The exploration and understanding of myxosporean,one of the crucial stressors causing fish disease,have always been highly regarded.The present study aims to fully understand a novel myxobolid species,Thelohanellus xi...The exploration and understanding of myxosporean,one of the crucial stressors causing fish disease,have always been highly regarded.The present study aims to fully understand a novel myxobolid species,Thelohanellus xiushanensis n.sp.infecting the gill filaments of Carassius auratus from Chongqing,China,as well as the associated pathological impacts.A multifaceted analysis at various levels and perspectives was carried out by the approach integrating morphology,molecular systematics,histopathology,combined host and habitat,as well as SSU rDNA data.The results indicated that its mature myxospores displayed a tapering anterior and a blunt-rounded posterior,with a dropshape in front view and melon-seed shape in sutural view in morphology.The outer surface was covered with a transparent membrane sheath in valve view.The dimensions of myxospores were average(19.2±1.1)(17.1-21.0)×(10.0±0.7)(8.7-12.1)×(9.7±0.5)(9.1-10.8)μm.An elliptical polar capsule,containing four to five turns of single polar filament,measures(8.0±0.6)(6.9-9.1)×(6.6±0.3)(6.1-7.1)μm.Its SSU rDNA sequence demonstrated the closest similarity(99.95%)with an actinosporean Neoactinomyxum sp.NEO-7.Histopathological results indicated that numerous myxoplasmodia of T.xiushanensis n.sp.were located in the tips of the gill filaments,resulting in deformation and rupture of partial gill filaments.Furthermore,severely infected gill lamellae exhibited hyperplasia and fusion,accompanied by infiltration of numerous eosinophils.In addition,regenerated gill filaments were observed at the bases of partially ruptured gill filaments,indicating that the host’s gill tissue has the innate capacity to shed diseased tissues and regenerate new ones.This study has proved the present species and Neoactinomyxum sp.NEO-7 belong to the same myxosporean species but corresponding to different developmental stage,designated as a new species.This novel species is a potential pathogen for the host,which should not be ignored.This study not only enriches myxobolid biodiversity and demonstrates a potentially pathogenic agent,but also provides a valid diagnosis for the gill myxoboliosis caused by the present pathogen in aquaculture.展开更多
Bisphenol A （BPA） is the monomer component of polycarbonate plastics and classified as an endocrine disrupting chemical （EDC）. The reproductive toxicity of BPA has been extensively studied in mammals; however, rel...Bisphenol A （BPA） is the monomer component of polycarbonate plastics and classified as an endocrine disrupting chemical （EDC）. The reproductive toxicity of BPA has been extensively studied in mammals; however, relatively little information is available on the immunotoxic responses of fish to BPA. In this study, we investigated the effects of BPA on the immune functions of lymphocytes and macrophages in Carassius auratus. The effects of BPA were compared with those of two natural steroid hormones, estradiol and hydrocortisone. Proliferation of the two types of cells in response to PHA was measured using colorimetric MTT assay. Macrophage respiratory burst stimulated by Con A was measured using chemiluminescence assay. Results showed that BPA （0.054-5.4 mg/L）, estradiol （0.0002-2.0 mg/L） and hydrocortisone （5-50 mg/L） significantly induced Carassius auratus lymphocyte proliferation while higher doses of hydrocortisone （500-5000 mg/L） appeared to be inhibitory. BPA （0.005-50 mg/L）, estradiol （0.005-800 mg/L） and hydrocortisone （0.005-500 mg/L） markedly enhanced macrophage proliferation, whereas higher doses of BPA （500-1000 mg/L） appeared to inhibit cell proliferation. Furthermore, higher dosage of BPA （50 mg/L） and hydrocortisone （50 and 500 mg/L） suppressed the macrophages respiratory burst while estradiol is stimulative all the doses tested （0.05-500 mg/L）. In conclusion, BPA could have immunotoxicity to Carassius auratus and functional changes of lymphocyte and macrophage in Carassius auratus may be different between low and high dosages.展开更多
Specific immunoglobulin (IgY) from egg yolk against Aeromonas hydrophila was produced by immunization of White Leghorn hens with formalin-killed whole cells of A. hydrophila. ELISA test using A. hydrophila as the coat...Specific immunoglobulin (IgY) from egg yolk against Aeromonas hydrophila was produced by immunization of White Leghorn hens with formalin-killed whole cells of A. hydrophila. ELISA test using A. hydrophila as the coating antigen revealed that the specific antibody titer started to increase in the egg yolk at the 13th day post-immunization (P/N=2.18), reached the peak at the 56th day (P/N=13.82), and remained at high level until day 133 (P/N=7.03). The antibody was purified by saturated ammonium sulphate with a recovery rate of 63.5%. The specific IgY inhibited the growth of A. hydrophila at a concentration of 1.0 mg/ml during the 18 h incubation. Pre-treatment of polyploid gibel carps Carassius auratus Gibelio with specific IgY had a protection rate of 60% (6/10) against challenge with A. hydrophila, while none of the fishes in the control groups receiving sterile phosphate buffered saline (PBS) or non-specific IgY survived the challenge. Treatment of fishes with the specific IgY 4 h after the challenge also had lower mortality (70%, 7/10), a 30% reduction against the control PBS or non-specific IgY groups (10/10). These results indicate that specific IgY antibodies could be obtained easily from hens immunized with an inactivated A. hydrophila and could provide a novel alternative approach to control of diseases in fishes caused by this organism.展开更多
Under the indoor simulant conditions, toxic effects of crude-oil-contaminated soil which was put into aquatic environment on the young fishes Carassius auratus and their hepatic antioxidant system after a 20-d exposur...Under the indoor simulant conditions, toxic effects of crude-oil-contaminated soil which was put into aquatic environment on the young fishes Carassius auratus and their hepatic antioxidant system after a 20-d exposure were investigated. Results showed that the relationship between the mortality of C. auratus and the exposed doses could be divided into 3 phases： fishes exposed to the low dose groups （0.5-5.0 g/L） were dead due to the ingestion of crude-oil-contaminated soils in aquatic environment; at the medium dose groups （5.0-25.0 g/L） fishes were dead due to the penetration of toxic substances; at the high dose groups （25.0-50.0 g/L） fishes were dead due to environmental stress. The highest mortality and death speed were found in the 1.0 g/L dose group, and the death speed was sharply increased in the 50.0 g/L dose group in the late phase of exposure. The activities of superoxide dismutase （SOD）, catalase （CAT） and glutathione S-transferase （GST） and the content of malaondialdehyde （MDA） in the hepatic tissues of C. auratus were induced significantly. The activity of SOD was increased and then decreased. It was significantly inhibited in the 50.0 g/L dose group. The activity of CAT was highly induced, and restored to a level which is little more than the control when the exposed doses exceeded 10.0 g/L. The activity of GST was the most sensitive, it was significantly induced in all dose groups, and the highest elevation was up to 6 times in the 0.5 g/L dose group comparing with the control. The MDA content was significantly elevated in the 50.0 g/L dose group, and the changes of the MDA content were opposite with the changes of GST activity.展开更多
A feeding trial was conducted for nine weeks to investigate the effects of partially replacing Ca（H2PO4）2 with neutral phytase on the growth performance, phosphorus utilization, nutrient digestibility, serum biochem...A feeding trial was conducted for nine weeks to investigate the effects of partially replacing Ca（H2PO4）2 with neutral phytase on the growth performance, phosphorus utilization, nutrient digestibility, serum biochemical parameters, bone and carcass mineral composition, and digestive-enzyme-specific activity in crucian carp（Carassius auratus）.The diets prepared with 0.8%, 0%, and 1.8% Ca（H2PO4）2（1%=1 g/100 g） supplements were regarded as the P1E0, negative control（NC）, and positive control（PC） groups, respectively; the other three experimental diets were prepared with the addition of 200, 300, and 500 U/kg of neutral phytase, respectively, based on the P1E0 group.Three hundred and eighty-four fish（（1.50±0.01） g） were randomly distributed in the six treatments with four replicates each.The fish were initially fed with 2%–3% diets of their body weight per day, with feeding twice daily（08：00 and 16：00）, under a 12-h light/12-h dark cycle at the temperature of（27.56±0.89） ℃.The results showed that supplemental phytase at different levels in the diet improved the final body weight, average daily gain, feed conversion ratio, phosphorus utilization, and protein efficiency ratio of crucian carp（P〈0.05）.Phytase supplementation increased the mineral content in serum（P）, bone（P, Ca）, and carcass（P, Ca, Zn, Na, and Mg）（P〈0.05）; the trypsin and chymotrypsin activity soared when fed with the phytase-supplemented diets（P〈0.05）.We may conclude that supplemental dietary neutral phytase improved the growth performance, phosphorus utilization as well as nutrient utilization in crucian carp, and it can be considered an important nutritional replacement for Ca（H2PO4）2.展开更多
In Georgia, crucian carp Carassius carassius （Linnaeus, 1758） was known from only one locality after Kessler＇s record （1877-1878） with no new findings until 1985. Since then C. carassius rapidly and simultaneousl...In Georgia, crucian carp Carassius carassius （Linnaeus, 1758） was known from only one locality after Kessler＇s record （1877-1878） with no new findings until 1985. Since then C. carassius rapidly and simultaneously invaded almost all water bodies of Georgia. In 2004, it was for the first time noted that this invasive Carassius sp. could not be a C. Carassius, but was a form of Carassius gibelio （Bloch, 1792）. However no further data is available about this invasive species in Georgia. The aim of the present study was to investigate taxonomic status of Carassius sp. in Georgia using mtDNA phylogenetic analyses and mor- phometrie study of truss network system. Genetic analysis revealed that invasive Carassius sp. is closely related to the C. gibelio from Turkey and other countries. In contrast, morphometrically Carassius sp. from Georgia can be easily differentiated from those of Turkey indicating high intraspecific variability. This is the first time discussion on the current knowledge of the present distribution of invasive carp in Georgia with identifying current problems and future research directions needed.展开更多
Objective To study the biological effects of nanoscale copper oxide （nCuO）, zinc oxide （nZnO）, cerium dioxide （nCeO2） and their mixtures on Carassius auratus. Methods Juvenile fish （Carossius auratus） were exp...Objective To study the biological effects of nanoscale copper oxide （nCuO）, zinc oxide （nZnO）, cerium dioxide （nCeO2） and their mixtures on Carassius auratus. Methods Juvenile fish （Carossius auratus） were exposed to aqueous suspensions of nCuO, nZnO, and nCeO2 （alone and in mixtures） at concentrations of 20, 40, 80, 3.60, and 320 mg/L. The biomarkers-acetylcholinesterase （ACHE） in brain, sodium/potassium-activated ATPase （Na~/K＊-ATPase） in gill, and superoxide dismutase （SOD） and catalase （CAT） in liver-were determined after 4 days of exposure. Integrated biomarker response （IBR） was calculated by combining multiple biomarkers into a single value. Results AChE and SOD activities were significantly inhibited by all test metal oxide nanoparticles （NPs） at high concentrations （__.160 rag/L） with the exception of nCeO2. Na~/K＋-ATPase induction exhibited bell-shaped concentration-response curves. CAT activity was significantly inhibited at concentrations equal to or higher than 160 mg/L. The order of IBR values was nCeO2 = nZnO/nCeO2= nCuO/nCeO2 〈 nCuO/nZnO/nCeO2 〈 nZnO 〈 nCuO 〈 nCuO/nZnO. The joint effect seemed to be synergistic for nCuO/nZnO mixtures, additive for the ternary mixture and less than additive or antagonistic for the binary mixtures containing nCe02. Conclusion Concentration-dependent changes of enzymatic activities （ACHE, Na~/K＊-ATPase, SOD, and CAT） were observed in fish exposed to nanoscale metal oxides. IBR analysis allowed good discrimination between the different exposures and might be a useful tool for the quantification of integrated negative effects induced by NPs toward fish.展开更多
The freshwater fish Carassius auratus was chosen as an experimental subject, and their hepatic biochemical responses to the medium-term exposure of Benzo（k）fluoranthene （BkF） alone and in combination with PCB 118 ...The freshwater fish Carassius auratus was chosen as an experimental subject, and their hepatic biochemical responses to the medium-term exposure of Benzo（k）fluoranthene （BkF） alone and in combination with PCB 118 and dichlorodiphenyltrichloroethane （DDT） were investigated by measuring the reduced glutathione （GSH）, glutathione S-transferase （GST）, and thiobarbituric acid reactive substances （TBARS）, to assess sublethal effects. The hepatic GSH content was significantly inhibited by organic pollutants, alone and in mixtures, while the TBARS content was significantly induced after three days of exposure. Bell-shaped concentration-response charts of GST activities were obtained. Significant dose-response relationships were found for hepatic GSH and TBARS contents of all concentrations and for the GST activity, except at the highest concentration. The GSH content, GST activity, and TBARS content in Carassius auratus were confirmed as useful biomarkers of exposure to organic pollutions.展开更多
[Objective] The study aimed to the effects of various Cd2＋ concentrations and exposure time on erythrocyte micronuclei in peripheral erythrocyte micronuclei in Carassius auratus and Oriental weatherfish. [ Method ] U...[Objective] The study aimed to the effects of various Cd2＋ concentrations and exposure time on erythrocyte micronuclei in peripheral erythrocyte micronuclei in Carassius auratus and Oriental weatherfish. [ Method ] Using static water culture, Carassius auratus and Oriental weatherfish were exposed to solutions containing Cd2＋ with mass concentrations of 0.08, 1.72 and 6.84 mg/L, and blood was collected from tail veins to make smears which were observed under a oil lens afterwards. [ Result] In the initial exposure period, Carassius auratus and Onental weatherfish were unwell obviously, being afraid and unpeaceful and escaping everywhere. With the increase in Cd2＋ concentration, this phenomenon became more distinct. In addition, as the prolonging of exposure time, fishes moved slowly, powerlessly and less and reacted slowly, and moe and more excrement deposited at the bottom of aquariums. [ Conclusion] Cd2 ＋ could obviously induce Carassius auratus and Oriental weatherfish to generate micronuclei, showing certain dose-effect and time-effect relation under certain conditions.展开更多
Ten microsatellite loci were used for analyzing six populations of goldfish (Carassius auratus) with sarcoma. It showed that there was the highest genetic diversity among the white oranda with red cap (RC) population,...Ten microsatellite loci were used for analyzing six populations of goldfish (Carassius auratus) with sarcoma. It showed that there was the highest genetic diversity among the white oranda with red cap (RC) population, and the lowest among the white tigerhead (WT) population. However, the outcross existed among every population. There was huge genetic differentiation between WT and the other four populations. The average observed heterozygosity (HO) among populations ranged from 0.3571 to 0.7381. And significant genetic difference (FCT = 0.1891, P = 0.0186) appeared among goldfish varieties which can be classified into three groups (RT, WT;RL, BL, YC;RC). The software Principal Coordinate Analysis (PCA) and STRUCTURE showed that significant genetic differences were revealed between RC population of goldfish and other five populations.展开更多
Inorganic lead （Pb） is one of the most common environmental pollutants. Much evidence indicates that Pb exposure could directly affect fish growth and development. In this study, we investigated the cytotoxic effect...Inorganic lead （Pb） is one of the most common environmental pollutants. Much evidence indicates that Pb exposure could directly affect fish growth and development. In this study, we investigated the cytotoxic effects of Pb on cytoskeletal protein stability at both protein and mRNA level in crucian carp Carassius auratus. Pb（NO3）2 treatment in concentration of 100 μmol/L resulted in decreased expression of both α- and β-tubulin but γ-tubulin as assayed with SDS-PAGE, Western Blot, and ELISA. In vivo and in vitro analyses on protein expression of tubulins are consistent. The effect of Pb on mRNA expression varied among different tissues. Our results suggest that cytotoxicity of Pb at protein translation level is stronger than at mRNA expression level.展开更多
Procambarus clarkii is native to the south-central United States （Louisiana） and northeastern Mexico, and is a highly efficient predator that poses a damager to native species after its introduction or invasion. In ...Procambarus clarkii is native to the south-central United States （Louisiana） and northeastern Mexico, and is a highly efficient predator that poses a damager to native species after its introduction or invasion. In its natural habitat, P. clarkii consumes Carassius auratus, however, whether C. auratus recognizes P. clarkii as a predator is not yet clear. In laboratory experiments, we investigated whether experienced and inexperienced C. auratus recognize P. clarkii as a predatory threat and the specific sensory modality used by C. auratus to respond to chemical and visual stimuli from P. clarkii. In the chemical stimuli experiment, two kinds of chemical stimuli were used, water from a tub containing P. clarkii previously fed with C. auratus （C. auratus diet cues） and water from a tub containing unfed P. clarkii （P. clarkii cues）. In the visual experiment, experienced C. auratus decreased activity, but inexperienced C.auratus avoided the predator compartment. When C. auratus diet cues were presented, both experienced and inexperienced C. auratus increased the use of shelter, decreased activity in the initial response phase. Compared with the blank treatment, experienced C. auratus responded to P. clarkii cues by decreasing activity; however, inexperienced C. auratus showed no reduction in activity. C. auratus appears to recognize P. clarkii as a predator both through visual and chemical cues. Further analysis revealed that C. auratus may recognize R clarkii visually through the disturbances caused by P. clarkii movement and chemically by detecting conspecific alarm cues in the diet of P. clarkii. The results also indicate that ex- perienced C. auratus can recognize R clarkii by innate chemical cues from P. clarkii, whereas inexperienced C. auratus cannot [Current Zoology 57 （3）： 330-339, 2011].展开更多
Etrazine is one of the most widely used herbicides in China and the world. Acute and chronic toxicity tests werc carried out to assess the possible toxicity effect of atrazine on crucian carp （Carassius auratus）. Re...Etrazine is one of the most widely used herbicides in China and the world. Acute and chronic toxicity tests werc carried out to assess the possible toxicity effect of atrazine on crucian carp （Carassius auratus）. Results showed that 96 h LC,. of atrazine to Carassius auratus was 105.94 mg. L-1. The enzyme activities of superoxide dismutase （SOD）, catalase （CAT） and glutathione-S-transferases （GST） in kidney of Carassius auratus were all influenced by atraizine, and CAT was more sensitive to atrazine compared with SOD and GST. Atrazine residues in kidney of Carassius aura/us reached the stable state at day 19, and the bioaccumulation factors （BAF） of atrazine in kidney of Carassius auratus treated with 1.0 mg. L-1 and 10.0 mg. L-1 atrazine were 8.3 and 4.4, respectively. The research demonstrated that atrazine could cause oxidative stress to fish kidney, but atrazine was not easy to accumulate in Carassius auratus kidney, and the antioxidant enzymes could be used as biomarker to the early detection of pollution.展开更多
The growth and development of larvae and juveniles was morphologically investigated in Carassius auratus gibelio. The results showed that it took 52 h from fertilization to hatching at 22 - 25℃. The newly hatched lar...The growth and development of larvae and juveniles was morphologically investigated in Carassius auratus gibelio. The results showed that it took 52 h from fertilization to hatching at 22 - 25℃. The newly hatched larvae had transparent body, with the head fight near the yolk sac; the yolk sac accounted for 2/3 of larval volume, which was exhausted in the four-day-old larvae that started the exogenous nutrient period. The larvae were found to develop into juveniles from a few scales on the 20^th day after hatching to whole scales, fingerling, on the 28^th day after hatching. The relationship between total length（TL） and age in days（D） was described as ： TL = 0.001 2D3 - 0. 038 8/32 ＋ 1.043 2D ＋ 3. 945 8 （ r^2 = 0.998 ）. The relationship between body length （L） and body weight （W） of larvae and juveniles was expressed as： m = 1E -05L^3.3769（ r^2 = 0.982 7）. The formula between body length and body height during the development of the fish was described as ： H = 0.0（30 1L3 -0. 028 4L2 ＋ 1. 281 6L -7. 250 5 （ r^2 = 0. 988 6）. The findings provided the theoretical instruction for practical production of C. auratus gibelio.展开更多
基金National Natural Science Foundation of China(31970409)Projects of Chongqing Science and Technology Commission(cstc2021jcyj-msxmX0731)。
文摘The exploration and understanding of myxosporean,one of the crucial stressors causing fish disease,have always been highly regarded.The present study aims to fully understand a novel myxobolid species,Thelohanellus xiushanensis n.sp.infecting the gill filaments of Carassius auratus from Chongqing,China,as well as the associated pathological impacts.A multifaceted analysis at various levels and perspectives was carried out by the approach integrating morphology,molecular systematics,histopathology,combined host and habitat,as well as SSU rDNA data.The results indicated that its mature myxospores displayed a tapering anterior and a blunt-rounded posterior,with a dropshape in front view and melon-seed shape in sutural view in morphology.The outer surface was covered with a transparent membrane sheath in valve view.The dimensions of myxospores were average(19.2±1.1)(17.1-21.0)×(10.0±0.7)(8.7-12.1)×(9.7±0.5)(9.1-10.8)μm.An elliptical polar capsule,containing four to five turns of single polar filament,measures(8.0±0.6)(6.9-9.1)×(6.6±0.3)(6.1-7.1)μm.Its SSU rDNA sequence demonstrated the closest similarity(99.95%)with an actinosporean Neoactinomyxum sp.NEO-7.Histopathological results indicated that numerous myxoplasmodia of T.xiushanensis n.sp.were located in the tips of the gill filaments,resulting in deformation and rupture of partial gill filaments.Furthermore,severely infected gill lamellae exhibited hyperplasia and fusion,accompanied by infiltration of numerous eosinophils.In addition,regenerated gill filaments were observed at the bases of partially ruptured gill filaments,indicating that the host’s gill tissue has the innate capacity to shed diseased tissues and regenerate new ones.This study has proved the present species and Neoactinomyxum sp.NEO-7 belong to the same myxosporean species but corresponding to different developmental stage,designated as a new species.This novel species is a potential pathogen for the host,which should not be ignored.This study not only enriches myxobolid biodiversity and demonstrates a potentially pathogenic agent,but also provides a valid diagnosis for the gill myxoboliosis caused by the present pathogen in aquaculture.
基金Project supported by the National Natural Science Foundation of China (No. 20377022, 20237010)the National Basic Research Program (973) of China (No. 2002CB412307).
文摘Bisphenol A （BPA） is the monomer component of polycarbonate plastics and classified as an endocrine disrupting chemical （EDC）. The reproductive toxicity of BPA has been extensively studied in mammals; however, relatively little information is available on the immunotoxic responses of fish to BPA. In this study, we investigated the effects of BPA on the immune functions of lymphocytes and macrophages in Carassius auratus. The effects of BPA were compared with those of two natural steroid hormones, estradiol and hydrocortisone. Proliferation of the two types of cells in response to PHA was measured using colorimetric MTT assay. Macrophage respiratory burst stimulated by Con A was measured using chemiluminescence assay. Results showed that BPA （0.054-5.4 mg/L）, estradiol （0.0002-2.0 mg/L） and hydrocortisone （5-50 mg/L） significantly induced Carassius auratus lymphocyte proliferation while higher doses of hydrocortisone （500-5000 mg/L） appeared to be inhibitory. BPA （0.005-50 mg/L）, estradiol （0.005-800 mg/L） and hydrocortisone （0.005-500 mg/L） markedly enhanced macrophage proliferation, whereas higher doses of BPA （500-1000 mg/L） appeared to inhibit cell proliferation. Furthermore, higher dosage of BPA （50 mg/L） and hydrocortisone （50 and 500 mg/L） suppressed the macrophages respiratory burst while estradiol is stimulative all the doses tested （0.05-500 mg/L）. In conclusion, BPA could have immunotoxicity to Carassius auratus and functional changes of lymphocyte and macrophage in Carassius auratus may be different between low and high dosages.
基金Project (No. 2004C26026) supported by the Science and Technology Department of Zhejiang Province, China
文摘Specific immunoglobulin (IgY) from egg yolk against Aeromonas hydrophila was produced by immunization of White Leghorn hens with formalin-killed whole cells of A. hydrophila. ELISA test using A. hydrophila as the coating antigen revealed that the specific antibody titer started to increase in the egg yolk at the 13th day post-immunization (P/N=2.18), reached the peak at the 56th day (P/N=13.82), and remained at high level until day 133 (P/N=7.03). The antibody was purified by saturated ammonium sulphate with a recovery rate of 63.5%. The specific IgY inhibited the growth of A. hydrophila at a concentration of 1.0 mg/ml during the 18 h incubation. Pre-treatment of polyploid gibel carps Carassius auratus Gibelio with specific IgY had a protection rate of 60% (6/10) against challenge with A. hydrophila, while none of the fishes in the control groups receiving sterile phosphate buffered saline (PBS) or non-specific IgY survived the challenge. Treatment of fishes with the specific IgY 4 h after the challenge also had lower mortality (70%, 7/10), a 30% reduction against the control PBS or non-specific IgY groups (10/10). These results indicate that specific IgY antibodies could be obtained easily from hens immunized with an inactivated A. hydrophila and could provide a novel alternative approach to control of diseases in fishes caused by this organism.
基金supported by the National Natural Science Foundation of China (No. 20777040)the Hi-TechResearch and Development Program (863) of China (No.2007AA061201).
文摘Under the indoor simulant conditions, toxic effects of crude-oil-contaminated soil which was put into aquatic environment on the young fishes Carassius auratus and their hepatic antioxidant system after a 20-d exposure were investigated. Results showed that the relationship between the mortality of C. auratus and the exposed doses could be divided into 3 phases： fishes exposed to the low dose groups （0.5-5.0 g/L） were dead due to the ingestion of crude-oil-contaminated soils in aquatic environment; at the medium dose groups （5.0-25.0 g/L） fishes were dead due to the penetration of toxic substances; at the high dose groups （25.0-50.0 g/L） fishes were dead due to environmental stress. The highest mortality and death speed were found in the 1.0 g/L dose group, and the death speed was sharply increased in the 50.0 g/L dose group in the late phase of exposure. The activities of superoxide dismutase （SOD）, catalase （CAT） and glutathione S-transferase （GST） and the content of malaondialdehyde （MDA） in the hepatic tissues of C. auratus were induced significantly. The activity of SOD was increased and then decreased. It was significantly inhibited in the 50.0 g/L dose group. The activity of CAT was highly induced, and restored to a level which is little more than the control when the exposed doses exceeded 10.0 g/L. The activity of GST was the most sensitive, it was significantly induced in all dose groups, and the highest elevation was up to 6 times in the 0.5 g/L dose group comparing with the control. The MDA content was significantly elevated in the 50.0 g/L dose group, and the changes of the MDA content were opposite with the changes of GST activity.
基金Project supported by the National High-Tech R&D Program(863)of China(No.2013AA102803)
文摘A feeding trial was conducted for nine weeks to investigate the effects of partially replacing Ca（H2PO4）2 with neutral phytase on the growth performance, phosphorus utilization, nutrient digestibility, serum biochemical parameters, bone and carcass mineral composition, and digestive-enzyme-specific activity in crucian carp（Carassius auratus）.The diets prepared with 0.8%, 0%, and 1.8% Ca（H2PO4）2（1%=1 g/100 g） supplements were regarded as the P1E0, negative control（NC）, and positive control（PC） groups, respectively; the other three experimental diets were prepared with the addition of 200, 300, and 500 U/kg of neutral phytase, respectively, based on the P1E0 group.Three hundred and eighty-four fish（（1.50±0.01） g） were randomly distributed in the six treatments with four replicates each.The fish were initially fed with 2%–3% diets of their body weight per day, with feeding twice daily（08：00 and 16：00）, under a 12-h light/12-h dark cycle at the temperature of（27.56±0.89） ℃.The results showed that supplemental phytase at different levels in the diet improved the final body weight, average daily gain, feed conversion ratio, phosphorus utilization, and protein efficiency ratio of crucian carp（P〈0.05）.Phytase supplementation increased the mineral content in serum（P）, bone（P, Ca）, and carcass（P, Ca, Zn, Na, and Mg）（P〈0.05）; the trypsin and chymotrypsin activity soared when fed with the phytase-supplemented diets（P〈0.05）.We may conclude that supplemental dietary neutral phytase improved the growth performance, phosphorus utilization as well as nutrient utilization in crucian carp, and it can be considered an important nutritional replacement for Ca（H2PO4）2.
文摘In Georgia, crucian carp Carassius carassius （Linnaeus, 1758） was known from only one locality after Kessler＇s record （1877-1878） with no new findings until 1985. Since then C. carassius rapidly and simultaneously invaded almost all water bodies of Georgia. In 2004, it was for the first time noted that this invasive Carassius sp. could not be a C. Carassius, but was a form of Carassius gibelio （Bloch, 1792）. However no further data is available about this invasive species in Georgia. The aim of the present study was to investigate taxonomic status of Carassius sp. in Georgia using mtDNA phylogenetic analyses and mor- phometrie study of truss network system. Genetic analysis revealed that invasive Carassius sp. is closely related to the C. gibelio from Turkey and other countries. In contrast, morphometrically Carassius sp. from Georgia can be easily differentiated from those of Turkey indicating high intraspecific variability. This is the first time discussion on the current knowledge of the present distribution of invasive carp in Georgia with identifying current problems and future research directions needed.
基金supported by the National Natural Science Foundation of China(51079049,51209069)Qing Lan Project of Jiangsu Province
文摘Objective To study the biological effects of nanoscale copper oxide （nCuO）, zinc oxide （nZnO）, cerium dioxide （nCeO2） and their mixtures on Carassius auratus. Methods Juvenile fish （Carossius auratus） were exposed to aqueous suspensions of nCuO, nZnO, and nCeO2 （alone and in mixtures） at concentrations of 20, 40, 80, 3.60, and 320 mg/L. The biomarkers-acetylcholinesterase （ACHE） in brain, sodium/potassium-activated ATPase （Na~/K＊-ATPase） in gill, and superoxide dismutase （SOD） and catalase （CAT） in liver-were determined after 4 days of exposure. Integrated biomarker response （IBR） was calculated by combining multiple biomarkers into a single value. Results AChE and SOD activities were significantly inhibited by all test metal oxide nanoparticles （NPs） at high concentrations （__.160 rag/L） with the exception of nCeO2. Na~/K＋-ATPase induction exhibited bell-shaped concentration-response curves. CAT activity was significantly inhibited at concentrations equal to or higher than 160 mg/L. The order of IBR values was nCeO2 = nZnO/nCeO2= nCuO/nCeO2 〈 nCuO/nZnO/nCeO2 〈 nZnO 〈 nCuO 〈 nCuO/nZnO. The joint effect seemed to be synergistic for nCuO/nZnO mixtures, additive for the ternary mixture and less than additive or antagonistic for the binary mixtures containing nCe02. Conclusion Concentration-dependent changes of enzymatic activities （ACHE, Na~/K＊-ATPase, SOD, and CAT） were observed in fish exposed to nanoscale metal oxides. IBR analysis allowed good discrimination between the different exposures and might be a useful tool for the quantification of integrated negative effects induced by NPs toward fish.
基金supported by the Special Fund for Public Welfare Industry of Ministry of Water Resources of China(Grant No201001056)the Project of Jiangxi Provincial Department of Science and Technology (Grant No2010BSA20300)the Project of Jiangxi Provincial Department of Education(Grants No GJJ11246 and GJJ11636)
文摘The freshwater fish Carassius auratus was chosen as an experimental subject, and their hepatic biochemical responses to the medium-term exposure of Benzo（k）fluoranthene （BkF） alone and in combination with PCB 118 and dichlorodiphenyltrichloroethane （DDT） were investigated by measuring the reduced glutathione （GSH）, glutathione S-transferase （GST）, and thiobarbituric acid reactive substances （TBARS）, to assess sublethal effects. The hepatic GSH content was significantly inhibited by organic pollutants, alone and in mixtures, while the TBARS content was significantly induced after three days of exposure. Bell-shaped concentration-response charts of GST activities were obtained. Significant dose-response relationships were found for hepatic GSH and TBARS contents of all concentrations and for the GST activity, except at the highest concentration. The GSH content, GST activity, and TBARS content in Carassius auratus were confirmed as useful biomarkers of exposure to organic pollutions.
基金supported by the Project of Educational Commission of Shaanxi Province,China (08JK250)the Project of Shaanxi University of Technology (SLG0722)
文摘[Objective] The study aimed to the effects of various Cd2＋ concentrations and exposure time on erythrocyte micronuclei in peripheral erythrocyte micronuclei in Carassius auratus and Oriental weatherfish. [ Method ] Using static water culture, Carassius auratus and Oriental weatherfish were exposed to solutions containing Cd2＋ with mass concentrations of 0.08, 1.72 and 6.84 mg/L, and blood was collected from tail veins to make smears which were observed under a oil lens afterwards. [ Result] In the initial exposure period, Carassius auratus and Onental weatherfish were unwell obviously, being afraid and unpeaceful and escaping everywhere. With the increase in Cd2＋ concentration, this phenomenon became more distinct. In addition, as the prolonging of exposure time, fishes moved slowly, powerlessly and less and reacted slowly, and moe and more excrement deposited at the bottom of aquariums. [ Conclusion] Cd2 ＋ could obviously induce Carassius auratus and Oriental weatherfish to generate micronuclei, showing certain dose-effect and time-effect relation under certain conditions.
文摘Ten microsatellite loci were used for analyzing six populations of goldfish (Carassius auratus) with sarcoma. It showed that there was the highest genetic diversity among the white oranda with red cap (RC) population, and the lowest among the white tigerhead (WT) population. However, the outcross existed among every population. There was huge genetic differentiation between WT and the other four populations. The average observed heterozygosity (HO) among populations ranged from 0.3571 to 0.7381. And significant genetic difference (FCT = 0.1891, P = 0.0186) appeared among goldfish varieties which can be classified into three groups (RT, WT;RL, BL, YC;RC). The software Principal Coordinate Analysis (PCA) and STRUCTURE showed that significant genetic differences were revealed between RC population of goldfish and other five populations.
基金Supported by National Natural Science Foundation of China (No.30571414,No 30640015)Changsha Municipal Project of Science and Technology (No.K051127-72).
文摘Inorganic lead （Pb） is one of the most common environmental pollutants. Much evidence indicates that Pb exposure could directly affect fish growth and development. In this study, we investigated the cytotoxic effects of Pb on cytoskeletal protein stability at both protein and mRNA level in crucian carp Carassius auratus. Pb（NO3）2 treatment in concentration of 100 μmol/L resulted in decreased expression of both α- and β-tubulin but γ-tubulin as assayed with SDS-PAGE, Western Blot, and ELISA. In vivo and in vitro analyses on protein expression of tubulins are consistent. The effect of Pb on mRNA expression varied among different tissues. Our results suggest that cytotoxicity of Pb at protein translation level is stronger than at mRNA expression level.
基金We would like to thank the undergradu- ate students from Guangxi Normal University, Yueni Huang, Chun Lan, and Caigui Nong, for their assistance in our experiment. This study was financially supported by Guangxi Science Foundation （2011GXNSFE018005）, Guangxi Key Laboratory of Environmental Engineering, Protection, and Assessment Kadoorie Farm ＆ Botanic Garden Corporation, Hong Kong and the Creative Team Project of the universities of Guangxi province, China.
文摘Procambarus clarkii is native to the south-central United States （Louisiana） and northeastern Mexico, and is a highly efficient predator that poses a damager to native species after its introduction or invasion. In its natural habitat, P. clarkii consumes Carassius auratus, however, whether C. auratus recognizes P. clarkii as a predator is not yet clear. In laboratory experiments, we investigated whether experienced and inexperienced C. auratus recognize P. clarkii as a predatory threat and the specific sensory modality used by C. auratus to respond to chemical and visual stimuli from P. clarkii. In the chemical stimuli experiment, two kinds of chemical stimuli were used, water from a tub containing P. clarkii previously fed with C. auratus （C. auratus diet cues） and water from a tub containing unfed P. clarkii （P. clarkii cues）. In the visual experiment, experienced C. auratus decreased activity, but inexperienced C.auratus avoided the predator compartment. When C. auratus diet cues were presented, both experienced and inexperienced C. auratus increased the use of shelter, decreased activity in the initial response phase. Compared with the blank treatment, experienced C. auratus responded to P. clarkii cues by decreasing activity; however, inexperienced C. auratus showed no reduction in activity. C. auratus appears to recognize P. clarkii as a predator both through visual and chemical cues. Further analysis revealed that C. auratus may recognize R clarkii visually through the disturbances caused by P. clarkii movement and chemically by detecting conspecific alarm cues in the diet of P. clarkii. The results also indicate that ex- perienced C. auratus can recognize R clarkii by innate chemical cues from P. clarkii, whereas inexperienced C. auratus cannot [Current Zoology 57 （3）： 330-339, 2011].
基金Supported by the Natural Science Foundation of China (30170162)Wuxi Science and Technology Bureau Foundation (CL045001)
文摘Etrazine is one of the most widely used herbicides in China and the world. Acute and chronic toxicity tests werc carried out to assess the possible toxicity effect of atrazine on crucian carp （Carassius auratus）. Results showed that 96 h LC,. of atrazine to Carassius auratus was 105.94 mg. L-1. The enzyme activities of superoxide dismutase （SOD）, catalase （CAT） and glutathione-S-transferases （GST） in kidney of Carassius auratus were all influenced by atraizine, and CAT was more sensitive to atrazine compared with SOD and GST. Atrazine residues in kidney of Carassius aura/us reached the stable state at day 19, and the bioaccumulation factors （BAF） of atrazine in kidney of Carassius auratus treated with 1.0 mg. L-1 and 10.0 mg. L-1 atrazine were 8.3 and 4.4, respectively. The research demonstrated that atrazine could cause oxidative stress to fish kidney, but atrazine was not easy to accumulate in Carassius auratus kidney, and the antioxidant enzymes could be used as biomarker to the early detection of pollution.
基金Supported by Key Laboratory of Special Wildlife Resources in Fanjing Mountain(QJH KY[2011]005)Innovative Talent Team for Protection and Useof Special Wildlife Resources in Fanjing Mountain(QJHRCTD[2012]08)
文摘The growth and development of larvae and juveniles was morphologically investigated in Carassius auratus gibelio. The results showed that it took 52 h from fertilization to hatching at 22 - 25℃. The newly hatched larvae had transparent body, with the head fight near the yolk sac; the yolk sac accounted for 2/3 of larval volume, which was exhausted in the four-day-old larvae that started the exogenous nutrient period. The larvae were found to develop into juveniles from a few scales on the 20^th day after hatching to whole scales, fingerling, on the 28^th day after hatching. The relationship between total length（TL） and age in days（D） was described as ： TL = 0.001 2D3 - 0. 038 8/32 ＋ 1.043 2D ＋ 3. 945 8 （ r^2 = 0.998 ）. The relationship between body length （L） and body weight （W） of larvae and juveniles was expressed as： m = 1E -05L^3.3769（ r^2 = 0.982 7）. The formula between body length and body height during the development of the fish was described as ： H = 0.0（30 1L3 -0. 028 4L2 ＋ 1. 281 6L -7. 250 5 （ r^2 = 0. 988 6）. The findings provided the theoretical instruction for practical production of C. auratus gibelio.
