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日本新糠虾消化系统组织学研究 总被引：2，自引：0，他引：2
对日本新糠虾消化系统进行了组织学观察。日本新糠虾消化道可分为三大部分：前肠、中肠和后肠,组织结构由内向外均分为粘膜层、粘膜下层、肌层和外膜4层。其中,前肠由口、食道、胃等组成;中肠有中肠前盲囊和中肠腺等附属结构。中肠腺腺管上皮细胞由4种类型细胞组成,分别称为胚细胞（E细胞）、纤维细胞（F细胞）、吸收细胞（R细胞）和泡状细胞（B细胞）。 相似文献
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三疣梭子蟹幼体中肠腺发育的组织学和细胞学研究 总被引：3，自引：0，他引：3
将蚤状幼体 I期 (Z1)到仔蟹共六期三疣梭子蟹幼体固定 ,作横切、纵切和平切的连续切片 ,观察中肠腺的解剖学及组织学特征 ,并研究其细胞的超微结构。三疣梭子蟹的中肠腺起自前、中肠交界处 ,分左右两部分 ,每部分三叶 ,由总管与幽门胃和中肠相通 ,中肠腺管的长度和数量随幼体发育而增加。管壁的上皮细胞在各期幼体均可分为四种类型 :E-细胞 (胚细胞 )、F-细胞 (纤维细胞 )、R-细胞 (吸收细胞 )和 B-细胞 (分泌细胞 ) ,它们在中肠腺管中的分布位置和功能各有不同。 相似文献
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于1990年6月—7月,用南京丰年虫无节幼体作饵料,在培养皿中对日本沼虾溞状幼体作单只培养,测定了各期溞状幼体(Z_1—Z_9)的日摄食量及总摄食量,并观察了饥饿条件下溞状幼体的生长与成活情况。实验表明,Z_1,Z_2阶段,不投饵并不影响其变态和成活率;但自Z_1孵出连续饥饿5d后,即使投饵,溞状幼体也不能正常蜕壳和成活;Z_3阶段是摄食量增加的突变期。南京丰年虫无节幼体是日本沼虾幼体的适口饵料,P_1育成率可达70％。 相似文献
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波纹龙虾消化系统光镜和扫描电镜的观察 总被引：2，自引：0，他引：2
对波纹龙虾Panulirus homaru消化系统进行了光镜和扫描电镜的观察.结果表明,波纹龙虾的消化系统由消化道和消化腺组成.消化道的组织结构由粘膜层、结缔组织层,肌层和外膜层构成;粘膜层由大量单层柱状上皮细胞和基膜构成.除中肠以外,其余各部分管壁均有几丁质.食道、中肠和后肠壁结缔组织中分布有腺体.胃和食道等的肌层为横纹肌.消化腺主要是肝胰腺,由无数的肝小管组成,肝小管均由位于基膜上的一层细胞构成.这些细胞有分泌细胞、储存细胞、吸收细胞和胚细胞四种类型.在扫描电镜下,消化道各段黏膜上皮表面均形成大小不一、具有形态各异的多级皱褶,以肠道中的纵褶及其上的横褶最为明显.除中肠和肠球外整个消化道均有较发达的纤毛丛.中肠和肠球中的微绒毛主要作用是增加吸收面积. 相似文献
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鱼类消化系统的组织结构特点与食性密切相关。为了探究岛礁性鱼类黑魢的消化生理特点, 文章以黑鱾(Girella leonina)为研究对象, 采用苏木精-伊红(H.E)染色法研究其消化系统的组织结构特点, 探讨其组织结构特点与食性、环境适应性之间的相关性。结果显示: 1) 食道向腔内形成纵向6个粗大皱褶, 该皱褶具明显横纹肌, 扩张性较强, 黏膜上皮间分布着黏液细胞, 呈锥形; 2) 黑鱾为“V”形胃, 可分为贲门部、胃体部和幽门部3个部分, 胃腺横切面为圆形, 管腔由数个腺细胞围成, 胃肌层平滑肌层极厚, 为内环肌层外纵肌层结构, 其中胃体部固有层处胃腺最为发达, 胃黏膜形成许多皱襞, 幽门胃具多级分枝皱褶; 3) 幽门处分布有150多条分枝状盲囊, 盲囊腔内充满黏膜褶, 黏膜上皮由单层柱状上皮细胞组成, 不具有杯状细胞; 4) 肝脏分为左右两叶, 组织结构呈现出一般硬骨鱼类的共性, 肝细胞体积较大, 呈多边形, 大小约为30μm; 5) 肠道具有4个肠曲, 比肠长值约为1.52±0.06, 介于植食性和肉食性鱼类之间, 整个肠道均有大量杯状细胞分布, 肠道内具发达的小肠绒毛凸起, 绒毛基部上皮向固有层内陷形成肠腺, 腺体开口于相邻绒毛基部之间, 前中肠作为主要消化吸收场所, 其绒毛数量和高度要大于后肠。文章研究了黑鱾消化系统组织学特征与其消化、吸收的关系, 认为黑鱾消化系统具备典型杂食性鱼类消化系统的特征。 相似文献
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鱼类消化系统的组织结构特点与食性密切相关。为了探究岛礁性鱼类黑魢的消化生理特点,文章以黑鱾(Girella leonina)为研究对象,采用苏木精-伊红(H.E)染色法研究其消化系统的组织结构特点,探讨其组织结构特点与食性、环境适应性之间的相关性。结果显示:1)食道向腔内形成纵向6个粗大皱褶,该皱褶具明显横纹肌,扩张性较强,黏膜上皮间分布着黏液细胞,呈锥形;2)黑鱾为"V"形胃,可分为贲门部、胃体部和幽门部3个部分,胃腺横切面为圆形,管腔由数个腺细胞围成,胃肌层平滑肌层极厚,为内环肌层外纵肌层结构,其中胃体部固有层处胃腺最为发达,胃黏膜形成许多皱襞,幽门胃具多级分枝皱褶;3)幽门处分布有150多条分枝状盲囊,盲囊腔内充满黏膜褶,黏膜上皮由单层柱状上皮细胞组成,不具有杯状细胞;4)肝脏分为左右两叶,组织结构呈现出一般硬骨鱼类的共性,肝细胞体积较大,呈多边形,大小约为30μm;5)肠道具有4个肠曲,比肠长值约为1.52±0.06,介于植食性和肉食性鱼类之间,整个肠道均有大量杯状细胞分布,肠道内具发达的小肠绒毛凸起,绒毛基部上皮向固有层内陷形成肠腺,腺体开口于相邻绒毛基部之间,前中肠作为主要消化吸收场所,其绒毛数量和高度要大于后肠。文章研究了黑鱾消化系统组织学特征与其消化、吸收的关系,认为黑鱾消化系统具备典型杂食性鱼类消化系统的特征。 相似文献
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许氏平鲉消化道的组织化学研究 总被引：2，自引：2，他引：2
运用组化方法对许氏平消化道碱性磷酸酶、酸性磷酸酶、羧酸酯酶和粘液物质进行了定位及半定量研究。发现幽门盲囊和肠上皮细胞顶端胞质和纹状缘具碱性磷酸酶活性 ;胃粘膜上皮细胞核上方胞质、幽门盲囊及肠上皮细胞顶端胞质中检测到酸性磷酸酶活性 ;在胃贲门部和盲囊部、幽门盲囊以及肠的上皮细胞内还检测到羧酸酯酶活性。整个消化道的粘膜层中存在许多粘液细胞。食道上皮含大量酸性粘液细胞 ,胃上皮细胞均含有中性粘液 ,而肠道由前向后中性粘液物质逐渐减少 ,酸性粘液物质逐渐增多。研究结果表明许氏平食道和直肠有润滑和微弱的吸收作用 ,胃有消化脂类和吸收二糖及短链脂肪的功能 ;幽门盲囊有较强的吸收脂类的功能 ;前肠、中肠和后肠有活跃的细胞内消化和吸收功能 相似文献
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岩虫消化管组织学、组织化学和超微结构的初步研究 总被引：1，自引：0，他引：1
运用光学显微镜、透射电镜和组织化学方法初步研究了岩虫（Marphysa sanguinea）消化管的组织结构和消化酶的分布。结果显示：岩虫消化管呈长直管状，可分为口咽腔、食道、肠和后肠。组织化学研究表明食道粘膜层固有层有分泌酸性粘多糖、中性粘多糖和混合粘多糖3种粘液细胞；肠及消化盲囊的上皮细胞游离端及顶部胞质均检测到碱性磷酸酶、酸性磷酸酶和酯酶的活性。透射电镜显示食道粘膜固有层的粘液细胞可分为含低电子密度颗粒、高电子密度颗粒和电子透明颗粒3种。肠和消化盲囊绒毛发达，上皮细胞表面具丰富微绒毛，游离端细胞质中可见酶原颗粒、吞饮小泡、丰富的粗面内质网及溶酶体。肠纤毛沟由纤毛柱状上皮细胞组成，带环状横纹的纤毛小根插入细胞内部，纤毛小根之间散布着丰富的线粒体、溶酶体等结构。 相似文献
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Chandralata Raghukumar G. Sheelu P. A. Loka Bharathi Shanta Nair C. Mohandass 《Marine Georesources & Geotechnology》2001,19(1):1-16
In order to assess the impact of deep-sea mining on the in situ benthic life, we measured the microbial standing stock and concentration of organic nutrients in the deep-sea sediments of the Central Indian Ocean Basin in the Indian pioneer area. Sediments were collected using box core and grab samples during September 1996. The total bacterial numbers ranged from 10 10 -10 11 cells per g -1 dry weight sediment. There was a marginal decrease in the number of bacteria from surface to 30 cm depth, though the subsurface section registered a higher number than did the surface. The highest numbers were encountered at depths of 4-8 cm. The retrievable number of bacteria were two orders less in comparison with the direct total counts of bacteria. An almost homogeneous distribution of bacteria, total organic carbon, living biomass, and lipids throughout the depth of cores indicates active microbial and benthic processes in the deep sea sediments. On the other hand, a uniform distribution of total counts of bacteria, carbohydrates, and total organic carbon in all the cores indicates their stable nature and suggests that they can serve as useful parameters for long-term monitoring of the area after the benthic disturbance. Further studies on temporal variability in this region would not only verify the observed norms of distribution of these variables but would also help to understand restabilization processes after the simulated benthic disturbance. 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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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
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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
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Geoacoustic Inversion via Genetic Algorithm and Its Application to Manganese Sediment Identification
An acoustic inversion method using a wide-band signal and two near field receivers is proposed and applied to multiple layered seabed models including a manganese sediment. The inversion problem can be formulated into a probabilistic model comprised of signals, a forward model, and additive noise. The forward model simulates wide-band signals, such as chirp signals, and is chosen to be the source-waveletconvolution plane wave modeling method. The wavelet matching technique, using weighted least-squares fitting, estimates the sediment sound-speed and thickness on which determination of the possible numerical ranges for a priori uniform distribution is based. The genetic algorithm is applied to a global optimization problem to find a maximum a posteriori solution for determined a priori search space. Here the object function is defined by an L 2 norm of the difference between measured and modeled signals. Not only the marginal pdf but also its statistics are calculated by numerical evaluation of integrals using the samples selected during importance sampling process of the genetic algorithm. 相似文献
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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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The advanced piston corer (APC) has been used by the Ocean Drilling Program since 1985 for recovering soft sediments from the ocean floor. The pullout force measured on extracting the core barrel from the sediment is shown to correlate with the average shear strength of the sediment core measured in the ship's laboratory. A simple rule of thumb is derived relating the shear strength of the sediment to the pullout force. Multiple APC holes at individual sites allow the consistency of the pullout measurements to be assessed. The effects of different operational procedures during APC coring are also explored. Although generally applicable, the correlation between pullout force and laboratory measurements of shear strength breaks down for some APC holes, possibly because of the disturbance of some sediment types during the APC coring process. A better understanding of the physical process of APC coring, and its effect on the properties of the sediment both inside and immediately outside the core barrel, would indicate what confidence can be put on the measurement of pullout force as a way of evaluating the in situ shear strength of deep sea sediments. 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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