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为探讨石斑鱼——鞍带石斑鱼(Epinephelus lanceolatus)♂×斜带石斑鱼(Epinephelus coioides)♀杂交子一代青龙斑二倍体和三倍体的血液学及生化特征,采用显微观察、瑞士染色、生化指标检测等方法对青龙斑二倍体(2n=48)与三倍体(3n=72)的血细胞形态大小、血液生理生化指标以及它们的显微结构进行比较研究。结果表明,青龙斑三倍体的血细胞、红细胞、细胞核和白细胞均显著大于二倍体,容积比为3:2;红细胞数随倍性增加而减少,差异显著;在血细胞形态上,二倍体红细胞核短径/长径比值为0.79,略呈圆形,三倍体红细胞核短径/长径比值为0.69,呈椭圆形;在三倍体血细胞中存在一些异常形状的纺锤形和月牙形红细胞,在生化指标上,二倍体与三倍体存在显著性差异,其中三倍体血红蛋白、血小板含量明显小于二倍体;平均血细胞体积、平均血小板体积、血细胞压积的含量显著大于二倍体;二倍体与三倍体青龙斑鱼血液中各种无机盐的含量均在正常范围之内,但三倍体含量低于二倍体。 相似文献
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通过对小黄鱼(♀)×大黄鱼(♂)杂交子代及其双亲染色体核型和线粒体COI基因序列的比较分析,旨在对其杂交遗传特性进行研究。其中染色体核型分析表明:小黄鱼的核型为2n=6sm+42t,NF=54;大黄鱼的核型为2n=2sm+22st+24t,NF=72;杂交子代为2n=8sm+12st+28t,NF=68。杂交子代和亲本在染色体数目上一致,但在组型上存在差异,可能是由于杂交过程中双亲染色体组发生了融合和重配。同时,对杂交子代及其亲本672bp的COI基因同源序列进行分析,表明杂交子代与其母本小黄鱼的序列几乎一致,利用Kitumra-2-Parameter-Distance双参数模型分析显示杂交子代与小黄鱼的遗传距离为0.011,该数值接近其种内平均遗传距离。基于COI基因片段序列构建的系统树显示,杂交子代与小黄鱼聚成一支。杂交子代在线粒体COI基因上表现出严格的母系遗传特征。 相似文献
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真鲷、黑鲷及其杂交子代的染色体构成与AFLP分析 总被引：1，自引：0，他引：1
采用核型分析和AFLP技术对真鲷、黑鲷及其杂交子代进行遗传差异分析。结果显示真鲷、黑鲷和杂交子代均含有48条染色体,核型分别为2n=2st+46t,NF=48、2n=4m+4sm+2st+38t,NF=56和2n=30m+8sm+2st+8t=48,NF=86,杂交子代核型与其父、母本种均不一致。两对AFLP选扩引物组合在真鲷、黑鲷和杂交子代中共扩增到278个条带,其中黑鲷特异性条带93条、真鲷特异性条带108条;杂交子代中分别出现了21条父本种(黑鲷)特异条带和67条母本种(真鲷)特异条带,另出现了15条非双亲条带。杂交子代与真鲷、黑鲷的遗传相似系数和遗传距离分别为0.113、0.350和2.180、1.050,表明杂交子代总体上更偏向于母本种。染色体核型和AFLP条带分析结果表明真鲷(♀)×黑鲷(♂)所获得的杂交子代为含有48条染色体的异源二倍体,且父、母本遗传物质在杂交中发生了部分重组,杂交子代表现出一定的偏母系遗传特性。 相似文献
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4种石斑鱼染色体核型研究 总被引：15，自引：0，他引：15
以蜂巢石斑鱼(Epinephelus merra)、鲑点石斑鱼(Epinephelus fario)、点带石斑鱼(Epinephelus malabaricus)及黑边石斑鱼(Epinephelus fasciatus)为材料,胸腔注射PHA及秋水仙素溶液,取头肾细胞经空气干燥法制片。经核型分析,蜂巢石斑鱼与鲑点石斑鱼核型一样,2n=48=4m 6sm 4st 34t,NF=62;点带石斑鱼与黑边石斑鱼的核型一样,2n=48=48t,NF=48。由染色体数目2n=48可知,4种石斑鱼在鱼类系统中划分为高位类;由核型组成不同,可以将4种石斑鱼分为两大类：蜂巢石斑鱼与鲑点石斑鱼属于一大类;点带石斑鱼与黑边石斑鱼属于另一大类。此外,按总臂数多少来分,蜂巢石斑鱼与鲑点石斑鱼为特化类群：点带石斑鱼与黑边石斑鱼为原始类群。 相似文献
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研究了平鲷（Rhabdosargus sarba）自然群体和人工诱导雌核发育的染色体核型,结果表明：平鲷自然群体和雌核发育二倍体的染色体没有明显的形态结构差异,数目均为2n=48,中部着丝点染色体2对,亚中部着丝点染色体1对,亚端部着丝点染色体2对,端部着丝点染色体19对,其核型公式为4m＋2sm＋4st＋38t,染色体总臂数（NF）54,染色体上未见随体、次缢痕,也未发现有明显异形的性染色体;雌核发育单倍体染色体数目n=24,中部着丝点染色体有2条,亚中部着丝点染色体1条,亚端部着丝点染色体2条,端部着丝点染色体19条,核型公式为2m＋1sm＋2st＋19t,染色体总臂数（NF）27,单倍体染色体数量是其二倍体染色体的一半,其形态和结构与同源的另一套染色体相似.根据鲷科几种主要鱼类的核型,结合它们之间的杂交后代的性状表现和遗传亲和力、个体发育及其基本生物学特征分析,在分类学上平鲷可以归入鲷属,与黑鲷（Sparus macrocephalus）和黄鳍鲷（Sparus latus）同为一属. 相似文献
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斑石鲷(Oplegnathus punctatus)雌、雄鱼核型及Ag-NORs带型分析 总被引：1，自引：0，他引：1
为研究斑石鲷雌、雄鱼染色体的形态与结构,本文采用植物血球凝集素(PHA)及秋水仙碱体内注射法,取头肾细胞采用冷滴片结合空气干燥的方法获取了斑石鲷雌、雄鱼染色体的中期分裂相,分别对其进行了常规的吉姆萨和硝酸银染色并进行核型和带型分析。结果显示:(1)雄性斑石鲷核型为2n=47、1m+2sm+44t、NF=50,雌性斑石鲷核型为2n=48、2sm+46t、NF=50。(2)斑石鲷雌、雄鱼染色体相对长度分别为(2.30±0.37)—(6.87±0.42)及(2.28±0.30)—(10.33±0.86),雄性斑石鲷具有一条体型巨大的异形中部着丝粒染色体,其相对长度达到其它染色体的2—5倍。(3)染色体经银染后,发现含有2个Ag-NORs位点的分裂相最多,位点位于一对亚中部着丝粒染色体短臂末端,呈短棒状,且具有活性异形现象。(4)本研究中雄性斑石鲷具有一条异形性染色体,可能是性染色体Y,我们推测其染色体的性别决定类型可能为X1X1X2X2/X1X2Y型。本研究为鲈形目鱼类的细胞遗传学研究提供了基础资料,并将为进一步开展斑石鲷遗传育种等研究奠定基础。 相似文献
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夏牙鲆(♂)与牙鲆(♀)人工杂交的细胞遗传学初步研究 总被引：6，自引：0，他引：6
于2004年11～12月在青岛薛家岛养鱼场采用夏牙鲆(Paralichthysdentatus)的精子与牙鲆(Paralichthysolivaceus)的卵子实施了多次人工杂交实验,并进行了父本母本鱼类个体、子代的染色体制片观察和细胞中DNA相对含量的流式细胞仪检测。结果表明,夏牙鲆染色体数为48,核型为2n=48t、臂数NF=48;子代的染色体数和核型与父母本的一样,也为2n=48t;子代的细胞中DNA的相对含量也表明其为二倍体。因此,可以明确其为杂交的后代,而不是雌核发育。 相似文献
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Arne Schnack-Friedrichsen Angela M. Davis Jim D. Bennell Dei G. Huws 《Marine Georesources & Geotechnology》2001,19(4):221-243
The interdependence between the seismo-acoustic properties of a marine sediment and its geotechnical/physical parameters has been known for many years, and it has been postulated that this should allow the extraction of geotechnical information from seismic data. Though in the literature many correlations have been published for the surficial layer, there is a lack of information for greater sediment depths. In this article, a desktop study on a synthetic seafloor model illustrates how the application of published near-surface prediction equations to subsurface sediments (up to several tens of meters burial depth) can lead to spurious predictions. To test this further, acoustic and geotechnical properties were measured on a number of sediment core samples, some of which were subjected to loading in acoustically-equipped consolidation cells (oedometers) to simulate greater burial depth conditions. For low effective pressures (representing small burial depths extending to around 10 meters subsurface), the general applicability of established relationships was confirmed: the prediction of porosity, bulk density, and mean grain size from acoustic velocity and impedance appears generally possible for the investigated sedimentary environments. As effective pressure increases through, the observed relationships deviate more and more from the established ones for the near-surface area. For the samples tested in this study, in some instances increasing pressure even resulted in decreasing velocities. There are several possible explanations for this abnormal behavior, including the presence of gas, overconsolidation, or bimodal grain size distribution. The results indicate that an appropriate depth correction must be introduced into the published prediction equations in order to obtain reliable estimates of physical sediment properties for greater subsurface depths. 相似文献
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Shigehisa Nakamura 《Marine Geodesy》2000,23(1):55-61
Specific properties of the interannual sea level variations and annual tides in the Northwestern Pacific were studied. Several tide stations were monitored. The monthly mean sea level for the year of 1995 was analyzed at each tide station. A seismic event in 1995, some tectonic activity around the subject area, and the Kuroshio (the oceanic western boundary current) may possibly contaminate results which would have occurred from the astronomical annual tide alone. 相似文献
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The effect of different fixation and storage protocols on the flow cytometric (FCM) simultaneous analysis of bacterioplankton and phytoplankton in coastal seawater samples (Mediterranean coastal lagoons) was investigated. FCM measurements (cell number, fluorescence and scatter characteristics) were obtained through DAPI staining. Three fixatives [glutaraldehyde (GA), formaldehyde (FA) and paraformaldehyde (PFA)] and two storage (3 months duration) methods (5 °C and −196 °C) were tested. Two dominant populations were detected in studied samples: bacteria and eukaryotic picophytoplankton. Adding fixatives (2% final concentration) appears necessary to obtain FCM exhaustive counts of all the bacteria and phytoplanktonic cells. This was related to the permeation effect of fixatives which allowed a better DAPI staining of the cells. Maximum fluorescence, i.e. optimal staining of the cells was obtained with FA or PFA, and significant lower fluorescences with GA. Fixed samples stored at 5 °C induced rapid cell loss. Only storage in liquid nitrogen of samples fixed with FA or PFA, allows mid-term (≥4 months) preservation of bacteria or picophytoplankton cell numbers, and limited evolution of DAPI-induced fluorescence and scatter characteristics. 相似文献
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《海洋学报(英文版)》2014,(9):F0003-F0003
<正>Acta Oceanologica Sinica(AOS)is a comprehensive academic journal edited by the Editorial Committee of Acta Oceanologica Sinica and is designed to provide a forum for important research papers of the marine scientific community which reflect the information on a worldwide basis.The journal publishes scholarly papers on marine science and technology,including physics,chemistry,biology, 相似文献
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The relationship between the flux of exotic benthic foraminiferal tests (i.e. tests which are supplied from open-sea sources alone) in a tidal inlet and that of bulk sediment was analysed, which can be expressed as two first-order linear equations. According to this relationship, in order to determine net sediment transport directions in the entrance, the test concentration in surficial sediments of the tidal basin can be compared against a ‘ critical level ’. The critical level is determined for the conditions that no net transport of bulk sediment is present within the entrance. If the observed concentration (averaged over the tidal basin) is higher than the simulated critical level, then the net sediment transport is directed to landward. This method is applied to the analysis of net sand transport at Christchurch Harbour, a tidal inlet system located in southern England. In this investigation, concentrations of exotic foraminiferal tests in the surficial sediments of the tidal basin and ebb tidal delta area were obtained from the analysis of sea-bed sediment samples. A series of probable critical levels were calculated based upon the data sets with regard to: (1) sediment discharge from the rivers; (2) magnitude of sediment discharge within the entrance during the ebb; (3) the test concentration outside the harbour; (4) the thickness of the moving layer; and (5) two parameters associated with dispersive processes. The results show that the concentration in the tidal basin sediment is higher than a number of simulated critical concentrations for representative cases. Consequently, the high level of the concentration of exotic benthic foraminiferal tests within the harbour should be explained as a result of landward net transport of sands within the entrance. 相似文献
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The behaviour of an axially pre-loaded cylindrical member of an offshore structure, hit by a supply ship, has been investigated. The effects of axial pre-loading on the dynamic properties of members, the extent of damage and propagation of dynamic instability in the tubular members have also been investigated. Numerical models have been validated using available experimental data from the literature although these are mostly static with no pre-loading. Axial pre-loading was found to change the dynamic characteristics of some cylindrical members quite dramatically while it had no significant effect on others. The study examined whether there was any change in the behaviour between local and global modes when the loading was dynamic rather than static. The effect of damping on the dynamic instability of axially pre-loaded tubes under lateral dynamic loads was also studied. It was observed that for some geometries the quasi-static response can be used to define the boundary between bounded and unbounded dynamic responses. The main contribution of this study, compared with previous investigations reported in the literature, is that both pre-loading and dynamic effects have been included. 相似文献
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Rahul Sharma 《Marine Georesources & Geotechnology》2000,18(3):237-250
Observations on seafloor features from subbottom profiling and seabed photography data show that the undisturbed and natural conditions before the benthic disturbance undergo a substantial change after operation of the disturber. The effects can be seen in the form of deep trenches and grooves, formed by the action of the sleds and the pumping of the sediment along its path, as well as sediment piles on either side of the track. Biological traces such as fecal coils, casts, tubes, burrows, and trails get obliterated in the areas of disturbance and resedimentation. The smooth, uniform nature of the seafloor observed in predisturbance phase shows microtopographic changes in and around the disturbed area as a result of sediment excavation and resettlement. Vertical mixing as well as lateral transport of sediment alter the geological, biological, physical, and chemical conditions on the seafloor, which need to be monitored over time to assess the process and the time taken for restoration of environmental conditions. 相似文献
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Vance P. Vicente 《Marine Ecology》1989,10(2):179-191
Abstract. Long-term changes in the distributional patterns of commercial sponges ( Spongia spp. and Hippospongia spp.) within the West Indian Region indicates that: 1) commercial sponges had a widespread distribution throughout the whole West Indian Region and were ubiquitous in very shallow water until about the first half of the present century; 2) they were fished commercially not only in the traditional northern Caribbean sites (Florida, Gulf of Mexico, Bahamas) but also in the Greater ( e. g. , Hispaniola, Jamaica) and Lesser Antilles; and 3) they became extinct throughout most of the Lesser Antilles ( e. g. , Puerto Rico, Vieques, St. Thomas) sometime during the first half of this century. Mortalities of spongiids within the Antilles were found to differ from other marine mortalities in that: 1) species disappeared from a large region; 2) species vanished from different habitats and depths; and 3) natural populations never recovered. Species richness patterns suggest that commercial sponge genera ( Spongia and Hippospongia ) evolved under slightly cooler elimatic conditions than those found at present, and that these extinctions occurred as a direct or indirect effect of positive thermal anomalies in sea surface and atmospheric temperatures between 1900–1950. The concept that species diversity is stable on a regional scale is questioned. 相似文献