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1.
为了解黄、渤海生态系统交错带长山列岛邻近水域鱼类群落种类组成和多样性,根据2016年10月,2017年1月、5月及8月进行的鱼类资源底拖网调查数据,应用相对重要性指数、物种多样性指数、k优势度曲线等方法,研究了长山列岛邻近海域鱼类群落种类组成、物种多样性时空变化及其与环境因子的关系。结果表明: 该海域共计捕获鱼类77种,以温水性、底层、洄游性鱼类为主,优势种组成季节变化明显,春季、冬季主要优势种为黄鮟鱇,夏季以日本鲭、鳀等中上层鱼类为主。全年共计出现洄游性鱼类46种,季节间物种迁移指数均在100以上,其中秋季物种迁移指数最大。鱼类群落物种丰富度指数在春季最高、Shannon多样性指数和均匀度指数在秋季最高。夏季物种丰富度指数与表层水温呈显著负相关;冬季物种丰富度指数与水深、底层水温呈极显著正相关,Shannon多样性指数与底层水温呈极显著正相关。长山列岛邻近海域作为黄、渤海两大生态系统的交错带,鱼类群落表现出高物种多样性、洄游种多以及明显的时空异质性。  相似文献   

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长江下游水生动物群落生物多样性变动趋势初探   总被引:20,自引:0,他引:20  
对1990-1999年间长江下游江段生物多样性的变动趋势进行了研究,并就群落稳定性与多样性的关系进行了探讨,结果表明,物种多样性指数量大值为1.1112,最小值为0.0327,反映物种均匀度,丰盛度的指数都有不同程度的下降,而反映优势度的指数却有一定程度的上升,优势度指数最大值为1,最小值为0.34046,优势种前6位分别为杂虾,青虾,餐条,吻Qu,蛇Qu,黄颡,表明长江下游江段的生物多样性正在逐步丧失,经济鱼类数量趋减,小型野杂鱼类数量趋增。  相似文献   

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清远水利枢纽是北江干流与珠江河口之间第一座枢纽, 为探究清远水利枢纽建坝筑库后库区鱼类群落结构特征及变化, 于2017-2018年在清远水利枢纽至飞来峡水利枢纽库区进行渔业资源调查, 共采集鱼类49种, 隶属于6目16科44属, 以鲤(Cyprinus carpio)、鲮(Cirrhina molitorella)、赤眼鳟(Squaliobarbus curriculus)等为优势种类, 鱼类生态类型以杂食性、定居性鱼类为主。与水坝截流前2006-2007年调查结果比较, 库区鱼类种类数大大减少, 洄游性鱼类种数明显下降, 鱼类群落丰富度指数、香农多样性指数下降, 定居性、杂食性鱼类种类所占比例增加, 相似性百分比分析(SIMPER)显示造成水坝建设前后库区鱼类群落结构时间变化的指示物种为: 尼罗罗非鱼(Tilapia niloticus)、花鰶(Clupanodon thrissa)、大眼鳜(Siniperca kneri)、纹唇鱼(Osteoichilus salsburyi)等, 丰度生物量比较曲线(ABC曲线)显示库区鱼类群落结构受到严重干扰。研究结果可为库区渔业资源增殖放流、水坝生态调度以及渔业资源管理提供本底资料。  相似文献   

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东江源头区域鱼类物种多样性及群落组成的特征   总被引:1,自引:0,他引:1       下载免费PDF全文
生物多样性和鱼类群落结构的变化是反映人类作用及环境变化对鱼类群落影响的重要指标。2010年我们的调查结果显示,覆盖整个东江源头区的12个采样点收集和鉴定的鱼类标本共计7目18科56属74种。除陈氏新银鱼(Neosalanx tangkahkeii)、齐氏罗非鱼(Tilapia zillii)和食蚊鱼(Gambusiaaffinis)3种为外来物种外,其余71种均为土著鱼类。主要以鲤形目(77.5%)、鲇形目(9.9%)和鲈形目(8.4%)为主。优势种为宽鳍鱲(Zacco platypus),占14.87%,其次为马口鱼(Opsariichthys bidens)(9.93%)和侧条光唇鱼(Acrossocheilus parallens)(9.36%)。本研究还以G-F指数、Shannon-Wiener指数、Pielou’s均匀性指数、Margalef丰富度指数和Simpson指数评估了东江源头区域的鱼类多样性;东江源头区域鱼类群落以杂食性、定居性、中下层和底栖种类为主,源头这种鱼类群落组成结构与东江下游鱼类具有相同趋势,但相似性指数仅为0.39。拦河建坝是导致洄游性、半洄游性鱼类减少的主要原因,其次,水体污染、河道取沙、过度捕捞及有害渔具渔法的使用仍是源头区域生物多样性的主要胁迫因素。  相似文献   

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海州湾鱼类群落功能多样性的时空变化   总被引:2,自引:0,他引:2  
功能多样性是联系物种、生态环境和生态系统功能的基础.从功能多样性的角度研究群落结构,有助于更好地理解生物多样性与生态系统功能之间的关系.本研究根据2011—2017年(除2012年外)春、秋季海州湾渔业资源底拖网调查数据,选取反映鱼类摄食、运动、生态适应性、繁殖行为和种群动态特征的13个功能性状,利用功能丰富度指数、功能均匀度指数、功能离散度指数和群落特征加权平均数指数(CWM),研究了海州湾鱼类群落功能多样性的季节、年际和空间的变化.结果表明: 海州湾鱼类群落功能多样性指数具有显著的季节差异,其中秋季功能丰富度指数显著高于春季,春季功能离散度指数显著高于秋季,鱼类洄游是造成功能多样性指数季节变化的主要原因;CWM分析表明,春季鱼类群落优势种为营养级较高、运动能力较强、生长系数、恢复力和脆弱性较高的冷/暖温性鱼类,秋季则相反,春、秋季鱼类群落均以产浮性卵鱼类为主;鱼类群落功能多样性指数呈现一定的年际变化,其中春、秋季各功能多样性指数在不同年际均呈波动趋势,表明海州湾鱼类群落稳定性较低;鱼类群落功能多样性指数呈现显著的空间差异,其中20 m以深远岸水域功能离散度指数较高.海州湾鱼类群落功能多样性具有明显的时空变化特征,鱼类生态位与其对资源的利用均随季节、年际和空间而变化.  相似文献   

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长江口崇明东滩鱼类群落组成和生物多样性   总被引:7,自引:0,他引:7  
对2004-2006年每年的5-8月长江口崇明东滩鱼类群落组成和生物多样性进行了调查.结果表明:崇明东滩鱼类群落共有14目22科37属39种,以鲈形目最多,鲤形目次之,鱼类群落可分为4个生态类型,其中淡水鱼类13种、河口定居性鱼类6种、洄游性鱼类4种、近海鱼类16种,群落优势种为长蛇绚(Saurogobio dumerili)、中国花鲈(Lateo-labrax maculatus)、窄体舌鳎(Cynoglossus gracilis)、刀鲚(Coilia ectenes)、鮻(Liza haematochei-la)和鲻(Mugil cephalus)共6种;多样性特征值平均指标为Margalef丰富度指数(R)为2.30,Shannon-Wiener多样性指数(H')为1.95,Wilhm多样性改进指数(H")为2.17,Mc-Naughton优势度指数Dn和Dw分别为0.60和0.45,Simpson单纯度指数(C)为0.22,Pielou均匀度指数(J')为0.59;崇明东滩鱼类群落中体质量<50 g的小型鱼类占绝对优势,经济鱼类趋于小型化,生物多样性呈下降趋势.为了保护崇明东滩的鱼类资源,应加大重要种群和生境保护和恢复的力度.  相似文献   

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上海大莲湖鱼类群落组成及生物多样性   总被引:1,自引:0,他引:1  
Yue F  Luo ZK  Wu D  Pei EL  Wang TH 《动物学研究》2010,31(6):657-662
于2009年4月11—19日、4月27—5月8日和5月20—29日3个时间段对大莲湖的鱼类群落特征及其多样性组成进行了调查,共收集鱼类样本24061尾,隶属11科17属22种。群落优势种为鲫(Carassius auratus),占样本个体总数的76.38%;Shannon-Wiener多样性指数(H′)为1.0027,Simpson优势度指数(λ)为0.5959,Pielous均匀度指数(J′)为0.3244,Margalef种类丰富度指标(D)为2.0816,相对稀有种数(R)为90.91%;鱼类群落可分为3个生态类型:江海洄游性鱼类有3种、河湖洄游性鱼类1种和定居性鱼类18种。鱼类食性可分为5种类型:食鱼性鱼类9种、食无脊椎动物性鱼类2种、杂食性鱼类7种、食浮游生物性鱼类有3种和草食性鱼类1种。研究结果表明:大莲湖鱼类群落的多样性指标处于较低水平,稳定性较低;相对于黄埔江下游地区,大莲湖的食鱼性鱼类比例较高,说明位于黄浦江上游的大莲湖之水质好于下游流域。为保护和持续利用大莲湖鱼类资源,应加强监管和对生态环境的保护。  相似文献   

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高山地区甘蓝田节肢动物群落特征   总被引:1,自引:0,他引:1  
对湖北省高山地区自然天敌控制害虫的甘蓝田的节肢动物群落结构进行了研究.结果表明:自然天敌控制害虫的甘蓝田内害虫优势种为小菜蛾(Plutella xylostella )、甘蓝蚜(Brevicoryne brassicae)和甘蓝夜蛾(Mamestra brassicae);天敌优势种为菜蚜茧蜂(Diaeretiella rapae)、菜蛾绒茧蜂(Cotesia plutella)、草间小黑蛛(Erigonidum gramiaicolum)和大灰食蚜蝇(Syrphus corollae).害虫及天敌亚群落物种的丰富度、多样性、均匀度及集中性在时间序列上有变化;害虫亚群落优势集中性高,优势种突出,群落多样性及均匀性指数较低,天敌亚群落的多样性和均匀性指数较高,优势集中性较低,群落相对比较稳定.经聚类分析,害虫和天敌亚群落的14个时序群落分别被划分为4类和3类.  相似文献   

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根据2016—2017年南渡江鱼类资源调查数据,通过分析渔获生物量、相对重要性指数IRI、Pielou均匀性指数、Margalef丰富度指数和Shannon多样性指数评估了南渡江的鱼类生物多样性。基于鱼类生物完整性指数IBI构建了两套评价体系,分别评价了南渡江的局部健康状况及其与历史的差异。鱼类多样性研究结果表明:群落中存在尼罗罗非鱼(Oreochromis niloticu)、鳙(Aristichthys nobilis)、海南似鱎(Toxabramis houdemeri)、(Hemiculter leucisulus)等16种优势种;Margalef丰富度指数和Shannon多样性指数均显示,以南渡江源头及河口采样点的数值较高,中部采样点数值较低;Pielou均匀性指数则表现为南渡江中部采样点数值高,两端采样点的低。鱼类生物完整性评价结果表明:南渡江保存了历史的大部分鱼类,各项百分比指标与历史的变化幅度在0.2%~10.5%,而种类指标变化范围在0~4种;从南渡江局部江段来看,中游江段评价得分仅为19分,远低于其他江段的36~46分。研究表明:南渡江鱼类生物多样性和生物完整性保存完好,河流健康状况好;在河流内部,源头和河口生物多样性高且完整性好,而河流中游健康状况差。  相似文献   

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瓯江干流丽水段渔业资源群落结构的季节变化   总被引:1,自引:0,他引:1  
根据2009年春(3月)、夏(6月)、秋(9月)、冬(12月)瓯江干流丽水段(28°16′47.03″N—28°24′42.66″N、119°42′31.41″E—119°57′13.03″E)的渔业资源调查资料,对瓯江干流丽水段鱼类的资源状况、重要种类的生态优势度、多样性指数、群落结构等动态变化进行了分析。结果表明:瓯江干流丽水段现有鱼类47种、隶属于5目、12科、34属,较1972年的66种减少了28.8%;四季全部调查水域中出现的优势鱼种有圆吻鲴、大眼华鳊、黄颡、唇鱼骨、圆尾鮠、江黄颡、薄颌光唇鱼和鲤8种,其中圆吻鲴和大眼华鳊为常年优势种,其他6种为某一季节的优势种;不同季节优势度变化范围为0.578~0.747,以冬季最高;Margalef指数(D)介于2~4,Shannon指数(H)介于1~2,Pielou均匀度指数(J)介于0.3~0.6,依此判定瓯江干流丽水段渔业资源群落的多样性属于正常水平。群落季节更替指数和迁移指数揭示该流域鱼类群落结构具有明显季节性变化,而群落相似性指数(Jaccard指数和Sorenson指数)揭示3个生境的鱼类种群相似度均属于中等不相似。  相似文献   

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In experiments on Black Sea skates (Raja clavata), the potential of the receptor epithelium of the ampullae of Lorenzini and spike activity of single nerve fibers connected to them were investigated during electrical and temperature stimulation. Usually the potential within the canal was between 0 and –2 mV, and the input resistance of the ampulla 250–400 k. Heating of the region of the receptor epithelium was accompanied by a negative wave of potential, an increase in input resistance, and inhibition of spike activity. With worsening of the animal's condition the transepithelial potential became positive (up to +10 mV) but the input resistance of the ampulla during stimulation with a positive current was nonlinear in some cases: a regenerative spike of positive polarity appeared in the channel. During heating, the spike response was sometimes reversed in sign. It is suggested that fluctuations of the transepithelial potential and spike responses to temperature stimulation reflect changes in the potential difference on the basal membrane of the receptor cells, which is described by a relationship of the Nernst's or Goldman's equation type.I. P. Pavlov Institute of Physiology, Academy of Sciences of the USSR, Leningrad. I. M. Sechenov, Institute of Evolutionary Physiology and Biochemistry, Academy of Sciences of the USSR, Leningrad. Pacific Institute of Oceanology, Far Eastern Scientific Center, Academy of Sciences of the USSR, Vladivostok. Translated from Neirofiziologiya, Vol. 12, No. 1, pp. 67–74, January–February, 1980.  相似文献   

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Shapes of curves of pH-dependence of reactions   总被引:14,自引:14,他引:0  
A simple case is considered in which the rate of a two-step reaction depends on pH because the intermediate formed in the first step has to gain (or lose) a proton before it can react in the second step, and in which the rate-determining step therefore changes with pH. The curves of reaction rate against pH are shown to be symmetrical, and the sharpest peak possible has a width at half its height of 1.53pH units, i.e. of 2log(3+2 radical2). Any particular curve for this situation proves to be identical with a curve that could be generated for the pH-dependence of a single-step reaction in which the rate is proportional to the concentration of a particular ionic form of a reactant. Curves for the latter situation, however, can have forms impossible for the former case in which the rate-determining step changes, but only if the protonations that activate and deactivate the reactant are co-operative. The peak can then become even sharper, and its width at half its height can fall to 1.14pH units, i.e. to 2log(2+ radical3).  相似文献   

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Dietary intakes of tomatoes and tomato products containing lycopene have been shown to be associated with decreased risk of chronic diseases such as cancer and cardiovascular diseases in numerous studies. Serum and tissue lycopene levels have also been inversely related to the risk of lung and prostate cancers. Lycopene functions as a very potent antioxidant, and this is clearly a major important mechanism of lycopene action. In this regard, lycopene can trap singlet oxygen and reduce mutagenesis in the Ames test. However, evidence is accumulating for other mechanisms as well. Lycopene at physiological concentrations can inhibit human cancer cell growth by interfering with growth factor receptor signaling and cell cycle progression specifically in prostate cancer cells without evidence of toxic effects or apoptosis of cells. Studies using human and animal cells have identified a gene, connexin 43, whose expression is upregulated by lycopene and which allows direct intercellular gap junctional communication (GJC). GJC is deficient in many human tumors and its restoration or upregulation is associated with decreased proliferation. The combination of low concentrations of lycopene with 1,25-dihydroxyvitamin D3 exhibits a synergistic effect on cell proliferation and differentiation and an additive effect on cell cycle progression in the HL-60 promyelocytic leukemia cell line, suggesting some interaction at a nuclear or subcellular level. The combination of lycopene and lutein synergistically interact as antioxidants, and this may relate to specific positioning of different carotenoids in membranes. This review will focus on the growing body of evidence that carotenoids have unexpected biologic effects in experimental systems, some of which may contribute to their cancer preventive properties in models of carcinogenesis. Consideration of solubility in vitro, comparison with doses achieved in humans by dietary means, interactions with other phytochemicals, and other potential mechanisms such as stimulation of xenobiotic metabolism, inhibition of cholesterogenesis, modulation of cyclooxygenase pathways, and inhibition of inflammation will be considered. This review will point out areas for future research where more evidence is needed on the effects of lycopene on the etiology of chronic disease.  相似文献   

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