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海洋蔓足类在宿主体上常有固定的定着位置。同一个种在不同宿主体上的定着位置亦不相同。龟藤壶是以蔓足朝向宿主前进寸水流流过宿主体表的方向定向(0~°方式)的;薄壳龟藤壶在蟹体上,均以蔓足背向口器形成的水流进行定向;三角藤壶在贻贝壳上以±180°方式定向;薄壳星藤壶和高峰星藤壶在宿主体上以0—±180°方式定向;细板条茗荷在海蛇体上以0—±90°方向定向。在单向流向的码头,鳞笠藤壶、高峰星藤壶以蔓足朝向潮流影响较大的方向定向;在双向流向的海区,鳞笠藤壶、纹藤壶和白脊藤壶以峰板朝上、吻板朝下,与波轴呈约直角方向定向。在开敞性海岸,日本笠藤壶以峰板朝下、吻板朝向波浪冲散后水流下落的方向定向;龟足则在岩缝间以同样方式定向。海洋蔓足类具有对各种形式的水流产生反应的定向机制,据此,可为水文学家和古地理学家提供生物学的依据。 相似文献
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九龙江口硬相潮间带藤壶类动物的群落生态 总被引：1，自引：1，他引：1
福建九龙江口硬相潮间带共有8种藤壶,其中以绿鳞笠藤壶Tetraclita squamosa squamosa,白脊藤壶Balanus albicostatus和泥藤壶Balanus uliginosus为优势种。根据藤壶优势种的分布状况,九龙江口硬相潮间带藤壶群落可分为三种类型:1.日本鳞笠藤壶Tetraclitasquamosa japonica-绿鳞笠藤壶群落;2.白脊藤壶-绿鳞笠藤壶群落;3.泥藤壶-白脊藤壶群落。研究结果还表明,各藤壶群落的附着密度和生物量均随盐度的降低而减少。生物量一般春季较高,夏、秋季较低;附着密度则冬季较高,春季较低。潮汐是影响河口区硬相潮间带藤壶垂直分布的主要因素。 相似文献
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九龙江口红树林上附着动物的生态 总被引：12，自引：2，他引：12
福建九龙江口红树林附着动物７种，白脊藤壶Ｂａｌａｎｕｓ ａｌｂｉｃｏｓｔａｔｕｓ和白条地藤壶Ｅｕｒａｐｈｉａ ｗｉｔｈｅｒｓｉ在数量上占绝对优势，是危害红树的主要附着动物。附着动物在河口红树林区的数量分布随着盐度的降低而减少，其栖息密度和生物量的高峰期在夏，秋两季。生长茂密的红树林（郁蔽度大于０．５），附着动物主要分布于水流畅通的向海边缘和潮沟边缘的红树上。水流畅通程度是影响附着动物在红树林区向纵 相似文献
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对厦门海区的纹藤壶Ｂａｌａｎｕｓａｍｐｈｉｔｒｉｔｅａｍｐｈｉｔｒｉｔｅ和鳞笠藤壶Ｔｅｔｒａｃｌｉｔａｓｑｕａｍｏｓａｓｑｕａｍｏｓａ雄性生殖系统进行解剖学,组织学和细胞化学的研究,结果表明：两种藤壶的雄性生殖系统均由精巢,输精管,贮精囊接器４部分组成,精巢内依次排列有精原细胞,精母细胞,精子细胞和成熟精子,输精管由一层上皮细胞围成,内见可成熟精子,贮精囊前端管壁结构与输精管相似,后端管壁厚,可 相似文献
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湛江港浮标污损生物生态研究 总被引：7，自引：0，他引：7
１９９１年在湛江进行浮标污损生物调查。该海区污损生物的种类组成共９３种，附着厚度２１－７１ｍｍ，湿重３．１０－７２．５３ｋｇ／ｍ＾２，覆盖面积９８％－１００％。优势种网纹藤壶Ｂａｌａｎｕｓｒｅｔｉｃｕｌａｔｕｓ，变化短齿蛤Ｂｒａｃｈｉｄｏｎｔｅｓ ｕａｒｉａｂｉｌｉｓ，刺巨藤壶Ｍｅｇａｂａｌａｎｕｓｕｏｌｃａｎｏ钟巨藤壶Ｍｅｇａｂａｌａｎｕｓ ｔｉｎｔｉｎｎａｂｕｌｕｍ ｔｉｎｔｉｎｎａｂｕｌｕｍ 相似文献
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大亚湾码头桩柱的污损生物群落 总被引：4，自引：1，他引：4
研究大亚湾8座码头桩柱的污损生物群落,记录了223种生物。桩柱潮间带部分的生物群落在不同潮位上有极为明显的分带,各带都有代表种。中潮带生物的数量最大,湿重最高记录高达27.6kg/m~2,主要是由于棘刺牡蛎重叠附着的结果。 随着码头暴露程度不同,污损生物有很大差别。白条地藤壶、白脊藤壶、黑荞麦蛤和两种瘤海鞘是隐蔽处的表征种。鳞笠藤壶、中华小藤壶、大洋纵列海鞘和无柄珊瑚藻是暴露处的表征种。 相似文献
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１９９１年在湛江港进行浮标污损生物调查。该海区污损生物的种类组成共９３种，附着厚度２１—７１ｍｍ，湿重３．１０—７２．５３ｋｇ／ｍ２，覆盖面积９８％─１００％。优势种为网纹藤壶Ｂａｌａｎｕｓｒｅｔｉｃｕｌａｔｕｓ、变化短齿蛤Ｂｒａｃｈｉｄｏｎｔｅｓｖａｒｉａｂｉｌｉｓ、刺巨藤壶Ｍｅｇａｂａｌａｎｕｓｖｏｌｃａｎｏ、钟巨藤壶Ｍｅｇａｂａｌａｎｕｓｌｉｎｔｉｎｎａｂｕｌｕｍｔｉｎｔｉｎｎａｂｕｌｕｍ和翡翠贻贝Ｐｅｒｎａｖｉｒｉｄｉｓ。位于不同位置的浮标，其污损生物群落组成和生物量不同，同一浮标的不同部位（体侧，底部，尾外侧，尾管内）的污损生物也有一定差别。 相似文献
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舟山海区几种藤壶的食性分析 总被引：1，自引：0，他引：1
舟山海区五种藤壶的食性成分分析表明：其胃含物可分为浮游动物、浮游植物、有机碎屑及无机颗粒四类。浮游动物以挠足类为主，浮游植物以硅藻为主。不同大小个体的藤壶摄食偏向有所差别：大个体藤壶较多地摄食大型的烧足类等浮游动物，而小个体藤壶较多地摄食小型的硅藻等浮游植物和有机碎屑。藤壶食物成分种类与其生活海区中的浮游生物种类相一致，并随海区中浮游生物种类和数量变化而变化。通过测定发现，分布于外海的三角藤壶的食物颗粒度明显大于近海虾塘中的纹藤壶的食物颗粒度。 相似文献
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舟山虾塘纹藤壶的繁殖生物学研究 总被引：1，自引：0，他引：1
应用挂板试验方法,研究了舟山对虾养殖塘纹藤壶的繁殖生物学。底径为５．０～１２．０ｍｍ间的怀卵个体数量最多,怀卵率随底径的增大而升高;受精卵的卵径,随胚胎发育逐渐增大。幼体表现出随机分布的附着方式。底径增大、壳高增长和湿重增加是生长表观现象。 相似文献
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南沙群岛珊瑚礁砾洲地貌特征 总被引：3，自引：0，他引：3
通过对南沙群岛永暑礁、西门礁和安达礁3个砾洲的现场调查,基于理论最低潮面和平均海面分别计算了砾洲的可能分布范围和平均出露范围,获得了砾洲的地形地貌特征。3个砾洲均为向西北凸出的弧形,呈北东-南西向展布。永暑礁和西门礁砾洲周边地势较高,中部相对低洼,分布有多条砾脊,边缘向海侧主砾脊高度最大,内部多条较低的次砾脊相交于主砾脊并汇聚于砾洲东部;安达礁砾洲则中部凸起地势较高,周边较低,无多重砾脊分布。推断砾洲的发育由最初珊瑚枝块堆积于中部形成凸起,逐渐向北东和南西两侧以砾脊形式扩展,最终形成砾洲由内向外的洼地-砾脊-砾滩的地貌分带模式。砾洲的地形地貌特征表明,南沙群岛砾洲的发育主要受北东-南西向水动力条件季节性交替的控制,反映了南海海区盛行季风的影响。南沙群岛珊瑚礁砾洲的地貌特征为深入研究南海珊瑚礁灰沙岛地貌发育演化及动力机制提供了基础数据。 相似文献
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WANG Weiguo 《海洋学报(英文版)》2011,30(5):125-140
The ridge like seafloor highs with various geological origins can be classed into mid-ocean ridges,transverse ridges related to transform faults,hot spot/mantle plume originated ridges,microcontinent rifted from major continent,intra-plate arc formed by interaction of two oceanic plates,and tectonic ridges uplifted by later tectonic activity.Those ridges moved towards the convergent continental margins along with the underlain plate drifting and formed so-called accreted ridges commonly trending at a high angle to the continental margins.At divergent continental margins,the continental crusts were extended and thinned accompanying with magmatism,which formed high terrains protruding or parallel to the coastal line.The ridges worldwide have various origins and the crustal thicknesses and structures of them are diversity.The crusts beneath the microcontinents,and the transverse ridges along the transform margin,and the seafloor highs beside the passive continental margins are continental,while the crusts of other ridges are oceanic.Article 76 of the United Nations Convention on the Law of the Sea (UNCLOS) has classed the seafloor highs worldwide into three legal categories,namely oceanic ridges,submarine ridges and submarine elevations,for the purpose to delineate the outer limit of the coastal States’ continental shelf beyond 200 nautical miles.To define the categories of the legal seafloor highs to which the ridges with various geological origins belong,the continuities in morphology and geology including the rock types,crustal structures,origins and tectonic setting of the ridges and the coastal States’ land mass with its submerged prolongation should be taken into account.If a ridge is continuous both in morphology and geology with the coastal States’ land mass and its submerged prolongation,it is a submarine elevation stipulated in Article 76.If it is discontinuous in morphology,the ridge should be regarded as oceanic ridges.If a ridge is continuous in morphology but discontinuous in geology with the coastal States’ land mass and its submerged prolongation,then it is a submarine ridge as stipulated in Article 76. 相似文献
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Sand ridges off Sarasota, Florida: A complex facies boundary on a low-energy inner shelf environment
David Twichell Gregg Brooks Guy Gelfenbaum Valerie Paskevich Brian Donahue 《Marine Geology》2003,200(1-4):243-262
The innermost shelf off Sarasota, Florida was mapped using sidescan-sonar imagery, seismic-reflection profiles, surface sediment samples, and short cores to define the transition between an onshore siliciclastic sand province and an offshore carbonate province and to identify the processes controlling the distribution of these distinctive facies. The transition between these facies is abrupt and closely tied to the morphology of the inner shelf. A series of low-relief nearly shore-normal ridges characterize the inner shelf. Stratigraphically, the ridges are separated from the underlying Pleistocene and Tertiary carbonate strata by the Holocene ravinement surface. While surficial sediment is fine to very-fine siliciclastic sand on the southeastern sides of the ridges and shell hash covers their northwestern sides, the cores of these Holocene deposits are a mixture of both of these facies. Along the southeastern edges of the ridges the facies boundary coincides with the discontinuity that separates the ridge deposits from the underlying strata. The transition from siliciclastic to carbonate sediment on the northwestern sides of the ridges is equally abrupt, but it falls along the crests of the ridges rather than at their edges. Here the facies transition lies within the Holocene deposit, and appears to be the result of sediment reworking by modern processes. This facies distribution primarily appears to result from south-flowing currents generated during winter storms that winnow the fine siliciclastic sediment from the troughs and steeper northwestern sides of the ridges. A coarse shell lag is left armoring the steeper northwestern sides of the ridges, and the fine sediment is deposited on the gentler southeastern sides of the ridges. This pronounced partitioning of the surficial sediment appears to be the result of the siliciclastic sand being winnowed and transported by these currents while the carbonate shell hash falls below the threshold of sediment movement and is left as a lag. The resulting facies boundaries on this low-energy, sediment-starved inner continental shelf are of two origins which both are tied to the remarkably subtle ridge morphology. Along the southeastern sides of the ridges the facies boundary coincides with a stratigraphic discontinuity that separates Holocene from the older deposits while the transition along the northwestern sides of the ridges is within the Holocene deposit and is the result of sediment redistribution by modern processes. 相似文献
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Jean-Marie Auzende Loren Kroenke J. -Y. Collot Y. Lafoy Bernard Pelletier 《Marine Geophysical Researches》1996,18(2-4):289-304
New bathymetric and geophysical data were collected in the region east of the island of Malaita during the SOPACMAPS II cruise of the French research vessel L'ATALANTE. This region, part of the Malaita Anticlinorium was interpreted as a piece of oceanic crust from the Ontong Java Plateau obducted over the old Solomon Islands arc during collision between the Pacific and Australian plates. It has been generally accepted that convergent motion between the Australia and Pacific plates since the Late Miocene was absorbed exclusively along the San Cristobal trench, southwest of the Solomon Islands Arc.Bathymetry, imagery, and geophysical data (magnetism, gravity, seismic) acquired during the SOPACMAPS II survey allow us to classify the successive parallel ridges mapped within the region as being recent volcanic, oceanic crust, or deformed sedimentary ridges.Seismic profiling provides evidence of successive compressive events along the Malaita margin caused by the relative motion between the Solomon Islands and the Pacific plate. The main phase of convergence probably occurred during Oligocene-early Miocene time, but some relative motion between the two domains are still being absorbed along the East Malaita boundary. The existence of active faulting in the sedimentary cover throughout the region and the present-day deformation of the outer sedimentary ridge is a good illustration of this phenomenon. 相似文献
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冰脊对极地船舶及海洋工程结构的冰载荷设计及冰区安全运行具有重要的影响,其几何形态是重要的考虑因素。为研究冰脊的几何形态,本文基于Voronoi切割算法构造扩展多面体海冰单元,并使其相互冻结形成平整冰;采用离散单元法模拟海冰在相对运动时挤压形成冰脊的动力过程,统计分析脊帆高度、龙骨宽度、龙骨深度、龙骨水平倾角等主要几何参数,并确定这些几何参数间的对应关系。将离散元模拟结果同冰脊现场观测资料对比分析以验证扩展多面体离散元方法模拟冰脊形成过程的可行性。在此基础上讨论冰厚、冰速、海冰强度等因素对冰脊形态的影响。本文采用离散元方法对冰脊形成过程及几何特性的数值分析可为深入开展冰脊的形成机理及其对船舶、海洋工程结构物的冰载荷分析提供参考依据。 相似文献
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Erosional shelf ridges in the mid-eastern Yellow Sea 总被引：1，自引：0，他引：1
In the mid-eastern Yellow Sea, closely spaced high-resolution seismic profiles and a 44-m-long sediment core (YSDP-104) were analyzed to reveal the internal structures and stratigraphy of the shelf ridges currently shaped by tidal currents. Three depositional sequences (sequences I, II and III in descending order) can be recognized. Sequence III, the substratum of the ridges, consists of coarse-grained sediments in the lower part (non-marine deposits) and tide-influenced muddy sediments in the upper part (probable transgressive to highstand systems tract). Sequence II represents internal ridge sediments, similar in character to sequence III, but is demarcated by an undulatory ridge topography. According to radiocarbon dating of marine muds, these sequences range in age from 47,000 to 28,000 years B.P., representing two cycles of short-term sea-level fluctuations during oxygen isotope stage 3. Sequence I consists mostly of late-Holocene transgressive sand veneer on the ridge surface. It also includes minor amounts of early-Holocene muddy sediments occasionally underlying the sand. Most of the ridges are presently undergoing erosion by tidal currents, forming widespread sand dunes on the entire surface. 相似文献
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In the mid-eastern Yellow Sea, closely spaced high-resolution seismic profiles and a 44-m-long sediment core (YSDP-104) were analyzed to reveal the internal structures and stratigraphy of the shelf ridges currently shaped by tidal currents. Three depositional sequences (sequences I, II and III in descending order) can be recognized. Sequence III, the substratum of the ridges, consists of coarse-grained sediments in the lower part (non-marine deposits) and tide-influenced muddy sediments in the upper part (probable transgressive to highstand systems tract). Sequence II represents internal ridge sediments, similar in character to sequence III, but is demarcated by an undulatory ridge topography. According to radiocarbon dating of marine muds, these sequences range in age from 47,000 to 28,000 years B.P., representing two cycles of short-term sea-level fluctuations during oxygen isotope stage 3. Sequence I consists mostly of late-Holocene transgressive sand veneer on the ridge surface. It also includes minor amounts of early-Holocene muddy sediments occasionally underlying the sand. Most of the ridges are presently undergoing erosion by tidal currents, forming widespread sand dunes on the entire surface. 相似文献