive tract, but also external bait properties such as sources of protein, feed palatability and so on; Relating genes of genetic manipulation is the major determinant of diets. Size of the farming industry of the fish especially carnivorous fish could be enlarged by improvement of the feeding, urging the fish depending on the ice fresh feeding or the live fish to receive breeding artificial feed, and the economic benefits of aquaculture industry will be improved a lot. This article summarizes the fish feeding of gene regulation and improvement, combining with feeding related gene polymorphism and artificial feed protein source in order to provide help to the genetic improvement of fish feeding .

To further promote the in-depth development of the research on artificial fish nest technology and the popularization and application of fishery resources proliferation technology, we summarize the development status of artificial fish nest breeding technology at home and abroad, sum up the research examples of different types of artificial fish nests in fishery resources proliferation, and expound the effects of artificial fish nest breeding technology on increasing yield and efficiency. In addition, we summarize the types, structures and materials of artificial fish nests, put forward the requirements of site selection, construction and management of artificial fish nests, discuss the development prospect of artificial fish nest, and point out the key research direction of artificial fish nest technology.

With the rapid development of global aquaculture, fish welfare has received increasing attention. Man-made noise is one of the rising research objects. With the expansion of industrial activities, people have gradually realized the stress effect of man-made noise on fishes. We described the principle of fish hearing as well as research advances in effects of man- made noise on fish hearing, information masking, behavior, physiology and biochemistry. Finally, we suggested that noise research should be expanded to more species, and the development of corresponding equipment should be accelerated.

In order to explore the way of water spinach planting in floating bed affecting the water micro-ecological environment of tilapia aquaculture ponds, water spinach floating beds were set up in the ponds under the 10% coverage. These ponds served as the treatment group, while the other ponds without floating beds served as the control group. After the vigorous growth of water spinach, the samples of water from treatment ponds, control ponds, and the samples of water spinach roots were collected respectively. The DNA of the samples was extracted, part of them was used to amplify the 16S rRNA genes and carry out the high-throughput sequencing, to investigate the effect of water spinach planting on the bacterial community structure in water, and analyze the relationship between the root system of water spinach and the bacterial community structure of surrounding water. Another part of DNA was used to conduct the fluorescent quantitative PCR to determine the copy number of nitrogenase gene, and analyze the effect of water spinach planting on the nitrogenase genes in tilapia aquaculture pond ecosystems. The results showed that the direct effect of water spinach planting on the community structure of planktonic bacteria in the water was not significant; however, the root biofilm of water spinach played an important role as a key part of the pond micro-environment. At the same time, water spinach root biofilm also increased the number of nitrogen-fixing microorganisms per unit volume in pond water.

In order to provide more discriminant basis for Bagridae fish breeding, through the form and framework data determination of Hybrid groupⅠ(Pelteobagrus vachelli, Pelteobagrus fulvidraco and their positive and negative hybridF₁ generation), and Hybrid groupⅡ(Pelteobagrus vachelli, Pelteobagrus fu lvidraco, Leiovassis crassilabrus, Pelteobagrus fulvidraco♀×Leiovassis crassilabrus♂ F₁ generation, and Pelteobagrus vachelli♀×Leiovassis crassilabrus♂ F₁ generation), two methods of clustering and discriminant were analyzed, clustering results showed that hybridF₁ generations showed some of the maternal effects in GroupⅠ; in GroupⅡ, Pelteobagrus fulvidraco♀×Leiovassis crassilabrus♂ F₁ generation showed more similar to its mother and Pelteobagrus vachelli♀×Leiovassis crassilabrus♂ F₁ generation tend to be more familiar to its father. Discriminant anlysise results showed: the GroupⅠpositive and negative hybridF₁ generations showed evenly to their father and mother features, no more apparently showed male or female characteristic; In GroupⅡ, 5 population discriminant accuracy rate was 95.33%, clearly showed the difference between each group morphology. The conclusion: (1) The positive and negative hybrid generations of Pelteobagrus vachelli and Pelteobagrus fulvidraco, Pelteobagrus vachelli♀×Leiovassis crassilabrus♂ F₁ generation represent significant maternal effects; well Pelteobagrus vachelli♀×Leiovassis crassilabrus♂ F₁ generation represent more paternal effects; (2) Comprehensive use of proportion of trait parameters and calibration framework parameters had more ability than used alone to improve discrimination ability of shape classification. The more detailed parameters, the stronger the discriminant ability.

From the perspective of supply and demand, this paper analyzed the current status, characteristics, existing problems and future development trends of the tilapia industry. The development of tilapia supply and demand is characterized by a high concentration of supply and scattered domestic consumption; products are mainly supplied to the international market and highly dependent on foreign countries; demanding countries are diversified and trade volume is greatly affected by the US market. China's tilapia demand has changed significantly, especially due to the uncertainty of the US market, which has caused a partial surplus of tilapia supply. It is expected that the demand for tilapia would decline significantly in the future, but this decline will be alleviated after the impact of COVID-19 and the demand will continue to grow. Due to market uncertainty and other reasons, China’s tilapia supply will increase at a low level, or even decrease.

Starting from the problems faced by the sustainable development of domestic aquaculture industry, we independently developed the ‘biomass refining’ technology and the complete set of equipment, extracted water-soluble organic carbon materials with high activity and small molecules from natural plants, and introduced them into aquaculture. Combined with years of research and practice, we analyzed the economic and social benefits, and proved that the plant derived small molecule organic carbon had high activity and could play an important role in aquaculture.

Through field investigation lasting 26 days in May, September of 2009 and July of 2010 with the way of trapping, catching and buying. we studied the fish species, distribution and diversity. in order to know the fish resource status in the Fuyuan section of Heilongjiang River. The results showed that there were totally 49 species of fish belonging to 38 genera, 14 families, 8 orders in this river. Most of them were small mesopelagic or demersal fish and Saurogobio dabryi, Phoxinus percnurus and Pelteobagrus fulvidraco are dominant species. comprised with other studies, species diversity level and population number of fishes in this river are lower, and 27 species, 7 families and 1 orders of fish have been absented. It has been suggested that fish species diversity has been damaged and the fish resources should be utilized reasonable and conservation in the Fuyuan section of Heilongjiang River.

This study aims to investigate the differences of biological indexes and meat nutrients of Cyprinus carpio from earth pond reared mode and rice field reared mode (earth pond reared is defined as ER and rice field reared as RR, respectively). Three ER and three RR carps (approximately 800 g) were collected to measure and compare the biological indexes. In addition, the contents of conventional nutrients, amino acids and fatty acids of meat were analyzed and compared between ER and RR. The results showed that the condition factor and meat yield of ER were significantly higher than those of RR, while higher caudal peduncle length/caudal peduncle depth ratio was recorded in RR. Higher contents of crude fat, crude protein, ash, total essential amino acids, total nonessential amino acids, total amino acids and total monounsaturated fatty acids, and the essential amino acid score of meat were detected in ER, while significantly higher contents of total polyunsaturated fatty acids, ∑n-6 PUFA, and total highly unsaturated fatty acids were recorded in RR. In conclusion, the RR has slender body, lower meat yield and lower conventional nutrient contents; the meat amino acids contents of ER are higher than that of RR, while the meat fatty acids composition of carps of the two modes has their own advantages, respectively.

Marine fish have high nutritional value and is popular with the people, and the market is short of supply. China is the largest mariculture country in the world, and has accumulated rich experience in the exploration and practice of marine fish farming. Based on the data of China Fisheries Yearbook and FishstatJ database from Food and Agriculture Organization of the United Nations, the author combines qualitative & quantitative methods to sort out the development of mariculture industry since the founding of the P. R. China, including species structure, regional distribution characteristics, aquaculture models and cost-benefit indicators. The author also analyzes the paths of technological change of marine fish farming, disease prevention and control, nutritional needs and diet formulation, fine management and aquaculture engineering facilities, thus to reveal the evolution rule and provide reference for formulating the sustainable development strategy of marine fish farming.

The paper aims to study the large-scale freshwater fish farming and industrial space optimization. Based on the standard ellipse model, the grass carp with the largest output of freshwater fish was selected as the research object. The spatial distribution pattern (agglomeration degree, gravity center, scope and direction), evolution characteristics and influencing factors of grass carp industry development were analyzed based on the scale of grass carp industry in 31 provincial-level administrative regions of China from 2006 to 2016. The spatial agglomeration of grass carp industry in China shows a trend of discrete agglomeration. The steady increase of output in the upper and middle reaches of the Yangtze River basin and the enlargement of grass carp culture in arid and semi-arid areas in northwest China have promoted the shift of the standard ellipse of grass carp industry to the west and north. The spatial distribution of grass carp industry development presents decentralized agglomeration. Grass carp farming gradually changes from extensive farming to fine farming. The spatial transmission mechanism of grass carp industry development is from the central and eastern regions to the west and north. This is mainly due to the good environmental adaptability of grass carp, relatively low cost in the central and western regions and the expansion effect of the market.

To investigate the effects of water parameters on the concentrations of heavy metals in water and fish muscle in recirculating aquaculture systems (RAS), using tilapia (Oreochromis niloticus) weighed (57.9±0.87) g as experimental creature, we conducted a 60-day experiment in 8 small RASs simulating the actual work condition with changing several water parameters including alkalinity, dissolved oxygen (DO) and total suspended solid (TSS). The results showed that at the end of the experiment, alkalinity had obvious effect on the content of Cu, Zn in water and content of Zn in muscles; dissolved oxygen had obvious effect on the content of Cu in water and contents of Cu, Zn in muscles; TSS had no significant effect on contents of heavy metals in both water and muscles. However, in such experimental conditions, the contents of heavy metals in the muscle (the edible part of fish) of tilapia were under the limits of the national and industrial standards.

This study elaborates a new species in a karst cave near the foot of Longshan Mountain, Xiaoxinzhai Village, Shupi Township, Qiubei County, Wenshan Zhuang and Miao Autonomous Prefecture, Yunnan Province, China. The new species is a member of Sinocyclocheilus, and named as Sinocyclocheilus longshanensis Li et Wu sp. nov. according to the name of collection region. Morphological observation shows that the new species has 7 branched dorsal-fin rays, trailing edges of the last unbranched dorsal-fin ray is serration; normal eyes; sub-upper mouth; humped back; black-brown round spots distributed on exposed body surface; 59~62 lateral line pores. The new species can be distinguished from Sinocyclocheilus maculayus, which has humped back; black-brown round spots distributed on exposed body surface; 81~88 lateral line pores. The new species can be distinguished from Sinocyclocheilus yangzongensis, which has flat back; golden body color; 71~81 lateral line pores. The new species also can be distinguished from other species of Sinocyclocheilus by having the described combination of morphological characteristics.

Income level and urbanization rate are the important factors influencing the consumption of aquatic products, to explore the impact of per capita GDP growth on per capita consumption of aquatic products is useful to evaluate the characteristic of per capita consumption of aquatic products in China. This paper analyzed the relationship between the per capita consumption of aquatic products and the per capita GDP from 1981 to 2015 by using the method of econometric analysis such as cointegration theory and error correction model. The results show that there is a long-term cointegration relationship between per capita consumption of aquatic products and per capita GDP. The change of per capita GDP is the one-way Granger cause of per capita consumption of aquatic products, namely, the increase of economic income could help to increase the consumption of aquatic products. The impact of per capita GDP on per capita consumption of aquatic products is greater than the impact of per capita consumption of aquatic products on per capita GDP, and maintaining the level of income growth is an important measure to promote consumption of aquatic products.

As the core of industry 4.0, Internet of Things technology has become a hot word around the world. As a large agricultural country, in agricultural production, China needs to introduce new technologies to construct a production mode with less consumption, pollution avoidance, low cost and mass production in limited resources. This paper introduces IOT technology combined with Siemens S7-1500 controller, node-red and other Internet of Things tools, connecting sensors and PC station to form a set of PLC controlled fish vegetable symbiosis system. TIA portal serves as the programming configuration software to configure and test the sensor and controlled object, to design the electrical system, to assemble the electrical cabinet of the external control system, and to realize the automatic control of the fish vegetable symbiosis system. The design changes the traditional high-density farming mode, and could act as another type of integrated farming mode imitating nature. It holds the characteristics of low energy consumption, high yield, high profit, good product and no pollution.

In order to know the species distribution, population biology and catches of icefish in Taihu Lake, studies were carried out by the survey of six sampling sites in Taihu Lake. The results showed that there were three species of icefish which were Protosalanx hyalocranius, Salangichthys jordani and Salangichthys tangkahkeii, and Salangichthys tangkahkeii had the highest proportion. Spatial distribution of the three species was not uniform. Values of biological measure in winter (December) showed that the average body length of Protosalanx hyalocranius was 102.7-160.8 mm and its average weight was 3.0-15.4 g. The average body length and the average weight of Salangichthys spring stock was 69.3-71.6 mm and 0.9-1.3 g, respectively. And the average body length and the average weight of Salangichthys autumn stock was 30.5-44.2 mm and 0.1-0.2 g, respectively. 62.7%-96% Salangichthys individuals belonged to the spring stock, which indicated that spring stock was the dominant stock of Salangichthys in Taihu Lake. The catches of icefish from 2010 to 2013 were 1185-2052 t with a sharp annual change. The study obtained the latest basic data of icefish in Taihu Lake and provided reference for the conservation and utilization of icefish resources in Taihu Lake.

By adding Chlorella to tilapia aquaculture water, this study aims to explore the optimal concentration of Chlorella for the degradation of N and P and the regulation of microbial community in aquaculture water. Control group (NC), low concentration group (LC), middle concentration group (MC) and high concentration group (HC) were set to explore the effects of different concentrations of Chlorella on reducing the concentration of N and P in tilapia aquaculture water. The 16S rRNA high-throughput sequencing technology was used to analyze bacteria community structure changes of aquaculture water body. Compared with other treatment groups, N and P nutrition of water body in HC group decreased, and the degradation rate of nitrogen in three forms was NH₄⁺-N>NO₃^--N>NO₂^--N. Compared with NC group, the microbial diversity of MC and HC group decreased. The relative abundance of Proteobacteria in each treatment group increased, while that of Bacteroidetes decreased, and the relative abundance of Bacteroidetes in HC group was the highest, the community richness was significantly correlated with the content of NH₄⁺-N. In summary, Chlorella can absorb N and P nutrition from aquaculture water, regulate aquaculture water microbial community structure, and improve aquaculture water quality. The study could provide a theoretical basis for aquaculture production practice.

In order to research the correlation of morphometric attributes of Synodus macrops and the effects on the body weight, 150 Synodus macrops were collected and the attributes including body length (X₁), body width (X₂), body depth (X₃), head length (X₄) and weight (Y) were measured and analyzed by correlation analysis and path analysis. The results showed that, all correlation coefficients between morphometric attributes and weight achieved very significant difference (P＜0.01). The path coefficient of body length (X₁), body width (X₂), body depth (X₃) to the body weight all achieved significant level (P＜0.01). These morphometric attributes were the most important determination to body weight. Among them body length had the largest direct effect on body weight, and body depth and body width ranked in order. The head length affected body weight indirectly. The diversification of decision coefficients analysis was consisted with the path analysis. Eliminating the head length which had no significantly direct effect on body weight, the multiple regression equation was constructed: Y=-50.198+0.299X₁+0.695X₂+1.238X₃(R²=0.930).

In order to ensure the creatures safe living through winter and summer by scientific regulation of water temperature of fishpond, water temperatures of different vertical layers of fishpond and the shore air temperature were researched at different time scales from March 2011 to February 2012 in Wuhan. The results showed that diurnal change trend of water temperatures at different depths of the fishpond was in consistent with that of the shore air temperature which had relatively smaller amplitude. The amplitude of air temperature and water temperature of each layer under clear weather was significantly greater than that of cloudy days. Monthly averaged air temperature and water temperature of each layer increased from March to July, especially in April. Water temperature decreasing with increasing depth was significantly obvious under clear weather than that under cloudy days. The monthly averaged air temperature and water temperature of each layer decreased from August to February of the next year, especially in January. The variation of water temperature with depth took on fall- rise- fall or fall- rise modes. On the seasonal scale, the decreasing rate of water temperature with increasing depth decreased from spring to autumn. Water temperature with increasing depth presented a fall-rise-fall mode in winter. The results could provide guidance for the scientific management of fish ponds in Wuhan, and could also lay foundation of water temperature forecast for aquaculture.

Opsariichthys bidens and Acrossocheilius hemispinus are two kinds of indigenous freshwater fish in Fujian Province. They have good market foundation, development potential and broad promotion prospects. However, in the process of large-scale artificial breeding, it is found that the parent fish of the two indigenous freshwater fish have common problems such as slow gonadal development, poor synchronization, low amount of eggs and poor egg quality, which seriously affect the industrialization process of the two fish varieties. The strengthening cultivation of parent fish is beneficial to improve fish reproductive performance in order to obtain a large number of high-quality fish fry, so the strengthening cultivation of parent fish is particularly important. At present, the study of strengthening cultivation of parent fish has become an important, complex and extensive research topic. This paper expounds on the research status of strengthening cultivation of parent fish of the two indigenous freshwater fish from the aspects of parent fish strengthening concept, strengthening methods (nutritional strengthening and environmental stimulation) and parent fish conservation scheme. This paper also analyzes the current problems and shortcomings in the cultivation, and puts forward corresponding suggestions, so as to promote the high-quality development of Opsariichthys bidens and Acrossocheilius hemispinus.

To study the effects of different fish oxytocin and their combinations on the reproductive performance of hybrid yellow-headed catfish, three kinds of fish oxytocin were selected, each hormone had 3 levels, and a total of 9 combinations were injected into the breeding parents. Different-dosage combinations of the three kinds of fish oxytocin had a great influence on the induced spawning rate, fertilization rate and hatching rate. The induced spawning rate, fertilization rate and hatching rate of group 9 was 90.0%, 84.7%, 88.9%; and the induced spawning rate, fertilization rate and hatching rate of group 8 was 92.5%, 83.2%, 85.1%. Different doses of the same oxytocin had a certain effect on the effective time of the parent fish. The effective time of group 9 was the shortest (23 h), while that of group 2 was the longest (30 h). In group 9, the combination of luteinizing hormone-releasing hormone, domperidone and human chorionic gonadotropin had the best combination effect.

Larimichthys crocea technological innovation can help strengthen the research and management of Larimichthys crocea industry. The study utilizes the sample data of Larimichthys crocea cage cultivation collected in Ningde of Fujian Province, and comparative analysis、sensitivity analysis and breakeven analysis are used to compare common varieties with new varieties. The result shows that per unit cost of new varieties’ production in feed and fixed worker wage are fully reduced, besides the profitability is also improved due to the adoption of new varieties. So it’s of great significance to promote the sustainable and healthy development of this industry.

To analyze the competitive advantage of China’s characteristic freshwater fish industry, this paper carries out an analysis in 31 provinces and regions based on Michael Porter's diamond model. This paper also constructed the competitiveness evaluation index system of characteristic freshwater fish industry, mainly focused on four main export species of Oreochromis niloticus, Anguillas, Ictalurus punctatus and Acipenser sturio, so as to explore the competitive advantage and international competitiveness of the industry. The results show that: (1) China’s characteristic freshwater fish industry has obvious resource endowment advantages in production competitiveness factors, in terms of market demand factors, the consumption of characteristic freshwater fish is increasing day by day; in terms of related industries, market structure and competition, the technical content and economic added value of processed products of characteristic freshwater fish needs to be improved, the industrialized application of specialized feed for characteristic freshwater fish is not enough, and the number of large-scale enterprises needs to be increased; in terms of opportunities and government policies, a green and healthy ecological breeding system has been gradually established; (2) the resource endowment coefficient of characteristic freshwater fish is always above 1.0, which has obvious advantages of resource endowment; the international market share of China’s characteristic freshwater fish is 73.22%, the trade competitiveness index is close to 1; the revealed comparative advantage coefficients of tilapia and eel are both greater than 6, indicating that China’s characteristic freshwater fish products have obvious competitive advantages in the domestic and foreign markets.

The objective of this paper was to provide useful advices for optimizing industrial distribution, promoting the utilization of patent and leading industry innovation. This paper took Chinese Academy of Fishery Sciences as an example and used quantitative analysis to elaborate the time distribution of the fishery patent, research on the IPC classification, theme words, the top ten fishery research fields and percentage of valid patent. The results showed that the developing process could be divided into three periods which were slowly, fast and fluctuated developing period, respectively. Most patents were related to traditional aquaculture technics such as feed processing and breeding or traditional fishery technics such as offshore cage. But patents related to industrial aquaculture were not much. Besides, fishery patent authorization rate was higher than the overall patent authorization rate in China. But the technology transformation of the granted patent was not optimistic, maintaining time of valid patent was short and technic exportation was insufficient.

The aims are to learn the effect of eugenol on fish culture, and determine whether the stress response may be reduced by moderate anesthesia. By proper anesthesia and no anesthesia on Tilapia mossambica, the dynamic changes of cortisol and lactic acid in T. mossambica plasma after treatment in different periods were tested. The results showed that when the concentration of eugenol gradually increased within the range of 10-120 mg/L, the duration of anesthesia was gradually shortened, and the recovery time gradually increased, and the best concentration was 45 mg/L. Samples were taken after 0, 30 and 60 min, the concentration of cortisol in eugenol group was reduced, while there was no significant difference at different time (P>0.05) and that in the contrast group was obviously increased (P<0.05). The cortisol concentration of eugenol group at 0 min was lower than that of the contrast group and significantly lower than that of the contrast group (P<0.01) at 30 and 60 min. The lactic acid concentration in the two groups almost remained the same at 0 min, and that in contrast group at 30 min and 60 min was greatly higher than that at 0 min (P<0.05), and obviously higher than that of the eugenol group at 0, 30 and 60 min (P<0.05), therefore, the difference of lactic acid concentration in the eugenol group was slight. It indicates that with ideal anesthetic dose, eugenol can effectively avoid the increase of cortisol and lactate acid concentration, and reduce capture stress of T. mossambica.

To provide a scientific basis for the nutritional evaluation of Acrossocheilius parallens muscle, the contents of routine nutrition components, fatty acids and amino acids in muscle were determined and analyzed by biochemical method. The results showed that the contents of water, crude protein, crude fat and crude ash in A.parallens muscle were (77.20±0.42)%, (19.70±0.22)%, (3.25±0.07)% and (1.30±0.01)%, respectively. There were 21 kinds of fatty acids in the muscle, including 8 saturated fatty acids (SFA) and 13 unsaturated fatty acids (UFA). The proportion of UFA and essential fatty acid (EFA) was 68.07% and 21.76%, respectively. There were 17 kinds of amino acids in the muscle, including 7 essential amino acids (EAA), 2 semi-essential amino acids (HEAA) and 8 non-essential amino acids (NEAA). EAA and umami amino acid (UAA) accounted for 40.85% and 37.55% of the total amino acids, respectively. The amino acid composition of A.parallens muscle was well balanced. The amino acid score (AAS) of A.parallens muscle was more than 1 except Valine, the chemical score (CS) was more than 0.5, and the essential amino acid index (EAAI) was 86.19, indicating that the quality of protein was good. To sum up, the high nutritional value of the A.parallens is a kind of high-quality economic freshwater fish with high development value.

Fish fingerling is the foundation and key element for development of aquaculture industry, it determines the yield and quality of fish. In this paper, we summarized the production status of Chinese tilapia fingerlings from four aspects: distribution, variety structure, production technology and industrial chain, analyzed the existing problems, such as weak supervision, limit coverage of good varieties, lack of professionals, high mobility of technical workers, cost increase of production and operational risk. Furthermore, we put forward some corresponding countermeasures for development, such as strengthening breeding research to improve the construction of tilapia fingerling breeding system, raising the threshold of fingerling production and establishing a market access system, perfecting the system of fingerling traceability, and developing countermeasures for the prevention and treatment of tilapia streptococcal diseases.

Rice-fish farming, with small investment, quick effect, low risk and high profit, is an important means of poverty alleviation through the development of green industry. The authors analyzed rice-fish farming modes in Hunan, such as government predominance type of Chenzhou Ctiy, market-oriented type of Nanxian County, and government plus market type of Chenxi County, for poverty alleviation. It is suggested that the long-term plan, mechanism of industrialization and performance evaluation, construction of infrastructural facilities, research on policy of rice-fish farming should be enhanced for poverty alleviation through industrial development.

To investigate the effects of different parental genetic backgrounds on the muscle nutrients of hybrid tilapia (Oreochromis niloticus× O. aureus), we compared the muscle nutrient composition differences among four varieties of hybrid tilapia. The contents of nutritional components, amino acid and fatty acid were analyzed by common methods. The results showed that the moisture content of the four varieties of hybrid tilapia was 79.19%-79.82%, the crude protein content was 17.44%-18.03%, the crude lipid content was 2.13%-2.25%, and the ash content was 0.90%-0.99%, respectively. There was no significant difference among the varieties (P > 0.05) in the above four nutritional components. The total amounts of essential amino acids (EAA) and non-essential amino acids (NEAA) were similar among different varieties of hybrid tilapia, but the contents of arginine, phenylalanine, threonine and alanine were significantly affected by the parental genetic backgrounds (P< 0.05). There was no significant difference in the total amount of saturated fatty acids (SFA) among the hybrid varieties (P > 0.05). However, the total amounts of monounsaturated fatty acids (MUFA) and polyunsaturated fatty acids (PUFA) were significantly influenced by female parents (P < 0.05). The present results could clarify the effect of parental selection on muscle nutrient composition difference in hybrid tilapia varieties, and provide technical assistance in obtaining hybrid tilapia fry of better muscle quality.

The preliminary study showed that the integrated mode for water quality control, named as “5% water spinach (Ipomoea aquatica Forsk.) + 10% filler + algae splashing (Chlorella pyrenoidose)” is worth popularizing. To further verify the effect, the purification effect of different water spinach planting ratios on nitrogen and phosphorus in pond water was studied. Water quality indexes, such as TN (total nitrogen), NH₃-N (ammonia nitrogen), TP (total phosphorus), COD_Mn (permanganate), TSS (total suspended solid), pH and DO (dissolved oxygen), were determined by setting the planting proportion of 5%, 8% and 10% of water spinach, the environmental and economic benefits were also evaluated. The results showed that the TN, NH₃-N, TP, COD_Mn and TSS in tilapia pond were reduced to a certain extent by the cultivation of water spinach. The removal rates of TN and TP were 10%-15% and 20%-40% respectively. The 5% water spinach planting group also had the good removal effect on NH₃-N and COD_Mn, and the economic benefit of this mode was good, which was suitable for application.

The study aims to further obtain information about antibacterial control measures in major trading countries of aquatic products, improve the maximum residue limit (MRL) standard system of fishery antibacterials in China’s aquatic products and enhance the quality and safety level and international competitiveness of China’s aquatic products. The maximum residue limit standard systems of fishery antibacterials in aquatic products of China, Codex Alimentarius Commission (CAC), European Union (EU), and major trading countries (the United States, Japan and etc.) were compared in this study. Besides, the similarities and differences between China and major trading countries in maximum residue limits for fishery antibacterials were analyzed. The results indicate that there are differences in the quantities, limit values and drug types for fishery antibacterial MRLs in aquatic products between China and the above countries and international organizations, among which Japan sets the most maximum residue limit standards with 31 items, followed by EU with 26 items, China with 22 items, CAC and the USA with 5 items. Aiming at the existing problems of maximum residue limit standards for fishery antibacterials in China, this study puts forward suggestions on increasing the basic research of fishery antibacterials, taking a leading role or actively participating in the formulation of fishery antibacterial MRLs, keeping up with the development trend of international standards and strengthening international cooperation and exchange.