• <tr id="yyy80"></tr>
  • <sup id="yyy80"></sup>
  • <tfoot id="yyy80"><noscript id="yyy80"></noscript></tfoot>
  • 99热精品在线国产_美女午夜性视频免费_国产精品国产高清国产av_av欧美777_自拍偷自拍亚洲精品老妇_亚洲熟女精品中文字幕_www日本黄色视频网_国产精品野战在线观看 ?

    Influence of total dissolved gas-supersaturated water on silver carp (Hypophthalmichthys molitrix)

    2016-03-03 00:59:06LuCaoRuifengLiangYoucaiTuoYongLiKefengLi
    Water Science and Engineering 2016年4期

    Lu Cao,Rui-feng Liang*,You-cai Tuo,Yong Li,Ke-feng Li

    State Key Laboratory of Hydraulics and Mountain River Engineering,Sichuan University,Chengdu 610065,China

    Influence of total dissolved gas-supersaturated water on silver carp (Hypophthalmichthys molitrix)

    Lu Cao,Rui-feng Liang*,You-cai Tuo,Yong Li,Ke-feng Li

    State Key Laboratory of Hydraulics and Mountain River Engineering,Sichuan University,Chengdu 610065,China

    Dam discharges over spillways are the main reason for the gas-supersaturated water generated in rivers.Localaquatic organisms,especially fish,readily develop gas bubble disease(GBD)in a river with total dissolved gas supersaturation(TDGS).Sometimes,fish will die after a specifi c exposure period,which negatively affects the biological equilibrium.In this study,the infl uence 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 levelwas 120%or higher,and all the silver carp exposed to a TDGS level of 140%died within 10 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 afterthey were exposed to gas-supersaturated water with a TDGS levelof 140%.The CAT activity changed with time;itincreased 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.

    Total dissolved gas supersaturation;Silver carp;CAT activity;Gas bubble disease;Median lethal time;Median lethal concentration

    1.Introduction

    The upper Yangtze River is located in southwestern China, a region filled with water resources,high dams,and habitats for many commercial fish.When water is discharged over the spillway of a dam,the air around the high-speed water willroll into the downstream water,generating gas-supersaturated water,in which the dissolved gas exceeds the normal level. Totaldissolved gas supersaturation(TDGS)was firstidentified in the Columbia and Snake rivers in the 1960s.After dams were constructed along the Columbia River,the TDGS level reached 125%(Ebel,1969).Weitkamp et al.(2003)pointed out that,during the process of release of water from dams onthe Clark Fork River in 1997,the TDGS level observed was close to 150%.Jiang et al.(2008)found that the TDGS level was over 130%when water was discharged from the Zipingpu Dam.Gas-supersaturated water was also generated in the areas downstream of the Three Gorges Dam,Ertan Dam,and other dams in prototype observation(Qu etal.,2011),and the TDGS levels downstream of the Gongzui,Ertan,and Three Gorges dams were 142.5%,140%,and 138%,respectively.

    Gas-supersaturated waterleads to gas bubble disease(GBD) in fi sh(Gorham,1901),and the release of dissolved gas is very slow.Therefore,the TDGS infl uence region reacheshundreds of kilometers(Feng et al.,2010).Because of this,the fi sh in the areas downstream of dams during the discharge period suffer from TDGS.Beiningen and Ebel(1970)detected TDGS levels reaching 143%and a large numberofjuvenile and adultsalmon as well as rainbow trout dying in the downstream area.Lutz (1995)showed that fish dying downstream of the Red Rock Damduring the period from1983 to 1994 were associated with a TDGS levelin excess of 110%.Many researchers then pointedoutthatjuvenile fi sh died from GBD during the period of water discharge into the Columbia River(Parametrix,2003)and the Xin'anjiang Reservoir in China(Wu,1994).Backman et al. (2000)and Backman and Evans(2002)collected adult sockeye salmon and steelhead atthe Bonneville Dam from 1995 to 1999 and found that fi sh quickly developed GBD when the TDGS levelwas higherthan 126%butseldom developed GBD when the TDGS level was lower than 125%.To intensively study the infl uence of TDGS on fish in China,laboratory experiments were performed by some researchers at Sichuan University(Huang et al.,2010;Liu et al.,2011;Chen et al., 2012;Wang etal.,2015).

    Silvercarp(Hypophthalmichthysmolitrix)are one ofthe four famous commercial fish widely distributed in major river systems in China(Welcomme,1989).They readily suffer from TDGS.Catalase(CAT)is a common enzyme that is widely distributed in nearly all living organisms,including animals, vegetables,fruits,and microorganisms,and is especially concentrated in the livers.CAT can catalyze the decomposition of H2O2into oxygen and water(Chelikani et al.,2004). Therefore,it is a very important enzyme that protects the cell from oxidative damage.Jin et al.(2010)investigated the toxic effects of pollutants on Carassius auratus by measuring the CATactivity,because the CAT activity can reflectthe degree of toxicity of pollutants.

    Recently,mass fish deaths have been reported(Zhu,2010; CCTV,2014),and there are large numbers of high and superhigh dams being constructed in China.Therefore,the threat of TDGS is becoming more and more serious.This study focused on the influence of TDGS on silver carp by exposing them to different levels of gas-supersaturated water to find the time that 50%mortality occurred at a specifi c TDGS level(median lethaltime,LT50)and the TDGS levelatwhich 50%mortality occurred at a specifi c time(median lethal concentration, LC50).CAT activities were also measured to explore the physiological change of silver carp.

    2.Materials and methods

    2.1.Experimental fish and instruments

    All the silver carp in the experiments were six months old and transported from Sichuan Fisheries Research Institute,in China.Before the experiments,they were placed in fully aerated water for four days withoutfeeding.The water temperature was stable at 21°C and the pH value was held at7.1 to 7.8.

    The experimentalinstruments included Point Four Trackers (Point Four Systems Inc.,Canada),water thermometers, rulers,electronic scales,and magnifying glasses.

    2.2.Acute-lethal experiments

    Gas-supersaturated water was generated in a laboratory by pumps,compressors,and autoclaves.Air from the compressor mixed with the water from the pump in the autoclave,generating gas-supersaturated water.Then,through adjustment of the ball valve to change the release of dissolved gas,different levels of gas-supersaturated water were generated(Fig.1).The TDGS level in the fresh water was 100%.

    Twenty fi sh were placed into tanks with respective TDGS levels of 140%,135%,130%,125%,120%,110%,and 100% for 72 h.The behavior and the time to death of each fi sh were observed and recorded during the experimentalperiod.LT50of each TDGS level and LC50at 12,24,48,and 72 h were calculated to analyze the influence of gas-supersaturated water on silver carp.

    2.3.CAT activity test

    The CAT activity can reflect the physiological situation of silver carp and the influence of TDGS on silver carp.Thus,in this study,the CAT activity was chosen as a detectable substance to value the TDGS effects and the method of determination was based on Montavon et al.(2007).H2O2can be absorbed at a 240 nm wavelength.Because of the reaction of CAT and H2O2,the content of H2O2and the absorbance will decrease.Thus,the change of absorbance can reflect the activity of CAT.In this experiment,fish were sampled and killed, and 0.2 g muscles and gills were weighed and homogenized with liquid nitrogen.Then,a 1.6 mL phosphate buffer solution (with a pH value of 7.8)was added to centrifuge the homogenized muscles and gills(at 12000 r/min and 4°C for 25 min).The supernatant was the enzyme extraction.The absorbance of a phosphate buffer solution(with a pH value of 7.0)was adjusted to zero.Then,the change of the absorbance of a test solution,containing 2.75 mL of phosphate buffer solution(with a pH value of 7.0),0.15 mL of H2O2solution (with a concentration of 0.3%),and 0.1 mL of enzyme extraction,over 1 min was measured.The CAT activity can be calculated using Eq.(1)and the CAT activity is expressed in the unit of U/g fresh weight(FW):

    where ACATis the CAT activity;⊿240is the change of absorbance over 1 min;Vtis the volume of phosphate buffer solution with a pH value of 7.8,and Vt=1.6 mL;W is the weightof muscles or gills,and W=0.2 g;Vsis the volume of enzyme extraction,and Vs=0.1 mL;and t is the time of testing the absorbance,and t=1 min.

    Fig.1.Gas-supersaturated water generation system.

    According to the results of the acute-lethal experiment, LT50at the TDGS level of 140%was 5.62 h,so 5.62 h shouldbe the upper limit of the CAT activity test.From the beginning to 5 h later,three fish were taken out every hour to detect the CAT activity in their fresh muscles and gills.Atthe same time, three fish in fresh water were taken out in the same way,but the CAT activity was only tested at the beginning,middle,and end of the experiment,because the CAT activity was almost stable if the environment of the fi sh remained unchanged.

    A comparison of the CAT activity of fish in gassupersaturated water and that in fresh water shows physiological changes in the fish exposed to gas-supersaturated water.

    2.4.Statistical analysis

    LT50and LC50were calculated using the probability unit method and linear regression.To calculate LT50,logarithms of the time to death of each fi sh and the corresponding probability units of mortality were dotted in a coordinate system.A fitting line was generated,from which the logarithms of LT50corresponding to the probability units of 50%mortality could be obtained.LC50was calculated the same way as LT50,but the x-axis and y-axis were changed to the logarithms of the TDGS level and the corresponding probability units of mortality at a specific time,respectively.

    3.Results

    3.1.Acute-lethal experiments

    In the first 1.25 h,the fi sh at each TDGS level swam in the usual way and did not show any abnormal action.Fish at the TDGS level of 140%began behaving abnormally after 1.25 h. First,they became irritable,swam faster,and moved up and down.This situation continued for about 2 h.Then,their action began to slow down,and their bodies lost balance and gradually grew sluggish.With the passage of time,their bodies began rotating and spiraling in the water,and then suddenly accelerated when exposed to a stimulus.In the fi nal10-20 min, the fish lost their ability to swim,died,and stayed at the bottom or surface of the water.All the fish that died experienced this process before their death.However,the fish in other groups showed abnormal activity later on in the experiment and the activity lasted longer.In the 72-h experiment, only the fish at TDGS levels of 110%and 100%did not die. The phenomena in the dead fi sh were almost the same: exophthalmia,gills and fi n bleeding,bubbles formed in fins, and so on.

    The time to death of fish at different TDGS levels was recorded and drawn in Fig.2.All the fish at the TDGS levels of 140%,135%,and 130%died within 10,20,and 54 h, respectively.However,only 55%and 25%of the fish died at the TDGS levels of 125%and 120%,respectively.

    According to the regulation of death,LT50of the fish in gas-supersaturated water was calculated,except at the TDGS level of 120%,at which less than 50%of the fish died within 72 h.The LT50values at TDGS levels of 140%,135%,130%, and 125%were 5.62,11.22,28.84,and 67.71 h,respectively.

    Fig.2.Mortality of silver carp at different TDGS levels.

    In this study,the LC50values for exposure time in gassupersaturated water at 12,24,48,and 72 h was calculated. The LC50values decreased from 137.47%at 12 h to 130.91% at 24 h,126.11%at 48 h,and 122.96%at 72 h.

    3.2.CAT activity test

    The CAT activity in muscles and gills of the fi sh exposed to fresh water and gas-supersaturated water with a TDGS levelof 140%is shown in Fig.3 from the beginning of the experiment to 5 h later.In fresh water,the CAT activity was stable and only changed slightly,and the CAT activity was about 190 U/g in the muscles and 380 U/g in the gills.When silver carp were exposed to gas-supersaturated water,the CAT activity decreased at fi rst and then increased signifi cantly within 2 h. As time continued,the CAT activity decreased slowly and it was fi nally lower than that in fresh water.The same process occurred in the muscles and gills of silver carp,but the CAT activity in muscles decreased faster than in gills.

    4.Discussion

    4.1.Acute-lethal experiments

    The occurrence of mortality in each TDGS group was the same as in Bouck(1980),in which the death of silver carp was slow ateach TDGS levelatthe beginning,there was a massive spike in deaths in the middle of the time period,and towards the end there were few dead fi sh as those remaining had a strong tolerance.The mortality in this study was mainly associated with two factors:the TDGS leveland exposed time.When exposed to a lowerTDGS level(110%),no fi sh died.However,silvercarp at TDGS levels of125%and 120%began to die after48 h and 60 h of exposure,respectively.Untilthe end of this experiment,only 25%ofthe silvercarp died ata TDGS levelof120%and 55%of the silvercarp died ata TDGSlevelof125%.Similarresultswere found in other studies.Gu¨ltepe etal.(2011)found no mortality occurring in their experiment,in which rainbow trout were placed in gas-supersaturated water with TDGS levels of 104% and 115%.The fi sh at a TDGS level of 115%even showed an increase in swimming activity and panic episodes.

    Fig.3.CAT activity in muscles and gills of silver carp in gassupersaturated water with TDGS level of 140%and in fresh water.

    Matthew et al.(2000)conducted laboratory experiments to evaluate the relationship between GBD and mortality in Chinook salmon and steelhead.They pointed outthatthere was a substantial amount of inter-individual variation in terms of susceptibility to GBD.Beeman et al.(2003)also compared the LT50values of different species of fish exposed to gassupersaturated water in the Columbia River,and showed a variation with regard to both TDGS levels and differentspecies. For differentsizes of fi sh of the same species,the tolerances to different TDGS levels also differed(Gunnarslietal.,2009).For silvercarp,LT50presented an increase by multiple times with the decrease ofthe TDGS level.Forexample,LT50was increased by 5.6 h when the TDGS level diminished from 140%to 135%. However,LT50was increased by 38.87 h when the TDGS level diminished from 130%to 125%.The results of silver carp were compared with those of Chinese sucker,Prenant's schizothoracin,and rock carp through experiments performed atthe State Key Laboratory of Hydraulics and Mountain River Engineering of Sichuan University,in China,with the same experimental equipment and methods(Chen et al.,2012;Liu et al.,2011; Huang et al.,2010;Wang et al.,2015).Fig.4 shows the LT50values of these three species and silver carp at TDGS levels of 140%,135%,and 130%.Itindicates differenttolerances to gassupersaturated water.Itisobviousthatthe tolerance ofsilvercarp is greaterthan thatofotherfi sh.However,athigher TDGS levels, the LT50values of these four species show similarresults within 5 h.Thus,when the TDGS levelis high enough,the fish in this gas-supersaturated water will die within a very short time. Furthermore,when fish are exposed to low gas-supersaturated water,different fish show different tolerances.Some fi sh,like Chinese sucker,rock carp,and Prenant's schizothoracin,die within shortertime compared with silvercarp(Chen etal.,2012; Liu etal.,2011;Wang etal.,2015).

    In addition,the LC50value for silver carp was calculated. The results show that when the TDGS level is 137.47%,50% of fi sh will die within 12 h,and if the TDGS level diminishes to 122.96%,50%mortality occurs from 12 h to 72 h.In comparison,at a TDGS level of 130%,50%mortality occurs in Chinese sucker within 10 h(Chen et al.,2012).Silver carp have a stronger tolerance to TDGS but the impact of TDGS still exists.

    4.2.CAT activity

    CAT is the main enzyme whose activity changes when the environment changes.In this experiment,CAT activities were measured to value the influence of gas-supersaturated water on silver carp.Gu¨ltepe et al.(2011)chose carbonic anhydrase to study the effects of gas-supersaturated water on rainbow trout, as carbonic anhydrase is also an important enzyme in fish. They found thatwhen fi sh were exposed to gas-supersaturated water,the activity of carbonic anhydrase was reduced.Liu (2006)pointed out the relationship between the stocking densities of Chinese sturgeon and CAT activity in blood.Qu et al.(2006)found that the CAT activity in gills and muscles of tilapia increased fi rst and decreased under the normal level when exposed to phenol.

    When fi sh were exposed to gas-supersaturated water,the CATactivitiesofrock carp and Chinese suckerwere recorded by Liu et al.(2011)and Chen etal.(2012),respectively.Liu etal. (2011)exposed rock carp to gas-supersaturated waterwith a low TDGS level for 42 days,and found that the CAT activity increased first and then decreased.However,there is no such pattern in Chinese sucker.In thisstudy,the CATactivity ofsilver carp also increased fi rstand then decreased,similarly to thatin rock carp.However,silver carp were exposed to highly gassupersaturated water and rock carp were exposed to low-level gas-supersaturated water.When silver carp were exposed to highly gas-supersaturated water,the CATactivity in the gills and muscles suddenly increased.Then,the CAT activity began to decrease when silvercarp adapted to the environment.The CAT activity continued to decrease until silver carp died due to the severe poisoning by TDGS.

    Fig.4.LT50of Chinese sucker,rock carp,Prenant's schizothoracin, and silver carp at TDGS levels of 130%,135%,and 140%.

    The influence of TDGS on silver carp is a continuous process.Reducing the TDGS level or changing the exposure process may be an effective way to diminish the harm to silver carp or other fish,but this requires more research.

    5.Conclusions

    (1)Death of silver carp occurred when they were exposed to gas-supersaturated water for three days and the TDGS level reached 120%.In contrast,silvercarp survived forthree days at a TDGS level of 110%.Thus,when silver carp stayed in lowlevel gas-supersaturated water,they could survive,but the duration for which they can survive requires more study.

    (2)In comparison with Chinese sucker,Prenant's schizothoracin,and rock carp,silver carp survived longer in lowlevel gas-supersaturated water,but they were all unable to survive for a long time in highly gas-supersaturated water.

    (3)When exposed to highly gas-supersaturated water,silver carp showed some changes in their bodies.The CAT activity suddenly increased,but,after a period of time,the CAT activity recovered.However,the toxicity of TDGS caused the reduction of CAT activity until the fish died.

    Acknowledgements

    The authors are grateful to Mr.Shi-chao Chen,Ms.Bo Li, Mr.Wen Jiang,Mr.Song Wu,and Mr.Zhi-guang Zhang at Sichuan University in China,for their help during the experiments.They also appreciate the advice of Ms.Xiao-jia He for modifying this paper.

    Backman,T.W.H.,Evans,A.F.,Robertson,M.S.,2000.Symptoms of Gas Bubble Trauma Induced in Salmon(Oncorhynchus spp.)by Total Dissolved Gas Supersaturation of the Snake and Columbia Rivers,USA. Bonneville Power Administration,Portland.

    Backman,T.W.H.,Evans,A.F.,2002.Gas bubble trauma incidence in adultsalmonidsin the Columbia Riverbasin.N.Am.J.Fish.Manag.22(2),579-584. http://dx.doi.org/10.1577/1548-8675(2002)022<0579:GBTIIA>2.0.CO;2.

    Beeman,J.W.,Venditti,D.A.,Morris,R.G.,2003.Gas Bubble Disease in Resident Fish below Grand Coulee Dam,Final Report of Research.U.S. Geological Survey,Reston.

    Beiningen,K.T.,Ebel,W.J.,1970.Effect of John Day Dam on dissolved nitrogen concentrations and salmon in the Columbia River.Trans.Am. Fish.Soc.99(4),664-671.http://dx.doi.org/10.1577/1548-8659(1970) 99<664:EOJDDO>2.0.CO;2.

    Bouck,G.R.,1980.Etiology ofgasbubble disease.Trans.Am.Fish.Soc.109(6), 703-707.http://dx.doi.org/10.1577/1548-8659(1980)1092.0.CO;2.

    Chelikani,P.,Fita,I.,Loewen,P.C.,2004.Diversity of structures and properties among catalases.Cell.Mol.Life Sci.61(2),192-208.http:// dx.doi.org/10.1007/s00018-003-3206-5.

    Chen,S.C.,Liu,X.Q.,Jiang,W.,Li,K.F.,Du,J.,Shen,D.Z.,Gong,Q.,2012. Effects of total dissolved gas supersaturated water on lethality and catalase activity of Chinese sucker(Myxocyprinus asiaticus Bleeker).J. Zhejiang Univ.Sci.B 13(10),791-796.http://dx.doi.org/10.1631/ jzus.B1200022.

    China CentralTelevision(CCTV),2014.40 Tons of Dead Fish from the Lower Jinsha River were Disposed,and Poisoning may be Excluded.http://news. cntv.cn/2014/07/19/ARTI1405750580177886.shtml[Retrieved Mar.15, 2016].

    Ebel,W.J.,1969.Supersaturation of nitrogen in the Columbia River and its effect on salmon and steelhead trout.Fish.Bull.68(1),1-11.

    Feng,J.J.,Li,R.,Li,K.F.,Li,J.,Qu,L.,2010.Study on release process of supersaturated totaldissolved gas downstream of high dam.J.Hydroelectr. Eng.29(1),7-12(in Chinese).

    Gorham,F.P.,1901.The gas bubble disease of fi sh and its causes.Bull.U.S. Fish Comm.19,33-37.

    Gunnarsli,K.S.,Toften,H.,Mortensen,A.,2009.Effects of nitrogen gas super saturation on growth and survival in larvalcod(Gadus morhua L.). Aquaculture 288(3), 344-348. http://dx.doi.org/10.1016/j.aquacul ture.2008.11.039.

    Gu¨ltepe,N.,Ates?,O.,Hisar,O.,Beydemir,S.,2011.Carbonic anhydrase activities from the rainbow trout lens correspond to the development of acute gas bubble disease.J.Aquat.Anim.Health 23(3),134-139.http:// dx.doi.org/10.1080/08997659.2011.616848.

    Huang,X.,Li,K.F.,Du,J.,Li,R.,2010.Effects of gas supersaturation on lethality and avoidance responses in juvenile rock carp(Procypris rabaudi Tchang).J.Zhejiang Univ.Sci.B 11(10),806-811.http://dx.doi.org/ 10.1631/jzus.B1000006.

    Jiang,L.,Li,J.,Li,R.,Li,K.F.,2008.Research on the prototype observation of totaldissolved gas in the downstream of Zipingpu dam.Adv.Water Sci. 19(3),367-371(in Chinese).

    Jin,Y.F.,Shi,W.L.,Ren,G.,Han,L.,2010.Effects of combined toxicity of LAS and Cd2+on Cd accumulation and antioxidant enzyme activities in Carassius auratus.J.Zhejiang Univ.Agric.Life Sci.36(2),230-236. http://dx.doi.org/10.3785/j.issn.1008-9209.2010.02.017(in Chinese).

    Liu,S.Y.,2006.Effect of Environmental Stress on Free Radical Level and Antioxidant Enzymes Activities of Chinese Sturgeon,Acipenser sinensis. M.S.Dissertation.Huazhong AgriculturalUniversity,Wuhan(in Chinese).

    Liu,X.Q.,Li,K.F.,Du,J.,Li,J.,Li,R.,2011.Growth rate,catalase and superoxide dismutase activities in rock carp(Procypris rabaudi Tchang) exposed to supersaturated total dissolved gas.J.Zhejiang Univ.Sci.B 12(11),909-914.http://dx.doi.org/10.1631/jzus.B1100071.

    Lutz,D.S.,1995.Gas supersaturation and gas bubble trauma in fish downstream from a midwestern reservoir.Trans.Am.Fish.Soc.124(4),423-436.http:// dx.doi.org/10.1577/1548-8659(1995)124<0423:GSAGBT>2.3.CO;2.

    Matthew,G.M.,Lisa,K.W.,Alec,G.M.,2000.Progression and severity of gas bubble trauma in juvenile salmonids.Trans.Am.Fish.Soc.129(1),174-185. http://dx.doi.org/10.1577/1548-8659(2000)129<0174:PASOGB>2.0.CO;2.

    Montavon,P.,Kukic,K.R.,Bortlik,K.,2007.A simple method to measure effective catalase activities:Optimization,validation,and application in green coffee.Anal.Biochem.360(2),207-215.http://dx.doi.org/10.1016/ j.ab.2006.10.035.

    Parametrix,K.,2003.Total Dissolved Gas Biological Effects.Rockey Reach Hydroelectric Project FERC Project No.2145 Draft.Public Utility District No.1 Chelan Wenatchee,Washington.

    Qu,J.H.,Chen,J.Z.,Hu,G.D.,Wu,W.,2006.Dynamic changes of catalase and glutathione-s-transferase in the different tissues of tilapia exposed to phenol.Ecol.Environ.15(4),687-692(in Chinese).

    Qu,L.,Li,R.,Li,J.,Li,K.F.,Deng,Y.,2011.Field observation of total dissolved gas supersaturation of high-dams.Sci.China Technol.Sci.54(1), 156-162.http://dx.doi.org/10.1007/s11431-010-4217-8.

    Wang,Y.M.,Li,K.F.,Li,J.,Li,R.,Deng,Y.,2015.Tolerance and avoidance characteristics of Prenant's schizothoracin Schizothorax prenanti to total dissolved gas supersaturated water.N.Am.J.Fish.Manag.35,827-834. http://dx.doi.org/10.1080/02755947.2015.1052160.

    Weitkamp,D.E.,Sullivan,R.D.,Swant,T.,DosSantos,J.,2003.Behavior of residentfi sh relative to totaldissolved gassupersaturation in the LowerClark Fork River.Trans.Am.Fish.Soc.132(5),856-864.http://dx.doi.org/ 10.1577/T02-025.

    Welcomme,R.L.,1989.International Introductions of Inland Aquatic Species (No.294).Food and Agriculture Organization of the United Nations, Rome.

    Wu,C.G.,1994.Bubble disease of steelhead trout.Chin.Fish.10,27(in Chinese).

    Zhu,X.Q.,2010.During the Last Two Weeks,Many Dead Fish Floated in the River at Ciqikou.http://news.sina.com.cn/c/2010-08-01/024517893512s. shtml[Retrieved Mar.15,2016].

    Received 24 March 2016;accepted 26 July 2016

    Available online 6 January 2017

    This work was supported by the National Natural Science Foundation of China(Grant No.51379136).

    *Corresponding author.

    E-mail address:ruifengliangscu@126.com(Rui-feng Liang). Peer review under responsibility of Hohai University.

    ?2016 Hohai University.Production and hosting by Elsevier B.V.This is an open access article under the CC BY-NC-ND license(http:// creativecommons.org/licenses/by-nc-nd/4.0/).

    久久亚洲真实| 91在线观看av| 在线观看免费视频日本深夜| 精品国产一区二区三区四区第35| 成在线人永久免费视频| 欧美日韩福利视频一区二区| 久久久久久久久免费视频了| 又紧又爽又黄一区二区| 久久精品国产亚洲av香蕉五月 | 久久精品亚洲精品国产色婷小说| 丝瓜视频免费看黄片| 欧美黑人欧美精品刺激| 嫁个100分男人电影在线观看| 国产亚洲欧美98| 免费观看精品视频网站| 黄网站色视频无遮挡免费观看| 精品一区二区三卡| 亚洲一码二码三码区别大吗| 99久久综合精品五月天人人| 香蕉久久夜色| 乱人伦中国视频| 91精品三级在线观看| 久久精品91无色码中文字幕| 久久久国产一区二区| 天天躁日日躁夜夜躁夜夜| 三上悠亚av全集在线观看| 久久久精品免费免费高清| 狠狠婷婷综合久久久久久88av| 一进一出抽搐动态| 黄色a级毛片大全视频| 变态另类成人亚洲欧美熟女 | 丰满饥渴人妻一区二区三| 一区福利在线观看| 亚洲av熟女| 操美女的视频在线观看| 中文字幕精品免费在线观看视频| 日韩成人在线观看一区二区三区| 香蕉丝袜av| 三级毛片av免费| 亚洲精品av麻豆狂野| 热re99久久精品国产66热6| 国产av一区二区精品久久| 欧美激情高清一区二区三区| 女人精品久久久久毛片| 老司机深夜福利视频在线观看| 嫩草影视91久久| 国产一区二区三区综合在线观看| 欧美日韩福利视频一区二区| 王馨瑶露胸无遮挡在线观看| 精品亚洲成国产av| 香蕉丝袜av| 日本撒尿小便嘘嘘汇集6| 一区二区三区激情视频| 国产真人三级小视频在线观看| 亚洲九九香蕉| 欧美黄色淫秽网站| 久久精品亚洲精品国产色婷小说| 亚洲第一av免费看| a级毛片在线看网站| 色综合欧美亚洲国产小说| 成人永久免费在线观看视频| 国产真人三级小视频在线观看| 黄频高清免费视频| 少妇的丰满在线观看| 日韩免费高清中文字幕av| 亚洲精品在线观看二区| 91成年电影在线观看| 18禁黄网站禁片午夜丰满| 怎么达到女性高潮| 日韩制服丝袜自拍偷拍| 久久久国产精品麻豆| 亚洲人成电影免费在线| 色播在线永久视频| 国产在线一区二区三区精| 国产欧美亚洲国产| 亚洲一卡2卡3卡4卡5卡精品中文| 午夜日韩欧美国产| 免费看a级黄色片| 久久精品人人爽人人爽视色| e午夜精品久久久久久久| 久久精品国产综合久久久| 久久精品国产a三级三级三级| 岛国毛片在线播放| 最新在线观看一区二区三区| 欧美激情久久久久久爽电影 | 不卡一级毛片| 欧美激情极品国产一区二区三区| 国产区一区二久久| 9热在线视频观看99| 在线观看一区二区三区激情| 亚洲精华国产精华精| 欧洲精品卡2卡3卡4卡5卡区| 黑人巨大精品欧美一区二区mp4| 国产高清激情床上av| 精品福利永久在线观看| www.熟女人妻精品国产| 一区二区三区激情视频| 久久久久精品人妻al黑| 久久九九热精品免费| 黑人欧美特级aaaaaa片| 18禁观看日本| 久久精品人人爽人人爽视色| 成年女人毛片免费观看观看9 | 啦啦啦 在线观看视频| 一区在线观看完整版| 精品国内亚洲2022精品成人 | 国产精品偷伦视频观看了| 久久影院123| 成人特级黄色片久久久久久久| 国产精品免费一区二区三区在线 | a级毛片黄视频| 久久亚洲精品不卡| 国产色视频综合| 国产成人av激情在线播放| 激情视频va一区二区三区| 日本精品一区二区三区蜜桃| 国产极品粉嫩免费观看在线| 老司机亚洲免费影院| 精品一区二区三卡| a在线观看视频网站| 精品国产乱子伦一区二区三区| 国产精品综合久久久久久久免费 | 18禁观看日本| 黄频高清免费视频| 精品第一国产精品| 精品人妻1区二区| 欧美日韩乱码在线| 国产aⅴ精品一区二区三区波| 建设人人有责人人尽责人人享有的| www.999成人在线观看| 免费观看a级毛片全部| 91精品国产国语对白视频| 乱人伦中国视频| 狠狠婷婷综合久久久久久88av| 成人三级做爰电影| 热re99久久精品国产66热6| 在线天堂中文资源库| 国产欧美日韩综合在线一区二区| 一本综合久久免费| 1024香蕉在线观看| 99热国产这里只有精品6| 王馨瑶露胸无遮挡在线观看| 久热这里只有精品99| 十八禁人妻一区二区| 看免费av毛片| 亚洲成人免费av在线播放| 国产伦人伦偷精品视频| 欧美久久黑人一区二区| 国产野战对白在线观看| 母亲3免费完整高清在线观看| 久久人妻av系列| 国产高清视频在线播放一区| 欧美在线一区亚洲| 两个人看的免费小视频| 91字幕亚洲| 国产有黄有色有爽视频| 高清av免费在线| 又紧又爽又黄一区二区| 天天添夜夜摸| 色尼玛亚洲综合影院| 欧美成人午夜精品| 老汉色av国产亚洲站长工具| 黄色片一级片一级黄色片| 在线观看舔阴道视频| 天天影视国产精品| 男人操女人黄网站| 啦啦啦视频在线资源免费观看| 国产一区有黄有色的免费视频| 亚洲黑人精品在线| 精品国产国语对白av| 日韩欧美一区视频在线观看| 一级作爱视频免费观看| www日本在线高清视频| 午夜福利一区二区在线看| 91国产中文字幕| 亚洲成人手机| 午夜福利一区二区在线看| 后天国语完整版免费观看| 91在线观看av| 一进一出好大好爽视频| 在线观看免费午夜福利视频| a级毛片黄视频| 亚洲视频免费观看视频| 国产区一区二久久| 婷婷成人精品国产| 亚洲国产欧美一区二区综合| 一区二区三区国产精品乱码| 久久久精品免费免费高清| av福利片在线| 国产精品98久久久久久宅男小说| 黑丝袜美女国产一区| 丰满人妻熟妇乱又伦精品不卡| 悠悠久久av| 91成年电影在线观看| www.精华液| 一级黄色大片毛片| 18禁美女被吸乳视频| 亚洲精品国产色婷婷电影| 久久久久久人人人人人| 中国美女看黄片| 久久国产亚洲av麻豆专区| 在线视频色国产色| 免费观看a级毛片全部| 无限看片的www在线观看| 啦啦啦免费观看视频1| 超色免费av| 男男h啪啪无遮挡| 亚洲精品在线观看二区| 亚洲国产欧美一区二区综合| 午夜日韩欧美国产| 一本一本久久a久久精品综合妖精| 操美女的视频在线观看| 日本黄色视频三级网站网址 | 亚洲一区中文字幕在线| videosex国产| 黄色丝袜av网址大全| 大型黄色视频在线免费观看| 亚洲国产欧美一区二区综合| 天天躁日日躁夜夜躁夜夜| 热99久久久久精品小说推荐| 国产亚洲欧美98| 亚洲精品一卡2卡三卡4卡5卡| 欧美日本中文国产一区发布| 日韩欧美在线二视频 | 免费在线观看亚洲国产| 国产精品乱码一区二三区的特点 | 午夜影院日韩av| 亚洲五月天丁香| 亚洲精品久久午夜乱码| 国产又色又爽无遮挡免费看| 性少妇av在线| 亚洲va日本ⅴa欧美va伊人久久| 日韩欧美国产一区二区入口| 最新的欧美精品一区二区| 亚洲精品国产一区二区精华液| 水蜜桃什么品种好| 亚洲九九香蕉| av国产精品久久久久影院| avwww免费| 国产国语露脸激情在线看| 老熟妇乱子伦视频在线观看| 精品久久久久久久毛片微露脸| 国产片内射在线| 亚洲精品在线观看二区| 国产精华一区二区三区| 9热在线视频观看99| 成人免费观看视频高清| 欧美久久黑人一区二区| av欧美777| 99香蕉大伊视频| 亚洲午夜精品一区,二区,三区| 日韩熟女老妇一区二区性免费视频| 黑人猛操日本美女一级片| 好男人电影高清在线观看| 亚洲av欧美aⅴ国产| 亚洲成人手机| 91麻豆精品激情在线观看国产 | 色播在线永久视频| 男女床上黄色一级片免费看| 免费久久久久久久精品成人欧美视频| 国产一区有黄有色的免费视频| 久久性视频一级片| 亚洲精品成人av观看孕妇| 国产一区二区三区在线臀色熟女 | 国产精品免费视频内射| 一夜夜www| 日日爽夜夜爽网站| 国产蜜桃级精品一区二区三区 | 一区二区日韩欧美中文字幕| 狂野欧美激情性xxxx| 一进一出抽搐gif免费好疼 | 精品久久久久久久久久免费视频 | 他把我摸到了高潮在线观看| 亚洲第一欧美日韩一区二区三区| 悠悠久久av| a级毛片在线看网站| 脱女人内裤的视频| 80岁老熟妇乱子伦牲交| 成熟少妇高潮喷水视频| 日韩成人在线观看一区二区三区| 国产麻豆69| 丰满饥渴人妻一区二区三| 亚洲七黄色美女视频| 少妇猛男粗大的猛烈进出视频| 久久久精品免费免费高清| 亚洲精品乱久久久久久| av中文乱码字幕在线| 1024视频免费在线观看| 我的亚洲天堂| 18禁观看日本| 日韩视频一区二区在线观看| 99热网站在线观看| 日日爽夜夜爽网站| 91字幕亚洲| 女性生殖器流出的白浆| 99精品久久久久人妻精品| 日日夜夜操网爽| 国产成人欧美| 日韩三级视频一区二区三区| tocl精华| 亚洲 欧美一区二区三区| 欧美日韩亚洲高清精品| 人人妻人人爽人人添夜夜欢视频| 男人的好看免费观看在线视频 | 久久午夜亚洲精品久久| 欧美精品亚洲一区二区| 精品免费久久久久久久清纯 | 国产一区二区三区综合在线观看| 黑人猛操日本美女一级片| 国产精品影院久久| 欧美日韩福利视频一区二区| 不卡一级毛片| 最新的欧美精品一区二区| 亚洲自偷自拍图片 自拍| 日本黄色日本黄色录像| 成人影院久久| 久久狼人影院| 最新在线观看一区二区三区| 嫩草影视91久久| 欧美亚洲 丝袜 人妻 在线| av不卡在线播放| 久久久水蜜桃国产精品网| 多毛熟女@视频| 男女午夜视频在线观看| 又大又爽又粗| 757午夜福利合集在线观看| 91成年电影在线观看| 搡老乐熟女国产| 精品一区二区三卡| 性少妇av在线| 99久久人妻综合| 午夜精品久久久久久毛片777| 老熟妇乱子伦视频在线观看| 精品国产乱码久久久久久男人| 午夜免费鲁丝| 日本精品一区二区三区蜜桃| 一级毛片女人18水好多| 另类亚洲欧美激情| 亚洲精华国产精华精| 王馨瑶露胸无遮挡在线观看| 美女高潮喷水抽搐中文字幕| 久久人妻av系列| 黄色女人牲交| www.熟女人妻精品国产| 另类亚洲欧美激情| 欧美国产精品一级二级三级| 国产在线一区二区三区精| 欧美色视频一区免费| 成人特级黄色片久久久久久久| 这个男人来自地球电影免费观看| 侵犯人妻中文字幕一二三四区| 18禁美女被吸乳视频| 亚洲国产欧美网| 捣出白浆h1v1| 精品国产乱子伦一区二区三区| 国产主播在线观看一区二区| 欧美一级毛片孕妇| 国产亚洲精品第一综合不卡| 亚洲成a人片在线一区二区| 三上悠亚av全集在线观看| 久久精品亚洲av国产电影网| 日韩中文字幕欧美一区二区| 青草久久国产| 婷婷成人精品国产| 日本一区二区免费在线视频| 精品电影一区二区在线| 波多野结衣一区麻豆| 少妇 在线观看| 亚洲精品中文字幕一二三四区| 男男h啪啪无遮挡| 国产一区二区激情短视频| 国产成人av激情在线播放| 午夜免费观看网址| 国产精品一区二区免费欧美| 亚洲成av片中文字幕在线观看| 最近最新中文字幕大全电影3 | 99久久国产精品久久久| 悠悠久久av| 成人黄色视频免费在线看| 亚洲中文字幕日韩| 在线观看免费日韩欧美大片| 黄色成人免费大全| 视频在线观看一区二区三区| 亚洲中文字幕日韩| 亚洲一卡2卡3卡4卡5卡精品中文| 亚洲专区中文字幕在线| 日本wwww免费看| 国产深夜福利视频在线观看| 国产区一区二久久| 搡老岳熟女国产| 色婷婷av一区二区三区视频| 巨乳人妻的诱惑在线观看| 精品久久蜜臀av无| 99re在线观看精品视频| 亚洲精品国产一区二区精华液| 国产高清激情床上av| 日韩欧美在线二视频 | xxxhd国产人妻xxx| 美女高潮到喷水免费观看| 黄色毛片三级朝国网站| 19禁男女啪啪无遮挡网站| 亚洲精品av麻豆狂野| 视频区欧美日本亚洲| 黄色毛片三级朝国网站| 天天添夜夜摸| 欧美性长视频在线观看| 夜夜爽天天搞| 一级黄色大片毛片| 久久九九热精品免费| 国产亚洲精品久久久久久毛片 | 王馨瑶露胸无遮挡在线观看| 欧美午夜高清在线| 夜夜夜夜夜久久久久| 亚洲欧美激情在线| 99精国产麻豆久久婷婷| 黄色毛片三级朝国网站| 免费高清在线观看日韩| 欧美 亚洲 国产 日韩一| 少妇裸体淫交视频免费看高清 | 国产精品亚洲一级av第二区| 大香蕉久久成人网| 国产成人欧美| 精品国产一区二区久久| tube8黄色片| 婷婷丁香在线五月| 少妇被粗大的猛进出69影院| 91大片在线观看| 国产欧美日韩精品亚洲av| 精品久久久久久久久久免费视频 | 久久精品人人爽人人爽视色| 国产亚洲精品一区二区www | 亚洲精品中文字幕在线视频| 99香蕉大伊视频| 老熟妇仑乱视频hdxx| 久99久视频精品免费| 12—13女人毛片做爰片一| 桃红色精品国产亚洲av| 老汉色∧v一级毛片| 一区在线观看完整版| ponron亚洲| 国产国语露脸激情在线看| av中文乱码字幕在线| 女人被狂操c到高潮| 国产精品久久久av美女十八| 午夜成年电影在线免费观看| 欧美黄色片欧美黄色片| 91精品国产国语对白视频| 成在线人永久免费视频| 亚洲va日本ⅴa欧美va伊人久久| 亚洲av第一区精品v没综合| 老司机在亚洲福利影院| 十八禁人妻一区二区| 身体一侧抽搐| 极品人妻少妇av视频| 99国产极品粉嫩在线观看| 国产97色在线日韩免费| 巨乳人妻的诱惑在线观看| 黄色丝袜av网址大全| 亚洲成av片中文字幕在线观看| 一级毛片女人18水好多| 亚洲性夜色夜夜综合| 色婷婷久久久亚洲欧美| 麻豆av在线久日| 国产99白浆流出| 中文字幕人妻熟女乱码| 十八禁高潮呻吟视频| 亚洲精品国产一区二区精华液| 国产不卡av网站在线观看| 国产精品国产av在线观看| 色尼玛亚洲综合影院| 99精品欧美一区二区三区四区| 国产成人免费无遮挡视频| 精品久久久久久久毛片微露脸| 两性午夜刺激爽爽歪歪视频在线观看 | 99国产综合亚洲精品| 好看av亚洲va欧美ⅴa在| 69av精品久久久久久| 久久国产精品影院| 亚洲熟女精品中文字幕| 精品亚洲成a人片在线观看| 国产亚洲欧美精品永久| 亚洲av美国av| 久久国产亚洲av麻豆专区| 51午夜福利影视在线观看| 久久国产精品影院| 三级毛片av免费| 国产真人三级小视频在线观看| 久久人妻av系列| 一个人免费在线观看的高清视频| 成年人午夜在线观看视频| 国产色视频综合| 亚洲少妇的诱惑av| 法律面前人人平等表现在哪些方面| 日本精品一区二区三区蜜桃| 国产成+人综合+亚洲专区| 久久精品成人免费网站| 大型黄色视频在线免费观看| 国产男女内射视频| 国产欧美亚洲国产| 久久久久国产精品人妻aⅴ院 | 乱人伦中国视频| 国产精品久久电影中文字幕 | 亚洲欧洲精品一区二区精品久久久| 人人妻人人爽人人添夜夜欢视频| 少妇猛男粗大的猛烈进出视频| 国内毛片毛片毛片毛片毛片| 水蜜桃什么品种好| 制服诱惑二区| 91字幕亚洲| 久久久国产成人精品二区 | 国产精品久久久久久人妻精品电影| 成人特级黄色片久久久久久久| av福利片在线| 天天影视国产精品| 久久人人爽av亚洲精品天堂| 一个人免费在线观看的高清视频| 亚洲专区国产一区二区| 一进一出抽搐动态| 精品视频人人做人人爽| 两性夫妻黄色片| 婷婷成人精品国产| 女人被狂操c到高潮| 他把我摸到了高潮在线观看| 免费一级毛片在线播放高清视频 | 亚洲精品国产精品久久久不卡| 高清欧美精品videossex| 最新的欧美精品一区二区| 91字幕亚洲| 亚洲avbb在线观看| av有码第一页| 9热在线视频观看99| 成人黄色视频免费在线看| 亚洲成人免费av在线播放| 成人18禁高潮啪啪吃奶动态图| 女性生殖器流出的白浆| 9热在线视频观看99| 免费观看a级毛片全部| 12—13女人毛片做爰片一| 一级作爱视频免费观看| 麻豆成人av在线观看| 51午夜福利影视在线观看| netflix在线观看网站| 国产欧美亚洲国产| 久久影院123| 亚洲伊人色综图| 99久久国产精品久久久| 日韩中文字幕欧美一区二区| 久久天躁狠狠躁夜夜2o2o| 亚洲午夜精品一区,二区,三区| 香蕉丝袜av| 亚洲一区二区三区不卡视频| 午夜福利免费观看在线| 亚洲成人手机| 国产av精品麻豆| netflix在线观看网站| 一个人免费在线观看的高清视频| 国产成人免费无遮挡视频| 欧美激情极品国产一区二区三区| 精品国产乱子伦一区二区三区| 亚洲久久久国产精品| 国产成人av激情在线播放| 男女床上黄色一级片免费看| 久久人人爽av亚洲精品天堂| 免费在线观看完整版高清| 国产日韩一区二区三区精品不卡| 国产91精品成人一区二区三区| 久久ye,这里只有精品| 国产av一区二区精品久久| 国产人伦9x9x在线观看| 另类亚洲欧美激情| e午夜精品久久久久久久| 不卡一级毛片| 制服诱惑二区| 午夜激情av网站| 19禁男女啪啪无遮挡网站| 精品久久久久久久久久免费视频 | a级片在线免费高清观看视频| 丝袜美足系列| 十八禁网站免费在线| 亚洲国产欧美网| 精品国产乱码久久久久久男人| 在线观看免费视频日本深夜| 一区在线观看完整版| 久久狼人影院| 美女福利国产在线| 欧美黑人欧美精品刺激| 无限看片的www在线观看| 大香蕉久久成人网| 在线观看一区二区三区激情| 精品午夜福利视频在线观看一区| 亚洲精品粉嫩美女一区| 777久久人妻少妇嫩草av网站| 国产极品粉嫩免费观看在线| 午夜免费观看网址| 国产在视频线精品| 男人操女人黄网站| 两个人免费观看高清视频| 一区二区三区国产精品乱码| 一区二区三区精品91| 久久国产乱子伦精品免费另类| 黄色怎么调成土黄色| 交换朋友夫妻互换小说| 国产深夜福利视频在线观看| 久久午夜综合久久蜜桃| 久久99一区二区三区| 纯流量卡能插随身wifi吗| 黄色丝袜av网址大全| 成在线人永久免费视频| 丝袜在线中文字幕| 夫妻午夜视频| 99精国产麻豆久久婷婷| 亚洲精品在线美女| av网站在线播放免费| 国产亚洲欧美在线一区二区| 在线观看66精品国产|