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1.
贝尼登类单殖吸虫是象山港海水养殖鱼类中一类危害严重的寄生虫。应用PCR扩增及DNA序列分析的分子生物学手段,并结合对成虫的形态学分析,对象山港养殖大黄鱼体表寄生的贝尼登类单殖吸虫(记作XSp)进行了种类鉴定,结果表明XSp从形态特征上属于新贝尼登虫属,与梅氏新贝尼登虫高度相似。扩增得到XSp的28S rDNA和ITS1序列长度分别为393和427 bp,与梅氏新贝尼登虫和鱾新贝尼登虫的5个28S rDNA 序列、2个ITS1序列的比对分析显示相似性除1个为97.4%外其余均大于99%,提示XSp与这几个鱾新贝尼登虫和梅氏新贝尼登虫为种内关系,而XSp与贝尼登虫的3个28S rDNA 和1个ITS1序列相似性分别为84.3%~89.5%和60.2%。系统进化树显示该吸虫与梅氏新贝尼登虫和鱾新贝尼登虫形成一个紧密的簇,而与贝尼登虫亲缘关系较远。根据普通生物学和序列特征分析,将XSp定种为梅氏新贝尼登虫,并且支持Whittington和Horton (1996)提出的梅氏新贝尼登虫和鱾新贝尼登虫为同种异名的分类观点。 相似文献
2.
两种新贝尼登虫28S rRNA序列分析及其亲缘关系探讨 总被引：2，自引：3，他引：2
采用一对特定引物对形态相近的单殖吸虫纪新贝尼登虫和梅氏新贝尼登虫的基因组DNA进行PCR扩增,获得其28SrRNA的350bp左右的特异片段.测序后经软件分析发现两者同源的337bp序列仅存在一个碱基的差异,遗传相似度达99.70%,甚至高于不同海区不同宿主梅氏新贝尼登虫间99.41%的相似度,与贝尼登虫属3个虫种的同源序列间的遗传差异度为2.08%～11.73%.通过UPGMA和MP聚类分析也可看出,纪新贝尼登虫和梅氏新贝尼登虫的遗传相似性是极为相近的.虽然两种新贝尼登虫的形态特征和遗传多样性极为相似,但它们是否同属于一个种还不能确定,需要经进一步的形态系统比较和更多的基因分析才能得出客观的、公认的结果. 相似文献
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4.
利用改进的蛋白银染色法，研究了宽四虫（Steiiniasp．）的形态及其无性生殖周期中核器和纤毛器的发育演化过程。其发生过程为：1．大核改组带出现后，口原基出现在老口围带后方之腹棘毛左侧，其内的毛基体组装成整齐排列的小膜，构成新AZM，老AZM后部也发生部分更新的现象。2．颇腹根棘毛原基各5列，分别以3：3。3：4：3方式分化成前、后仔虫的额、腹、横棘毛。3．在第1－3列背触毛中，分别于前、后仔虫的中部范围产生第1—3列新原基，每列原基向两端伸展替代老背触毛列，成为前、后仔虫相应的第一列新背触毛。4．在前后第3列背触毛原基后端发生前、后第4列原基，它稍偏向第3列原基的右侧，向前伸展成第4列背触毛；在虫体腹面，前、后右缘棘毛原基的前方出现第5、6列背触毛原基，后发育为第5、6列背触毛，在虫体演化过程中转位到背面。 相似文献
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我国的养殖香鱼正面临着严重的香鱼格留虫（Glugea plecoglossi）感染。本研究联合运用环介导等温扩增技术（LAMP）和横向流动试纸条（LFD）的检测技术，建立了快速便捷地检测G. plecoglossi的LAMP-LFD方法。该方法以G. plecoglossi的β微管蛋白基因为检测靶标，在其保守区域设计并筛得6条特异性引物（其中上游内引物用生物素标记），进行LAMP反应，产物再与异硫氰酸荧光素（FITC）标记的特异性探针杂交，在LFD上进行结果判断。结果表明，LAMP-LFD方法能够特异性地检出G. plecoglossi，对梅氏新贝尼登虫、刺激隐核虫、肝肠胞虫阳性的虾组织、派氏异尖线虫、内弯宫脂线虫、鳗弧菌香鱼分离株、杀香鱼假单胞菌，以及香鱼组织等的检测均呈阴性。优化后，LAMP的反应条件为65℃反应45min，与探针杂交的条件为65℃反应5min，加之5min的显色时间，整个检测时程为55min。利用该方法能够检测到2.0fg/μL的含β微管蛋白的质粒DNA，针对G. plecoglossi基因组DNA的检测灵敏度为14.0pg/μL；能够从感染强度达到100个虫体/克的香鱼肝组织中稳定地检测到虫体。该方法可在简单的恒温加热设备（如水浴锅）中完成核酸扩增和探针杂交，无需昂贵的仪器装置。综上，香鱼格留虫LAMP-LFD方法操作便捷、灵敏度高、特异性好、检测快速，而且设备依赖性低，完全适合于基层检测的需求。 相似文献
6.
孙世春 《中国海洋大学学报(自然科学版)》1994,(3)
中国单针类纽虫一新记录孙世春（水产学院微藻研究所）１９９１年４月于青岛太平角（３６°０４＇Ｎ．１２０°１９＇Ｅ）海滨采到一种小型纽虫，经鉴定为一国内新记录──山冈四眼纽虫（ＴｅｔｒａｓｔｅｍｍａｙａｍａｏｋａｉＩｗａｔａ，１９５４）（图１－４）。虫体... 相似文献
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敏捷瘦体虫（UrosomoidaagiliformisFOISSNER，1982）为小型腹毛目纤毛虫。利用银染法对该种二分裂期间的形态发生学进行初步研究，指出该虫形态发生的主要过程为：1．伴随大核改组带的出现，口原基发生于老口围带的下方，后演化为后仔虫的口围带。在前仔虫，老口围带及口侧膜完全保留并被继承；2．体棘毛场首先出现后一组棘毛原基，后形成前棘毛场，随后各自独立演化成前后仔虫的8：3／4：2／3模式的额-腹-横棘毛；3．在背触毛中，分别于前、后仔虫的中部产生前、后3列新原基，每列原基向其两端伸展替代老背触毛列，成为前、后仔虫相应的3列新触毛；接着，在右缘棘毛原基右前端发生前、后第4列背触毛。 相似文献
8.
饵料对花尾胡椒鲷仔稚鱼存活和生长的影响 总被引：7，自引：0，他引：7
采用6种饵料分别投喂花尾胡椒鲷15日龄的仔鱼,15d后测定其成活率、全长、体重和捕苗操作后1d的死亡率。结果表明,投喂经自制的乳化鱼肝油强化的卤虫无节幼体或经自制的乳化鱼肝油强化的卤虫无节幼体加轮虫,花尾胡椒鲷仔稚鱼的成活率最高（86％～98％）,生长快,捕苗操作后的死亡率低（0％～2．7％）;投喂轮虫,花尾胡椒鲷仔稚鱼的成活率也较高（86％～88％）,但捕苗操作后的死亡率较高（5．9％～9．1％）,而生长最慢;投喂未经营养强化的卤虫无节幼体,仔稚鱼成活率最低（68％～78％）,捕苗操作后的死亡率最高（48．3％～542％）;投喂桡足类或桡足类加轮虫,成活率较高（78％～90％）,捕苗操作后未发现死亡,但生长较慢。龙尾胡椒鲷15日龄仔鱼在停止投饵的情况下,4d即全部死亡。可以认为,经营养强化的卤虫无节幼体是花尾胡椒鲷仔稚鱼的最佳饵料,桡足类也是花尾胡椒鲷仔稚鱼的优质饵料。 相似文献
9.
斜带石斑鱼仔、稚鱼的摄食与生长特性 总被引：1，自引：0，他引：1
据2005年10～12月，在集美大学水产学院海水育苗试验场的试验数据，采用生态学方法对人工培育的斜带石斑鱼仔、稚鱼的摄食习性与生长特性进行了分析．结果表明，在水温为26．5～28．5℃时，仔鱼在孵出第4天开口摄食，开口饵料为牡蛎受精卵和担轮幼虫．以后随着鱼体的生长，依次投喂臂尾轮虫、卤虫无节幼体、桡足类、鱼糜．对422尾仔、稚鱼观察结果表明，其摄食率达95．1％，消化道饱满系数波动在0．96％～34．15％之间，日摄食指数在45．83％～82．08％之间，其摄食具有明显的昼夜节律，仔鱼摄食高峰出现在11：00和15：00，稚鱼摄食高峰出现在13：00和17：00，仔、稚鱼夜间基本不摄食．对较大个体的饵料生物有明显的选择性．摄食量（Y）与体重（形）的关系式为Y=0．017W＋0．198，全长（LT）与日龄（D）的关系式为Lr=2．229e^0.038D，体重（形）与日龄（D）的关系式为形=0．063e^0.130D，全长（LT）与体重（形）的回归方程为W=0．0047LT^3.319． 相似文献
10.
提高日本对虾人工育苗成活率的研究 总被引：3，自引：0，他引：3
通过日本对虾Penaeusjaponicus人工育苗中饵料配给、水质处理和控制,以及幼体病害防治的单因子和多因子正交试验及大面积生产验证,对提高日本对虾人工育苗成活率的几项关键措施进行了探讨。结果表明：（1）在Z期,添加螺旋藻Spiralsp.粉10g·（1．0×106尾·d）-1、光合细菌2ml·（m3·d）-1和Z3期添加卤虫Artemia无节幼体1-2个·ml-1,使Z1－M1期幼体的成活率提高10％-15％;（2）用36％甲醛0．065－0．13mmol·dm-3和光合细菌2ml·（m3·d）－1处理并改良育苗水质,以及在N期1次性加水75％,至M3期加满,P1-5期换水6％－10％,P6-10期换水15％－20％,用此方法控制育苗水质,作用显著;（3）用间投联用0．5g·（m3·d）－1抗菌素的方法预防幼体细菌病效果良好;（4）在10个总水体为543m3的育苗池中,共育出P8-10期的虾苗3．026×107尾,单位平均出苗量为5．5×104尾·m－3,N-P8-10期的成活率最高达65％,平均为54．6％。 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
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
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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
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
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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