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1.
Xu Zhaoli 《农业工程》2007,27(9):3678-3686
Distribution patterns and abundance of the euphausiids were examined in the East China Sea (23°30′ –33°00′N, 118°30′ –128°00′ E) in relation to temperature and salinity. The data were collected in 4 surveys from 1997 to 2000. The density or yield density model was used to predict optimum temperature and salinity of water for euphausiid distribution, and thereafter distribution patterns of euphausiids were determined based on the predicted parameters. Of 23 species, Euphausia pacifica, E. nana, Pseudeuphausia sinica and P. latifrons were numerically dominant. The analyses indicate that Euphausia pacifica is an offshore temperate water species, E. nana is an offshore temperate warm water species, P. sinica is a coastal subtropical water species and P. latifrons is an oceanic tropical water species. The 4 species occupied 4 different water masses, respectively, namely, cold water mass, cold and warm water mixed masses in winter and spring, cold and warm water mixed masses in summer and autumn, and warm water mass, which could be the good designators of individual water masses, respectively. The predicated optimal temperatures for E. tenera, S. carinatum, E. diomedeae, Stylocheiron affine, Nematoscelis sp., N. gracilis, N. atlantica, Stylocheiron sp. and S. suhmii are all > 25°. These species are mainly distributed in southern Kuroshio in winter and spring, Kuroshio, the Taiwan Warm Current and Tsushima Current in summer and autumn, the equatorial waters of Pacific Ocean and the eastern waters of the Taiwan Strait. They are called as oceanic tropical water species. Nematoscelis tenella and T. tricuspidata are referred to as offshore subtropical water species according to their geographic distributions even if they are halobionts. Euphausia sanzoi is considered as a typical offshore subtropical water species, which inhabited waters below 25°. Stylocheiron microphthalma, occupying warm current waters where temperature and salinity are nearly 25° and 34 in summer and autumn, belongs to oceanic tropical water species. In the same way, E. similes, E. mutica, Euphausia sp., E. brevis and E. recurva are classified into offshore subtropical water species in accordance with the optimum temperature and salinity of waters as well as locations and seasons of their occurrence. Optimum temperature, rather than salinity, is a better parameter in determining the distribution patterns of euphausiids.  相似文献   

2.
东海磷虾类优势种的生态适应   总被引:8,自引:7,他引:8  
徐兆礼  陈亚瞿 《生态学报》2005,25(9):2227-2233
根据1997~2000年东海23°30′~33°N、118°30′~128°E海域4个季节海洋调查资料,对东海磷虾类优势种的生态特征进行了研究,运用定量定性方法探讨了这些优势种的生态环境适应类型。结果表明:东海磷虾类的优势种主要有小型磷虾Euphausianana、中华假磷虾Pseudeuphausiasinica、宽额假磷虾Pseudeuphausialatifrons和太平洋磷虾Euphausiapacifica等4种;中华假磷虾和宽额假磷虾属于适应夏秋季环境的暖温种和暖水种,小型磷虾和太平洋磷虾为适应冬春季环境的温水种;暖水种往往具有较高的丰度和出现频率,温水种的出现率相对较低;温水种有很高的聚集强度。中华假磷虾系近岸暖温种;宽额假磷虾是外海暖水种;小型磷虾最适温度相对较高,分布区偏外海,是高盐温水种;太平洋磷虾最适温度相对较低,分布区偏近海,虽是高盐温水种,但高分布区的盐度往往低于小型磷虾。  相似文献   

3.
东海水螅水母环境适应与生态类群   总被引:4,自引:0,他引:4  
根据1997—2000年东海23°30′—33°00′ N、118°30′—128°00′ E海域4个季节海洋调查资料,依据丰度和同步表层温、盐度数据,采用曲线拟合构造了数学模型,并结合地理分布分析对东海水螅水母最适温度、最适盐度和生态类群进行了研究.结果表明:东海水螅水母适温环境多样,最适温度低于20 ℃的有15种,在20 ℃~22.5 ℃之间的有8种,在22.5 ℃~25 ℃之间的有12种,超过25 ℃的有17种;大多数物种(32种)最适盐度为32~34,大于34的有13种,在30~32之间的有6种,低于30的仅出现2种.水螅水母大多数物种生存的盐度区间较窄,它们的数量和分布范围有限.嵊山秀氏水母等2种属暖温带近海种,八囊摇篮水母等13种属暖温带外海种,宽外肋水母等8种属亚热带近海种,半口壮丽水母等5种具有热带大洋种特征,四叶小舌水母等25种属亚热带外海种.东海水螅水母的许多物种可作为东海水团重要的指示种.  相似文献   

4.
东海浮游枝角类和涟虫类生态适应性   总被引:2,自引:0,他引:2  
徐兆礼  高倩  陈华  陈佳杰  蔡萌 《生态学杂志》2007,26(11):1782-1787
根据1997-2000年东海23°30′-33°00′N、118°30′-128°00′E海域4个季节海洋综合调查资料,以及2002-2003年长江口外海29°00′-32°00′N、122°00′-123°30′E海域4个季节资料,对浮游枝角类、涟虫类丰度和同步的表层温、盐度数据进行曲线拟合,构造数学模型,计算各物种分布的最适温度和盐度,分析其地理分布和生态特征,确定物种的生态类型。结果表明:鸟喙尖头溞(Penilia avirostris)、肥胖三角溞(Evadne tergestina)是亚热带近海种,具有广温广盐的生态特征;诺氏三角溞(Evadne nordmanni)、萨氏异涟虫(Heterocumasarst)和细长涟虫(Iphinoe tenera)是亚热带外海种,其中诺氏三角溞具有暖温种的特征,后两种涟虫(Bodotria ovalis)是典型的亚热带外海种;卵圆涟虫仅仅在长江口近海出现,是亚热带近海种。东海浮游枝角类大多数物种最适盐度偏低,尤其是鸟喙尖头溞和肥胖三角溞,它们的高丰度分布区是沿岸水团的标志。  相似文献   

5.
长江口及邻近海域浮游磷虾类数量和分布的季节特征   总被引:4,自引:0,他引:4  
陈佳杰  徐兆礼  朱德弟 《生态学报》2008,28(11):5279-5285
根据2002~2003年长江口29°00′~32°00′N、122°00′~123°30′E海域4个季节的海洋调查,运用定量、定性方法,探讨长江口邻近海域浮游磷虾类总丰度的季节变化特征以及与渔场的关系,丰度的季节差异与水团的关系,分析了优势种的数量变动、对磷虾类的贡献及对环境的适应情况,并与东海外海的生态特征作了比较。结果表明,长江口及邻近海域磷虾类丰度季节变化主要受温度的影响,平面分布变化与盐度有关。平均丰度夏季最高(10.46ind/m3),冬季最低(0.32ind/m3)。本次调查共发现8种,优势种为中华假磷虾(Pseudeuphausia sinica)、太平洋磷虾(Euphausia pacifica)和小型磷虾(Euphausia nana),其中中华假磷虾四季皆为优势种,太平洋磷虾是春、秋和冬季的优势种,小型磷虾仅仅是春秋季的优势种。中华假磷虾在春、夏和冬季对总丰度的贡献率较高,并占绝对优势,其更适应夏季咸淡水交错水域的环境,而太平洋磷虾和小型磷虾更适应东海近海暖温高盐环境。长江冲淡水势力强弱和中华假磷虾的数量对磷虾类时空分布有重要影响,中华假磷虾对咸淡水环境的适应则是影响该种数量变化的另一个重要原因。  相似文献   

6.
东海海樽类生态类群统计分析   总被引:5,自引:1,他引:4  
徐兆礼  孙军  林茂 《生态学报》2008,28(11):5698-5705
依据1997~2000年在东海23°30′~33°00′N、118°30′~128°00′E4个季节的海洋调查资料,采用曲线拟合,构造数学模型和极大值分析等数学方法,研究海樽类最适温度和盐度,籍此进一步分析其生态类群。结果表明,Yield Density模型可以应用于大多数海樽类最适温度和盐度的统计推断。依据物种分布的最适温度和盐度值,并参考其地理和季节分布特征,认为梭形纽鳃樽(Salpa fusiformis)属暖温带外海种;羽环纽鳃樽长柄亚种(Cyclosalpa pinnata polae)和安纽鳃樽(Ritteriella amboinensis)为热带大洋种;双尾纽鳃樽东方亚种(Thalia decocratica orientalis)、小齿海樽(Doliolum denticulatum)和软拟海樽(Dolioetta.gegenbauri)等其余13种为亚热带外海种。海樽类多数物种可以作为水团的指示种。梭形纽鳃樽往往出现在沿岸水和外海水混合水团偏高盐水一侧。羽环纽鳃樽长柄亚种高丰度分布在台湾暖流控制的水域,是台湾暖流的指示种。双尾纽鳃樽东方亚种高丰度水域,能够较为准确地反映黑潮入侵陆架水团和沿岸水交汇的位置。  相似文献   

7.
东海浮游糠虾类生态类型划分及其对水团的指示作用   总被引:3,自引:0,他引:3  
徐兆礼  沈盎绿 《应用生态学报》2007,18(10):2347-2353
根据1997-2000年东海23°30′-33°N、118°30′-128°E海域4个季节海洋调查资料,对浮游糠虾类丰度和同步的表层温、盐度数据进行曲线拟合,构造数学模型,计算糠虾类分布的最适温度和盐度,分析其地理分布和季节分布特征,确定物种的生态类型.结果表明:宽尾刺糠虾(Acanthomysis latiscauda)、漂浮囊糠虾(Gastrosaccus pelagicus)、中华节糠虾(Siriel-la sinensis)和美丽拟节糠虾(Hemisiriella pulchra)是亚热带近海种,同时具有暖温种的特征;极小假近糠虾(Pseudanchialina pusilla)、东方原糠虾(Promysis orientalis)、小红糠虾(Erythropsminuta)和双眼准异糠虾(Anisomysis bipartoculata)虽是亚热带外海种,但具有热带大洋种特征.东海浮游糠虾类大多数物种的最适温、盐度偏低,冬春季在东海近海有更多的分布,因而具有暖温近海类型的生物学特征,这是该类浮游动物区别于其它浮游动物类群的重要特征.宽尾刺糠虾、中华节糠虾和美丽拟节糠虾的较高丰度区,也正是长江冲淡水与暖流水团交汇、沿岸水团与外海高盐水团交汇的位置.小红糠虾和双眼准异糠虾可作为暖流指示种.四刺端糠虾(Doxomysis quadrispinosa)和东方原糠虾是台湾暖流指示种.其它种均不是良好的水团指示种.  相似文献   

8.
北黄海秋、冬季浮游动物多样性及年间变化   总被引:5,自引:0,他引:5  
杨青  王真良  樊景凤  邵魁双  李宏俊 《生态学报》2012,32(21):6747-6754
2009年秋、冬季在北黄海全海域121°30'-124°00'E、37°30'-40°00'N范围开展了浮游动物多样性监测及年间变化研究,探讨浮游动物多样性对海流及全球变化的指示。共鉴定出浮游动物8大类28种(不含6大类浮游幼虫和鱼卵仔鱼),类群组成以暖温性近岸种和广温广盐种为主,兼有少量冷温性和暖水性外海种。聚类分析将浮游动物群落划分为:北黄海高盐水团群落、北黄海混合水团群落、北黄海沿岸低盐水团群落。2009年秋、冬季在北黄海均监测到暖水种小齿海樽和肥胖箭虫,前者形成秋季浮游动物优势种,但1959年调查显示它们向北分布不能抵达北黄海,这些暖水种的向北扩布可能预示着黄海暖流的增强。2009年秋、冬季北黄海主要暖温种中华哲水蚤和强壮箭虫丰度也较1959年同期有所升高。研究表明全球变化影响下温带海域北黄海浮游动物暖水种种类增加、分布北移,暖温种丰度升高,这与亚热带海域东海浮游动物对气候变暖的响应模式不同,能够为浮游动物对全球变暖的区域响应机制研究提供参考资料。  相似文献   

9.
东海栉水母对温度和盐度生态适应的Yield-Density模型   总被引:2,自引:0,他引:2  
根据1997-2000年东海23°30′N-33°N、118°30′E-128°E海域4个季节海洋调查资料,采用物种丰度和同步表层温度、盐度数据的曲线拟合,构造数学模型,结合地理分布分析,研究了栉水母分布最适温度和最适盐度,分析了栉水母的生态类型.结果表明:瓜水母(Beroe cucumis)的丰度和温度,掌状风球水母(Hormiphora palmata)和卵型瓜水母(B.ovata)的丰度和盐度的相关性不显著;蝶水母(Ocyropsis crystallina)、球型侧腕水母(Pleurobrachia globosa)、瓜水母,掌状风球水母和卵型瓜水母的丰度与其对应的温度或盐度均符合Yield-Density模型;瓜水母最适温度和卵型瓜水母最适盐度依据散点图估计,掌状风球水母最适盐度不明显,其他物种最适温、盐度均由Yield-Density模型极值点计算;东海栉水母所有物种均系亚热带外海种,其中球型侧腕水母、瓜水母和掌状风球水母具有较宽的温、盐度分布区间,卵型瓜水母和蝶水母是冬、春季暖流水团的指示种.  相似文献   

10.
东海中南部外海虾类群落结构特征分析   总被引:9,自引:1,他引:8  
依据2006年5月(春)、8月(夏)、11月(秋)和2007年2月(冬)在东海中南部外海(26°00′N-28°30′N ,126°00′E以西)海域虾类资源调查资料,分析了虾类的种类组成、优势度、多样性等群落结构特征。共采获虾类32种,隶属于11科22属,优势种有长角赤虾(Metapenaeopsis longirostris)、戴氏赤虾(Metapenaeopsis dalei)、高脊管鞭虾(Solenocera alticarinata)、东海红虾(Plesionika izumiae)、九齿扇虾(Ibacus novemdentatus)、假长缝拟对虾(Parapenaeus fissuroides)、凹管鞭虾(Solenocera koelbeli)、大管鞭虾(Solenocera crassicornis)、哈氏仿对虾(Parapenaeopsis hardwickii)和中华管鞭虾(Solenocera crassicornis),其中长角赤虾、戴氏赤虾、东海红虾、假长缝拟对虾和哈氏仿对虾是主要优势种,常见种是须赤虾(Metapenaeopsis barbata)、日本囊对虾(Penaeus japonicus)、脊单肢虾(Sicyonia cristata)、葛氏长臂虾(Palaemon gravieri)、日本鼓虾(Alpheus japonicus)、全刺拟长额虾(Parapandalus spinipes)和齿额红虾(Plesionika dentirostris)。东海中南部外海大部分虾类属于高温高盐生态群落,虾类丰度空间分布呈现120m等深线以西的站位高,120m等深线以东站位低的特征,但是秋季和冬季的生物丰度普遍减小,冬季整个海域的虾类丰度基本达到全年的最低值。不同季节中,秋季种类最多(22种),其次是冬季(20种),春、夏季较少(分别为17种、18种);Margalef指数(D)和Shannon-Wiener多样性指数 以夏秋季较高,春冬季较低,整个海区四个季节的均匀性指数 较为稳定。从空间分布来看,4个季节中东海中南部外海120m等深线以西站位多样性指数高于120m等深线以东的站位;运用聚类和非线性多维标序对群落结构的相似性进行分析,结合水深等环境因子,表明东海中南部外海虾类可分为两个群聚类型,即深海域群聚和外缘群聚。  相似文献   

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It has now been over twenty years since a novel herpesviral genome was identified in Kaposi's sarcoma biopsies. Since then, the cumulative research effort by molecular biologists, virologists, clinicians, and epidemiologists alike has led to the extensive characterization of this tumor virus, Kaposi's sarcoma-associated herpesvirus(KSHV; also known as human herpesvirus 8(HHV-8)), and its associated diseases. Here we review the current knowledge of KSHV biology and pathogenesis, with a particular emphasis on new and exciting advances in the field of epigenetics. We also discuss the development and practicality of various cell culture and animal model systems to study KSHV replication and pathogenesis.  相似文献   

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Comprises species occurring mostly in subtidal habitats in tropical, subtropical and warm-temperate areas of the world. An analysis of the type species, V. spiralis (Sonder) Lamouroux ex J. Agardh, a species from Australia, establishes basic characters for distinguishing species in the genus. These characters are (1) branching patterns of thalli, (2) flat blades that may be spiralled on their axis, (3) width of the blade, (4) primary or secondary derivation of sterile and fertile branchlets and (5) position of sterile and fertile branchlets on the thalli. Application of the latter two characters provides an important basic method for separation of species into three major groups. Osmundaria , a genus known only in southern Australia, was studied in relation to Vidalia , and its separation from the Vidalia assemblage is not accepted. Species of Vidalia therefore are transferred to the older genus name, Osmundaria. Two new species, Osmundaria papenfussii and Osmundaria oliveae are described from Natal. Confusion in the usage of the epithet, Vidalia fimbriala Brown ex Turner has been clarified, and Vidalia gregaria Falkenberg, described as an epiphyte on Osmundaria pro/ifera Lamouroux, is revealed to be young branches of the host, Osmundaria prolifera.  相似文献   

17.
Fifteen chromosome counts of six Artemisia taxa and one species of each of the genera Brachanthemum, Hippolytia, Kaschgaria, Lepidolopsis and Turaniphytum are reported from Kazakhstan. Three of them are new reports, two are not consistent with previous counts and the remainder are confirmations of very scarce (one to four) earlier records. All the populations studied have the same basic chromosome number, x = 9, with ploidy levels ranging from 2x to 6x. Some correlations between ploidy level, morphological characters and distribution are noted.  相似文献   

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肝癌中HBV和HCV基因和抗原的分布及意义   总被引:1,自引:0,他引:1  
采用原位分子杂交方法检测HCV RNA及HBV X基因;采用免疫组织化学方法研究HCV核心抗原,非结构区C33c抗原及HBxAg在肝细胞肝癌中的定位及分布.结果表明(1)HCV RNA、HBV X基因在肝细胞肝癌组织检出率分别为40%(55/136)和82%(112/136).HCV RNA定位于癌细胞的胞浆内,阳性细胞呈散在、灶状及弥漫分布三种形式;HBV X基因在肝癌细胞中的分布呈胞浆型、核型及核浆型,阳性细胞也呈上述三种分布形式;(2)HCV C33c抗原、核心抗原在肝细胞肝癌中的阳性率为81%(133/164)及86%(141/164).C33c抗原定位于癌细胞及肝细胞的胞浆内;核心抗原既定位于癌细胞核中,又可定位于胞浆中.C33c抗原阳性细胞以灶状分布为主;而核心抗原阳性细  相似文献   

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For a plant selection model with frequency-independent viabilities, fertilities and selfing rates, it is shown that apart from global fixation, for certain parameter combinations a protected polymorphism and facultative fixation (either allele may become fixed according to initial frequencies) may both occur. Facultative fixation requires different selling rates for the dominant and recessive type. Protection of the polymorphism requires resource allocation for male and female function. In this connection the problem of purely genetically caused population extinction is discussed.
For general frequency dependence and regular segregation, the chances for establishment of a completely recessive gene are compared to those of a completely dominant gene. It is proven that the process of establishment of the recessive gene, despite a fitness advantage, may be considerably endangered by drift effects if random mating prevails. The recessive gene may reach the same effectivity in establishment as a dominant gene, only if the recessive homozygote mates exclusively with its own type during the period of establishment.  相似文献   

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