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1.
The experimental results showed that:1) The embryonic development of bay scallop is inhibited ata dissolved oxygen range of 1.38-3.64×10~(-3)at 23℃,and completely blocked below the lower limit.2)The tolerance of larvae to anoxia increased with larval sizes and was related to their oxygen debt.3)The scallop larvae exhibited specific behavioral responses to oxygen deficiency,which finally led tovelum disintegration and larval death.The possible relationship between environmental oxygen deficien-cy and the disease of disintegration of the larval Velum is also discussed.In this study,considerableoxygen debt was found in bay scallop larvae,which was greater in small animals.Based on the worksof previous authors,a new concept is proposed for the estimation of oxygen debt,namely,thecompensatory rate of oxygen debt(CROD).This can be used in intra-or interspecific comparison ofoxygen debt.The results can be helpful in the management of water quality and for the prevention oflarval diseases encountered in scallo  相似文献   

2.
INTRODUCTIONFromthe1990’s,thescallop,C.farreri,culturedinthenorthernChinaSea,deterioratedinsize,healthandoutputbecauseofhighstockingdensities,shortageofnaturalfoodanddiseases.Massmortalityof50%-90%occurredinJiaozhouBay,Qingdao,andSishiliwanBay,Yantai,fromJulyto…  相似文献   

3.
INTRODUCTIONThes0uthembayscallop,AmpeandiansconamtaSay,isanAmpenirradiansInrnaforsouthamsubepedesdistributingalongthecoastSfromNorthCarolinat0Florida,andisanirnPohantshellfishforfisherieSinthesouthrmU.S.A.,butthere-sonisdmingduetoexanivecapture.ThesouthemsubspedeswasfuStintIDdutalinl99lintoChinabytheInstituteofdrinology,ChineSeAcadeInyofSdenas,andshowedwonderfulprospan,althoughthedeveopmentalbiol0gy,espedllytheeffedofboortantenvirDnmentalfactors(forexamPlesandtyorternPeratwonthis…  相似文献   

4.
The effects of membrane penetrating anti-freezing agents(MPAAs), DMSO(dimethyl sulfoxide),glycerol,EG(ethylene glycol) and methanol in combination with different cryoprotective additives suchas carbohydrates,macromolecules and inorganic compounds on the spermatozoon vitality of Chinesescallop,Chlamys farreri,during 1 h 0℃ equilibrium were investigated.When only MPAAs existed,the detrimental effects of different MPAAs ranked in the following order:DMSO相似文献   

5.
INTRODUCTIoNGlyOProtein'sroleinthevedousbioactivitiesofcelllifewasPaldcloseattentiontoinrecentyearsWhenanuInberofantitUInractiveglycoproteinswerefoundinsuccessionintheInarinemolusca(driS-etal-,l985;kisugiJ-etal.,1989).Thehighan-titumoractivityoftheglycoproteinfromPatinOPectenyeSSoensisofJaPaninterestedPharma-cologists(~S.etal.9l987).TheadductorofChamy(forecten)farmri,acultivatedshellfishdistributedrnaidealongthenorthemcoastofChina,isValuableandtastymdrineproductverypoPulartoman.T…  相似文献   

6.
INTRODUCTIONInmollusccytogenetics,tetraploidisanimportantsubjectbecauseofits1 0 0 %triploidproduc tion.Thetriploidswereprovedlargerthandiploidsby 73 %inbayscallop ,Argopectenirradians(Tabarini,1 984 )andby 3 2 % 59%innoblescallop ,Chlamysnobilis (KomaruandWada ,1 989) .Butthedifficultiesassociatedwithtriploidproductionlimiteditswideuseinmolluscaquac ulture.Normally ,thetriploidswereinducedbyinhibitingpolarbodyII (Allenetal.,1 989) ,butthismethodcannevermakethetriploidproductionreach 1…  相似文献   

7.
DAX1, a member of nuclear receptor superfamily, has a function in the sex determination and gonadal differentiation of several vertebrate species. However, little information about DAX1 of invertebrates is available. Here we cloned a homolog of scallop (Chlamys farreri Jones and Preston 1904) dax1, Cf-dax1, and determined its expression characteristics at mRNA and protein levels. The cDNA sequence of Cf-dax1 was 2093 bp in length, including 1404 bp open reading frame (ORF) encoding 467 amino acids. Unlike those of vertebrates, no conserved LXXLL-related motif was found in the putative DNA binding region of Cf-DAX1. Fluorescence in situ hybridization showed that Cf-dax1 located on the short arm of a pair of subtelocentric chromosomes. Tissue distribution analysis using semi-quantitative RT-PCR revealed that Cf-dax1 expressed widely in adult scallop tissues, with the highest expression level found in adductor muscle, moderate level in mantle, gill and testis, and low level in kidney, ovary and hepatopancreas. The result of quantitative real-time PCR indicated that the expression of Cf-dax1 was significantly higher (P<0.05) in testis than in ovary at the same stage, showing a sex-dimorphic expression pattern. Furthermore, immunohistochemical detection found that Cf-DAX1 mainly located in spermatogonia and spermatocytes of testis and in oogonia and oocytes of ovary, implying that DAX1 may involve in gametogenesis of bivalves.  相似文献   

8.
ImODUonONRespirationandexereionareimPortantaspeCtSofbioenergCties.TheaspthetionInetabolismandexcretionofscallopswerestudiedbydifferentmwherspeayne,l97l,BayneandNewell,l983,Bricelj,l987,MackayandShumway,l98O,Mdriky,l973,FujiandHashizume,l974,Madrinald,l988,ShumwayCtal.,l988,Vahl,l972,l978).Themetabolicrateofbivalvesisinfluentalbyanumberofvariables,indudingternperature,bodysize,oxygenimsion,foodconantfation,reproductvestate,aCtivity1ev-elandphySiologicalcondition.Themetabolicrateofscal…  相似文献   

9.
INTRODUCTIONRespirationandexcretionaretwoimportantaspectsofbioenergetics.Themetabolicrateofbi valvesisinfluencedbyanumberofvariables,includingtemperature ,bodysize,oxygentension ,foodconcentration ,reproductivestate ,activitylevelandphysiologicalcondition .Theimpactsoftemperatureontherespirationandexcretionofscallopshadalreadybeenreportedindetail (BayneandNewell,1 983 ;MacDonald ,1 988;MackayandShumway,1 980 ;Shumway ,1 991 ;Yangetal.,1 998) ,whiletheeffectsofsalinityontherespirationan…  相似文献   

10.
Several polyculture models of scallop Chlamys farreri and kelp Laminaria japonica currently employedin Sungo Bay and other parts of northern China are described in this paper. Economic benefits of differ-ent polyculture models are analysed based on the growth rate, culture density and market price. In addi-tion, site selection, critical environmental conditions and polyculture problems are discussed in detail.  相似文献   

11.
Histological characteristics of gametogenesis of two kinds of scallops, gonochoric Chinese scallop, Chlamys farreri and hermaphroditic bay scallop, Argopecten irradians were investigated in this study. Spermatogenesis in C. farreri has different developmental stages: spermatogonia, primary spermatocyte, second spermatocyte, spermatid and spermatozoon. A large number of same developmental stage spermatic cells converge at a definite area of the testis. Premeiotic, previtellogenic and vitellogenic oocytes can be found during oogenesis in C. farreri, where oocyte distribution is obviously irregular. The A. irradians gonad consists of two different parts in one individual: one part functions as testis, the other as ovary. Between these two parts is a special appearance area, where a large number of spermatic cells are bound with two layers of acellular substance with many oocytes in it.  相似文献   

12.
Galileo、GPS和Galileo/GPS组合系统实用性的比较   总被引:8,自引:0,他引:8  
Galileo卫星无线导航系统是类似于GPS的系统,它将从2008年开始服务。对这两种系统以及它们的组合系统(对不同纬度的测站),从期望可观测的卫星数、大地高与钟差的相关性、定位精度、东西向与南北向定位误差之比等方面进行了比较。  相似文献   

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