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Copyright of Acta Agriculturae Zhejiangensis is the property of Acta Agriculturae Zhejiangensis Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

With the rapid development of aquaculture in China in recent decades, the country now faces environmental problems, such as high energy consumption and severe environmental pollution. The Yangtze River Basin is the most important area for freshwater aquaculture production in China, accounting for more than half of the total production. The environmental issues induced by aquaculture have received widespread consideration in this area. However, the freshwater farming-induced environmental issues in the Yangtze River Basin were rarely evaluated in prior research. Life cycle assessment (LCA) is a valid tool for assessing environmental impacts and resources and is widely deployed in the industrial sector. It can quantify the impact of a product or service on different environmental indicators at various stages of the production process, thereby aiding in the identification of the best measures to reduce environmental impacts. The LCA is more effective than traditional environmental impact assessment methods; thus, it has been gradually applied in other fields, such as agriculture and aquaculture, in recent years. In aquaculture, LCA has been used to evaluate the environmental impact of various farming models or species in a laboratory setting. However, little attention has been paid to large-scale systems, such as the Yangtze River Basin. The two most important farming models in China are the pond farming model and the integrated rice-fish farming model. Among them, the integrated rice-fish farming model is regarded as environmentally friendly and an important step towards realizing the sustainable development of aquaculture in terms of the efficient utilization of water and land resources. Therefore, in this study, the environmental effects of pond farming and integrated rice-fish farming models were investigated in the Yangtze River Basin using the LCA method. A total of 20 monitoring points were established in the Yangtze River Basin, including 5 for integrated rice-fish farming and 15 for pond culture. In the integrated rice-fish farming model, the life cycle consists of two stages: Feed supply and breeding. In pond culture, the life cycle consists of three stages: Feed supply, power supply, and breeding. We analyzed the values of energy use (EU), global warming potential (GWP), acidification potential (AP), eutrophication potential (EP), and water use (WU) in the pond farming and integrated rice-fish farming models using the LCA method, assessed the contribution rate of each phase for environmental indices, and compared the environmental impact of the two farming models. In order to establish the inputs and outputs of an aquaculture system, experimental measurements and surveys were conducted to collect data. The collected data mainly included feed consumption, electricity consumption, water consumption, total phosphorus and total nitrogen emissions, and greenhouse gas (CH4 and N2O) emissions. The data were analyzed by the LCA software eBalance. In this study, the weight gain of 1 ton of aquaculture products served as the functional unit, and the results were standardized and evaluated in order to compare the environmental impacts of various impact indicators. The results showed that the standardized and weighted evaluation values of WU, EP, GWP, AP, and EU in the integrated rice-fish farming model were 11.650, 0.770, 0.141, 0.096, and 0.003, respectively, and the total environmental impact indicator was 12.660. In the pond farming model, the values of WU, EP, GWP, AP, and EU were 31.453, 1.187, 0.210, 0.174, and 0.007, respectively, and the total environmental impact indicator was 33.031. The environmental impacts of integrated rice-fish farming were lower than those of pond farming. The contribution rate analysis of the three stages of the life cycle to environmental impact showed that the contribution rates of EU, GWP, and AP in the feed supply stage were higher than those in the power supply and breeding stages. EP was primarily associated with the feed supply stage and pollutant discharge stages of the breeding process, and WU was principally concentrated on the breeding stage. Overall, the LCA results showed that the integrated rice-fish farming model had a more environmentally friendly effect than the pond farming model, which indicates that the Yangtze River Basin has considerable development potential. WU was the most influential environmental impact indicator and the main restriction factor in aquaculture; it was mainly associated with the breeding stage. Therefore, moderately increasing stocking density was an effective strategy for reducing water resource consumption and improving water resource utilization rates. In addition to WU, the main environmental impact index of the pond culture model and integrated rice-fish farming models comprised EP, followed by GWP, AP, and EU. The contribution rate analyses of the two models showed that the aquaculture-induced environmental impacts could be mitigated by improving feed production technology, establishing accurate feeding technologies, applying advanced effluent water treatment technologies, and appropriately increasing stocking density in the Yangtze River Basin. In summary, in this study, we compared the environmental impacts between the pond culture and integrated rice-fish farming models in the Yangtze River Basin using the LCA method. In addition, we analyzed the differences between environmental impacts at different production stages. These data served as a reference for the sustainable development and optimization of aquaculture in the Yangtze River Basin.

Rice flower carp (Cyprinus carpio rubrofuscus) has high economic value because of its tender meat. However, a comprehensive scientific evaluation of the meat quality and nutritional value of rice flower carp is still needed. At the same time, because of its fast growth and strong disease resistance, rice flower carp is widely popularized in rice field culture but without any research comparing its quality with the pond culture method. Although rice farming has high ecological value, the fish yield is low and its specifications are abnormal, which cannot guarantee the stability and safety of the commercial fish supply and limit the potential rice flower carp industrial benefits. In addition, some studies have shown that fish muscle quality can be affected by environmental conditions. This study aimed to comprehensively evaluate the muscle quality and nutritional value of the rice flower carp and investigate the relationships between the nutritional values and its culture conditions, providing data to increase the rice flower carp yield, economic efficiency, and farmed varieties available. Therefore, 6 000 Quanzhou rice flower carp (2.35±0.08 g) were randomly divided into ponds and rice field groups for the experiment (three replicates per group, with a density of 15 000/hm2). The pond culture group was fed with 3% of the commercially established everyday food per fish weight, while the rice field group was not fed. After 12 weeks, the fish were submitted to a 24 h period without food and anesthetized using MS-222 (USA, Sigma). The length and weight of 100 fish were measured for each treatment. For the rice field group and pond group, respectively, the lengths were (13.56±0.49) cm and (14.10±0.23) cm, and the weights were (73.19±7.02) g and (101.20±4.57) g. The muscle quality of 30 fish from each treatment was measured, including basic nutritional components, texture characteristics, and amino acid and fatty acid compositions. The nutritional level was compared between the pond and rice field groups using the FAO/WHO amino acid score, whole egg protein comparison, protein amino acid score (AAS), chemical score (CS), and essential amino acid index (EAAI). Moreover, no significant differences between the two culture methods were observed in relation to the total ash (P > 0.05). The crude protein and crude fat contents in the rice field group were significantly lower than in the pond group (P < 0.05), while moisture was significantly higher (P < 0.05). The viscosity of the rice field group was significantly lower than that of the pond group (P < 0.05), but the cohesion and shear force were significantly higher than those of the pond group (P < 0.05). There was no significant difference in the other texture indexes (P > 0.05). Essential amino acids (EAA) in both groups met the FAO/WHO standard. Among the 18 amino acids measured, the total amino acids (TAA), delicious amino acids (DAA), essential and nonessential amino acids (NEAA) were significantly lower in rice field conditions than in pond (P < 0.05), while the EAA/TAA and EAA/NEAA ratios were significantly lower in the pond group (P < 0.05). According to the amino acid score (AAS) and chemical score (CS), glutamic acid (Glu) was the most common amino acid in both groups, while the first and second limiting amino acids were tryptophan (Trp) and valine (Val). Among the 22 fatty acids observed, the contents of tridecanoic, pentadecanoic, palmitoleic, heptadecanoic, and docosatetraenoic acids were not significantly different between the two groups (P > 0.05). In contrast, the contents of linoleic, linolenic, and arachidonic acids in the pond group were significantly higher than those in the rice field group (P < 0.05), while 14 other fatty acids showed significantly lower contents in the pond group (P < 0.05). The monounsaturated fatty acid (MUFA) contents in the pond group were significantly higher (P < 0.05), while the EPA+DHA and n-3PUFA/n-6PUFA were significantly lower than those in the rice field group (P < 0.05). Overall, the contents of four main flavor amino acids (glutamic acid, glycine, alanine, and aspartic acid) in the rice field group were significantly lower than those in the pond group (P < 0.05). In conclusion, rice flower carp reared in both pond and rice field is a high-quality protein source. However, different cultural environments significantly influence the rice flower carp muscle nutritional value and quality, wherein a higher nutrient composition and amino acid score were observed in the pond environment. Concerning the fatty acids content, the muscle of rice flower carp reared in rice fields had higher EPA+DHA content and N-3/N-6 polyunsaturated fatty acid ratio, which is more suitable for people with hyperlipidemia and cardiovascular diseases. In addition, in terms of texture, the muscle of rice flower carp is chewier under the rice field rearing condition. Nevertheless, N-3PUFA shortages were observed in both culture conditions. Besides, fish in the pond group had better muscle nutrition than the rice field group. Different culture conditions can change rice flower carp's fatty acid composition and content to a certain extent, but none of the two conditions tested here could completely allay the lower N-3PUFA problem. Therefore, increasing the N-3PUFA content of rice flower carp is the key to improving its nutritional value, and pond culture conditions make this process easier to be manually controlled.

In order to achieve accurate and reliable prediction of the dissolved oxygen in ponds and mitigate aquaculture risks, we propose a predictive model based on Feature Construction (FC) pretreatment and Temporal Convolutional Network (TCN) coupled with Bidirectional Gate Recurrent Unit (BiGRU). By constructing statistical features, environmental factor features and seasonal features from the samples, deep-level correlations between variables are explored. Then, the structural feature sequences are processed using multiple layers of convolution and dimensionality reduction through TCN, while preserving the global temporal characteristics and removing redundant information. By integrating BiGRU to model the reduced features, accurate prediction of dissolved oxygen levels is achieved. Furthermore, the Sand Cat Swarm Optimization (SCSO) algorithm is employed to optimize the non-parametric Kernel Density Estimation (KDE) for estimating the distribution range of dissolved oxygen prediction errors. The experimental results indicate that the proposed model achieves superior performance compared to other comparative models, with respective values of 0.027 5 for Mean Squared Error (MSE), 0.143 2 for Mean Absolute Error (MAE), 0.165 8 for Root Mean Squared Error (RMSE), and 0.94 for the Coefficient of Determination (R²). Meanwhile, the interval estimation effectively covers the fluctuation range of dissolved oxygen, thereby quantifying the uncertainty in the prediction process. In the short-term prediction of dissolved oxygen levels in ponds, this model demonstrates notable accuracy and robustness. It is instructive for water quality monitoring in aquaculture and the enhancement of farming efficiency. [ABSTRACT FROM AUTHOR]

In response to the current situation that most of the bait feeders in pond culture rely on manpower, which is labor-intensive, and it is difficult to feed the baiting boats on steep sloping banks, an energy-saving feeding truck without power discharging has been designed. The truck uses a rotating discharging valve for feeding, and a scissor lift platform for adjusting the height of feeding. Through the design of the spherical limit rotating connector located at the discharge port of the rotating discharging valve to adjust the inclination angle of the feeding tube to realize the non-powered discharging, a new type of telescopic feeding tube is designed based on cylindrical cam. The feeding truck can realize directional, fixed-distance and fixed-point feed addition through the movement of the truck body, the lifting and lowering of the scissor lift platform, and the adjustment of the inclination angle and length of the feeding tube. The prototype of the feeding truck was made, and the feeding test was carried out with the baiting boat and stationary baiting machine as the feeding target, and the test results show that the feeding truck has the universality for different specifications of feeds, and the telescopic length of 1.2 m and the lifting height of 1.5 m can satisfy the feeding needs of the baiting boat and stationary baiting machine, and the adjusting is flexible, and the rate of feeding is 6.2 kg/min. The designed feeding truck is flexible in use, and it can replace the manual feeding to the baiting boat and stationary baiting machine. It can replace manual feeding for baiting boat and fixed baiting machine, reduce manual labor intensity, improve the mechanization level of breeding process, and lay the foundation for further automation and intelligence. [ABSTRACT FROM AUTHOR]

In order to realize the pond culture of Opsarüchthys bidens in northern China, the autumn fingerling breeding experiment of Cpsariichthys bidens was carried out in two ponds in Liaoyang area of Liaoning Province from May to October 2021. The results showed that the average body length of summerlings in the two ponds was 31.85 mm and the average body mass was 0.28 g after 30 and 33 days of cultivation, respectively. After 123 and 125 more days of cultivation, the average body mass of autumn fingerlings in the two ponds reached 36.50 g and 46.25 g, respectively. The total mass of autumn fingerlings was 12 300 kg, the average survival rate was 61.9%, and the average feed coefficient was 1.62. In July, the maximum value of the specific growth rate of the total length of the juvenile was 4.00%/d, and the maximum value of the daily mass growth of the juvenile was 0.49 g in Septem- ber. There was a power function relationship between the total length and body mass of juvenile fish from fry to au- tumn fingerling. It is suggested that the water temperature should be maintained at 20-25 °C and the density should be controlled at about 225 000 fishes per hectare under the condition of pond culture. [ABSTRACT FROM AUTHOR]

Copyright of South China Fisheries Science is the property of South China Fisheries Science Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Northwest A & F University - Natural Science Edition is the property of Editorial Department of Journal of Northwest A&F University (Natural Science Edition) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

【Objective】The study was conducted to understand the growth and development law of Siniperca chuatsi Guangqing No.1 (hereinafter called mandarin fish) fed with compound diet and cultivated in pond so as to provide references for the breeding and large-scale culture of mandarin fish.【Method】The morphological parameters and growth performance of mandarin fish fed with compound diet at different month-ages in a whole cultivation period were measured. Three nonlinear models, Logistic, Gompertz and Bertalanffy, were used to construct the growth curves of both body mass and body length of the mandarin fish.【Result】The maximum absolute body weight gain and absolute body length gain were found at 5-month-age fish, and 3-month-age fish, respectively. While the relative body weight gain and body length gain began to decrease from 4 months age. Morphological parameters, including condition factor (CF), viscerosomatic index (VSI) and mesenteric fat index (MFI) increased while hepatosomatic index (HIS) and intestine & stomach index (ISI) decreased as the fish month ages increased. The three models could simulate the growth curve of mandarin fish well, with a degree of fit R2 ≥ 0.97. Correlation analysis between the model predicted value and the measured value showed that the Logistic model was better than the other two models. The growth models for body mass and both length were as follows respectively, Wt=1230.808/(1+39.666e-0.760t), R2=0.989; Lt=40.871/(1+3.076e-0.387t), R2=0.990. The growth inflection point for body mass was at 4.843 months, corresponding to body mass and both length of 615.404 g and 20.436 cm, respectively.【Conclusion】Logistic model is more suitable to describe the growth process of mandarin fish, and it can predict the growth data of different stages, which will provide theoretical basis for further breeding and large-scale culture of mandarin fish fed with compound diet.

Copyright of Journal of Food Safety & Quality is the property of Journal of Food Safety & Quality Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

An efficient aerobic denitrifying bacteria species was isolated from water in a Ctenopharyngodon idellus culture pond in Zhongshan City, Guangdong Province in March 2018. The bacteria were identified as Pseudomonas furukawaii by morphological observation, physiological and biochemical characteristics, and 16S rDNA sequence analysis. This strain was named Pseudomonas furukawaii ZS1. The denitrification characteristics of the strain and the effects of the carbon source, temperature, pH, C/N ratio and shaking speed on the denitrification ability of strain ZS1 were investigated. The results showed that P. furukawaii ZS1 was an efficient denitrifier under aerobic conditions. The content of nitrate nitrogen (NO3-) decreased from 48.93 mg/L to 1.27 mg/L, the removal efficiency of -N was 97.40%, and the removal rate was 0.993 mg/L/h; the content of total nitrogen (TN) decreased from 52.04 mg/L to 8.40 mg/L, the removal efficiency was 83.86%, and the removal rate was 0.909 mg/L/h. Single-factor experiments indicated that the optimal conditions for denitrification activity in P. furukawaii ZS1 were a carbon source of sodium acetate, sodium citrate or glucose; temperatures ranging from 25 to 35°C; a pH of 7.0 to 10.0; a C/N ratio of 15 to 25; and a shaking speed of 100 to 200 r/min. The above results showed that the strain could quickly and effectively remove nitrogen through aerobic denitrification. Therefore, the P. furukawaii ZS1 strain can be used as a candidate strain for the treatment of pond culture wastewater through biological denitrification. [ABSTRACT FROM AUTHOR]

Copyright of Environmental Science & Technology (10036504) is the property of Editorial Board of Environmental Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Agro-Environment Science is the property of Journal of Agro-Environment Science Editorial Board and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Pond aquaculture plays a very important role in China's aquaculture industry and is the main source of aquatic product supply. To improve the effect of pond aquaculture, a partitioned recirculating aquaculture pond system (PRAPS) was designed and built based on the characteristics of pond aquaculture in freshwater, which consisted of feeding fish culture zone (20% of water surface) and filter-feeding fish culture zone (80% of water surface). The structure of facilities and equipment of PRAPS was optimized by setting up the overflow weir, propeller flow device, paddlewheel device, and pollutant absorption and collecting device. Tests on the mechanical properties revealed that both propeller flow device and paddlewheel device could achieve the design demand; the energy efficiency of the propeller flow device was about 340 m3/(kW·h), the flow rate was around 204 m3/h, and the no-load running noise was 60 dB; the energy efficiency of the paddlewheel device was about 360 m3/(kW·h), the flow rate was around 180 m3/h, and the no-load running noise was 67 dB; the total flow rate of the overflow weir was about 331 m3/h. The exchange capacity was totally about 7 900 m3/day, accounting for about 50% of the pond water capacity. Additionally, the system could reduce the total energy consumption and farming pollution and effectively improve the pond aquaculture ecological effect, which met the production requirement of energy saving and environmental protection. It was conducive to improve the water quality of the pond though the impeller disturbed the water. The pollutant could be gathered into the middle of bottom by the collecting device, and removed out of system by the pollutant absorption device, in which way the transparency of water was improved, and the content of TN (total nitrogen) and TP (total phosphorus) in the system was decreased. The propeller flow device and paddlewheel impeller stirring water could realize water convection in large scale, so the water was exposed to sunshine and air, which could increase the dissolved oxygen in the water. Tests showed that the dissolved oxygen of the middle and lower layer in the test pond was 59.5% higher than the control pond; the content of TN in the test pond was 21.4% lower than the control pond; the content of TP was 53.1% lower than the control pond; the chlorophyll a concentration in the test pond was lower than the control pond. Because the breeding density in the test pond was higher than the control pond, the content of ammonia nitrogen and nitrite nitrogen in the system was increased. Overall the water quality in the test pond was better than the control pond. For the PRAPS, the one-time investment was big at the beginning and it needed professional and technical personnel to maintain, while the PRAPS had a high economic efficiency. The yield of bream in the test pond was 10 280 kg, and the food coefficient was 1.7; the yield of bream in the control pond was 8 488 kg, and the food coefficient was 2.1. The result showed that the yield of bream increased by 21.1% using the PRAPS, the feed coefficient decreased by more than 23.5%, and the annual output value increased by 6%. The result provides the reference for the model establishment of healthy breeding pond system, which is helpful to make PRAPS become a more mature and reliable novel pond aquaculture system. [ABSTRACT FROM AUTHOR]