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Grass carp belongs to Cypriniformes, Cyprinidae, and Cyprinus family, and is typically referred to as the four famous domestic fishes, black carp, silver carp, and bighead carp, respectively. The annual production of Chinese grass carp is consistently among the highest, with an output of 5.905 million tons in 2022, accounting for 24.3% of total of freshwater fish production. Reproduction is the core process of fish reproduction. Normal gonad development is a prerequisite for fish reproduction. At present, there are few reports on the sex differentiation of Chinese grass carp. Studying the differentiation and development of grass carp gonads can provide a typical model for gonadal development of cyprinid fish. In contrast, the start and completion time of gonadal differentiation are one of the key factors inducing sex reversal in fish using hormones. Research on gonadal differentiation and development in grass carp can also lay the foundation for the establishment of a unisexual population of grass carp.Sex-related genes play important roles in biological processes such as sex determination, gonadal differentiation, and reproduction and development in fish. In most differentiated teleost fish, genes such as dmrt1, sox9, foxl2, amh, and cyp19a1a, are considered the key genes involved in sex regulation. cyp19a1a plays a key role in the gonadal differentiation and ovarian development of teleost fish by aromatizing androgens into estrogen via aromatase activity. This gene is specifically expressed in the gonads and is used served as a characteristic gene for sex differentiation towards females. Anti-Müllerian hormone (amh) regulates the structure of reproductive organs and the differentiation and development of reproductive cells. In fish such as carp, rainbow trout, and grass carp, the expression level of the amh gene in the testes is significantly higher than that in the ovaries, and is often used as a characteristic gene for male differentiation.To explore the sex differentiation and developmental patterns of grass carp gonads, this study analyzed the tissue structure and expression differences of sex characteristic genes cyp19a1a and amh in the gonads of grass carp at 1, 2, 3, 4, 5, 6, 12, 24, 36, and 48 months of age using tissue sectioning technology and real-time fluorescence quantification technology. The results of tissue sectioning showed that grass carp exhibited reproductive ridges at 1-month-old. At 2 months of age, primitive germ cells were first observed in the reproductive crest, marking the formation of their primitive gonads. At 3-month- old, ovarian cavities and lobules were observed in the gonads of female grass carp. At 4-month-old, oogonia was observed, indicating anatomical differentiation at 3-month-old and cytological differentiation at 4-month-old. At the age of 4 and 5 months, ductus deferens and spermatogonia were respectively observed in male grass carp gonads, indicating anatomical differentiation at 4 months and cytological differentiation at 5 months. The ovaries of 24, 36, and 48-month-old grass carp were in the first, second, third, and fourth stages of development, respectively, while the testes were in the second, second, third, and fourth stages of development, respectively. At 48 months of age, the gonads of grass carp have matured. The fluorescence quantitative results showed that the expression level of the female characteristic gene cyp19a1a in the ovary showed an overall trend of first increasing, then decreasing, and then increasing again. The expression level of this gene was significantly upregulated at 2 months of age (P < 0.05), and reached its peak at 3, 6, and 48 months of age. During these three periods, anatomical changes were observed in the female gonads in the tissue sections, with a large proliferation of oocytes and the gonads tending to mature. The expression level of the male characteristic gene amh in the testes showed an overall trend of first increasing and then decreasing. At 2 months of age, the expression level of this gene was significantly upregulated (P < 0.05). At 5 months of age, it reached the peak when there were a large proliferation of spermatogonia in the gonads, and then remained low expression until gonadal maturity.In summary, this study confirmed that the initiation time of grass carp gonadal development is approximately 2 months old, and the differentiation time of male and female gonads is approximately 3 and 4 months old, respectively. By the age of 6 months, both male and female grass carp gonads completely differentiated. These results not only enrich the reproductive physiology data of grass carp but also provide a reference basis for the study of hormone-induced sex reversal technology in grass carp.

In order to identify biomarkers of lipid deterioration in grass carp (Ctenopharyngodon idella) muscle during cold storage, the lipid profile change of the grass carp muscle stored at 4 ℃ for different periods (3, 6, and 9 d) was investigated by UPLC-Q Exactive HF-X. Multivariate statistical analysis and one-way ANOVA were used to screen the differential lipids during the cold storage, and then to enrich the metabolic pathways involved in the differential lipids through the KEGG database. The results showed that the pH in grass carp muscle decreased gradually, while the thiobarbituric acid reactive substance, total free fatty acid content, and volatile base total nitrogen increased gradually, reaching 0.82 µg/kg, 168.22 µg/10 g and 23.63 mg/100 g, respectively, on the 9 d of cold storage. A total of 1265 lipid molecules belonging to 5 categories and 35 subclasses were identified in the chilled grass carp muscle. Glycerol phospholipids (GP) and glycerol esters (GL) were the main components of lipids in grass carp muscle. There was no significant difference in lipid profile between grass carp muscle refrigerated for 3~6 days (P>0.05), but there were significant changes in lipid composition when refrigerated for 9 days. Fatty acyl (FA) and sphingolipids (SP) were the major different lipids in the early stage of refrigeration (3~6 days), and GP was the main lipids with significant changes in the late stage of refrigeration (6~9 days). A total of 20 different lipid molecules were screened from multivariate statistical difference analysis, and they were mainly glycerol ester and glycerol phospholipid, among which PE (16:1e/22:6) showed significant differences (P

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In order to explore the effects of NaHCO3 stress on antioxidant enzymes and tissue structure of gill and hepatopancreas of grass carp, three NaHCO3 concentration groups (10, 20, 30 mmol/L) were used to stress grass carp with NaHCO3, and the antioxidant enzymes (SOD, CAT) activity and histopathological observation of gill and hepatopancreas were carried out. The results showed that under NaHCO3 stress, the activities of SOD and CAT in gill and CAT in hepatopancreas of grass carp increased first and then decreased within 72 h, and only the activity of SOD in hepatopancreas increased within 72 h. In each experimental group, the activities of antioxidant enzymes in the two tissues were significantly different from those in the blank group. Compared with the blank group, in the gill tissue of grass carp in the experimental group, the gill filaments were seriously folded and wrinkled, the PVC of the flat epithelial cells was seriously exfoliated, and the MRC of the mitochondria-enriched cells was swollen; in the hepatopancreas, the swelling of the pancreatic cells, the increase of the intercellular space, the deviation of the hepatocyte nucleus and the decrease of the vacuolization were observed. Studies have shown that NaHCO3 stress can affect the antioxidant level of grass carp and cause tissue damage to the gills and hepatopancreas of grass carp, and the degree of damage increases with the increase of concentration. This study could provide reference for the breeding and application of grass carp in saline-alkali waters. [ABSTRACT FROM AUTHOR]

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The objective of study was to investigate the softening effect and mechanism of Garcinia gummi-gutta on grass carp bones. The pattern of change in the hardness of grass carp bones was studied during pickling using a G. gummi-gutta juice-based marinade at different temperatures (5, 10, 25, and 40 ℃). At the same time, changes in the composition and structure of grass carp bones and in the acidity and pH of the marinade were also determined. The results showed that the hardness of grass carp bones gradually decreased with pickling time, which decreased by 71.5%–79.4% after 25 days of pickling (P < 0.05). The ash content decreased by 11.90%–16.65% (P < 0.05), and the moisture content by 4.23%–13.08% (P < 0.05). The dense and ordered microstructure became loose and porous. This was because the reaction of H+ with hydroxyapatite in fish bones enabled calcium to be dissolved from fish bones and the consumption of H+ in the pickling solution decreased its acidity and increased its pH. Malic acid was played a major role in softening fish bones. Infrared spectroscopic analysis showed that the triple helix structure of fish bone collagen was not destroyed, but the absorption peak corresponding to amide A shifted to a higher wavenumber, suggesting a reduction in the number of hydrogen bonds, which might be related to the loss of hydroxyapatite in fish bones.

The aim of this study was to investigate the response of grass carp feeding, growth, and antioxidant capacity to dietary protein content when using yellow mealworms as the main protein source. With yellow mealworms as the main protein source, 6 experimental diets with different protein level (25.25%, 29.43%, 33.38%, 37.96%, 41.40% and 45.70%, named as TMF1, TMF2, TMF3, TMF4, TMF5, and TMF6 group, respectively) were designed. The grass carp juveniles with initial weight of (3.63± 0.01) g were fed with the experimental diets for 8 weeks. The results are as follows: ① the specific growth rate, weight gain rate, and protein efficiency ratio of grass carp decreased with the increase of yellow mealworm addition, all of which were significantly higher in TMF1 group than those in FMF4, TMF5 and TMF6 groups (P<0.05), the feeding rate showed a first increasing and then decreasing trend, while the survival rate and feed efficiency were not affected (P>0.05) by dietary mealworm addition. ② Different levels of dietary yellow mealworm inclusion had no significant effect on the condition factor and percentage of eviscerated weight of grass carp (P>0.05), but the hepatopancreas somatic index and mesenteric fat index of grass carp increased first and then decreased with the increase of yellow mealworm content. The mesenteric fat index of TMF2 group was significantly higher than that of other groups (P<0.05). ③ The total protein, content in the serum of grass carp first increased and then decreased with the increase of yellow mealworms content. And the total protein content in the TMF4 group was significantly higher than those in other groups (P<0.05), but was not different from that in TMF3 group. The serum cholesterol content in TMF1 group was significantly lower than that in other groups, and the activity of aspartate aminotransferase in TMF4 and TMF6 group was significantly higher than that in TMF1, TMF2 and TMF3 group (P<0.05), while the content of triglyceride decreased significantly with the increase of the amount of yellow mealworms, which was significantly higher in the TMF1 group than those in TMF5 and TMF6 groups (P<0.05). The serum glucose in TMF1 group was significantly higher than that in TMF2 group (P<0.05), no other difference in serum glucose was observed. ④ The activities of SOD, T-AOC, MDA and GSH-Px in grass carp hepatopancreas decreased with the increase of yellow mealworms, and the GSH-Px activity as well the MDA content were significantly higher in TMF1 group than in other groups (P<0.05). However, the CAT activity did not vary significantly among groups (P>0.05). This study shows that the protein level of grass carp diet should not be more than 25.25% when yellow mealworms was used as the main protein source, and the increase of dietary yellow mealworms inclusion would depress the feeding, growth, and antioxidant performance of grass carp. [ABSTRACT FROM AUTHOR]

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The purpose of this experiment was to study the effects of different levels of compound acidifiers on the growth performance, nonspecific immunity, and serum biochemical indexes of grass carp. A total of 480 grass carps with similar weight were randomly divided into four groups with three replicates in each group and 40 grass carps in each replicate. Grass carp in the control group were fed with basic feed, while grass carp in the experimental group were fed with feed containing 0.1% (0.1% compound acidifier group), 0.2% (0.2% compound acidifier group) and 0.4% (0.4% compound acidifier group), respectively. The trial period was eight weeks. The results showed that compared with the control group, the powder weight, weight gain rate and specific growth rate of grass carp in the 0.2% compound acidifier group increased significantly (P<0.05), while the feed coefficient decreased significantly (P<0.05). The liver-body ratio of grass carp in the 0.1% compound acidifier group and 0.2% compound acidifier group was significantly increased (P<0.05). Compared with the control group, the crude fat content of grass carp muscle in each compound acidifier group increased significantly (P<0.05), and the water content of grass carp muscle in 0.2% compound acidifier group decreased significantly (P<0.05). Compared with the control group, the activity of lysozyme (LZM) and the content of triglyceride (TG) in serum of grass carp in the 0.2% and 0.4% compound acidulant groups were significantly increased (P<0.05), and the content of immunoglobulin M (IgM) in serum of grass carp in each compound acidulant group was significantly increased (P<0.05). The serum urea nitrogen (BUN) content decreased significantly (P<0.05), total protein (TP), glucose (GLU) content and alkaline phosphatase (AKP) activity increased significantly in the 0.2% compound acidifier group (P<0.05). The study indicates that adding the proper amount of compound acidifier in grass carp production can improve growth performance, improve body composition, enhance immunity, and improve some serum biochemical indexes, and the suitable addition level of compound acidifier is 0.2%. [ABSTRACT FROM AUTHOR]

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Objective： The effect of UV sterilization on the texture quality and flavor substances of the frozen grass carp meat was studied, and the best UV irradiation time was determined. Methods: The grass carp meat was pretreated with different UV irradiation times （0, 30, 60, 90, 150 min） at 30 W of UV radiation, then the quality parameters （apparent morphology, total number of bacteria on the surface of fish, juice loss rate, texture parameters, color, odor and sensory） and volatile components of the fish meat during chilling storage （0, 3, 6, 9 d） were measured. Results: It showed that the longer the UV irradiation time （0~150 min）, the better the bacteria reduction effect on the surface of fish, the lower the juice loss rate, and the later the putrefaction smell appeared. However, it had little effect on the texture, color of the fish, and the total bacteria during the latter of chilling storage （6~9 d）. In the detection of flavor substances, 90 volatile components were detected, mainly aldehydes, ketones, alcohols, esters, and acids. Octanal, nonanal, hexanal, 2,5-octadione, 1-hexanol, and 1-octen-3-alcohol were the main volatile components after UV treatment. In the later stage of cold storage, esters and acids were increased gradually, which might be related to the formation of the characteristic aroma of fish meat. Compared with the control group, UV irradiation time of 90 min showed the best comprehensive effect, and the quality was decreased with the extension of irradiation time. Conclusion: UV sterilization pretreatment can delay the deterioration of quality and the decline of flavor of refrigerated grass carp meat in the early stage of chilling storage but has little effect on the quality of grass carp meat in the later stage of chilling storage.

To investigate the relationship between the polymorphism of the nlrc3 gene in grass carp （Ctenopharyngodon idella） and resistance to Ichthyophthirius multifiliis, susceptible and resistant groups were selected from grass carp populations infected with I. multifiliis. The single nucleotide polymorphism （SNP） sites of the nlrc3 gene in the two groups were analyzed and compared. High-resolution melting （HRM） and Sanger sequencing techniques were used to validate the genotypes of the SNP sites, and the obtained SNP sites were analyzed for their association with the disease resistance traits in grass carp. The results showed that four SNPs sites were identified from the nlrc3 gene in grass carp, and three SNP sites （SNP1, SNP3, and SNP4） were successfully genotyped. Among them, SNP1 and SNP3 exhibited two genotypes each （AA and AG for SNP1, AA and GG for SNP3） and were significantly associated with resistance to I. multifiliis. The analysis of haplotype combinations and their correlation with disease resistance revealed that the genotype composed of SNP1 AG and SNP3 AA （D1） showed 100% disease resistance, while the genotype composed of SNP1 AG and SNP3 GG （D2） showed 95% disease resistance, both representing advantageous genotypes for disease resistance. The study demonstrated the existence of nlrc3 gene polymorphism in the entire population of I. multifiliis resistant grass carp, and different genotypes were significantly correlated with the ability to resist I. multifiliis infection. Among them, the D1 genotype with SNP1 AG and SNP3 AA combination exhibited the strongest resistance. These findings provide important theoretical and technical support for further breeding and prevention of I. multifiliis disease in grass carp. [ABSTRACT FROM AUTHOR]

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Feeding systems can dominate the primary efficiency and cost in aquaculture. The high management efficiency of feeding can also alleviate ecological environmental pollution. However, artificial identification has been widely used for fish feeding in the pond so far, leading to the time-consuming and laborious. Empirical feeding management cannot fully meet the large-scale pond aquaculture, in terms of production efficiency, environmental pressure, and aquaculture risk. In this study, a set of precision feeding systems was developed using fish feeding welfare. Four modules included water quality monitoring, decision control, drive execution, and remote monitoring. A systematic investigation was also implemented to clarify the effects of environmental factors on the physiology and energetics of fish. The affecting factors were then determined by the feeding demand of fish. The dissolved oxygen, temperature, and body growth were taken as the input parameters, whereas, the target demand was as the output parameters of the feeding system. The fuzzy PID control was combined with the particle swarm optimization (PSO) to realize the precision feeding operation. A comparative test of pond culture was carried out with the intensive grass carp as the research object, in order to verify the practicability and effectiveness of the system. A comprehensive evaluation was made from the aspects of regulation, growth performance, and economic and environmental benefits. The results showed that a stable and reliable control performance was achieved in the constructed precision feeding system, where the control error was less than 7%. The nash-sutcliffe (NS) index increased to 0.913 in the decision-making performance of the feeding system. whereas, the root mean squared error (RMSE) was reduced by 16.10, compared with the traditional. The feed conversion rate was significantly reduced by 11.73 % (P<0.05). Importantly, the aquaculture income increased by about 14 600 yuan/hm², whereas, the pollution was reduced by 241.40 kg per ton of fish produced. When the feed coefficient was 1.0, per ton of aquatic products brought about 500 kg of organic waste, 26 kg of nitrogen, and 13 kg of phosphorus. When the feed coefficient was 2.5, per ton of aquatic products produced 1 625 kg of organic waste, 117 kg of nitrogen, and 38 kg of phosphorus. By contrast, the grass carp produced per ton was equivalent to about 1 250 kg of organic waste, 86.70 kg of nitrogen, and 29.70 kg of phosphorus under the traditional feeding model. The total production of national grass carp in 2021 was 5.76×106 t. If all grass carp farming was adopted as the precise feeding system, it was equivalent to reducing the pollution emissions of 1.17×106 t organic waste, 9.43×104 t nitrogen, and 2.59×104 t phosphorus. The developed system can be expected to alleviate the environmental and ecological pollution caused by aquaculture. Strong comprehensive application performance can provide the theoretical reference and technical support for the research and development of other aquaculture modes and farmed fish. The feeding system should be further improved from three aspects in the future: monitoring quality and efficiency, decision-making model, and implementation cost. The sensor detection accuracy can be improved to optimize the processing efficiency of models. Systematic research of multiple feeding can be integrated using the logic line of “when to eat (feeding rhythm)-how much to eat (feeding demand characteristics)-how to eat”, in order to achieve an efficient and unified mode of breeding objects, feed, and machine. [ABSTRACT FROM AUTHOR]

To explore the effect of a chitosan-based preservative solution (10 mg/mL chitosan + 5 mg/mL tea polyphenol + 2 000 U/mL lysozyme) on the change in the muscle proteome of grass carp during cold storage, differential proteomic analysis of fresh fish and nine-day-stored fish with or without (control) preservative treatment was conducted by two-dimensional electrophoresis-mass spectrometry (2DE-MS). The results showed that the 2DE map of the preservative-treated group was not obviously different from that of the fresh group, except for a decrease in the abundance of fast troponin T and an increase in the abundance of slow troponin T and adenylate kinase isoenzyme. However, the 2DE profile of the control group differed greatly from that of the fresh group in both the number and signal intensity of protein spots. Further analysis showed that the abundance of fast troponin T, tropomodulin 4, synaptopodin 2 and pyruvate kinase type M were down-regulated, while the abundance of myosin heavy chain, myosin light chain 1, α-actin, α-tropomyosin and intermediate light meromyosin were up-regulated. Moreover, compared with the preservative-treated group, the abundance of three troponins T were decreased, while the abundance of myosin heavy chain, intermediate light meromyosin, α-actin, α-tropomyosin and creatine kinase M-type were increased in the control group, suggesting that creatine kinase could serve as an indicator for evaluating grass carp muscle spoilage. This study demonstrates that the chitosan-based composite preservative can maintain the stability of grass carp muscle protein during cold storage.

In order to study the effect, of the water purification plant, Myriophyllum spicatum L., on feeding the grass carp, the effects of the experimental diets supplemented with different amounts of M. spicatum, including 0 (CK), 5% (Ml), 10 % (M2), 20% (M3) and 30% (M4) on the growth, muscle quality and safety of grass carp were discussed. The results showed that: the weight gain rate of grass carp in M2 group was the largest (323. 40%), the survival rate was the highest (98. 45%), and the feeding coefficient was the lowest (1. 32). There was no significant difference in the contents of crude protein, crude fat and crude ash in the muscle of grass carp in each treatment group, but the water ratio of the treatment M2 supplemented with 10% M. spicatum powder (M2) was significantly lower than that of the control treatmen匚 After the experiment, the heavy metals (such as total mercury, cadmium, chromium, lead and total arsenic), volatile base nitrogen, enrofloxacin and florfenicol in grass carp were in line with GB2736 -- 94 Hygienic Standard for Freshwater Fish" and GB31650 -- 2019 "Standard for Maximum Residue Limits of Veterinary Drugs in Food". The results showed that adding no more than 10% of M. spicatum powder in the diet could promote the growth of grass carp and improve the quality of their muscles. [ABSTRACT FROM AUTHOR]

To explore the changes in physicochemical characteristics of muscle protein of grass carp during cold storage, the muscle protein samples were prepared from the grass carp fillets which were refrigerated at 4 ℃ for 0, 2, 4, 6, 8 and 10 d, respectively. And their molecular weight (MW) distribution, water holding capacity（WHC）, solution viscosity, thermodynamic property, as well as salt solubility of actomyosin were determined by size exclusion HPLC, rheometer and differential scanning calorimetry (DSC), etc. The results showed that the average MW of muscle protein was decreased during the whole cold storage period, while the WHC decreased severely in the early stage of cold storage and was dropped by 56.12% at the 8th day. The apparent viscosity of muscle protein decreased quickly at low shear rates, and fell from 0.89 Pa·s of 0 d to 0.05 Pa·s of 10 d at a shear rate of 20 s−1. The salt solubility of actomyosin declined obviously and dropped by 40.96% after 6 d of cold storage. Moreover, two endothermic peaks were observed in DSC curves of the protein samples from refrigerated fish muscles, and the onset temperature (Te) and peak temperature (Tm) of the biggest peak were both maximized at the 6th day, while its corresponding enthalpy change (∆H) was minimized. The results indicated that the 6th day of cold storage was a key time point for complex changes of grass carp muscle proteins. This study provides basic data for better understanding the deterioration mechanism of grass carp muscle during cold storage.

Low-temperature preservation is an important storage method for grass carp. Although low temperature can not completely inhibit the activity of enzymes in fish, it can significantly decrease the activity of enzymes and inhibit the growth and reproduction of microorganisms in fish, thereby prolonging the shelf life of fish. When the storage temperature is relatively low, the quality and taste of grass carp are not easily lost, thereby delaying its spoilage. In response to the national development plan of the cold chain circulation in the "14th Five-Year Plan", it is necessary to delay the shelf life of grass carp and reduce the quality change of grass carp through effective preservation technology. This paper summarizes the effects of low-temperature preservation of grass carp on microbial and enzyme activities and reviews the principles and methods of several common low-temperature preservation methods of grass carp (cooling preservation, ice temperature preservation, micro-freezing preservation, frozen preservation, modified low-temperature preservation, compound preservation and new preservation technology), and their application in grass carp preservation, preservation effect. This study aims to provide a reference for low-temperature grass carp preservation and find a more practical and economical way of grass carp preservation.

The effects of vacuum-assisted high pressure curing on the histological structure and sensory and physicochemical quality of grass carp pieces were studied. Fish pieces cured at normal pressure (control) or at high pressures (0, 2.3, 4.6 and 6.9 kPa) in vacuum were evaluated for salt content, histological structure and total volatile basic nitrogen (TVB-N) content, water content and water distribution. Results indicated that during curing, salt gradually penetrated into fish tissue, and vacuum curing resulted in a decreased yield of the fish product, an increase in shear force, hardness, resilience and viscosity, a decrease in thiobarbituric acid reactive substance (TBARs) value, water content and centrifugal loss, and an increase in the intercellular spaces. After vacuum-assisted high pressure curing treatment, the salt content was increased, the product yield was decreased, and the whiteness was increased. The fish cured at 6.9 kPa had the lowest shear force, hardness, cohesiveness, elasticity, and viscosity, but the TVB-N content was not significantly changed, and the juice loss rate was increased. In conclusion, vacuum-assisted high pressure curing can improve the quality of cured fish, and slow down the spoilage rate.

The experiment was to explore effect of Yupingfeng polysaccharide complex microecological preparation on growth and intestinal flora of grass carp. A total of 360 healthy grass carp were randomly divided into three groups, divided into basic feed group (control group/group A), compound microecological preparation (group B) and Yupingfeng polysaccharide compound microecological preparation (group C) with three replicates in each group and 40 grass carp in each replicate. The test period was 21 d. The results showed that the final weight and weight gain rate of grass carp in group C were significantly higher than those in control group (P<0.05). The intestinal muscle thickness and lipase activity of grass carp in group C were significantly higher than those in control group (P<0.05). The intestinal flora richness was significantly increased on 14~21 d. The dominant gut microbiota of grass carp were Protea and Firmicum, dominant genera of bacteria were Gemnobacillus and Anaerobic bacteria. The study indicates that addition of Yupingfeng compound microecological preparation in bait can improve growth performance, intestinal digestive enzyme activity and intestinal microorganisms of grass carp. [ABSTRACT FROM AUTHOR]

In this paper,63 fish were used as samples to screen the microsatellite molecular markers re- lated to the growth traits of Grass carp. The results of the K-S analysis and the QQ map showed that the growth traits of the body length. the body height. and the body weight are in a normal distribution. The effect of the microsatellite markers on the growth traits was analyzed by SPSS 20.0 and 13 genotypes were obtained. Also it was found that the D gene had negative regulatory effect on the growth of Grass carp. while the B and C genes could suppress the expression of the D gene. The association analysis of microsatel lite markers with growth traits showed that the 4 pair primers of HLJC107. HLJC111.C2056.and HLJC-9 were respectively related to different growth traits of Grass carp. Among them, the HLJC107 locus was ex- tremely related to the body length, the body height, and the body weight. The HLJC111 locus was signifi- cantly correlated with the body length and the body weight. The HLJC-9 locus was extremely related to the body length and the body height. The C2056 locus was only related to the body weight. Based on the re sults.it can be used as candidate loci for applying to molecular markers assisted breeding of Grass carp. [ABSTRACT FROM AUTHOR]

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Copyright of Shipin Kexue/ Food Science is the property of Food 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.)

A method was established for determination of 11 pesticide residues in grass carp sample based on cheap analytical filtration syringe (CAFS) clean-up column coupled with ultra-performance liquid chromatography/quadrupole-linear ion trap mass spectrometry (UPLC-QTRAP-MS/MS). Using acetonitrile as extraction solvent, the sample was ultrasonic, frozen and centrifuged, and the supernatant was quickly purified once by CAFS clean-up column with 50 mg PSA. After separated by UPLC, the analytes were determined by QTRAP-MS/MS. Matrix-matched calibration curves and the external standard method was employed for quantification. The results showed that the linear relationships of the 11 pesticides were good within 1.0-50.0 μg/kg, and the correlation coefficients were greater than 0.99. The limit of quantification were 1.0-2.0 μg/kg. The recoveries of 11 pesticides at different spiking levels were 83%-119%, and the intra-day and inter-day relative standard deviations were 2.6%-20% and 0.7%- 15%, respectively. The method is economical, simple, efficient, sensitive and reproducible, and could be used as a routine method for the detection of pesticide residues in grass carp. [ABSTRACT FROM AUTHOR]

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Copyright of Storage & Process is the property of Tianjin Academy of Agricultural Sciences 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.)

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Copyright of Journal of Chinese Institute of Food Science & Technology / Zhongguo Shipin Xuebao is the property of Journal of Chinese Institute of Food Science & Technology Periodical 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.)

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Fish passing is closely related to the water flow and fish behavior in a fish-way experiment. The complex mechanism is often simulated on the basis of the flow field in most model tests, although the numerical simulation is still time-consuming and laborious. Moreover, a typical fish is generally selected to conduct the fish passing experiments, but the fish habits vary mainly on the type of fish, particularly on the contradiction of “fishway cannot meet the needs of all fish”. Therefore, it is very necessary to consider the fish behavior in the numerical simulation of the flow field in the fish-way. An Agent-based model was widely used to simulate the fish behavior in recent years. However, the complicated calculation and difficult implementation usually occur especially in the case of complex behavior in the fish movement. Alternatively, a Cellular Automata (CA) model was highly suitable for the various complex systems. In this study, a feasible fish behavior model was proposed for the fish movement system in the fish-way using the integrated Agent-CA. The fish was treated as agents with independent behavior, where each agent was randomly chosen in the direction of movement through the probability of grid attraction, thereby evolving the whole process of fish behavior in the combined Agent-CA model. The model assumed that the different movement modes were taken for the fish, according to the velocity fields. Three velocity zones were divided according to fish behavior. The variety of movement patterns were set in each velocity field, while the probability of grid attraction was calculated using the patterns of fish movement behavior in the model. The patterns of fish movement behavior included obstacle-avoiding, mainstream seeking, random, upstream forward, upstream backward, and sprint behavior. A field experiment of fish passing was conducted to verify the efficiency of the model in the simulation. First of all, three kinds of vertical slot fish-ways were built with G/B=0.1, 0.25, and 0.5, by changing the relative length G/B of the guide wall. An experimental fish was selected as an eighty-five grass carp with a body length range of (10±2) cm. Secondly, the fish experiments were conducted in the three types of vertical slot fish-ways to record the track, particularly the characteristic track. And then, the velocity fields of three fish-ways were calculated using CFD numerical calculation, thereby serving as the Cellular space data in the fish behavior model. Finally, a randomly generated Agent (fish) was selected to simulate the fish behavior, with the body length in the range of (10±2) cm in the last fish-way chamber. The distribution of simulated and characteristic track of the Agent (fish) was obtained after repeating 85 times. Specifically, the scope of simulated track (W/B) for G/B=0.1, 0.25 and 0.5 were 42.5%, 1.1%, and 34.4%, while, the scope of simulated characteristic track (W/B) for G/B=0.1, 0.25 and 0.5 were 23.5%, 7.7%, and 2.3%, respectively. The data demonstrated that the constructed model can represent the main track of actual fish, but it is difficult to simulate the movement of a few fish deviating from the mainstream. The Agent-CA fish behavior model in fish-way can greatly contribute to clarifying the behavior laws of fish movement in modern aquaculture production. [ABSTRACT FROM AUTHOR]

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Copyright of Shipin Kexue/ Food Science is the property of Food 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.)

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Copyright of Shipin Kexue/ Food Science is the property of Food 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 Hydrobiology / Shuisheng Shengwu Xuebao is the property of Editorial Department of Journal of Hydrobiology 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 Shipin Kexue/ Food Science is the property of Food 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 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.)

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Copyright of Journal of Hydrobiology / Shuisheng Shengwu Xuebao is the property of Editorial Department of Journal of Hydrobiology 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 Shipin Kexue/ Food Science is the property of Food 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 Shipin Kexue/ Food Science is the property of Food 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 Shipin Kexue/ Food Science is the property of Food 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 Shipin Kexue/ Food Science is the property of Food 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.)