[Objective] The aim was to carry out isozyme analysis of jin silver carp (Hypophthalmichthys molitrix Var Jing). [Method] The isozyme of AAT, EST, α-GPD, GPI, IDH, LDH, MDH, ME, PGM and PROT of muscles and liver in t...[Objective] The aim was to carry out isozyme analysis of jin silver carp (Hypophthalmichthys molitrix Var Jing). [Method] The isozyme of AAT, EST, α-GPD, GPI, IDH, LDH, MDH, ME, PGM and PROT of muscles and liver in two populations of the silver carp (Hypophthalmichthys molitrix): Jin silver carp (a breed through selective breeding) and artificially propagated population bought from Jingzhou city, Hubei Province were examined by horizontal starch gel electrophoresis. [Result] Eighteen loci were observed in two populations. Two loci of GPI* and PGM* in Jing silver carp population and the locus of GPI* in Jingzhou population were polymorphic. The proportions of polymorphic loci (maximum allele frequency≤0.99) of Jing silver carp and Jingzhou populations were 11.11% and 5.56% respectively, expected heterozygosity were 0.015 0 and 0.001 1 respectively. The Nei’s genetic distances were 0.000 59 between two populations. The result of chi-square test of the GPI* gene in two populations showed that their genetic structure has very significant difference. [Conclusion] This study provided a theoretical basis for large-scale extension of Jing silver carp.展开更多
Silver carp were introduced into the pre-sedimentation pond to control excessive phytoplankton in raw water. The effectiveness of the filter-feeding silver carp on phytoplankton control and the effect of silver carp o...Silver carp were introduced into the pre-sedimentation pond to control excessive phytoplankton in raw water. The effectiveness of the filter-feeding silver carp on phytoplankton control and the effect of silver carp on phytoplankton community were investigated. The results showed that Microcystis could be effectively removed by silver carp stocked in the pre-sedimentation pond, and simultaneously, the concentration of single-cell phytoplankton increased obviously. The difference in phytoplankton species and single- cell phytoplankton size between in the water and in the gut of silver carp indicated that phytoplankton smaller than 5 μm, such as Chamydomonas and Platymonas, were almost not be filtered by silver carp, phytoplankton with the size between 5 and 20μm could be partly filtered, and large size phytoplankton, mainly colony-forming Microcystis could be filtered almost completely. These filter- feeding characteristics directly caused the phytoplankton size distribution biased toward miniaturization. Therefore, this biological treatment using silver carp could be applied only to deal with groups of Microcystis-dominated eutrophic water, and was not appropriate in water bodies where single-cell micro phytoplankton were dominant. Especially when silver carp are used in water treatment, a cautious attitude should be taken based on the evaluation of phytoplankton biomass and species structure features in raw water.展开更多
The concentration of organochlorine pesticides（OCPs） in tissues and organs of silver carp（Hypophthalmichthys mofitrix） from Guanting Reservoir were investigated to evaluate the pollution potential and distribution...The concentration of organochlorine pesticides（OCPs） in tissues and organs of silver carp（Hypophthalmichthys mofitrix） from Guanting Reservoir were investigated to evaluate the pollution potential and distribution of OCPs. A total of 16 OCPs were measured and the concentrations were in the range of 1.61-69.01 ng/g wet weight（ww） for total OCPs, 0.16- 0.75 ng/g ww for HCB. 0.75 -26.80 ng/g ww for SHCH（sum of α-,β-, γ- and δ-HCH） and 0.68-35.94 ng/g ww for SDDT（ sum of p, p＇-DDE, p, p＇-DDD, o, p＇-DDT and p, p＇- DDT）. The mean concentrations of total OCPs, HCB, ∑HCH, and ∑DDT were 18.04, 0.96, 7.14 and 9.28 ng/g ww, respectively. Among the organochlorine pesticides, β-HCH and p, p＇-DDE were the most dominant compounds in tissue and organ with the average concentrations of 4.42 and 8.14 ng/g, respectively. The results obtained in this study show that the levels of 16 OCP residues found in silver carps are low and pose no threat to human health and wildlife fed upon them on the basis of existing related quality guidelines. However, recent input of lindane and DDT might still exist in the area investigated and further investigation should be carried on.展开更多
Three artificial gynogenetic clones of silver carp were produced for the analysis of restriction enzyme digestion patterns of ND5-ND6 region from mtDNA of the clones. It is revealed that all intraclonal individuals sh...Three artificial gynogenetic clones of silver carp were produced for the analysis of restriction enzyme digestion patterns of ND5-ND6 region from mtDNA of the clones. It is revealed that all intraclonal individuals shared completely the same digestion patterns but among interclonal individuals did not. The three clones were mixed and cultured in a pond together for two years, and restriction endonuclease digestion patterns of ND5-ND6 were used as genetic markers to assess the growth performance of each clone.展开更多
[Objectives]The effects of water chestnut powder on the gel properties and quality of silver carp surimi were investigated.[Methods]The surimi gel was prepared by adding 0%,1%,2%,3%,4%and 5%of water chestnut powder to...[Objectives]The effects of water chestnut powder on the gel properties and quality of silver carp surimi were investigated.[Methods]The surimi gel was prepared by adding 0%,1%,2%,3%,4%and 5%of water chestnut powder to the surimi of silver carp.The gel properties,water-holding capacity,cooking loss,whiteness value,puncture and texture profile analysis(TPA)indexes of surimi products were determined to assess the effects of adding different amounts of water chestnut powder on surimi gel.[Results]The results showed that the gel strength,breaking force and depression distance of surimi products increased first and then decreased with the increase of the addition of water chestnut powder.Compared with the control group,the hardness and chewiness of surimi gel in TPA could be significantly improved by adding water chestnut powder.When the addition of water chestnut powder was 2%,the maximum water-holding capacity was 83.68%;the cooking loss rate was the lowest;and the whiteness value was the highest.Adding 2%of water chestnut powder could significantly improve the gel properties of silver carp surimi and obtain a good gel product.[Conclusions]This study provides a scientific basis for the effective utilization of water chestnut resources and the development of new fish surimi products.展开更多
Silver carp is one of the most important planktivorous fish in Chinese aquaculture and plays a significant role controlling cyanobacterial blooms. A balanced gut microbiota is crucial for growth and health of the host...Silver carp is one of the most important planktivorous fish in Chinese aquaculture and plays a significant role controlling cyanobacterial blooms. A balanced gut microbiota is crucial for growth and health of the host because of its important roles in immune defense, digestion of complex carbohydrates, and production of enterocytes. In our study, the dominant bacterial and cellulolytic bacterial （Clostridium 1, Clostridium 111, Clostridium XIVab, and Fibrobacter） communities in the contents and mucus of the silver carp gut （foregut, midgut, and hindgut） were analyzed by denaturing gradient gel electrophoresis and quantitative polymerase chain reaction （qPCR） analyses. The results revealed that the dominant and cellulolytic bacterial communities were significantly different among gut regions as well as in contents and mucus. Bacterial diversity and richness in contents and mucus increased along the gut and were higher in contents than those in local mucus. A sequence analysis of gut samples exhibited the conservative phylotypes of Proteobacteria, Actinobacteria, and Firmicutes. The gut of silver carp harbored an abundance of cellulolytic bacteria, particularly Clostridium XIVab. The foregut segment had the highest proportions of the four cellulolytic bacteria, followed by the midgut and hindgut. However, the proportions of cellulolytic species in the silver carp gut was much lower than those in the terrestrial vertebrate gastrointestinal tract. We conclude that gut bacteria could help silver carp obtain energy from cyanobacteria, which may be why silver carp can maintain high growth rates during cyanobacterial blooms.展开更多
The effect of various concentrations of nitrobenzene on the mortality and abnormality rate of bighead and silver carp embryos were studied to provide reference for the evaluation of the effect of nitrobenzene to aquat...The effect of various concentrations of nitrobenzene on the mortality and abnormality rate of bighead and silver carp embryos were studied to provide reference for the evaluation of the effect of nitrobenzene to aquatic organisms and aquatic environment. The results showed that the development of bighead and silver carp embryos was delayed, the mortality and abnormality rates were raised when the embryos were treated with ≥0.010 mg·L^-1 nitrobenzene, and with ≥0.085 mg· L^-1 nitrobenzene, the mortality rates showed 100%展开更多
The effect of washing and temperature on the activity of cathepsins of Silver carp was studied.The result showed that the activity of cathepsin L was higher than those of cathepsin B and H.The total catalysis activity...The effect of washing and temperature on the activity of cathepsins of Silver carp was studied.The result showed that the activity of cathepsin L was higher than those of cathepsin B and H.The total catalysis activity of these three enzymes was the highest at 55℃ after washing.The inhibiting effect of soybean protein and potato starch on cathepsin L also had been studied,the results showed that soybean protein and potato starch could decrease activity of cathepsins L significantly.展开更多
The hydrolysis process for Silver carp by-products was studied. Protein hydrolysate was prepared with proteolytic enzyme, Alcalase. Hydrolysis conditions were optimized by the regression model of three factors five le...The hydrolysis process for Silver carp by-products was studied. Protein hydrolysate was prepared with proteolytic enzyme, Alcalase. Hydrolysis conditions were optimized by the regression model of three factors five levels quadratic rotation perpendicular regressive design. The optimum hydrolysis conditions of hydrolyzing the protein of Silver carp by-products were determined to be concentration of enzyme (E/S) 3.33%, pH 8.54, hydrolyzing temperature 58 ℃, reaction time 90 min, concentration of substrate 8%. Nitrogen recovery was more than 75%.展开更多
Fish sauce is a kind of condiments processed from fish. The L9（34） orthogonal tests have been carried out to inspect the effects of technological conditions for fermentation on the comprehensive quality of fish sauc...Fish sauce is a kind of condiments processed from fish. The L9（34） orthogonal tests have been carried out to inspect the effects of technological conditions for fermentation on the comprehensive quality of fish sauce. The conditions of the orthogonal tests are following: the fermentation temperature takes values of 35℃, 40℃ and 45℃, the percentage of Koji values of 40%, 20% and 10% and the percentage of salt values of 10%, 14% and 18%. The obtained experimental results indicate that fermentation temperature plays an important role in the improvement of sauce quality. The optimal technological conditions for sauce fermentation are of 10% salt, 45℃ and 40% koji mixed. The composition of fish sauce processed from offal of silver carp-surimi processing under the above-mentioned conditions and two commercial products have been analyzed. The results show that fish sauce processed from fish offal is nutritious and delicious. It is suggested that the fermentation of fish sauce is a potential and promising pathway to make full use of freshwater fish resources and offal in fish processing. In this study, fuzzy theory and analytic hierarchy process have been applied and the quality evaluation has been established by the combination of physico-chemical indices and sensory evaluation. The comprehensive evaluation has been taken to reflect the optimal factors for the process of sauce fermentation. The quality indexes for fish sauce contain sensory evaluation, amino nitrogen, total nitrogen, specific gravity, volatile basic nitrogen, salt concentration, brown index and acidity, represented by y1, y2, y3, y4, y5, y6, y7, y8, and y9, respectively. They form a group U= {y1, y2, y3, y4, y5, y6, y7, y8, y9,}. Using the fuzzy functions, the values of all these factors are transformed into fuzzy degrees of single factor, i.e. numerical values between 0 and 1. The fuzzy degrees of single factor in several samples are made up a matrix R. Following that, a weight of each index can be determined in the comprehensive evaluation. In the analytic hierarchy process, the weight can be obtained by the cross comparison between two different factors. The results show that the weights （W） of sensory evaluation, amino nitrogen, total nitrogen, specific gravity, volatile basic nitrogen, salt concentration, brown index and acidity are 0.356, 0.189, 0.107, 0.054, 0.097, 0.063, 0.061 and 0.073 respectively. Finally the aggregated fuzzy degree （B） of different samples is computed by B=W·R, which can be taken as the final result of comprehensive evaluation. The larger this value is, the higher the quality of sauce product would be.展开更多
[Objectives]This study was conducted to improve the gel properties of freshwater surimi and its products. [Methods] Tuanfeng lotus seed powder was added to frozen silver carp, and the relationship between the addiamou...[Objectives]This study was conducted to improve the gel properties of freshwater surimi and its products. [Methods] Tuanfeng lotus seed powder was added to frozen silver carp, and the relationship between the addiamount of Tuanfeng lotus seed powder(1%, 2%, 3%, 4% and 5%) and the quality of surimi products was studied, so as to improve the quality of surimi products. [Results] The water holding capacity(86.71%±0.36%), hardness(3 566.64±51.15) g, chewiness(2 697.16±15.81) g and gel strength(692.54±23.19) of surimi products increased to the maximums when the addition amount of lotus seed powder was 3%. Meanwhile, the cooking loss rate was reduced to the minimum(13.00%±0.17%), and the sensory quality was the best, although the whiteness of surimi products decreased slightly with the increase of Tuanfeng lotus seed powder. Therefore, the quality of silver carp surimi products could be improved obviously when the dosage of Tuanfeng lotus seed powder was 3%. [Conclusions] This study provides more new ideas for improving the quality of silver carp surimi products, and simultaneously makes the development of lotus seed food more diversified.展开更多
Dam discharges over spillways are the main reason for the gas-supersaturated water generated in rivers.Local aquatic organisms,especially fish,readily develop gas bubble disease(GBD) in a river with total dissolved ga...Dam discharges over spillways are the main reason for the gas-supersaturated water generated in rivers.Local aquatic organisms,especially fish,readily develop gas bubble disease(GBD) in a river with total dissolved gas supersaturation(TDGS).Sometimes,fish will die after a specific exposure period,which negatively affects the biological equilibrium.In this study,the influence of TDGS on silver carp was explored.Silver carp were exposed to gas-supersaturated water with TDGS levels of 140%,135%,130%,125%,120%,and 110%to test the impact of TDGS.Some silver carp died when the TDGS level was 120%or higher,and all the silver carp exposed to a TDGS level of 140%died within10 h.In comparison with the Chinese sucker,Prenant's schizothoracin,and rock carp,silver carp seem less sensitive to TDGS.In addition,we tested the catalase(CAT) activity in the muscles and gills of silver carp after they were exposed to gas-supersaturated water with a TDGS level of140%.The CAT activity changed with time;it increased first and then decreased until it was lower than the initial CAT activity.The results of this study can provide basic data for developing a standard for environmental evaluation.展开更多
Study of the feeding capacity of silver carp and bighead carp by means of experimental ecologyshowed that the filtering frequency of silver carp was slightly greater than that of bighead carp,but thatthe latter’s suc...Study of the feeding capacity of silver carp and bighead carp by means of experimental ecologyshowed that the filtering frequency of silver carp was slightly greater than that of bighead carp,but thatthe latter’s suction volume was much greater than the former’s so the filtering rate(filtering frequency mul-tiplied by the suction volume)of silver carp was smaller than that of bighead carp.The filtering efficien-cy of silver carp for phytoplankton was greater than that of bighead carp for them.The removal ratesof silver carp for phytoplankton were greater than those of bighead carp,but for zooplankton the formerwere smaller than the latter.For food particles about 70 μm both removal rates were almost equal.The feeding habits of the two species in natural waters is also discussed in the paper.展开更多
Silver Carp (SC) (Hypophthalmichthys molitrix, Valenciennes, 1844) is a worldwide common fish for aquaculture and stocking in lakes and reservoirs. The fish is distributed through rivers, aquaculture and stocking in a...Silver Carp (SC) (Hypophthalmichthys molitrix, Valenciennes, 1844) is a worldwide common fish for aquaculture and stocking in lakes and reservoirs. The fish is distributed through rivers, aquaculture and stocking in about 90 countries around the world. SC was first introduced into Lake Kinneret in 1969 and continues onwards. Total number of stocked fingerlings (1969-2013) was 18.5 × 106 (average: 441 × 103 per year). The total catch (tons) of SC in Lake Kinneret was 3218 tons, average: 75 t/year. Studies on SC in East Lake, China, revealed that the fish was a phytoplanktivorous and percentage of consumed phytoplankton varied between 83% - 91% where Microcystis was the major item. In Lake Kinneret, the effects of SC and the Cichlid, Galilee St. Peters Fish (S. galilaeus) on Plankton resources are not independent and potentially competitors. SC is also known as efficient consumer of Microcystis. It was found that environmental conditions in Lake Kinneret were optimal for reasonable growth and recruitment of this fish to commercial fishery. The SC did not reproduce in Lake Kinneret and we recommended introducing annually 600 - 1000 × 103 fingerlings for the benefit of water quality protection and fishermen income.展开更多
Among fresh water fishes, silver carp because of fast growth rate and desired meat quality, is a dominant species in polyculture systems in Iran. This fish mainly feed on phytoplankton. In present survey kidney and in...Among fresh water fishes, silver carp because of fast growth rate and desired meat quality, is a dominant species in polyculture systems in Iran. This fish mainly feed on phytoplankton. In present survey kidney and intestine of 120 silver carp (Hypophtalmictys molitrix) from 4 regions in Khuzestan province-Iran have been studied. Tissue samples were provided from kidney and intestine and sectioned by routine method after paraffin embedding and finally stained with hematoxilin and eosin (H & E). The microscopic results were analyzed qualitatively and quantitatively. Microscopical analysis showed that kidney tissue had lesions including: edema, necrosis, uroliths, hemorrhage and degeneration. In different regions, fishes showed different prevalence of lesions. Edema and urolith were the most prevalent lesions (30 and 25 percent respectively). In histometric analysis the diameter of layers of intestine in some of the fish farms were significantly higher than the other regions. This increase was because of increase in muscular layer. The intensity of all lesions was estimated as light according to distribution of lesions. The probable cause of these lesions may be the high stocking density, intoxication, water quality problem such as excessive carbon dioxide. The only lesion in intestine was the excessive proliferation of mucus cells that this lesion may be created due to the improper plankton diet.展开更多
Silver carp mediated biological control techniques are often advocated for controlling cyanobacteria blooms in eutrophic water,which are often enriched with arsenic(As).How-ever,the transfer and fate of As during the ...Silver carp mediated biological control techniques are often advocated for controlling cyanobacteria blooms in eutrophic water,which are often enriched with arsenic(As).How-ever,the transfer and fate of As during the biological control of cyanobacteria blooms by silver carp in As-rich eutrophic water remain unclear.Based on the simulated ecosystem experiment,the accumulation of As in silver carp and the transfer and fate of As in the water-algae-silver carp system during Microcystis aeruginosa blooms controlled by silver carp were investigated.Microcystis aeruginosa showed high tolerance to As(V).The accumulation of As in different tissues of silver carp was different,as follows:intestine>liver>gill>skin>muscle.After silver carp ingested As-rich Microcystis aeruginosa,As accumulation in the intestine,liver,gill,and skin of silver carp was enhanced under the action of digestion and skin contact.Compared with the system without algal,As accumulation in the intestine,liver,gill,and skin of silver carp increased by 1.1,3.3,3.3,and 9.6 times,respectively,after incubation for 30 days in the system with Microcystis aeruginosa,while the accumulation of As in the muscle was only slightly increased by 0.56 mg/kg.This work revealed the transfer and fate of As during algal control by silver carp,elucidated the accumulation mechanism of As in water-algae-silver carp system,enriched our understanding of As bioaccumulation and transformation in As-rich eutrophication water,and provided a scientific basis for as-sessing and predicting As migration and enrichment in water-algae-silver carp system.展开更多
Myxozoans are common microscopic endoparasites in fish,and some are highly pathogenic to their wild and farmed fish hosts.In the present study,myxosporeans infection in the kidney of silver carp Hypophthalmichthys mol...Myxozoans are common microscopic endoparasites in fish,and some are highly pathogenic to their wild and farmed fish hosts.In the present study,myxosporeans infection in the kidney of silver carp Hypophthalmichthys molitrix(Valenciennes,1844)from Lake Taihu,was investigated,and two dominate species,Myxobolus lieni(Nie&Li,1973)and M.varius(Achmerov,1960),with infection prevalence 60.2%and 35.2%,respectively,were well characterized based on morphological,histopathological and DNA sequence data.M.lieni formed small roundish plasmodia in the epithelial cells of renal tubules.The mature myxospores appeared suborbicular,slightly flat in frontal view and fusiform shaped in sutural view.Dispersed myxospores of M.varius were found in the renal interstitium without forming plasmodia structures and enclosed within melano-macrophage centers.The spore appeared elliptical in frontal view,with wider anterior than posterior and shuttle shaped in sutural view.Interestingly,the occurrence of myxozoans in the kidney detected with SSU rDNA PCR and clone sequencing,revealed co-infection of five Myxobolus species.BLASTn search indicated SSU r DNA gene sequences obtained here were not identical to any sequence available in GenBank.Phylogenetic analyses showed that the five Myxobolus species detected here were clustered together,forming a separate clade of cyprinid-infecting myxozoans.展开更多
Multivariate analysis was adopted to analyze 30 morphometrical characteristics of 121 one-year-old juvenile silver carp （Hypophthalmichthys molitrix） and bighead carp （Aristichthys nobilis） bred during the 1950s ...Multivariate analysis was adopted to analyze 30 morphometrical characteristics of 121 one-year-old juvenile silver carp （Hypophthalmichthys molitrix） and bighead carp （Aristichthys nobilis） bred during the 1950s （＂the former population＂） and 2008 （＂the current population＂） and collected from the middle reach of the Yangtze River. The average discriminant accuracies of the former and current silver and bighead carp population were 94.2% and 98.0%, respectively. Discriminant analysis also revealed that significant differences in morphology occurred between the former and current populations of both carp in overall characteristics. One-way analysis of variance indicated that between former and current populations, silver carp showed highly significant differences （P0.01） in twelve of their characteristics and significant differences （P0.05） in eight of their characteristics, while bighead carp showed highly significant differences （P0.01） in eight of their characteristics and significant differences （P0.05） in eight of their characteristics. Six head morphology variables of the current silver and bighead carp were significantly or highly significantly larger than the former populations; fourteen characteristics of silver carp and ten characteristics of bighead carp of the current populations, mainly reflecting truck and tail morphology, were significantly or very significantly smaller than the former populations. Our results indicate that silver and bighead carp have developed a larger head and smaller truck and tail during the last 50 years. Due to such morphological changes, it seems apparent that the heads of these fish species need to be considered in regards to human diets, particularly in relation to economic and nutritious value.展开更多
Cadmium is a non-essential metal with a wide distribution that has severe toxic effects on aquatic animals. Changes in hematology and muscle physiology were examined in silver carp (Hypophthalmichthys molitrix) expose...Cadmium is a non-essential metal with a wide distribution that has severe toxic effects on aquatic animals. Changes in hematology and muscle physiology were examined in silver carp (Hypophthalmichthys molitrix) exposed to environmentally relevant levels of cadmium (0.01 mg L-1 ) for 96 h. Cadmium exposure induced significant increases in the red blood cell count, and in the plasma concentrations of cortisol, glucose, and lactate. This suggests that the dose of cadmium was sufficient to cause stress, possibly associated with impaired gas exchange at the gills. There were no changes in hemoglobin concentration or plasma protein concentration. Significant decreases in muscle energy fuels (ATP and glycogen), and increases in muscle lactate persisted until the end of the exposure period, respectively. The changes in muscle lactate and protein in silver carp differed from those observed in response to exposure of fish to cadmium and heavy metals in other studies. The study highlights the importance of selecting unpolluted release sites with suitable water conditions for the survival of newly released individuals for stock enhancement of the Xiangjiang River.展开更多
Ingredients: 4 silver carp of about 200 grams each, mushrooms, winter bamboo shoots, minced ginger root and scallions, cooking wine, broth, salt and MSG (optional). Method: 1. After cleaning the carp place them in a p...Ingredients: 4 silver carp of about 200 grams each, mushrooms, winter bamboo shoots, minced ginger root and scallions, cooking wine, broth, salt and MSG (optional). Method: 1. After cleaning the carp place them in a pot; add in all other ingredients and some broth, Seal the opening of the pot with kraft展开更多
文摘[Objective] The aim was to carry out isozyme analysis of jin silver carp (Hypophthalmichthys molitrix Var Jing). [Method] The isozyme of AAT, EST, α-GPD, GPI, IDH, LDH, MDH, ME, PGM and PROT of muscles and liver in two populations of the silver carp (Hypophthalmichthys molitrix): Jin silver carp (a breed through selective breeding) and artificially propagated population bought from Jingzhou city, Hubei Province were examined by horizontal starch gel electrophoresis. [Result] Eighteen loci were observed in two populations. Two loci of GPI* and PGM* in Jing silver carp population and the locus of GPI* in Jingzhou population were polymorphic. The proportions of polymorphic loci (maximum allele frequency≤0.99) of Jing silver carp and Jingzhou populations were 11.11% and 5.56% respectively, expected heterozygosity were 0.015 0 and 0.001 1 respectively. The Nei’s genetic distances were 0.000 59 between two populations. The result of chi-square test of the GPI* gene in two populations showed that their genetic structure has very significant difference. [Conclusion] This study provided a theoretical basis for large-scale extension of Jing silver carp.
基金supported by the National Natural Science Foundation of China (No.50778048)the National Key Technology R&D Program (No.2006BAJ08B02)
文摘Silver carp were introduced into the pre-sedimentation pond to control excessive phytoplankton in raw water. The effectiveness of the filter-feeding silver carp on phytoplankton control and the effect of silver carp on phytoplankton community were investigated. The results showed that Microcystis could be effectively removed by silver carp stocked in the pre-sedimentation pond, and simultaneously, the concentration of single-cell phytoplankton increased obviously. The difference in phytoplankton species and single- cell phytoplankton size between in the water and in the gut of silver carp indicated that phytoplankton smaller than 5 μm, such as Chamydomonas and Platymonas, were almost not be filtered by silver carp, phytoplankton with the size between 5 and 20μm could be partly filtered, and large size phytoplankton, mainly colony-forming Microcystis could be filtered almost completely. These filter- feeding characteristics directly caused the phytoplankton size distribution biased toward miniaturization. Therefore, this biological treatment using silver carp could be applied only to deal with groups of Microcystis-dominated eutrophic water, and was not appropriate in water bodies where single-cell micro phytoplankton were dominant. Especially when silver carp are used in water treatment, a cautious attitude should be taken based on the evaluation of phytoplankton biomass and species structure features in raw water.
基金The Main Basic Research Development Programof China(No. G1999045710) and KIPof CAS(RCEES No.9902)
文摘The concentration of organochlorine pesticides（OCPs） in tissues and organs of silver carp（Hypophthalmichthys mofitrix） from Guanting Reservoir were investigated to evaluate the pollution potential and distribution of OCPs. A total of 16 OCPs were measured and the concentrations were in the range of 1.61-69.01 ng/g wet weight（ww） for total OCPs, 0.16- 0.75 ng/g ww for HCB. 0.75 -26.80 ng/g ww for SHCH（sum of α-,β-, γ- and δ-HCH） and 0.68-35.94 ng/g ww for SDDT（ sum of p, p＇-DDE, p, p＇-DDD, o, p＇-DDT and p, p＇- DDT）. The mean concentrations of total OCPs, HCB, ∑HCH, and ∑DDT were 18.04, 0.96, 7.14 and 9.28 ng/g ww, respectively. Among the organochlorine pesticides, β-HCH and p, p＇-DDE were the most dominant compounds in tissue and organ with the average concentrations of 4.42 and 8.14 ng/g, respectively. The results obtained in this study show that the levels of 16 OCP residues found in silver carps are low and pose no threat to human health and wildlife fed upon them on the basis of existing related quality guidelines. However, recent input of lindane and DDT might still exist in the area investigated and further investigation should be carried on.
基金Project supported by the National Natural Science Foundation of China (No. 39830300).
文摘Three artificial gynogenetic clones of silver carp were produced for the analysis of restriction enzyme digestion patterns of ND5-ND6 region from mtDNA of the clones. It is revealed that all intraclonal individuals shared completely the same digestion patterns but among interclonal individuals did not. The three clones were mixed and cultured in a pond together for two years, and restriction endonuclease digestion patterns of ND5-ND6 were used as genetic markers to assess the growth performance of each clone.
基金Supported by High-level Cultivation Project of Huanggang Normal University(04201711903).
文摘[Objectives]The effects of water chestnut powder on the gel properties and quality of silver carp surimi were investigated.[Methods]The surimi gel was prepared by adding 0%,1%,2%,3%,4%and 5%of water chestnut powder to the surimi of silver carp.The gel properties,water-holding capacity,cooking loss,whiteness value,puncture and texture profile analysis(TPA)indexes of surimi products were determined to assess the effects of adding different amounts of water chestnut powder on surimi gel.[Results]The results showed that the gel strength,breaking force and depression distance of surimi products increased first and then decreased with the increase of the addition of water chestnut powder.Compared with the control group,the hardness and chewiness of surimi gel in TPA could be significantly improved by adding water chestnut powder.When the addition of water chestnut powder was 2%,the maximum water-holding capacity was 83.68%;the cooking loss rate was the lowest;and the whiteness value was the highest.Adding 2%of water chestnut powder could significantly improve the gel properties of silver carp surimi and obtain a good gel product.[Conclusions]This study provides a scientific basis for the effective utilization of water chestnut resources and the development of new fish surimi products.
基金Supported by the National Science and Technology Ministry(No.2014BAC09B02)the National Water Pollution Control and Management Technology Major Projects(No.2012ZX07101-002)
文摘Silver carp is one of the most important planktivorous fish in Chinese aquaculture and plays a significant role controlling cyanobacterial blooms. A balanced gut microbiota is crucial for growth and health of the host because of its important roles in immune defense, digestion of complex carbohydrates, and production of enterocytes. In our study, the dominant bacterial and cellulolytic bacterial （Clostridium 1, Clostridium 111, Clostridium XIVab, and Fibrobacter） communities in the contents and mucus of the silver carp gut （foregut, midgut, and hindgut） were analyzed by denaturing gradient gel electrophoresis and quantitative polymerase chain reaction （qPCR） analyses. The results revealed that the dominant and cellulolytic bacterial communities were significantly different among gut regions as well as in contents and mucus. Bacterial diversity and richness in contents and mucus increased along the gut and were higher in contents than those in local mucus. A sequence analysis of gut samples exhibited the conservative phylotypes of Proteobacteria, Actinobacteria, and Firmicutes. The gut of silver carp harbored an abundance of cellulolytic bacteria, particularly Clostridium XIVab. The foregut segment had the highest proportions of the four cellulolytic bacteria, followed by the midgut and hindgut. However, the proportions of cellulolytic species in the silver carp gut was much lower than those in the terrestrial vertebrate gastrointestinal tract. We conclude that gut bacteria could help silver carp obtain energy from cyanobacteria, which may be why silver carp can maintain high growth rates during cyanobacterial blooms.
文摘The effect of various concentrations of nitrobenzene on the mortality and abnormality rate of bighead and silver carp embryos were studied to provide reference for the evaluation of the effect of nitrobenzene to aquatic organisms and aquatic environment. The results showed that the development of bighead and silver carp embryos was delayed, the mortality and abnormality rates were raised when the embryos were treated with ≥0.010 mg·L^-1 nitrobenzene, and with ≥0.085 mg· L^-1 nitrobenzene, the mortality rates showed 100%
文摘The effect of washing and temperature on the activity of cathepsins of Silver carp was studied.The result showed that the activity of cathepsin L was higher than those of cathepsin B and H.The total catalysis activity of these three enzymes was the highest at 55℃ after washing.The inhibiting effect of soybean protein and potato starch on cathepsin L also had been studied,the results showed that soybean protein and potato starch could decrease activity of cathepsins L significantly.
基金Heilongjiang Province Science and Technology Key Project
文摘The hydrolysis process for Silver carp by-products was studied. Protein hydrolysate was prepared with proteolytic enzyme, Alcalase. Hydrolysis conditions were optimized by the regression model of three factors five levels quadratic rotation perpendicular regressive design. The optimum hydrolysis conditions of hydrolyzing the protein of Silver carp by-products were determined to be concentration of enzyme (E/S) 3.33%, pH 8.54, hydrolyzing temperature 58 ℃, reaction time 90 min, concentration of substrate 8%. Nitrogen recovery was more than 75%.
文摘Fish sauce is a kind of condiments processed from fish. The L9（34） orthogonal tests have been carried out to inspect the effects of technological conditions for fermentation on the comprehensive quality of fish sauce. The conditions of the orthogonal tests are following: the fermentation temperature takes values of 35℃, 40℃ and 45℃, the percentage of Koji values of 40%, 20% and 10% and the percentage of salt values of 10%, 14% and 18%. The obtained experimental results indicate that fermentation temperature plays an important role in the improvement of sauce quality. The optimal technological conditions for sauce fermentation are of 10% salt, 45℃ and 40% koji mixed. The composition of fish sauce processed from offal of silver carp-surimi processing under the above-mentioned conditions and two commercial products have been analyzed. The results show that fish sauce processed from fish offal is nutritious and delicious. It is suggested that the fermentation of fish sauce is a potential and promising pathway to make full use of freshwater fish resources and offal in fish processing. In this study, fuzzy theory and analytic hierarchy process have been applied and the quality evaluation has been established by the combination of physico-chemical indices and sensory evaluation. The comprehensive evaluation has been taken to reflect the optimal factors for the process of sauce fermentation. The quality indexes for fish sauce contain sensory evaluation, amino nitrogen, total nitrogen, specific gravity, volatile basic nitrogen, salt concentration, brown index and acidity, represented by y1, y2, y3, y4, y5, y6, y7, y8, and y9, respectively. They form a group U= {y1, y2, y3, y4, y5, y6, y7, y8, y9,}. Using the fuzzy functions, the values of all these factors are transformed into fuzzy degrees of single factor, i.e. numerical values between 0 and 1. The fuzzy degrees of single factor in several samples are made up a matrix R. Following that, a weight of each index can be determined in the comprehensive evaluation. In the analytic hierarchy process, the weight can be obtained by the cross comparison between two different factors. The results show that the weights （W） of sensory evaluation, amino nitrogen, total nitrogen, specific gravity, volatile basic nitrogen, salt concentration, brown index and acidity are 0.356, 0.189, 0.107, 0.054, 0.097, 0.063, 0.061 and 0.073 respectively. Finally the aggregated fuzzy degree （B） of different samples is computed by B=W·R, which can be taken as the final result of comprehensive evaluation. The larger this value is, the higher the quality of sauce product would be.
基金Supported by Scientific Research Program Steering Group Project of Department of Education of Hubei Province (B2020166)。
文摘[Objectives]This study was conducted to improve the gel properties of freshwater surimi and its products. [Methods] Tuanfeng lotus seed powder was added to frozen silver carp, and the relationship between the addiamount of Tuanfeng lotus seed powder(1%, 2%, 3%, 4% and 5%) and the quality of surimi products was studied, so as to improve the quality of surimi products. [Results] The water holding capacity(86.71%±0.36%), hardness(3 566.64±51.15) g, chewiness(2 697.16±15.81) g and gel strength(692.54±23.19) of surimi products increased to the maximums when the addition amount of lotus seed powder was 3%. Meanwhile, the cooking loss rate was reduced to the minimum(13.00%±0.17%), and the sensory quality was the best, although the whiteness of surimi products decreased slightly with the increase of Tuanfeng lotus seed powder. Therefore, the quality of silver carp surimi products could be improved obviously when the dosage of Tuanfeng lotus seed powder was 3%. [Conclusions] This study provides more new ideas for improving the quality of silver carp surimi products, and simultaneously makes the development of lotus seed food more diversified.
基金supported by the National Natural Science Foundation of China(Grant No.51379136)
文摘Dam discharges over spillways are the main reason for the gas-supersaturated water generated in rivers.Local aquatic organisms,especially fish,readily develop gas bubble disease(GBD) in a river with total dissolved gas supersaturation(TDGS).Sometimes,fish will die after a specific exposure period,which negatively affects the biological equilibrium.In this study,the influence of TDGS on silver carp was explored.Silver carp were exposed to gas-supersaturated water with TDGS levels of 140%,135%,130%,125%,120%,and 110%to test the impact of TDGS.Some silver carp died when the TDGS level was 120%or higher,and all the silver carp exposed to a TDGS level of 140%died within10 h.In comparison with the Chinese sucker,Prenant's schizothoracin,and rock carp,silver carp seem less sensitive to TDGS.In addition,we tested the catalase(CAT) activity in the muscles and gills of silver carp after they were exposed to gas-supersaturated water with a TDGS level of140%.The CAT activity changed with time;it increased first and then decreased until it was lower than the initial CAT activity.The results of this study can provide basic data for developing a standard for environmental evaluation.
文摘Study of the feeding capacity of silver carp and bighead carp by means of experimental ecologyshowed that the filtering frequency of silver carp was slightly greater than that of bighead carp,but thatthe latter’s suction volume was much greater than the former’s so the filtering rate(filtering frequency mul-tiplied by the suction volume)of silver carp was smaller than that of bighead carp.The filtering efficien-cy of silver carp for phytoplankton was greater than that of bighead carp for them.The removal ratesof silver carp for phytoplankton were greater than those of bighead carp,but for zooplankton the formerwere smaller than the latter.For food particles about 70 μm both removal rates were almost equal.The feeding habits of the two species in natural waters is also discussed in the paper.
文摘Silver Carp (SC) (Hypophthalmichthys molitrix, Valenciennes, 1844) is a worldwide common fish for aquaculture and stocking in lakes and reservoirs. The fish is distributed through rivers, aquaculture and stocking in about 90 countries around the world. SC was first introduced into Lake Kinneret in 1969 and continues onwards. Total number of stocked fingerlings (1969-2013) was 18.5 × 106 (average: 441 × 103 per year). The total catch (tons) of SC in Lake Kinneret was 3218 tons, average: 75 t/year. Studies on SC in East Lake, China, revealed that the fish was a phytoplanktivorous and percentage of consumed phytoplankton varied between 83% - 91% where Microcystis was the major item. In Lake Kinneret, the effects of SC and the Cichlid, Galilee St. Peters Fish (S. galilaeus) on Plankton resources are not independent and potentially competitors. SC is also known as efficient consumer of Microcystis. It was found that environmental conditions in Lake Kinneret were optimal for reasonable growth and recruitment of this fish to commercial fishery. The SC did not reproduce in Lake Kinneret and we recommended introducing annually 600 - 1000 × 103 fingerlings for the benefit of water quality protection and fishermen income.
文摘Among fresh water fishes, silver carp because of fast growth rate and desired meat quality, is a dominant species in polyculture systems in Iran. This fish mainly feed on phytoplankton. In present survey kidney and intestine of 120 silver carp (Hypophtalmictys molitrix) from 4 regions in Khuzestan province-Iran have been studied. Tissue samples were provided from kidney and intestine and sectioned by routine method after paraffin embedding and finally stained with hematoxilin and eosin (H & E). The microscopic results were analyzed qualitatively and quantitatively. Microscopical analysis showed that kidney tissue had lesions including: edema, necrosis, uroliths, hemorrhage and degeneration. In different regions, fishes showed different prevalence of lesions. Edema and urolith were the most prevalent lesions (30 and 25 percent respectively). In histometric analysis the diameter of layers of intestine in some of the fish farms were significantly higher than the other regions. This increase was because of increase in muscular layer. The intensity of all lesions was estimated as light according to distribution of lesions. The probable cause of these lesions may be the high stocking density, intoxication, water quality problem such as excessive carbon dioxide. The only lesion in intestine was the excessive proliferation of mucus cells that this lesion may be created due to the improper plankton diet.
基金supported by the National Natural Science Foundation of China(Nos.41572230 and 41172219)the Grant for Innovative Research Groups of the National Natural Sci-ence Foundation of China(No.41521001)+1 种基金the Special Scien-tific Research Project of Hanzhong City-Shaanxi University of Technology Co-construction State Key Laboratory(No.SXJ-2106)the Scientific Research Foundation of State Key Laboratory of Qinba Bio-Resource and Ecological Environment(No.SXC-2105).
文摘Silver carp mediated biological control techniques are often advocated for controlling cyanobacteria blooms in eutrophic water,which are often enriched with arsenic(As).How-ever,the transfer and fate of As during the biological control of cyanobacteria blooms by silver carp in As-rich eutrophic water remain unclear.Based on the simulated ecosystem experiment,the accumulation of As in silver carp and the transfer and fate of As in the water-algae-silver carp system during Microcystis aeruginosa blooms controlled by silver carp were investigated.Microcystis aeruginosa showed high tolerance to As(V).The accumulation of As in different tissues of silver carp was different,as follows:intestine>liver>gill>skin>muscle.After silver carp ingested As-rich Microcystis aeruginosa,As accumulation in the intestine,liver,gill,and skin of silver carp was enhanced under the action of digestion and skin contact.Compared with the system without algal,As accumulation in the intestine,liver,gill,and skin of silver carp increased by 1.1,3.3,3.3,and 9.6 times,respectively,after incubation for 30 days in the system with Microcystis aeruginosa,while the accumulation of As in the muscle was only slightly increased by 0.56 mg/kg.This work revealed the transfer and fate of As during algal control by silver carp,elucidated the accumulation mechanism of As in water-algae-silver carp system,enriched our understanding of As bioaccumulation and transformation in As-rich eutrophication water,and provided a scientific basis for as-sessing and predicting As migration and enrichment in water-algae-silver carp system.
基金supported the earmarked fund for China Agriculture Research System of MOF and MARA(CARS-45)Natural Sciences Foundation of China(32073019)。
文摘Myxozoans are common microscopic endoparasites in fish,and some are highly pathogenic to their wild and farmed fish hosts.In the present study,myxosporeans infection in the kidney of silver carp Hypophthalmichthys molitrix(Valenciennes,1844)from Lake Taihu,was investigated,and two dominate species,Myxobolus lieni(Nie&Li,1973)and M.varius(Achmerov,1960),with infection prevalence 60.2%and 35.2%,respectively,were well characterized based on morphological,histopathological and DNA sequence data.M.lieni formed small roundish plasmodia in the epithelial cells of renal tubules.The mature myxospores appeared suborbicular,slightly flat in frontal view and fusiform shaped in sutural view.Dispersed myxospores of M.varius were found in the renal interstitium without forming plasmodia structures and enclosed within melano-macrophage centers.The spore appeared elliptical in frontal view,with wider anterior than posterior and shuttle shaped in sutural view.Interestingly,the occurrence of myxozoans in the kidney detected with SSU rDNA PCR and clone sequencing,revealed co-infection of five Myxobolus species.BLASTn search indicated SSU r DNA gene sequences obtained here were not identical to any sequence available in GenBank.Phylogenetic analyses showed that the five Myxobolus species detected here were clustered together,forming a separate clade of cyprinid-infecting myxozoans.
基金National Natural Science Foundation of China (30630051)Aquaculture E-Institute of Shanghai Universities(03E009)Shanghai Leading Academic Discipline Project(S30701)
文摘Multivariate analysis was adopted to analyze 30 morphometrical characteristics of 121 one-year-old juvenile silver carp （Hypophthalmichthys molitrix） and bighead carp （Aristichthys nobilis） bred during the 1950s （＂the former population＂） and 2008 （＂the current population＂） and collected from the middle reach of the Yangtze River. The average discriminant accuracies of the former and current silver and bighead carp population were 94.2% and 98.0%, respectively. Discriminant analysis also revealed that significant differences in morphology occurred between the former and current populations of both carp in overall characteristics. One-way analysis of variance indicated that between former and current populations, silver carp showed highly significant differences （P0.01） in twelve of their characteristics and significant differences （P0.05） in eight of their characteristics, while bighead carp showed highly significant differences （P0.01） in eight of their characteristics and significant differences （P0.05） in eight of their characteristics. Six head morphology variables of the current silver and bighead carp were significantly or highly significantly larger than the former populations; fourteen characteristics of silver carp and ten characteristics of bighead carp of the current populations, mainly reflecting truck and tail morphology, were significantly or very significantly smaller than the former populations. Our results indicate that silver and bighead carp have developed a larger head and smaller truck and tail during the last 50 years. Due to such morphological changes, it seems apparent that the heads of these fish species need to be considered in regards to human diets, particularly in relation to economic and nutritious value.
基金supported by the National Natural Science Foundation of China (31100282,31000183,31000179)
文摘Cadmium is a non-essential metal with a wide distribution that has severe toxic effects on aquatic animals. Changes in hematology and muscle physiology were examined in silver carp (Hypophthalmichthys molitrix) exposed to environmentally relevant levels of cadmium (0.01 mg L-1 ) for 96 h. Cadmium exposure induced significant increases in the red blood cell count, and in the plasma concentrations of cortisol, glucose, and lactate. This suggests that the dose of cadmium was sufficient to cause stress, possibly associated with impaired gas exchange at the gills. There were no changes in hemoglobin concentration or plasma protein concentration. Significant decreases in muscle energy fuels (ATP and glycogen), and increases in muscle lactate persisted until the end of the exposure period, respectively. The changes in muscle lactate and protein in silver carp differed from those observed in response to exposure of fish to cadmium and heavy metals in other studies. The study highlights the importance of selecting unpolluted release sites with suitable water conditions for the survival of newly released individuals for stock enhancement of the Xiangjiang River.
文摘Ingredients: 4 silver carp of about 200 grams each, mushrooms, winter bamboo shoots, minced ginger root and scallions, cooking wine, broth, salt and MSG (optional). Method: 1. After cleaning the carp place them in a pot; add in all other ingredients and some broth, Seal the opening of the pot with kraft
