Abstract:To understand the effects of high-salinity on razor clam Sinonovacula constricta, the razor clams were cultured at salinity of 20 (control group) and 30 (experimental group) for 60 days. The growth and survival, Na⁺/K⁺-ATPase (NKA) activity in gills, and indexes of energy metabolism in hepatopancreas and serum were measured at the time point of 0, 10, 30, and 60 d. The results showed that the survival rate of razor clam cultured in experimental group was 45.1%±2.9% in 30-60 d. The specific growth rate of shell length, shell width, shell height and body weight of razor clam cultured in experimental group were 0.15%/d, 0.17%/d, 0.13%/d and 0.61%/d respectively in 60 days, and all of these indexes were significantly lower than those in the control group. The NKA activity of experimental group was significantly lower than control group at the time point of 0, 10, 30, and 60 d. The activity of hexokinase (HK) in hepatopancreas of control group was significantly higher than experimental group at the time point of 10 and 60 d, the same with glucose (GLU), lactic acid (LA) content and lactate dehydrogenase (LDH) activity in serum, which indicated that the anaerobic metabolism level of experimental group was lower than control group at those two time points. The GLU, LA content and LDH activity in serum of experimental group were significantly higher than those in the control group at the time point 30 d, which indicated that the anaerobic metabolism level of experimental group was higher than control group at the time point 30 d. The succinate dehydrogenase (SDH) activity in hepatopancreas of experimental group was significantly higher than control group at the time point 0, 10 and 30 d, which indicated that the level of aerobic metabolism of razor clam increased under high salt stress. In summary, razor clam can maintain a certain survival rate and a certain growth rate under long-term high-salt culture. The osmotic adjustment and the energy metabolism of razor clam have been affected under high-salt culture, and the osmotic adjustment increased its energy consumption. This study provides reference materials for further cultivation of new high-salt-tolerant strains of razor clam.

Abstract:The resources of the indigenous common carp was exploited which are bred in paddy field to become a paddy-field carp in Qingtian, Zhejiang Province. The gynogenesis in Qingtian paddy field carp was artificially induced by sperm inactivated via ultraviolet irradiation, and followed by meiotic chromosome doubling in the method of cold shock. The gynogenesis offspring (G₁) were obtained. Using common offspring (F₁) as standard, the morphological characteristics and gonad developments of the 160-day-old G₁ were observed. SNP technology was used for genetic identification of G₁ at the genomic level. The results showed G₁ had 3 types of body colors and different growth rates. Out of them, the black type shows the fastest growth, and an average body mass reached 392.45 g. The average growth rate of G₁ was significantly slower than F₁. G₁ showed morphological proportion's difference from F₁, and the ratio of total length/body depth was significantly different. In individuals, G₁'s ovaries developed in various periods, and ovaries of the large individuals had predominantly primary oocytes in stage Ⅲ which was similar to F₁. For the purity rate of genetic material of paddy field carp by SNP detecting, the average rate of homozygous loci 61.85% of G₁ was higher than 38.42% of maternal genome through gynogenesis technology, and some paternal genetic materials integrated into G₁'s individuals, resulting in the differences in body colors and growth rate. G₁ will be used for the conservation of genetic resources, and further for the selected breeding of Qingtian paddy field carp.

Abstract:9 missense mutation sites of body color related pathway genes were sequenced and investigated. In three small sample populations of Cynoglossus semilaevis with hyperpigmentation, pseudoalbino or normal body color, it was found that three mutation sites are significant correlation with pseudoalbino. Further verification by expanding samples showed that the C/T site at position 160 of type B endothelin receptor (ertB-160-C/T) was extremely significantly correlated with pseudoalbino. The G/A site at position 473 of tyrosinase (tyr-473-G/A) and the C/T site at position 1 178 of arachidonic acid 5-lipoxygenase (alox5-1178-C/T) were significantly correlated with pseudoalbino.The three mutation sites were located in the protein periplasmic-Binding-Protein-Type 1, tyosinase C-terminal and lipoxygenase domains. RT-qPCR assay revealed that:There was no evident difference in ertB expression in different colored areas of the skin of albino half-smooth tongue sole on the eyed side, however, the expression of ertB in the skin on the eyeless side was prominently higher than that in the skin on the eyed side,and the expression level of tyr in both pigmented and non-pigmented parts of the eyed side were remarkably higher than those of the eyeless side; The expression level of alox5 on the eyeless side was markedly higher than that on the eyed side; The alox5 expression in the albino area on the eyed side was prominently higher than that in the pigmented area on the eyed side. The mutation sites related to pseudoalbino of C. semilaevis cultured population provides a molecular basis for body color breeding of C. semilaevis in the future.

Abstract:Previous studies have shown that Acrossocheilus paradoxus from Taiwan and A. wuyiensis from Minjiang River are closely related species, and they are difficult to distinguish in morphological characteristics. Therefore, the validity of the two species is still controversial. In the present study, completemitochondrial COⅠ gene sequences were used to investigate the species validity of A. paradoxus and A. wuyiensis. A total of 21 haplotypes were obtained from 76 samples of 6 species in the genus. Phylogenetic trees constructed by maximum parsimony (MP), maximum likelihood (ML) and Bayesian (BI) methods showed that the two species formed a monophyletic group. Genetic distance analysis showed that the average Kimura 2-parameter distance between A. paradoxu s and A.wuyiensis was only 0.853%, far less than the 2% genetic distance threshold of DNA barcode among species. The ASAP method we also used to build species partitions, the result shows the two species were classified as the same species. Therefore, A.wuyiensis distributed in Minjiang River and A. paradoxus distributed in Taiwan should be a same species, and A.wuyiensis is the synonym of A. paradoxus.

Abstract:The outer gill of female Hyriopsis cumingii is not only a respiratory organ, but also performs the function of embryo sac during the reproduction period. The respiratory efficiency of female Hyriopsis cumingii was decreased during the breeding period. The annual changes of the outer gill tissue morphology of female Hyriopsis cumingii were observed by paraffin section, and the effects of hypoxia environment on the outer gill tissue morphology and enzyme activities of female Hyriopsis cumingii were explored. The results showed that the outer gill of female Hyriopsis cumingii was the thinnest in January, and increased to the thickest in May, which was 173.86% thicker than that in January. The gill gradually became thinner, and the width of the gill cavity also increased significantly with the thickness of the gill, and increased to the widest in June, which was 171.22% wider than that in January, and the gill cavity gradually narrowed there were a large number of early embryos. In hypoxia environment, the activity of lactate dehydrogenase (LDH) increased gradually in 1-5 days, reached the maximum value on the 5th day, increased by 131.1% compared with the control group, and decreased slowly in 5-9 days; The activity of superoxide dismutase (SOD) decreased gradually in 1-7 days, reached the minimum value on the 7th day, decreased by 40.53% compared with the control group, and increased slowly in 7-9 days; The activity of catalase (CAT) increased gradually in 1-7 days. The activity of succinate dehydrogenase (SDH) decreased from 1 to 9 days, and the lowest value appeared on the 9th day, which was 68.9% lower than that of the control group. After 5 days of hypoxia stress, the cilia on the lateral side of the outer gill were 79.58% wider than that of the control group, and the aqueduct of the outer gill were 248.73% wider than that of the control group. This study provided basic data for the changes of outer gill tissue structure of female Hyriopsis cumingii and the effects of low dissolved oxygen on the tissue structure and enzyme activities of outer gill of female Hyriopsis cumingii, and provided theoretical basis for improving the breeding technology of Hyriopsis cumingii.

Abstract:In order to explore the effect of adding Bacillus subtilis on the microbial community structure, nutrition of bioflocs and water quality in the process of system construction, the biofloc technology-aquaculture system was completed, the additive concentration of B. subtilis was group A, 10⁶ CFU/mL, group B,10⁵ CFU/mL, group C, 10⁴ CFU/mL, group D, 0 CFU/mL. The experimental results showed that:The concentration of B. subtilis had significant effect on the concentration of TSS and FV-30; The concentration of B. subtilis had a significant effect on the amino acid content and C/N of the floc; The concentration of B. subtilis had no significant effect on crude lipid and ash content; The amino acid and crude protein contents of adding B. subtilis groups were higher than those of the non-added group; The additive of B. subtilis had a significant effect on the relative abundance at phylum and genus level of bacteria; and increasing the concentration of B. subtilis additive led to an increase in the concentration of Bacillus in the biofloc. B. subtilis can be effectively enriched on bioflocs. The addition of B. subtilis can effectively improve the nutrient content of bioflocs, which is conducive to providing protein source for aquaculture.

Abstract:A 42-day study was made comparing the water indexes, growth performance, digestive enzyme and antioxidant enzyme activities of larvae red swamp crayfish (0.017 9±0.000 5) g reared feeding bioflocs, commercial diet and frozen rotifers (Brachionus calyciflorus). The results showed that:During the feeding period, the biofloc group had the lowest concentration of total phosphorus, ammonia nitrogen, nitrite nitrogen and nitrate nitrogen, significantly different from the other two groups. No significant difference was found in final weight, weight gain rate and specific growth rate of larvae crayfish among the three experimental groups while the survival rate of crayfish in the biofloc group was similar with that in the rotifer group and higher than the diet group significantly. Besides, the highest α-amylase and lipase activities were found in the diet group while the biofloc group was the lowest. The trypsin and pepsin activities of crayfish in the biofloc group were significantly higher than those in the diet group. The α-amylase, trypsin and pepsin activities of crayfish in the rotifer group were not different from the other two groups. The total antioxidant capacity (T-AOC) and catalase (CAT) activity of crayfish in the biofloc group was the highest while malondialdehyde (MDA) content was the lowest which were significantly different from the other two experimental groups. Bioflocs has more positive effects on the survival, growth performance, digestive enzymes and antioxidant capacity of larvae crayfish.

Abstract:A 56-day feeding trail was conducted to investigate the effects of methionine, cysteine and taurine on lipid accumulation and lipid metabolism of turbot (Scophthalmus maximus) fed high levels of dietary lipid. A high-lipid (16%) diet was used as the control diet, and 1.5% methionine (Met), 1.5% cysteine (Cys), and 1.5% taurine (Tau) was separately added into the control diets to obtain three test diets. Fish with average initial weight of (7.98±0.02) g was used. Each diet was fed to triplicate tanks of 30 fish. The feeding trial was conducted in flow-through seawater system. The results showed that no significant differences were observed among treatments in lipid content of whole body and muscle. Group Tau had the lowest liver lipid content, significantly lower than group Cys. The serum triacylglycerol and total cholesterol contents were the highest in group Tau, significantly higher than other groups. The dietary supplementation of sulfur-containing amino acids decreased the EPA content in fish body, while Tau increased the contents of C18:2n-6 and C18:3n-3. The dietary supplementation of sulfur-containing amino acids significantly regulated the lipid metabolism-related gene expression. Dietary Met supplementation up-regulated the liver mRNA expression of FAS; Dietary Cys supplementation up-regulated the liver mRNA expression of DGAT1; Dietary Tau supplementation down-regulated the hepatic mRNA expression of a series of lipogenic genes such as ACACβ, FAS, SREBP1, PPARα1, PPARγ and LXRα. Regarding the growth performance, group Tau had significantly higher final body weight of fish than other groups, but no significant difference was observed in survival, condition factor, hepatosomatic index and viscerosomatic index among dietary groups. Supplementation of methionine, cysteine and taurine in high-lipid diets regulates the lipid metabolism of turbot. Taurine appears to be able to reduce the hepatic lipid accumulation in turbot but cysteine tends to increase it.

Abstract:In order to investigate the effect of pupa peptide powder and maggot powder on the growth performance, body composition and digestive enzyme activities of juvenile mud crab (Scylla pseudoaculea), the basic diet was supplemented with 10% pupa peptide powder and maggot powder to feed the juvenile mud crab for 45 days. The results showed that:Weight gain and specific growth rate of the juvenile mud crab in pupa peptide diet group were significantly higher than those in basic diet group and maggot diet group, whereas survival rate of the juvenile mud crab in pupa peptide diet group was significantly higher than those in basic diet group; Water content of the juvenile mud crab in basic diet group was significantly lower than that in pupa peptide diet group and maggot diet group, whereas crude protein content of the juvenile mud crab showed the opposite result, crude lipid content of the juvenile mud crab was basic diet group>maggot diet group>pupa peptide diet group,protease and amylase activity of the juvenile mud crab was basic diet group

Abstract:In order to evaluate the effects of dietary Pennisetum sinese Roxb meal on the fat accumulation and intestinal microbiota composition of juvenile grass carp (Ctenopharyngodon idella), three isonitrogenous and isoenergetic purified diets containing 0% (control group), 10% and 20% Pennisetum sinese Roxb meal were designed (protein level 33%, fat level 8%), and fed juveniles grass carp[(28.51±0.04) g] for 8 weeks. Each diet was randomly assigned into triplicate tanks. The results showed that fish fed 10% and 20% pennisetum sinese Roxb meal significantly reduced their abdominal fat index. The microstructure of the tissue section showed the hepatic lipid droplets number and the adipocyte size in the Pennisetum sinese Roxb meal group were reduced compared with the control group. Serum levels of triglycerides (TG), total cholesterol (TC) and non-esterified fatty acids (NEFA) showed a downward trend with the Pennisetum sinese Roxb meal content increasing, and the 20% group had significantly lower values than the control group. The hepatic content of TG, TC, and NEFA were significantly decreased in the Pennisetum sinese Roxb meal supplemented groups. Five lipogenic genes including peroxisome proliferator-activated receptor γ (pparγ) in the liver and abdominal adipose tissue were significantly down-regulated after the fish consuming Pennisetum sinese Roxb meal. Peroxisome proliferator-activated receptor-α (pparα) and other three lipid catabolic genes were significantly up-regulated after the fish fed on the Pennisetum sinese Roxb meal-supplemented diets. The expression of farnesoid X receptor (fxr) gene in the liver was significantly up-regulated in fish feeding Pennisetum sinese Roxb meal. The metagenomics results of the intestinal flora showed the Ace, chao1, Shannon, and Simpson indexes of the intestinal microbiota of grass carp in the 10% and 20% Pennisetum sinese Roxb meal groups were significantly different from those in the control group, indicating dietary Pennisetum sinese Roxb meal increased the abundance and diversity of the intestinal flora of grass carp. From the perspective of phylum classification, the proportion of Firmicutes was significantly lowered in the Pennisetum sinese Roxb meal groups, whereas the proportion of Bacteroides showed an upward trend, and these two bacteria are reported to be associated with fat accumulation in mammals. The results demonstrate that Pennisetum sinese Roxb meal could reduce body fat accumulation, possibly via the improvement of intestinal flora composition in juvenile grass carp.

Abstract:In order to study the impacts to phytoplankton caused by fish cage farming activities, three seasonal investigations (winter, spring and autumn) on phytoplankton community and environmental factors in the Hailing Bay were carried out. In total,171 phytoplankton species were detected, with 76 species of diatom belonging to 29 genera, followed by dinoflagellates represented by 16 taxas (8 genera), blue-green algae by 4 taxa (2 genera).The range ofphytoplankton density was 22-3.054×10⁵ cells/L, which ranked as:autumn>spring>winter. In general, the phytoplankton density in the outer bay was higher than that in the inner bay except in spring. Themain dominant species were Thalassiosira subtilis and Thalassiothrix frauenfeldii in winter, T. subtilis and Skeletonema costatum in spring, S. costatum, and T. frauenfeldii in autumn. The range of Shannon-Wiener diversity index (H') were 1.44-4.11, 0.66-2.39 and 1.62-3.10 in winter, spring and autumn. Redundancy analysis suggested that the main variables affecting the dominant species were water salinity and pH in winter, ammonia (NH₄-N) and pH in spring, dissolved oxygenand nitrate (NO₃-N) in autumn.Under the influence of different runoff and aquaculture activity, most of the phytoplankton communities in autumn were easily clustered into similar communities; however, those in spring tended to be more varied. Close relationshipwas found among the results of cluster analysis of stations on phytoplankton community structures and environmentalfactors.

Abstract:In order to explore the structural attributes of fish assemblage and its relationship with environmental factors, and to reveal differences in structural characteristics between floating gillnet and benthic gillnet, fishes were caught from Songmushan Reservoir of Guangdong Province using multi-mesh gill nets. The results showed that 17 species, belonging to 4 orders and 6 families, were collected, with the most species-rich order of Cypriniformes (10 species). The index of relative importance (IRI) indicated that Toxabramis houdemeri (IRI:29.66%), Hemiculter leucisculus (18.98%), Oreochromis nilotica (18.46%), Hypophthalmichthys molitrix (14.85%) and Oreochromis mossambica (11.36%) were the dominant species, with T. houdemeri having the highest number per unit effort (NPUE:45.72%) and O. nilotica possessing the largest biomass per unit effort (BPUE:34.60%). No difference in fish composition between seasons was detected by cluster analysis, and no differences in species number, NPUE, and BPUE among seasons were observed. The species number, NPUE, and BPUE did not differed significantly between floating and benthic gillnet. However, a significant difference in numerical composition of fish assemblage between the two types of gillnet was tested, which was responsible for T. houdemeri. The significant higher NPUE for floating gillnets was found than that for benthic ones, but no differences in NPUE between them were detected for the other five fish species. Transparency, total phosphorus, and pH value were the key environmental factors that could be used to explain the temporal and spatial distribution. The results suggested that the low species richness would be related to the small area, low connectivity, invasion of alien fish species, and dominance in inflow river by men-made discharge ditch of this reservoir, and that the floating and benthic gillnets should be both included in sampling procedure for future study in fish community ecology of reservoirs.

Abstract:In order to investigate the changes of macrobenthos community in the intertidal zone of south Yellow Sea, a survey of 10 sections of three voyages was carried out in May, August and October 2019.The species composition, biomass, density and species diversity of the macrobenthos were analyzed by multivariate statistical analysis.A total of 103 species belonging to 10 phyla were found, including 59 species in spring, 70 species in summer and 56 species in autumn;The seasonal variation of biomass and biomass density was higher in summer than in spring and autumn, and higher in autumn than in spring and summer;Spatially, the biomass and biomass density of the northern, central and southern parts of the south Yellow Sea were compared, showing a trend of higher in the northern part than in the southern and central parts.The Shannon Wiener diversity index (H'), Margalef richness index (d) and Peilou evenness index (J) were 2.02-4.24, 0.83-4.00 and 0.63-0.93, respectively, with the mean values of 3.16, 2.35 and 0.85;The community diversity level in the north (3.53) was higher than that in the south (3.11) and the middle (3.02).The dominant species of macrobenthos in the south Yellow Sea were molluscs, annelids and crustaceans.The results of cluster analysis showed that the 10 transects could be divided into three groups, which were basically divided into the north, the middle and the south. The differences of benthic community in intertidal zone of the south Yellow Sea mainly came from the spatial changes.According to the clustering results, the typical species and divergent species of the three groups were calculated. The typical species in the north were mainly molluscs and crustaceans, the typical species in the middle were molluscs and annelids, and the typical species in the south were molluscs.The results supplement the basic data of macrobenthos in the intertidal zone of the southern Yellow Sea, and provide a scientific basis for the assessment and protection of the intertidal benthos resources.

Abstract:In order to explore the influence of different water quality control methods on the number of heterotrophic bacteria and vibrio in the bottom mud of sea cucumber farming ponds, three types of sea cucumber farming ponds, namely sea cucumber farming ponds under natural tide management (hereinafter referred to as natural ponds), sea cucumber farming ponds equipped with microporous aeration aerators (hereinafter referred to as microporous aeration ponds) and sea cucumber farming ponds equipped with water quality regulator ponds (hereinafter referred to as water quality regulator ponds) were selected. The annual changes in the number of heterotrophic bacteria and vibrio in the bottom mud of sea cucumber farming ponds were detected. The results showed that the number of heterotrophic bacteria in the bottom mud of sea cucumber cultivation ponds was 94 400-377 625 cfu/g in natural ponds, 62 633-247 309 cfu/g in microporous aeration ponds, and 115 037-273 071 cfu/g in water quality regulator ponds, of which natural ponds are highest in January and lowest in March, microporous aerated ponds are highest in May and lowest in June, and water quality regulator ponds are highest in April and lowest in August. The number of vibrio in the bottom mud in the sea cucumber culture ponds was 0-3 291 cfu/g in natural ponds, 35-5 412 cfu/g in microporous aeration ponds, and 0-3 037 cfu/g in water quality regulator ponds. All sea cucumber farming ponds showed the characteristics of "highest in spring and the lowest in winter". The ratio of vibrio to heterotrophic bacteria was relatively higher in April and May, and lower in February. Preliminary experiments are conducted to compare the effects of different water quality control methods on the number of microorganisms in the bottom of sea cucumber farming ponds, and provide a theoretical basis for improving the bottom quality of sea cucumber farming ponds and exploring microbial changes.

Abstract:Based on Landsat series satellite images, Google earth satellite images and object-oriented supervised classification method, the changes of coastal wetland landscape in Yancheng City, Jiangsu Province from 1990 to 2020 were analyzed on the basis of two-level classification of landscape. The results showed that:The total area of natural wetland landscape in Yancheng coastal zone showed a downward trend in the past 30 years, and the proportion of constructed wetland and non-wetland landscape area increased. The change trend of natural wetland area proportion in the study area was consistent with that in the partition, showing a trend of ‘decline-accelerated decline-slightly uplift’, and the change rate of intertidal mud beach was the highest. The proportion of intertidal saline marshes in the northern and southern Yancheng wetlands was 8.77% and 17.64%, respectively. The overall trend of coastal zone was ‘natural wetland-constructed wetland-non-wetland’. The wetland loss rate was the most significant from 2000 to 2010. The total area of wetland decreased by 360.27 km², and the average annual loss rate was as high as 1.29%. There were differences in the landscape transfer characteristics of Yancheng coastal zone in different periods. During 1990-2000, the landscape transfer directions of each wetland were relatively dispersed, and most of them were transferred within natural wetland or non-wetland. During 2000-2010, the transformation from tidal flat to aquaculture waters was dominant. During 2010-2020, cultivated land, rivers, woodlands and shallow waters all showed a trend of transformation to intertidal mud beaches. The most intense transformation trend of intertidal mud beaches, intertidal salt marsh waters and aquaculture waters was construction land. It is suggested that the main functions of natural wetlands in Yancheng coastal zone should be maintained with reasonable layout, planning and control of scale during the period of economic development.

Abstract:According to the fisheries data of Ommastrephes bartarmii combined with the sea surface temperature (SST) and sea surface height anomaly (SSHA) data obtained from 36°N to 48°N, 150°E to 170°E in northwest Pacific Ocean from September to November, 2006-2015, monthly habitat suitability index models (HSI) were established based on key marine environmental factors of different weighting scenarios, and monthly optimal model was selected and verified according to the model performance.Furthermore, the optimal HSI models predicted the habitat suitability, and the impacts of El Niño and La Niña on habitat suitability of O.bartramii are also compared, and the relationship between habitat quality and abundance, distribution are evaluated. The results showed that the weighting proportion of SI_SSTand SI_SSHA of the monthly optimal HSI models from September to November were as follows:0.9:0.1 in September, 0.7:0.3 in October, and 0.8:0.2 in November. Obviously, the contribution of SST was the highest, indicating that SST was the most important factor for spatial and temporal distribution of habitat. Moreover, comparing the impacts of El Niño years (2009 and 2015) and La Niña years (2007 and 2010) on habitat suitability,stocks abundance and latitudinal gravity center of fishing ground of O.bartramii, it is found that the La Niña events were more beneficial to the survival of O.bartramii than the El Niño events, and the suitable habitat area also increased the catch. Suitable SST moved north, resulting in a northward shift of fishing ground location as well.

Abstract:Diabetes is a metabolic disease with chronically increased blood sugar levels, which has a serious impact on human health. Long-term hyperglycemia may lead to obesity and hypertension. Currently, drugs used clinically to treat diabetes, such as sitagliptin and linagliptin, have problems such as great toxic and side effects. The development of high-efficiency and safe natural hypoglycemic active substances has become a current research hotspot. Dipeptidyl peptidase-Ⅳ inhibitory peptides are a class of biologically active peptides that can reduce blood sugar by inhibiting the activity of DPP-Ⅳ. DPP-Ⅳ inhibitory peptides derived from natural foods have the advantages of high safety, small side effects, long-term use, etc., and can be used in hypoglycemic functional foods. The abundant marine biological resources are an important source for the preparation of DPP-Ⅳ inhibitory peptides. The source, separation and purification, structural identification and functional activity evaluation of DPP-Ⅳ inhibitory peptides from marine biological protein sources at home and abroad were reviewed, and recommendations were proposed for the further development and application, aiming to develop DPP-Ⅳ inhibitory peptide functional foods for reference.

Abstract:In order to understand the distribution characteristics of total arsenic content, water-soluble arsenic species, and fat-soluble total arsenic content in different edible tissues (gonads, hepatopancreas, body meat, leg meat, clamp meat) of Eriocheir sinensis,inductively coupled plasma mass spectrometry and high performance liquid chromatography-inductively coupled plasma mass spectrometry were used to analyze the content of total arsenic, water-soluble arsenic species and fat-soluble total arsenic in different edible tissues of Eriocheir sinensis. The results showed:that the average content of total arsenic in female crabs showed a trend of gonadal>hepatopancreas>body and leg meat>clamp meat, and there was a significant difference; the average content of total arsenic in male crabs showed a trend of hepatopancreas>body, leg meat>clamp meat and gonads, and there were significant differences; the total arsenic content of different edible tissues of female and male crabs gradually increases with the increase of body weight, and the total arsenic content in the adult gonads and hepatopancreas of Eriocheir sinensis in 8 provinces is at a relatively stable level. the percentage of the 6 water-soluble arsenic in muscle tissue is 83.3%-99.6%, and the percentage of the 6 water-soluble arsenic in gonad and hepatopancreas tissue is 18.8%-51.8%, there was a significant difference in the percentage of water-soluble arsenic in muscle tissue and gonad, hepatopancreas tissue.The percentage of total fat-soluble arsenic in the gonadal (female) and hepatopancreas (female, male) tissues ranged from 14.3% to 72.6%, and there was no significant difference in the average percentage of total fat-soluble arsenic in the three tissues. The total arsenic content in the fat of the three tissues was positively correlated with the total arsenic content of the corresponding tissues, but there was no positive correlation with the percentage of the corresponding tissue fat. It can be seen that there are differences in total arsenic content in different edible tissues of Eriocheir sinensis, water-soluble arsenic is the main form of arsenic in muscle tissue, and arsenic betaine (AsB) is the main component of water-soluble arsenic, there is a certain amount of fat-soluble arsenic in the gonadal (female) and hepatopancreas tissues, there are no reports on the types, metabolism, potential toxicity and sources of fat-soluble arsenic in Eriocheir sinensis.

Abstract:Based on the spot investigation, the Shanghai aquaculture professional cooperatives to establish binary logistic regression model, will aquaculture professional cooperatives in rural the influence factors of industrial convergence will generalize for individual characteristics and resource endowment, cognitive and benefits policy risk forecast and related subsidies and support. The results showed that age, policy understanding, income expectation, risk expectation, government subsidies and training guidance had significant effects on the willingness of aquaculture specialized cooperatives to participate in rural industrial integration. Based on this, the paper puts forward some suggestions, such as cultivating high-quality young talents, increasing the propaganda of rural industrial integration policy, improving the profit of operators participating in rural industrial integration, reducing the risk of operators participating in rural industrial integration, providing tax incentives and financial subsidies, and strengthening the technical training and guidance of industrial integration.