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.

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.

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 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.

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.

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 .

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).

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.

The growth characteristics of Pseudorasbora parva cultured artificially were analyzed, in order to provide scientific basis for promoting culture of P. parva. P. parva were cultured artificially in the outdoor flowing water ponds from March 2016 to November 2016. The body weight, body length and total length were measured, respectively. Then the growth characteristics of P. parva were analyzed. The 180 days old fish had average total length of 3.96 cm, average body length of 3.23 cm and average body weight of 0.49 g. The special growth rate, daily weight gain and condition factor were affected by the change of water temperature significantly. The linear relation model between body length（LB）and total length（LT）was described as LT=1.0589LB 0.767,（R2=0.8628）, and the curve relation model between body length（LB） and body weight （W）of the P. parva was expressed as W=0.0466LB2.1623（R2=0.8306）. The coefficient variation was changed from 6% to 14% in body length, from 20% to 41% in body weight and changed from 1.45 to 5.31 in condition factor. P. parva shows strong adaptability under artificial culture condition, thus it indicated that P. parva should be cultured artificially on a large scale.

In order to improve the resistance and survival rate of juvenile grass carp (Ctenopharyngodon idellus ), the study investigated the effects of different doses ofHouttuynia cordata single preparations on the growth performance and physiological and biochemical indexes of juvenile grass carp after fed of different time, it could provide a theoretical guide forHouttuynia cordata as a feed additive to development and utilization. TheHouttuynia cordata powder added to the basic feed in proportion to the mass fraction of 1%, 2% and 3%. Grass carp individuals, the average weight of which was (10.83±0.57) g, fed of different concentrations of Houttuynia cordata single preparations. After fed of 30d, 60d and 90d, its growth index, muscle composition, lysozyme and SOD and other physiological and biochemical indexes were measured. Results showed: average weight and weight gain rate in group 2 increased significantly compared with those of the control group, and significantly higher than group 1 and group 3 at 30d, 60d and 90d(P <0.05). Every group could increase the lysozyme activity and NO content of grass carp, but only group 2 which fed 60d could significantly improve the lysozyme activity and NO content(P <0.05), but there was different reaction time between different organs. The SOD activity in every test group was much higher than those of the control group (P<0.05), and it gradually increased with the reaction time prolonged. The GOT and GPT activity in every test group were lower than those of the control group, and the GPT activity had significant difference between test groups and control group (P <0.05), so it showed some certain protective effect for liver cell. In a word, the optimum feeding time of Houttuynia cordata single Chinese herbal medicine feed additive was 30d to 60d and the optimum additive volume was 2%.

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%.

Freezing preservation can maintain the nutrition value of aquatic products. But ice crystals in aquatic products are prone to grow during the frozen storage and have great impacts on the product quality. It could easily lead to the mechanical damage, protein denaturation, increase of drip loss and decline of flavor and nutrition. Adding cryoprotectant is considered to be one of the most effective ways to prevent frozen aquatic products from protein denaturation. In this paper, functional mechanism and characteristics of cryoprotectant were reviewed. Cryoprotectant can not only improve Ca2 -ATPase activity of aquatic products, but also increase pH and maintain the flavor and nutrition, furthermore, it could inhibit ice crystal growth and reduce muscle tissue damage. Then the application of cryoprotectants including saccharides, composite phosphates, protein hydrolysates and antifreeze proteins was summarized. Modern analytical techniques and methods should be applied to obtaining the dynamic changing characteristics of protein molecule in order to clarify the mechanism of protein denaturation in future researches.

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 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.

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.

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.

From November in 2011 to May in 2012，fish species composition and fish fauna in the lower reach of Yalu River were studied. The results showed that：a total of 33 species were collected，the most species-rich orders were Cypriniformes（12 species） and Perciformes（8 species）. The composition of fish fauna is relatively complex，native fish，temperate water fish，and fish lived in a steady water or the slow water were dominant；the fish in the lower reach of Yalu River belongto different ecological types in migration，water temperature tolerance and feeding habit. The fish community type in Dandong reach of Yalu River was the type of eatuary fishery community. The fish germplasm resources were precious，so it is necessary for us to further strengthen the protection of the ecological environment，pay attention to water pollution in the lower reach of Yalu River.

To find out the output of oil sewage in the bilge compartment of marine fishing vessels of China, the bilge oil sewage of the marine fishing vessels in main fishing areas of China’s eastern coastal areas was sampled and investigated, and the estimation and analysis were carried out to know the annual total amount of the oil sewage discharged by China’s marine fishing vessels. The calculated data showed that the total annual displacement of China’s marine fishing vessels was about 136118 t, and the total annual oil discharge was about 5238 t. It is concluded that: the amount of oil pollution is not directly related to the ship age, however, the ship is in a better condition under the age of 5 years; the oil content of oil sewage is basically less than 5%, and the oil content of the lower water after a long static time is still higher than that of the discharge standard; and the oil sewage output from the marine fishing vessels is related to the daily management. Suggestions are put forward as: strengthening the publicity to improve fishermen’s awareness of environmental protection; strengthening supervision to reduce the emission of fishing vessels; encouraging fishing vessels to collect pollutants; strengthening cooperation and establishing coordinati on mechanism of various departments; strengthening research and development to promote technological innovation on oil sewage processing in the bilge compartment.

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 objective of this study was to investigate the influence of copper and manganese on apoptosis in blood cells of Oreochromis nilotcus and the antagonistic effect of iron and zinc. Atomic absorption spectrophotometry was used to analyze heavy mental content in fish blood and food, and flow cytometry was applied to analyze fish blood cell apoptosis. Juvenile Tilapia were randomly divided into 12 groups with 30 fish in each group. The challenge groups were fed with constant level of copper sulfate (0, 2000 mg/kg) and manganese sulfate (0, 120 mg/kg) diet, and the antagonized groups were fed with zinc sulfate (20, 320 mg/kg) and iron sulfate (150, 350 mg/kg). Twenty weeks later, the number of apoptotic cells in the blood obviously increased in copper group and manganese group. After adding iron and zinc, the number of apoptotic cells was lower than that of the copper group and manganese group. The numbers of apoptotic cells in the iron and zinc interventional groups were significantly higher than that in the control group. Copper and manganese can cause apoptosis in blood cells. However, those effects can be antagonized by iron and zinc.

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.

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.

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.

This study aims at investigating the effects of replacing soybean oil with rubber seed oil on growth performance, digestive enzyme activity and antioxidant capacity of Asian red- tailed catfish (Hemibagrus wyckioides), and determining the appropriate replacement rate of soybean oil by rubber seed oil. Five isoproteic and isolipidic experimental diets (R0, R25, R50, R75 and R100) were formulated with rubber seed oil replacing 0%, 25%, 50%, 75% and 100% soybean oil in diets, respectively. The feeding trial lasted for 8 weeks. The results showed that: (1) the weight gain and daily gain coefficient of fish fed R25 diet were significantly higher than that of the other diets (P<0.05); (2) the intestinal lipase activity was higher in R25, R50 and R75 diets, compared to R100 diet; the intestinal trypsin activity of R25 diet was significantly higher than that of the other diets; similarly, the hepatic lipase activity was higher in R25 diet compared with fish fed R75 and R100 diets; (3) with the increasing of rubber seed oil replacement level, the hepatic alanine transaminase, aspartate transaminase and glutamyl transpeptidase activities firstly increased and then decreased, the highest values were observed in R25 diet; the hepatic glutamate dehydrogenase activity of R100 diet was significantly lower than that of R0 diet; (4) the plasma peroxidase of R100 diet was significantly lower than that in R25 and R75 diets; similarly, the plasma total antioxidant capacity of R100 diet was significantly lower than that of R25 and R75 diets; the hepatic malondialdehyde content was significantly higher in R100 diet compared with fish fed the other diets. These results indicate that replacing 25%-75% soybean oil with rubber seed oil has no obvious negative effect on feed utilization and antioxidant capacity, and replacing 25% soybean oil is beneficial to improve the growth performance, but total replacement markedly depresses the antioxidant capacity of Hemibagrus wyckioides.

To get the CDO (Critical Dissolved Oxygen) of gasping for air and Pan Tong for Grass carp in spring, we carried out several simulation experiments in Jingzhou Agricultural Meteorological Station in spring. The results indicated that, the CDO of gasping for air and Pan Tong for Grass carp in spring was 0.30, 0.10 mg/L and lasted more than 30 min respectively. The results also showed that, there was a direct relationship between water turbidity level and dissolved oxygen ability of water body. The DO increment of pond water oxygenated in 14 hours was 1.98 mg/L higher than mild turbid running water oxygenated, and the DO of replacement of running water had been raised by 1.2-1.6 mg/L. So special attention on water quality should be paid in pond culture of fish in spring, and there would be a greater improvement of fishes’ living environment if water quality was improved, and gasping for air and Pan Tong might be held off or reduced to some extent, thus greater economic losses would be avoided.

Cyanobacteria bloom is a serious problem in aquaculture. In this paper, the formation of cyanobacterial blooms, the harm of cyanobacteria bloom, and the treatment methods were summarized. Among all the treatments, using the microorganism is a kind of effective method. Then paper explained the mechanism of control algae echanism with Bacillus and discussed future application of Bacillus in the controlling harmful algal and repairing water environment.

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.

With the development of the technique of computer and network, the fish biodiversity database had played an increasingly important role in the research work. The work on the biodiversity data has been increasingly important. This paper summarized the main fish biodiversity databases and analyzed the main problems during the construction of fish biodiversity databases. With the analysis of the successful case of FishBase, this study analyzed the main issues during the construction of fish biodiversity database and provided the essential reference for the researchers and managers.

To study the reproductive performance of tilapia from different parental combinations and the effect on the male rate of their offspring, hybrid experiment was carried out with the Nile tilapia as female parent and the blue tilapia as male parent. 900 Nile tilapia and 310 blue tilapia were chosen for hybrid production in the first experiment, the results showed that the average fry yield per Nile tilapia is 139.5, and the male rate is 93.3%; in the second experiment, 270 Nile tilapia and 195 blue tilapia were selected from the same population in the first experiment. According to the different proportion of female and male (2:1 in group A, 1.5:1 in group B and 1:1 in group C) for hybridization, the results are as following: the average fry yield per Nile tilapia in group C (166.2) is greater than that of the B (137) and C (109.7) (P<0.01). What’s more, the male rates of hybrid offspring in group C (97.1%) was extremely significant difference (P<0.01) compared with group A (94.1%) and B (95.2%). The results of the two experiments showed that the proportion of female and male 1:1 is the the best combination of hybrid tilapia. It is important for guiding tilapia hybrid and fry breeding.

With the improvement of living standards, people pay more and more attention to dietary quality； And several carnivorous fishes, such as perch, Channa argus and Siniperca chuatsi have been paid more attention because of their higher nutritive value. At present, these kinds of economic fish are in the transformation process of aquaculture model from the traditional pond culture to the pond engineering culture and from feeding the ice fresh fish to feed the artificial formula feed. This paper summarized the current aquaculture status and the indexes in the specific evaluation of nutritional value for these major freshwater aquatic products, and summarized the possible changes of nutritional value in the course of the conversion of the aquaculture model. After the discussion, it was found that the nutritional value, especially protein quality of economic fish such as perch and mandarin fish fed with formula feed were lower than those fed with ice fresh fish ，and the effect of this new aquaculture model with pond circulating water culture on the nutritive value of these carnivorous fishes was unclear for the nutritional value of the fish.However, seen from the present research, pond circulating water culture can effectively improve water quality and limit the accumulation of harmful substances to a certain extent. So this new aquaculture model has a positive effect on the edible quality of these kinds of economic fishes. This paper summarizes the mechanism of nutrient value formation during the transformation of aquaculture model for the main freshwater aquatic products, to provide a theoretical basis for the implementation of a new green and healthy sustainable aquaculture model.

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.

Taking the aquatic research institutes as typical cases, an empirical analysis was carried out on the transformation mechanism of scientific and technological achievements of scientific research institutions. The revenue-oriented transformation was one of the main modes of the transformation of fishery science and technology achievements in China's aquatic research institutes, including endogenous transformation and exogenous transformation. Taking the Fisheries Research Institute of Wuhan Academy of Agricultural Sciences and the Fishery Machinery and Instrument Research Institute of China Academy of Fishery Sciences as examples, this paper introduced the differences in the operation mechanism and promotion effect between the endogenous transformation and exogenous transformation, and pointed out the problems in both the two. Suggestions on speeding up the transformation of agricultural science and technology achievements were proposed.

To study the effect and mechanism of “using aquaculture to curb alkali saline-area” model on the saline-alkali land, the saline-alkali land in Jingtai County was used as test field, the solodization effect of aquaculture technology on sandy saline-alkali soil and loam saline-alkali soil was compared. The effects of aquaculture on saline and alkali migration were studied by regularly monitoring and analyzing the changes of water quality parameters in different types of soil and water before and after fish culture. The results showed that the aquaculture model could improve the soil environment of saline and alkaline areas to some extent, and the control effect on sandy soil was better than that on loam soil. In addition, the ammonia nitrogen produced during the cultivation did not show an upward trend, which indicated that it did not cause secondary pollution to the local area. The results of this study provided theoretical and technical support for the application and promotion of “using aquaculture to curb alkali saline-area” model in northwest China.

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.

At present, most tail water of aquatic animal culture is discharged into the environment directly, which has caused severe environmental pollution. To control the emission of aquaculture tail water effectively, the following strategies to farmers and policy managers in terms of thoughts and actions are put forward in line with the principle of overall systematicness and practicability: (1) to understand and maintain China’s basic state policy for environmental protection; (2) farmers need to improve their management level and establish new farming models; (3) managers should set up regional and intensive resource utilization and treatment standards of tail water emission, establish and improve relevant laws and insurance systems, and strengthen the governance.

To verify the practical culturing effect of a previously designed circulating water treatment system based on heterotopic pond restoration technology, a large-scale multi-species saturating culture experiment was carried out for 3 years. The effects of the system on water quality control was evaluated by measuring the total nitrogen (TN), total phosphorus (TP), chemical oxygen consumption (COD_Mn) and chlorophyll (Chla) in a common freshwater fish culturing pond. The results showed that in the early stage of the experiment, the total nitrogen level (TP) of the circulating water of the pond reached Class III of the Environmental Quality Standards for Surface Water (GB 3838—2002), and the total phosphorus level (TN) reached Class III to V. The average removal rate of TP, TN, COD_Mn and Chla was 40.13%, 45.02%, 43.37% and 86.6%, respectively. The removal efficiency of the system was significant. In the late stage of the experiment, with the continuous increase of the feed input, although the efficiency of the circulating system was greatly improved, the data of each index were still higher than expected. This experiment provides a new idea for the treatment of large-scale aquaculture water by circulating water in freshwater ponds.

The establishment of characteristic columns is of great significance to enhance the influence of popular agricultural science periodicals, to realize ‘dislocation competition’ and ‘characteristic journal management’ and to make the periodicals have ‘irreplaceable’ inner quality. Taking the Special column designed by the journal of Scientific Fish Farming as an example, the column is characterized by recording the industry process and serving the fishery economy. The column follows the guidance of national policies, highlights the planning awareness and focuses on hot spots, and it plays an important role in the spreading of information on meteorological disaster emergency, fishery food safety, development of rice-fish integrated farming model, and ‘company+fishery’ business model. The results show that the success of characteristic columns has promoted the brand construction of the periodical, and the publishing practice could be used as reference by peers.

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.

The technique of sperm cryopreservation of three rare migratory fishes in the Yangtze River was studied, including Acipenser baerii, Alosa sapidissima and Takifugu obscurus. The success of sperm cryopreservation was evaluated by post-thaw sperm motility. To explore methods for sperm cryopreservation, this study evaluated the effects of different extenders, cryoprotectants, their volume fractions, equilibration time and dilution ratios. The result showed that the best sperm cryopreservation of motility of Acipenser baerii was (45±5.00)% and Takifugu obscurus (60.5±2.69)% were obtained by following procedure: the ringer solution and the semen were mixed at ratio of 2:1 in volume and added 10% methanol, while the best sperm cryopreservation of motility of Alosa sapidissima (80.3±2.58)% was obtained by following procedure: the ringer solution and the semen were mixed at ratio of 3:1 in volume and added 10% methanol. Sperms were cryopreserved by three-step cooling progam. These results provided the methods to conserve genetic resources in three rare migratory fishes in the Yangtze River.

In order to forecast the trend of tilapia trade, and guide the healthy sustainable development of tilapia industry, the basic situation of China"s tilapia exports, exports of regional, and export target countries were analyzed, tilapia trade development trend was forecasted. The results showed that China"s tilapia products were mostly supplied to the international market. In recent years, export trade showed a good state basically, but the growth speed had slowdown gradually. To meet the international market demand, frozen tilapia fillets had become the most important products in China. Guangdong, Hainan, Guangxi, Fujian were the main tilapia export provinces. Chinese tilapia"s largest export target country is the United States. The increase of export target countries also represented China"s tilapia market was tend to be diversified. At the same time, tilapia industry"s future was faced with many problems, such as the increase of the trade competitiveness of competitors and decrease of the market, and the severe international trade environment. Sustained and stable development of tilapia industry must rely on the developing of domestic and foreign market, improving the quality of the products and building up the marketing channels, etc.