首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到19条相似文献,搜索用时 156 毫秒
1.
两种黄海潮间带海绵的元素与氨基酸成分分析   总被引:1,自引:1,他引:0  
应用能量色散X射线荧光光谱(EDXRF)分析了黄海潮间带繁茂膜海绵(Hymeniacidon perleve)和肾指海绵(Reniochalina sp.)的无机元素,其中硅是两种海绵中最多的无机元素。繁茂膜海绵较肾指海绵的锌含量高,参照文献数据推测这可能是该属海绵的特性。测定了2种海绵的含水量,有机碳、氮、氢元素和氯基酸在海绵干质量中的比例。分析了繁茂膜海绵在2002年8月到11月中主要无机元素的变化,发现繁茂膜海绵中的硅含量在降低。繁茂膜海绵的氨基酸总量远高于肾指海绵,2种海绵中含量较高的氨基酸是甘氨酸、谷氨酸、天冬氨酸、亮氨酸、缬氨酸、赖氨酸等。元素与氨基酸分析将对海绵细胞培养基开发有帮助。  相似文献   

2.
利用组织学和超微结构方法,对大连黄海海域的繁茂膜海绵(Hymeniacidonsp.)在自然海域的生长和生殖过程的组织学特征进行了近2a的观察。结果表明:繁茂膜海绵的生长呈现周期性变化,分为4个阶段:复苏期(3~5月)、生长旺盛期(6~8月)、衰退期(9~11月)和冬眠期(12月—次年2月)。繁茂膜海绵可以通过有性生殖进行繁殖,显著生殖期为8~10月,期间可以观察到卵细胞、精细胞囊、胚胎和幼虫。研究结果为深入研究繁茂膜海绵自然生长生殖特点,进而实现海绵组织块的继代培养和人工育种提供实验依据。  相似文献   

3.
通过模拟大气CO_2浓度升高,研究其对海绵滤食细菌功能的影响。在模拟大气CO_2浓度升高生态系统中,探究了大气CO_2浓度387、500、750和1 000mmol/mol环境下繁茂膜海绵(Hymeniacidon perlevis)滤食灭菌海水中大肠杆菌(Escherichia coli AS 1.1017)和灿烂弧菌(Vibrio splendidus)的能力。结果表明:在24 h实验期间,模拟大气CO_2从目前约387mmol/mol升高至500mmol/mol,繁茂膜海绵滤食大肠杆菌和灿烂弧菌效率提高了。当模拟大气CO_2 750mmol/mol时,繁茂膜海绵滤食海水中大肠杆菌和灿烂弧菌功能都下降了,说明繁茂膜海绵已经受到大气较高浓度CO_2损害。模拟大气CO_2为1 000mmol/mol时,繁茂膜海绵基本丧失了滤食海水中大肠杆菌和灿烂弧菌的功能。上述结果可为了解大气CO_2浓度对近岸海洋生态系统的影响提供科学依据。  相似文献   

4.
通过分析海绵清除大肠杆菌的过程,研究海绵净化细菌的机理。作者利用荧光显微镜和激光共聚焦显微镜观测等手段,监测和分析了绿色荧光大肠杆菌(Escherichia coli)在繁茂膜海绵(Hymeniacidon perlevis)体内、体外水环境中数量变化过程。在1 L含有3×107个/m L绿色荧光大肠杆菌的海水中放入鲜重(1.02±0.11)g的繁茂膜海绵24块,处理7 h,海水中的荧光大肠杆菌数量逐渐降低;而海绵体内荧光大肠杆菌数量在2 h时内逐渐增多,之后的2 h趋于稳定,4 h以后开始逐渐减少。水体中大肠杆菌不仅进入海绵体内,而且进入海绵细胞内。含有荧光大肠杆菌的海绵块转入无菌海水中后,海绵体内及细胞中大肠杆菌逐渐消失,而且大肠杆菌没有被释放到环境海水中。分析表明,繁茂膜海绵能够以摄食的方式净化水环境中的大肠杆菌。  相似文献   

5.
繁茂膜海绵原细胞形态学识别及分离纯化特点   总被引:1,自引:0,他引:1       下载免费PDF全文
利用透射电镜对繁茂膜海绵(Hymeniacdidon pelevis)的原细胞进行观察,确定其超微结构特点为:细胞核大,核仁显著.细胞质中富含线粒体和处于不同消化阶段的溶酶体.对繁茂膜海绵本体和芽体旺盛分生组织进行观察,发现原细胞在不同组织中形态多变.同时针对不同部位分别进行组织离散和原细胞富集,结果证明不同来源的富集...  相似文献   

6.
以黄海海域的繁茂膜海绵(Hymeniacidon perleve)为研究对象,考察了海绵细胞培养中细胞团的形成过程。细胞在培养24h后贴壁聚集,有类似胶原物质分泌。培养第5天形成的细胞团,中心致密,边缘有平滑的表皮结构。为控制培养中的微生物污染,比较了6种抗生素的使用效果,其中庆大霉素有较好的抑菌效果且不影响细胞成团,而两性霉素B对细胞的贴壁和成团有不利影响。  相似文献   

7.
迄今从各种生物体中发现的氨基酸已有180多种 ,但是参与蛋白质组成的常见氨基酸 (或称基本氨基酸 )只有20种。这20种氨基酸称为蛋白质氨基酸。除甘氨酸外 ,都有互称镜象的对映体D和L型。1924年化学家K.Frendenberg将L 氨基酸称为“天然” ,而D 氨基酸就成了“非天然”。很多年来 ,人们一直认为在生命物质中只存在天然L 氨基酸。随着分析方法的发展 ,人们对氨基酸的研究更加深入 ,不断在海洋动物、陆生动物、脊椎和无脊椎动物、藻类、种子植物以及人体中发现了各种D 氨基酸。虽然在生物科学中L 氨基酸是很重要的 ,但人们渐渐地认识到游离…  相似文献   

8.
病毒囊膜是包膜病毒除核衣壳外的另一主要成分。它主要由多种蛋白质构成,称为膜蛋白,膜蛋白以单聚体,二聚体,三聚体,甚至更多的聚合体的形式存在,具有中和抗体,与靶细胞受体结合,凝集红细胞,诱导细胞融合等多种功能,膜蛋白可采用将其基因整合入载体,并在昆虫细胞,哺乳细胞或细菌中获得体外表达,膜蛋白可在去污剂的作用下形成蛋白质-脂-去污剂的复合物而被溶解,其中去污剂的临界微团浓度,亲水物-亲脂物平衡值,荷电、紫外穿透性等是选择合适去污剂的主要参考因子,溶解后的膜蛋白多利用聚丙烯酰胺凝胶电泳、凝胶过滤层析,离子交换层析,亲和层析,高效液相层析等技术并结合梯度离心;分级沉淀等进行分离、纯化。  相似文献   

9.
福建长乐海域近江蛏营养成分分析与品质评价   总被引:1,自引:0,他引:1  
测试分析了福建长乐海域近江蛏(Sinonovacula rivularis)新鲜软体部的营养成分,并与部分经济蛏类进行比较.结果表明,近江蛏软体部的出肉率为48.1%±6.0%,软体部中的水分、蛋白质、脂肪和灰分质量分数分别为84.9%、9.4%、1.6%、1.4%.近江蛏软体部中含有人体所需的17种氨基酸(除色氨酸未测外),氨基酸含量为74.0mg/g,必需氨基酸(C EAA)占氨基酸总量(C TAA)的37.2%,鲜味氨基酸(C FAA)占氨基酸总量(C TAA)的49.6%,17种氨基酸中谷氨酸(Glu)含量最高.根据AAS和CS评价,第一限制性氨基酸为苯丙氨酸(Phe).赖氨酸(lys)的AAS评分最高,超过FAO/WHO模式和鸡蛋蛋白质.软体部的必需氨基酸指数(I EAA)为100.06,必需氨基酸(EAA)与非必需氨基酸(NEAA)的比值(C EAA/C NEAA)为59.1%,必需氨基酸(EAA)与氨基酸总量(CTAA)的比值(C EAA/C TAA)为37.2%,构成比例均接近FAO/WHO提出的优质蛋白质标准.近江蛏软体部和足部的多不饱和脂肪酸(PUFA)含量高于饱和脂肪酸(SFA)的含量,多不饱和脂肪酸(PUFA)中又以高度不饱和脂肪酸(HUFA)的组成为主,并且n-3PUFA的含量明显高于n-6PUFA的含量;DHA和EPA含量丰富,软体部的EPA与DHA质量分数分别为4.4%、3.0%,EPA含量高于DHA的含量,两者之和分别占多不饱和脂肪酸(PUFA)的80.4%、81.1%.近江蛏足部的PUFA含量、Cn-3/Cn-6比值以及C EPA+C DHA之和均高于软体部.近江蛏软体部中合有丰富的矿物质元素,尤其是Zn、Se含量十分丰富.表明近江蛏肌肉具有较高的营养价值.建议对近江蛏等底栖性贝类在食用前进行蓄养净化,并对其进行消费安全和人体健康风险评价.  相似文献   

10.
两种微藻凝集素对几种不同类型细胞的凝集作用   总被引:1,自引:0,他引:1  
经离子交换和分子筛层析从紫球藻(Porphyridium cruentum)和海水小球藻(Chlorella sp.)中分离纯化得到2种凝集素,研究它们对几种不同类型细胞即动物和人血红细胞、海洋和淡水微藻、细菌和真菌的凝集活性。研究结果表明,2种微藻凝集素对它们当中一些类型的细胞或种类具有不同程度的凝集活性,其中对水生聚胞藻(Synechocystis aquetilis)的凝集活性最强,最低质量浓度只需0.0313g/L。  相似文献   

11.
The parrotfish Sparisoma viride often grazes live coral from edges undermined by the Caribbean encrusting and excavating sponge Cliona tenuis. To test whether parrotfish biting action has an effect on the dynamics of the sponge–coral interaction, we manipulated access of parrotfishes to the sponge–coral border in two species of massive corals. When parrotfish had access to the border, C. tenuis advanced significantly more slowly into the coral Siderastrea siderea than into the coral Diploria strigosa. When fish bites were prevented, sponge spread into S. siderea was further slowed down but remained the same for D. strigosa. Additionally, a thinner layer of the outer coral skeleton was removed by bioerosion when fish were excluded, a condition more pronounced in D. strigosa than in S. siderea. Thus, the speed of sponge‐spread and the extent of bioerosion by parrotfish was coral species‐dependent. It is hypothesized that coral skeleton architecture is the main variable associated with such dependency. Cliona tenuis spread is slow when undermining live S. siderea owing to the coral’s compact skeleton. The coral’s smooth and hard surface promotes a wide and shallow parrotfish bite morphology, which allows the sponge to overgrow the denuded area and thus advance slightly faster. On the less compact skeleton of the brain coral, D. strigosa, sponge spread is more rapid. This coral’s rather uneven surface sustains narrower and deeper parrotfish bites which do not facilitate the already fast sponge progress. Parrotfish corallivory thus acts synergistically with C. tenuis to further harm corals whose skeletal architecture slows sponge lateral spread. In addition, C. tenuis also appears to mediate the predator–prey fish–coral interaction by attracting parrotfish biting.  相似文献   

12.
Sven Zea 《Marine Ecology》2011,32(2):162-173
The Caribbean sponge Cliona delitrix is among the strongest reef space competitors; it is able to overpower entire coral heads by undermining coral polyps. It has become abundant in reefs exposed to organic pollution, such as San Andrés Island, Colombia, SW Caribbean. Forty‐four sponge‐colonized coral colonies were followed‐up for 13 months to establish the circumstances and the speed at which this sponge advances laterally into live coral tissue and the coral tissue retreats. Cliona delitrix presence and abundance was recorded at seven stations to interpret current reef space and coral species colonization trends. The spread of C. delitrix on a coral colony was preceded by a band of dead coral a few millimeters to several centimeters wide. However, the sponge was directly responsible for coral death only when live coral tissue was within about 2 cm distance; coral death became sponge advance‐independent at greater distances, being indirectly dependent on other conditions that tend to accelerate its retreat. Cliona delitrix advanced fastest into recently killed clean coral calices; however, sponge spread slowed down when these became colonized by algae. The lateral advance of C. delitrix was slower than other Cliona spp. encrusting excavating sponges, probably owing to the greater depth of its excavation into the substratum. Cliona delitrix prefers elevated portions of massive corals, apparently settling on recently dead areas. It currently inhabits 6–9% of colonies in reefs bordering San Andrés. It was found more frequently in Siderastrea siderea (the most abundant local massive coral), which is apparently more susceptible to tissue mortality than other corals. Current massive coral mortality caused by C. delitrix could initially change the relative proportions of coral species and in the long‐term favor foliose and branching corals.  相似文献   

13.
Quantitative trends in sponge ecology research   总被引:2,自引:1,他引:1  
Abstract It is almost dogmatic that sponges are one of the most relevant groups in benthic marine communities, a statement generally based upon their diversity and abundance in natural communities. But beyond their conspicuousness, do we really know the role that sponges play in nature? Using a series of productivity indicators, this review evaluates the relevance of sponge research to the general scientific community, particularly the contribution of sponge ecology to the broader science of ecology. The relevance of sponge research ranked second out of eight taxonomic groups. Ecology accounted for most of the sponge research output but it ranked poorly compared to the relative importance of the ecological literature in the remaining taxonomic groups. Sponge ecology focused primarily on the species level of organization even though the relevance of these studies fell well below expected. This review suggests that the ecological relevance of sponges is insufficiently supported by ecological data and would benefit from better scientific support. Sponge ecology has the opportunity to contribute to the broader science of ecology in numerous topics where sponge research may be particularly relevant. Broader ecological contributions will help verify the ecological relevance that the great diversity and abundance of sponges suggest.  相似文献   

14.
Caribbean sponge species typical of coral reefs are generally inhibited from living in seagrass meadows by their vulnerability to predation by the large starfish Oreaster reticulatus (Linnaeus 1758). Although readily consumed by Oreaster , the conspicuous coral reef sponge species Lissodendoryx colombiensis Zea & van Soest, 1986 has expanded its habitat distribution to include a seagrass ( Thalassia testudinum Banks ex König, 1805) meadow in Belize, where individuals grow to volumes of nearly 7 l. By simple observation, L. colombiensis appears to be an inferior competitor in this system, because portions of many individuals are overgrown by seagrass sponge species. However, experimentally clustering seagrass sponges around L. colombiensis individuals deterred starfish from feeding on them, suggesting an advantage to being overgrown. Sizes of individual L. colombiensis can fluctuate widely over short time intervals, reflecting both a relatively fast growth rate and the high rate at which starfish consume this species. At the population level these fluctuations are not evident, as losses of L. colombiensis due to Oreaster are balanced by a combination of efficient recruitment, rapid regeneration and growth, and protection of portions of many individuals by the overgrowth of seagrass sponge species that are unpalatable to Oreaster . In turn, the seagrass sponges acquire stable perches on L. colombiensis individuals in this sediment-dominated habitat. Community ecology theory relating to diversity patterns in sessile organisms has focused on competition between space-requiring neighbors as the underlying process that inevitably decreases diversity unless curtailed. Sponges, with their propensity for engaging in beneficial interactions with neighbors, demand expansion of the theory to acknowledge how collaboration can increase abundance and species diversity within a community.  相似文献   

15.
Sponges are important components of coral reef fauna, although little is known of their temporal dynamics. Sponges dominate the lagoon system at Palmyra Atoll in the Central Pacific, which may not be its natural state. Here we examined the temporal variability and recruitment rates of these sponge assemblages to determine if they are stable and examined the evidence that a recent transition has occurred from a coral‐ to sponge‐dominated system. We found 24 sponge species in permanent quadrats in the lagoon between 2009 and 2011, and 11 species on our recruitment panels. The sponge assemblage composition and abundance did not vary significantly between years and appear stable. Many sponge recruits were found in both years that the panels were examined although higher rates were recorded in the second year of the study. While it seems very possible that a change to a sponge‐dominated lagoon is associated with declining environmental quality at Palmyra as a result of modifications over 70 years ago, without pre‐modification data on reef assemblage composition this remains speculative. Our observations of short‐term temporal stability in the sponge assemblages at Palmyra highlight the potential for sponge‐dominated reef states to be maintained in degraded reef environments that are seemingly unsuitable for coral survival.  相似文献   

16.
Coral reefs are increasingly threatened by anthropogenic disturbances and consequently coral cover and complexity are declining globally. However, bioeroding sponges, which are the principal agents of internal bioerosion on many coral reefs, are increasing in abundance on some degraded reefs, tipping them towards net carbonate erosion. The aim of this study was to identify the environmental factors that drive the erosion rates of the common Indonesian bioeroding sponge Spheciospongia cf. vagabunda . Sponge explants were attached to limestone blocks and deployed across seven sites characterized by different environmental conditions in the UNESCO Wakatobi Biosphere Reserve in Indonesia. Average bioerosion rates were 12.0 kg m?2 sponge tissue year?1 (±0.87 SE ), and were negatively correlated with depth of settled sediment (r  = ?.717, p  < .01) and showed weak positive correlation with water movement (r  = .485, p  = .012). Our results suggest that although bioeroding sponges may generally benefit from coral reef degradation, bioerosion rates may be reduced on reefs that are impacted by high sedimentation, which is a common regional stressor in the South‐East Asian Indo‐Pacific.  相似文献   

17.
Biogenic silica (BSi) in marine sediments is an important indicator of siliceous organism distributions and paleoproductivities. Organisms that have BSi skeletons include diatoms, silicoflagellates, radiolarians and sponges. This study presents, for the first time, the distribution of biogenic siliceous fragments in shallow water sediments around Taiwan and the Sunda Shelf, which belong to this rarely studied region of the South China Sea (SCS). Thirty-one surface sediment samples were collected from intertidal to depths of 1,100?m. Only sponge spicules were found in this study and the abundance varied in the range of 3?C7,910?n?g?1 sediment. Combining previous studies with ours, from shallow to deep, it was observed that BSi composition in the surface sediment of this area changed from sponge spicules in the Sunda Shelf, followed by sponge spicules and radiolarians in the southwestern SCS, to sponge spicules, radiolarians and diatoms in the southern SCS. Based on this study, the abundance of sponge spicules correlated positively and negatively with water depth and sediment grain size when coral reef sites were excluded. The low spicule abundance in shallow waters may have resulted from local current conditions and the dilution effect through riverine input of terrestrial sediment. Other possible explanations for the varying spicule abundance among sites are the difference in local fauna, such as coral reefs which usually have high diversity and abundance of sponges. The findings provide additional information on the process of recent BSi deposition which may help future studies in sedimentology, paleogeography and paleoenvironments.  相似文献   

18.
《Ocean Modelling》2008,20(3):270-292
The problem of computing within a limited domain surrounded by open boundaries is discussed within the context of the shallow-water wave equations by comparing three different treatments, all of which surround the domain by absorbing zones intended to prevent reflections of outgoing waves. The first, which has attracted a lot of attention for use in electromagnetic and aeroacoustic applications, is intended to prevent all reflections. However, it has not yet been developed to handle the second important requirement of open boundaries, namely the ability to pass information about external conditions into the domain of interest. The other two treatments, which absorb differences from a specified external solution, allow information to pass through the open boundary in both directions. One, based on the flow relaxation scheme of [Martinsen, E.A., Engedahl, H., 1987. Implementation and testing of a lateral boundary scheme as an open-boundary condition in a barotropic ocean model. Coastal Eng. 11, 603–627] and termed here the “simple sponge,” relaxes all fields toward their external counterparts. The other, a simplification and generalization of the perfectly matched layer, referred to here as the “pretty good sponge,” avoids absorbing the component of momentum parallel to the open boundary. Comparisons for a case that is dominated by outgoing waves shows the pretty good sponge to perform essentially as well as the perfectly matched layer and better than the simple sponge. In comparisons for a geostrophically balanced eddy passing through open boundaries, the pretty good sponge out-performed the simple sponge when the only external information available was about the advecting flow, but when information about the nature of the eddy in the sponge zones was also available, the simple sponge performed better. For the case of an equatorial soliton passing through the boundary and no information provided about its nature outside the open domain, again the pretty good sponge performed better. Proving useful for situations governed by nonlinear equations forced by external conditions and being easy to implement, the pretty good sponge should be considered for use with existing limited-area ocean models.  相似文献   

19.
Sponges are one of the principal agents of bioerosion and sediment production in coral reefs. They generate small carbonate chips that can be found in the sediments, and we investigated whether these could provide a means for assessment of bioerosion applicable to reef monitoring. We tested this hypothesis on samples from 12 Mexican coral reefs distributed along the Pacific coast, where boring sponges were particularly abundant, and quantified the amount of chips in samples of superficial sediment in three grain‐size fractions: fine (<44 μm), medium (44–210 μm) and coarse (>210 μm). The grain‐size distribution varied among reefs, with the majority of the sediment of most reefs being composed of coarse sands, and the medium and fine fractions dominating only at La Entrega and Playa Blanca. All the reefs presented clear evidence of bioerosion by sponges, with the characteristic chips present in the sediment, although at most sites the percentage of chips was very low (from 1% to 3% of the total sediment). Only at La Entrega and Playa Blanca did they constitute a significant fraction of the total sediment (18% and 16%, respectively). While not statistically significant, there was an interesting trend between sponge chips versus sponge abundance that suggests that quantification of the chips in the sediment could be used as a proxy for sponge erosion of the entire community, which cannot be estimated in by laboratory experiments. However, while this methodology could provide an integrated approach to monitor sponge bioerosion, more studies are necessary due to the influence of environmental factors on the transport and deposition of these chips.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号