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1.
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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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
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《中国海洋大学学报(自然科学版)》2016,(11)
利用活体观察和蛋白银染色技术对鬃异源棘尾虫(Tetmemena pustulata(Müller,1786)Eigner,1999)漠河种群的形态学及细胞发生学进行了详尽的研究。研究表明:本种群与其他种群在活体形态和纤毛图式特征方面十分吻合。无性生殖期间细胞发生学表现出的主要特征如下:1)老口围带为前仔虫所继承,老波动膜仅在前部发生更新;2)后仔虫口原基为表层独立发生;3)老棘毛II/2、III/2与IV/3、IV/2、V/4分别参与前、后仔虫额-腹-横棘毛原基的构建;4)前、后仔虫额-腹-横棘毛原基I-VI以“1∶3∶3∶3∶4∶4”的方式分化形成棘毛;5)前、后仔虫的缘棘毛原基分别由老结构反分化形成;6)背触毛发生为尖毛虫模式,但2列背缘触毛原基源于右缘棘毛原基前端断裂。本研究为该种背缘触毛原基起源的首次揭示。 相似文献
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寡毛双眉虫无性生殖期间的皮膜演化和细胞发生学 总被引：1，自引：0，他引：1
于１９９１年６月在青岛海区采集到一腹毛目纤毛虫,寡毛双眉虫。应用蛋白银技术研究了其无性生殖期间的细胞发生学,其特征为：１）ＡＺＭ原基独立地出现于远离模棘毛的前方而非紧靠老的横棘毛附近;２）口棘毛并非来自第一ＦＶＴ原基（在后仔虫）,而是由ＵＭ原基分化而来;３）老的ＡＺＭ将发生后半群的局部重建而非整个地由前仔虫简单继承。 相似文献
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钩刺尾刺虫无性生殖期的皮膜演化 总被引：2，自引：0，他引：2
借助蛋白银技术对海洋纤毛虫钩刺尾刺虫无性二分裂期间的形态发生进了观察(1991年7月10日),结果表明:(1)前仔虫也有一口原基出现并由其对老的口围带进行部分重建,另一部分未被更新的小膜将保留并为前仔虫所继承;(2)额棘毛分别来自第1、2棘毛原基及口侧膜原基;(3)形式上的右缘棘毛实为腹棘毛,来自第5列棘毛原基;(4)尾棘毛十分独特地由两组原基演化而成;(5)背触毛的发生为分步式进行.文中另对本属的演化模式及在游仆虫科中所体现的独特性做了讨论. 相似文献
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《中国海洋大学学报(自然科学版)》2016,(12)
有关研究证实,游仆类的银线系在超微结构水平上对应了由微管束构成的网络骨架结构,关于其在纤毛虫细胞分裂过程中的发生模式鲜有报道。本工作应用银浸染色法和扫描电镜术,以扇形游仆虫(Euplotes vannus)、镰游仆虫(Euplotes harpa)和包囊游仆虫(Euplotes encysticus)为代表,研究了游仆类纤毛虫3种类型皮层银线系的形态发生过程。研究表明,游仆虫3种类型银线系的形态发生过程呈现基本相同的模式:该3种纤毛虫新银线网在棘毛原基基体周围发生,据此推测口围带小膜、棘毛基体复合单元和背触毛基体单元不仅对相应纤毛器结构行使微管组织中心作用,也可能对相应皮层区银线网的发生具有定位和组织中心的作用;围绕在基体左侧的银线网先于右侧开始发育,据此推测银线系的分化可能也具有方向性;腹面银线系发生中离新结构发生区近的老结构先瓦解,由此使新结构不断延伸发展,据此推测老银线网对新结构的形成可能起到诱导及定向作用;背面银线系发生中在每一背触毛列的中部范围相邻2列新背触毛间的老银线网消失,背触毛左、右两侧的新银线网会合形成新银线网,并且前仔虫前半部分和后仔虫后半部分的老银线网保留下来共同组成新细胞的背面银线网,由此表明,其老银线网参与了新结构的组成并对新结构的形成具有物质贡献。 相似文献
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报道采自南海碣石水域(22°48′N,115°53′E)的一种海洋牛伪角毛虫—— 红色伪角毛虫Pseudokeronopsis rubra,利用蛋白银技术对其形态学及表膜下纤毛系进行了揭示,并与本种的其它种群做了比较研究。结果表明,本种具该科及属的典型特征,与种内其它种群有较大的不同。虫体长椭圆型,淡粉红色,活体长约(165-230)μm×(54-90)μm,表膜薄,高度柔软可曲;具球形,沿腹面棘毛、背触毛成纵列,并聚集成“簇状”的色素颗粒;口旁小膜带由62-88片小膜组成;具中腹棘毛28-38对;左、右缘棘毛各一列,末端不汇合;横棘毛5-8根,背触毛6-7列,无尾棘毛;大核数目众多,小核3-5枚。并给出采自南海碣石水域红色伪角毛虫活体的光学显微镜及制片后的照片,以期为该物种的鉴定工作提供可靠依据。 相似文献
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利用活体观察、蛋白银染色技术对淡水腹毛目纤毛虫—锈色尖毛虫 (Oxytricha ferrug-inea Stein,185 9)的青岛种群之活体形态学及纤毛图式做了研究。其特征如下 :虫体浅黄褐色 ;表膜下颗粒为铁锈色 ,聚合成组并作纵向不规则排列。口围带平均小膜数为 35。额、腹、横棘毛为典型8∶ 5∶ 5方式排布 ;尾棘毛恒为 1根。背触毛 5列 ,其中 4列完整 ,1列不完整。伸缩泡位于体左侧前1/ 3处 ,具两根收集管。与相近种比较表明 ,O.ferruginea与前人所报道的另一淡水种 O.aerugi-nosa极可能是同一种 ,因此本文建议将两者合并。 相似文献
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采用组织切片和显微观察方法,对孵化后１～３０ｄ的真鲷（Ｐａｇｒｕｓｍａｊｏｒ）仔稚鱼鳔的发育与分化发育进行了研究。结果表明：孵化后１～２ｄ的仔鱼,开始在消化道的前端背部出现鳔原基,接着出现导气管、鳔腔、气腺和迷网,而后鳔囊开始充气。到孵化后２０～３０ｄ,鱼鳔分化发育基本稳定。真鲷仔鱼鳔器官的分化发育早期大致可以分为两个阶段：一是鳔腔扩大阶段,约在仔鱼孵化后的３～４ｄ,此阶段的发育是非功能性的;二是鳔囊充气阶段,大约在孵化后９～１０ｄ左右出现,形成一个缓慢向前方伸展的椭圆形鳔囊,此阶段鳔的发育是功能性的。此时鳔器官的发育好坏对真鲷仔鱼的生理、生态影响很大,反映在成活率的高低方面显得非常明显。真鲷鳔器官的分化发育在仔稚鱼期基本完成。 相似文献
11.
海上大直径钢管桩打桩过程中,桩周土体受到强烈扰动而发生强度弱化,掌握桩周土体强度弱化规律对于准确预测打桩过程、保证工程安全具有重要意义。为研究土体强度弱化规律,开展了环剪试验模拟打桩对桩周土体的扰动,测试土体强度随剪切速率的变化规律,建立了描述土体强度弱化规律的拟合公式,引入到打桩分析软件中。研究结果表明：土体的强度折减程度不仅与土体本身的性质有关还受到土体的埋深和剪切速率的影响,埋深越深土体强度折减程度越低,剪切速率越高土体强度折减越高,在打桩分析中可采用这里推荐的线性折减方法来模拟不同深度处土体强度的折减规律。 相似文献
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Phylogenetic diversity and phenotypic characterization of cultivable bacterioplankton isolated from polar oceans 总被引：1，自引：0，他引：1
A set of 27 marine planktonic bacteria isolated from the polar regions was characterized by 16S rDNA sequencing and physiological and biochemical testing. More than half of these bacteria were positive for caseinase, gelatinase and 13-glucosidase, and could utilize glucose, maltose or malic acid as carbon source for cell growth. Twelve isolates expressed nitrate reduction activities. Except for one antarctic isolate BSwlO175 belonging to Actinobacteria phylum, these isolates were classified as γ-Proteobacteria, suggesting that γ-Proteobacteria dominated in cultivable marine bacterioplankton at both poles. Genus Pseudoalteromonas was the predominant group in the Chukchi Sea and the Bering Sea, and genus ShewaneUa dominated in cultivable bacterioplankton in the Prydz Bay. With sequence similarities above 97%, genus Psychrobacter was found at both poles. These 27 isolates were psychrotolerant, and significant 16S rDNA sequence similarities were found not only between arctic and antarctic marine bacteria （ 〉 99% ）, but also between polar marine bacteria and bacteria from other aquatic environments （ ≥ 98.8% ）, including temperate ocean, deep sea, pond and lake, suggesting that in the polar oceans less temperature-sensitive bacteria may be cosmopolitan and have a bipolar, even global, distribution at the species level. 相似文献
15.
Sediment properties, such as water content and density, have been used to estimate the dry and wet weights, as well as the volume of sediment recovered and discharged, during benthic impact experiments conducted in the Pacific and Indian Oceans. The estimates show that the weights of dry (355-1332 t) and wet sediment (1651-4888 t) recovered during the experiments, are not only a function of the total duration and distance covered during the experiment, but also depend on water content and density of the sediment. Estimation of dry sediment and its volumetric ratio in the discharge, are key parameters for calculating the discharged volume. The estimated volume of wet sediment recovered (1427-4049 m 3 ) as well as discharged (2693-6951 m 3 ) during the experiments, provide important inputs to evaluate the sediment resettlement and migration. Using these estimates, the average depth of excavation on the seafloor, can also been calculated. However, the stages of sediment recovery and discharge are expressed differently in some of the experiments. In order to standardize these, different stages have been identified, and definitions of certain terms have been suggested, for use in the future. The methods of calculating different properties, as well as weight and volume of discharged sediment are described in the paper for use in other applications concerning deep-sea discharges. 相似文献
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A vertically integrated model has been used to study the tidal circulation and currents in the Gulf of Kachchh along the west coast of India. The model is fully nonlinear and uses a semiexplicit finite difference scheme to solve the basic hydrodynamic equations on a staggered grid. The model is forced by prescribing the tides along the open boundary of the model domain. The flow is simulated both with and without the presence of the proposed tidal barrage across the Hansthal Creek in the Gulf of Kachchh. The results show a considerable change in the behavior of the tidal flow in the presence of the barrage. 相似文献
17.
利用中国GF-3卫星SAR和HY-2A卫星微波散射计的首次台风联合定量观测 总被引：4，自引：0，他引：4
<正>The typhoon,as a mature tropical cyclone that develops in the western part of the North Pacific Ocean with high wind speed and heavy rainfall,is one of the most lethal and costly of natural disasters for the densely populated countries of East Asia.It can be easily detected by space-borne sensors operated at microwave,visible or infrared bands(Liu et al.,2014).Synthetic Aperture Radar(SAR)is 相似文献
18.
G. Parthiban 《Marine Georesources & Geotechnology》2000,18(3):223-235
Particle fluxes were measured 7 m above the sea bottom during the predisturbance, disturbance, and postdisturbance periods by using time series sediment traps attached to seven deep-sea moorings deployed in the INDEX experiment site in the Central Indian Basin. The predisturbance particle fluxes varied between 22.3 to 55.1 mg m -2 day -1 . Increased and variable particle fluxes were recorded by the sediment traps during the disturbance period. The increase observed was 0.5 to 4 times more than the background predisturbance fluxes. The increases in particle fluxes (~4 times) recorded by the sediment trap located in the southwestern direction (DMS-1) were the greatest, which could be the result of preferential movement of resuspended particles generated during the deep-sea benthic disturbance along the general current direction prevailing in this area during the experimental period. Also, the traps located closer to the disturbance area recorded greater fluxes than did the traps far away, across the Deep Sea Sediment Resuspension System path. This variability in recorded particle fluxes by the traps around the disturbance area clearly indicates that physical characteristics such as grain size and density of the resuspended particles produced during the disturbance had an important effect on particle movement. The postdisturbance measurements during ~5 days showed a reduction in particle fluxes of ~50%, indicating rapid particle settlement. 相似文献
19.
Derek V. Ellis 《Marine Georesources & Geotechnology》2001,19(1):51-63
This article reviews information recently available from existing marine and coastal mining for responses to environmental issues affecting marine mining at different depths. It is particularly but not exclusively concerned with those issues affecting seabed biodiversity impact and recovery. Much information has been gathered in the past 10 years from shallow mining operations for construction aggregate, diamonds, and gold, from coastal mines discharging tailings to shallow and deep water, and from experimental deep mining tests. The responses to issues identified are summarized in a series of eight tables intended to facilitate site-specific consideration. Since impacts can spread widely in the surface mixing layer SML, and can affect the biologically productive euphotic zone, the main issues considered arise from the depth of mining relative to the SML of the sea. Where mining is below the SML, the issue is whether it is environmentally better to bring the extraction products to the surface vessel for processing (and waste discharge), or to process the extraction products as much as possible on the seabed. Responses to the issues need to be sitespecific, and dependent on adequate preoperational environmental impact and recovery prediction. For deep tailings disposal from a surface vessel, there are four important environmental unknowns: (1) the possible growth of "marine snow" (bacterial flocs) utilizing the enormous quantities of fine tailings particles (hundreds or thousands of metric tons per day) as nuclei for growth, (2) the possibility that local keystone plankton and nekton species may migrate diurnally down to and beyond the depth of deep discharge and hence be subjected to tailings impact at depth, (3) the burrow-up capability of deep benthos and their ability to survive high rates of tailings deposition, and (4) the pattern and rate of dispersion of a tailings density current through the deep water column from discharge point to seabed. Actions to obtain relevant information in general and site-specifically are suggested. 相似文献