共查询到20条相似文献，搜索用时 46 毫秒
1.
对中国沿海脉红螺7个自然居群的线粒体DNA 16S rRNA基因片段进行了扩增和测序,分析了107个个体511bp的碱基序列,结果没有发现插入,缺失突变的核苷酸位点.检测到了28个多态性核苷酸位点,共37种单倍型,单倍型1的同源性达到58.7%.大连居群的28l(G-A)和483(T- C)位点,烟台居群的17(A-G)位点、66(T- C)和247(T-C)位点,舟山居群的128(T-C)位点,秦皇岛居群的130(T-G)和161(A-G)位点,以及丹东居群的431(T-C)位点的变异可以作为居群分子遗传标记位点.居群内,烟台和大连居群的核苷酸差异数 K 以及平均核苷酸多样性指数 Pi 最高,青岛居群最低;居群间,大连居群在居群间核苷酸差异数K、居群间平均每位点核苷酸替代数Dxy 和居群间每位点净核苷酸替代数Da三个指标上都表现出比其他居群之间较高的水平,说明大连居群具有最为丰富的遗传多样性. 相似文献
2.
采用多变量形态分析方法,对黄、渤海海域的丹东、烟台、青岛、赣榆、昌黎和莱州6个地理居群的扁玉螺的表型形态变异进行了研究。主成分分析构建了3个主成分,第一、第二和第三主成分的贡献率分别为41.68%、28.45%和27.67%,累计贡献率达97.80%。聚类分析结果显示,烟台居群与青岛居群之间的形态最为接近,二者首先聚为一支;丹东居群与赣榆居群聚为另一分支;昌黎居群、莱州居群与其它居群的趋异程度较大。方差分析和Duncan’s多重比较表明,扁玉螺各居群之间的若干形态差异显著(P<0.05)。利用逐步判别法进行判别分析,建立了6个居群的判别函数,判别准确率P1为52.9%—86.5%,P2为52.4%—89.1%,综合判别准确率为74.4%。上述结果显示,6个居群的扁玉螺在表型形态上已出现了一定程度的变异,壳高、壳顶至胼胝高是反映其形态变异的主要性状,但各居群间的变异尚未分化到亚种水平。 相似文献
3.
脉红螺壳口通常有3种颜色:"黑白条纹螺"、"中间螺"和"橙色螺"。本论文对3种壳口颜色的脉红螺分别进行了形态学和mt16S rRNA、COⅠ基因片段序列比较分析。形态学分析结果表明,除厣宽/壳高、厣高/壳高、厣高/体螺层、厣高/壳口长、厣高/壳口宽、厣高/厣宽的形态学特征指数和出肉率不具有显著性差异外,其它形态特征和生物学相关变量具有显著差异,且对湿重的影响效果不同。"黑白条纹螺"壳口长和壳口宽对湿重影响最大,而"中间螺"和"橙色螺"各形态特征对湿重均无显著的直接影响。根据各形态特征均值建立的居群形态聚类图显示,"中间螺"和"橙色螺"形态差异较小,二者与"黑白条纹螺"的形态差异较大。然而基于mt16S rRNA和COⅠ基因片段序列分析结果显示,三种壳口颜色的脉红螺无遗传分化,为同一种。 相似文献
4.
脉红螺壳口通常有3种颜色：“黑白条纹螺”、“中间螺”和“橙色螺”。本论文对3种壳口颜色的脉红螺分别进行了形态学和mt16SrRNA、COI基因片段序列比较分析。形态学分析结果表明,除厣宽／壳高、厣高／壳高、厣高／体螺层、厣高／壳口长、厣高／壳口宽、厣高／厣宽的形态学特征指数和出肉率不具有显著性差异外,其它形态特征和生物学相关变量具有显著差异,且对湿重的影响效果不同。“黑白条纹螺”壳口长和壳口宽对湿重影响最大,而“中间螺”和“橙色螺”各形态特征对湿重均无显著的直接影响。根据各形态特征均值建立的居群形态聚类图显示,“中间螺”和“橙色螺”形态差异较小,二者与“黑白条纹螺”的形态差异较大。然而基于mt16SrRNA和COI基因片段序列分析结果显示,三种壳口颜色的脉红螺无遗传分化,为同一种。 相似文献
5.
随机抽取3月龄脉红螺稚螺103粒,开展其表型性状对体质量性状影响分析,以期为脉红螺人工选择育种提供较好的测度指标。实验测量了脉红螺壳长（X1）、壳宽（X2）、壳厚（X3）、壳口长（X4）、壳口宽（X5）等5种表型性状和体质量性状（Y）,运用相关性分析、多元回归分析、通径分析及决定系数分析等方法分析了表型性状对体质量性状的影响。结果表明,脉红螺各性状间的相关性均达到极显著水平（P<0.01）,拟合的多元线性方程为Y=-18.484 4+0.348 35X1+0.463 79X2,经自助法检验,在95%置信区间条件下,该方程决定系数（R2）范围为0.863 5~0.939 4,拟合度较好;壳长和壳宽对体质量的决定系数之和大于0.85,是最适宜用来预测体质量性状的两个表型性状指标。本研究成功分析出对脉红螺体质量直接影响作用最强的表型性状,为脉红螺选择育种理想测度指标的挑选提供了依据。 相似文献
6.
五个短蛸群体等位基因酶的遗传变异 总被引：11，自引：1，他引：11
采用水平淀粉凝胶电泳技术研究了山东沿海莱州（LZ），烟台（YT）、青岛（QD），日照（RZ）和大连（DL）五地短蛸自然群体的等位基因酶遗传变异。分析了AAT，ALP，EST，GRS，G6PD，SDH，CAT，SOD，IDH，GPI，PGM，G3PD，MPI，ME，MDH，CK，AK等同工酶在短蛸外套肌和肝脏组织中的表达情况，并对同工酶进行了生化遗传分析，LZ，YT，QD，RZ，DL五个群体的多态位点比例分别为15％，5％，10%,10%,10%(P0．99），群体平均杂合度观测值分别为0．024，0．001，0．009，0．007，0．006，平均位点有效等位基因数分别为1．200，1．022，1．061，1．103，1．077。结果表明，LZ群体的遗传多样性较高，同时，各群体中普遍存在杂合子缺失现象，对五个群体的遗传距离进行聚类分析，构建了系统树图。 相似文献
7.
8.
9.
中国沿海三疣梭子蟹的遗传结构和亲缘关系分析 总被引：3，自引：0，他引：3
应用CLUSTAL X 1.81对位排序软件和Molecular Evolutionary Genetics Analysis (MEGA) Version 3.1系统发育相关分析软件包,分析了渤海、黄海和东海不同群体的三疣梭子蟹mtDNA D-loop片段序列,(不包括引物)D-loop序列(不包括引物)长约1 241 bp,该片段AT、GC平均含量分别为75.8%和24.2%,AT含量均明显高于GC含量,种群间的遗传距离平均为0.025.依据D-loop序列,应用邻接法(NJ)、最小进化法(ME)及最大简约法(MP),构建中国沿海三疣梭子蟹亲缘关系的系统发生树,MP、NJ和ME树中所显示的三疣梭子蟹亲缘关系基本一致.NJ和ME树中来自东海的XM1与DT5聚为姊妹群;来自渤海的PL1与来自东海的YT1聚为姊妹群;来自东海的DT3与来自黄海的DD1聚为姊妹群,再与来自渤海的PJ1相聚形成一个单系;来自东海的ZS1与来自黄海的QD1聚为姊妹群;来自东海的DT4与来自黄海的YC1相聚,再与来自东海的YT2,YT3相聚.在MP树中,来自黄海的YC1与来自东海的DT4相聚为姊妹群,再与YT2相聚;来自渤海的PL1与来自东海的YT1聚为姊妹群;来自东海的XM1与DT5聚为姊妹群;来自东海的DT3与来自黄海的DD1聚为姊妹群,再与来自渤海的PJ1相聚;来自东海的ZS1与来自黄海的QD1聚为姊妹群;这些群最后再与来自东海的YT3相聚.结果显示中国沿海各海区三疣梭子蟹种群间存在明显的基因交流,亲缘关系的远近并不以海区划分和地理位置的远近为依据.洄游和长期以来跨海区的捕捞作业可能是三疣梭子蟹种群间基因交流的根本原因;蓬勃发展的三疣梭子蟹人工养殖和放流也会导致亲蟹和苗种跨海区交流,对三疣梭子蟹种质资源的保护将产生巨大影响. 相似文献
11.
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
12.
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
13.
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
14.
15.
《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
16.
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
17.
18.
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
19.
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
20.
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