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长江口鱼类食物网与营养结构的研究 总被引：4，自引：0，他引：4
鱼类食物网是海洋生态系统中物质循环与能量流动的重要途径,营养结构则是表明能量流动过程中不同消费者的营养水平以及消费者之间的营养关系,二者对研究海洋生态系统中鱼类捕食与被捕食、种间竞争、种群调节以及数量变动等都具有重要意义。但国内、外关于长江口鱼类食物网及营养结构的研究尚未见详细报道。
为探讨三峡工程对河口生态系统的影响,中国科学院海洋研究所于1985年9月至1986年8月对长江口及邻近海域进行了周年综合性本底调查,并对长江口鱼类食物类型作了简单的描述(刘瑞玉、罗秉征等,1987),本文根据以上资料对长江口60种主要鱼类的食物组成、摄食生态类型、食物网与营养结构进行了分析,以期为研究长江口生态系统的功能、生物生产过程以及合理开发利用长江口渔业资源提供科学依据。 相似文献
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全球赤潮生态学与海洋学（GEOHAB）国际合作计划 总被引：3，自引：0，他引：3
1 赤潮的一般特征海洋浮游藻类作为海洋食物网的基础环节 ,是海洋生态系统中的主要初级生产者。在海洋环境条件适宜的情况下 ,它们通常会迅速增殖 ,形成所谓的水华 ( Blooms) ,有时浮游植物的爆发性增殖会造成鱼类死亡 ,生态环境恶化 ,通过藻毒素污染海洋食物 ,从而对人类健康甚至生命造成威胁。国际科技界把这种现象称之为有害藻类水华 [Harmful AlgalBlooms ( HABs) ] ,通常情况下称为赤潮 ( Red Tides) ,其实这种叫法在科学上并不贴切。迄今为止 ,所记录到的赤潮生物 ( HAB Species)有 3 0 0多种 ,分别隶属于双鞭毛藻、其它鞭毛藻… 相似文献
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鱼类摄食生态研究的理论及方法 总被引：21，自引：1，他引：21
综合分析了鱼类摄食生态研究的理论，方法及其应用中的诸多问题：胃含物分析法，营养生境及食物重叠，食物链与食物网，营养结构与营养级，摄食器官的形态特征与摄食行为的关系，食物选择以及生理生太因子对鱼类摄食的影响；提出了食物排序的概念、优势度指数Ｄ及其判定公式，并以此比较客观地建立了摄食生态相似的鱼类群落主次食物的划分标准。 相似文献
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银鱼属小型的中上层鱼类,是沿岸海域、河口和湖泊的重要经济鱼类之一,主要分布在日本、朝鲜、苏联的亚洲沿岸、中国和越南。据报道,仅有1科8属17种。以我国产量最高,种类最多,达7属16种。九龙江口有尖头银鱼(Salanx acuticeps)、白肌银鱼(Leucasoma chinensis)和陈氏新银鱼(Neosalanx tangkahkeii),其中以尖头银鱼数量较大,占银鱼年产量的85%。有关尖头银鱼的食性研究,国内外未见专门报道。本文主要研究尖头银鱼的食料和食性,以便为九龙江口生态系统特别是食物网研究和开发利用该河口的银鱼渔业资源提供资料。 相似文献
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本研究对2011年春季和秋季在象山港海洋牧场采集的生物消费者及其食物源样品的碳、氮稳定同位素组成进行了分析,通过IsoSource模型计算该海域生物的食物网基础并利用氮稳定同位素数据计算消费者的营养级.结果表明:该海域生物消费者食物源的δ13C值范围介于-13.75％～-24.29％之间;根据δ13 C值可以将其食物源分为4类:浮游植物、大型海藻、悬浮颗粒有机物(POM)、沉积相颗粒有机物(SOM).浮游植物和SOM是该海域生物食物网的基础,对消费者的碳源贡献率(50.27％)比较大,大型海藻也是消费者的重要碳源(贡献率为35.5％),POM对消费者的碳源贡献率为13.7％.消费者的δ15 N值则介于5.40％ ～ 11.85％之间,消费者的营养级介于2.0～3.7级之间,不同食性的鱼类处于食物网中不同的地位,浮游生物食性的鱼类位于食物网的底端,游泳生物食性的鱼类处于食物链的上层. 相似文献
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东山湾鱼类食物网研究 总被引：17，自引：1，他引：17
本文分析了东山湾８５种经济鱼类的食物关系，结果表明，东山湾鱼类的食性类型可分为：浮游生物食性；底栖生物食性；游泳动物食性；浮游生物和底栖生物食性；底栖生物和游泳动物食性及浮游生物，底栖生物和游泳动物食性等６种，这些鱼类可分为４个营养级：（１）杂食性鱼类；（２）低级肉食性鱼类；（３）中级肉食性鱼类；（４）高级肉食性鱼类，其中低级肉食性鱼类占优势。东山湾 鱼类食物网的能量流动可简要归纳为６种途径，小公 相似文献
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黄海鱼类食物网的研究 总被引：80，自引：1，他引：80
于1985年3月—1986年10月和1988年5月间,对黄海海域40科69属80种鱼的食性及其相互关系进行了较系统地调查、分析。结果表明:1.黄海鱼类饵料分为4个生态类型;2.黄海鱼类摄食有明显的季节变化;3.黄海鱼类基本属于第二—第四营养级;4.日本鳀、脊尾褐虾、太平洋磷虾等优势饵料生物在黄海鱼类食物网中起着举足轻重的作用;5.黄海多数鱼类间的食物竞争关系基本是协调的。 相似文献
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Thomas E. Laidig Diana L. Watters Mary M. Yoklavich 《Estuarine, Coastal and Shelf Science》2009,83(4):629-637
In 2004, we surveyed demersal fishes and habitats on the continental shelf off central California (65–110 m depth) using the occupied submersible Delta. Our objectives were to estimate the relative abundance of habitats and to examine demersal fish species composition, diversity, density, and sizes relative to these habitats. A total of 112 transects were completed covering 32 km of seafloor. A higher density of fishes was estimated in boulder and cobble habitats than in mud and brachiopod beds. More than 80% of the fishes were small, measuring 20 cm or less in total length. Species with small maximum size (primarily pygmy rockfish, Sebastes wilsoni, and blackeye gobies, Rhinogobiops nicholsii) accounted for nearly half (49%) of the total number of 12,441 fishes. Most fishes were immature, with only 4 of 20 harvested species having more than 50% of the individuals larger than the size at first maturity. Our study area on the continental shelf may be an ontogenetic transition zone for immature fishes before they move to their adult habitat on the slope. Alternatively, historical fishing pressure may have contributed to the lack of large, mature fishes in the survey area. Understanding the importance of these habitats to fishes at various life stages will improve our ability to assess these deepwater fish stocks and effectively manage these living resources on an ecosystem basis. 相似文献
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《Marine Policy》2017
Groupers are highly targeted and vulnerable reef fishes. The effects of fishing pressure on the density of three reef fishes were investigated in 21 islands outside (n=15) and inside (n=6) a Marine Protected Area (MPA) at the Paraty Bay, Brazilian southeastern coast. Two valued groupers (Epinephelus marginatus and Mycteroperca acutirostris) and a non-target grunt (Haemulon aurolineatum) were studied. The total biomass of fish caught in each island was considered as a measure of current fishing pressure, while the island distance from the villages was considered as a measure of past fishing pressure. Fish densities were recordedin number and biomass. The biomass of M. acutirostris was inversely related to current fishing pressure, which did not affect the other two fishes. The density of E. marginatus increased with the island distance from one of the fishing villages, which indicated that past fishing may have had decreased the abundance of E. marginatus. Densities of the three fishes and fishing pressure did not differ between islands inside and outside the MPA. Data on fishing pressure, densities of groupers and coral cover were combined here to assign conservation scores to islands. A redefinition of MPA boundaries to reconcile fish conservation, fishing activities and fishers’ food security was proposed. 相似文献
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采用底层拖网法,用渔获率作为鱼类资源数量分布的指标,进行了杭州湾调查海域2012年5月(春季)、10月(秋季)2个季节的鱼类种类组成、区系特点、数量分布等研究。结果表明:(1)杭州湾海域春、秋两季共获得并鉴定出的鱼类有31种,隶属于9目15科,其中以石首鱼科和■虎鱼科的种类为最多,各有5种,分别占总种数的16.7%;鳀科鱼类次之,有4种,占总种数的13.3%,优势种有睛尾蝌蚪■虎鱼、龙头鱼、刀鲚、棘头梅童鱼;(2)根据鱼类适温性可将该海域的鱼类分为暖水性、暖温性和冷温性3种适温类型,以暖温性种类为主,暖水性种类次之,而冷温性种类极少,仅有1种;(3)根据其生态习性,可分为河口性、沿岸性和近海性3种生态类群;(4)渔获数量分布规律是春季在调查海域的内侧或者说中西部较高,而湾口较低,秋季则正好相反。 相似文献
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脂肪酸标记法是浮游动物食性研究的一种重要方法.将提取的脂质区分为中性脂和极性脂,可以进一步查明不同脂质在浮游动物食性研究中的作用.本研究通过分析不同脂质的脂肪酸构成,对2013年1月中国第29次南极考察期间在罗斯海采集的5种优势种桡足类的食性进行了研究.结果显示:5种桡足类的极性脂脂肪酸具有相似的组成,无法给出桡足类食性差异信息,食性信息主要体现于中性脂脂肪酸组成的差异.通过分析中性脂脂肪酸的组成信息,将5种桡足类的食性分为三类:Cala-noides acutus和Calanus propinquus主要摄食浮游植物,Metridia gerlachei及小型桡足类Oncaea curvata为杂食性种,Paraeuchaeta antarctica为肉食性种.本文的结果说明,在应用脂肪酸作为浮游动物食性标记的研究中,应尽量区分不同脂质种类的脂肪酸信息,从而得到更为精确的浮游动物食性信息. 相似文献
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鳜(Siniperca chuatsi)、大眼鳜(Siniperca kneri)、斑鳜(Siniperca schezeri)为鳜属中3种主要经济鱼类,具有较近的亲缘关系和相似的生活习性,但生长性状差异较大.为探索3种鳜鱼生长差异与基因差异间联系,以野生群体为材料,采用PCR扩增、电泳及测序等方法,对生长发育相关基因生长激素(GH)基因进行了多态性检测与分析.在第一内含子、第二内含子前段、第二内含子中段微卫星序列及第三内含子中均检测到多态性.各区域共检测到25种长度类型,其中4种为鳜与大眼鳜共有长度类型,3种为鳜、大眼鳜与斑鳜共有长度类型,其余18种为各物种特有长度类型.各区域长度类型共组成14种单倍型,无种间共有单倍型.序列长度差异主要由重复序列及DNA片段的插入或缺失形成.在第1内含子3'端-6位与第3内含子5'端+16位各发现一处靠近剪接位点的序列差异.根据多态性检测结果构建系统发育树,鳜与大眼鳜先聚为一枝.本研究可为进一步确认鳜鱼GH基因差异与生长性状间联系,并利用基因差异进行鳜鱼种质资源保护及分子育种奠定基础. 相似文献
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《African Journal of Marine Science》2013,35(1):421-437
Carnivorous zooplankton in the Benguela system have tended to be ignored by all but early taxonomists and a handful of recent researchers. An attempt is made here to address the importance of carnivores in this system but, because the database is poor, it was necessary to apply material from outside the region. The taxa covered include ctenophores, cnidarians (Scyphozoa and Hydrozoa, including Siphonophora), chaetognaths and hyperiid amphipods as well as such minor groups as pelagic gastropods and decapods. Most groups of carnivores within the Benguela are represented by only one or two "common" species. These tend to be epiplanktonic and generally concentrated inshore of the shelf-break, where their distributions are influenced by changes in local hydrography. Their densities frequently exceed those of herbivores. The dominant carnivores share a number of attributes: wide-ranging diets, high assimilation and growth efficiencies and mostly a Type I functional response to food concentration. They fall into two categories. The first is the gelatinous species, which have short lifespans and exhibit rapid growth and often massive reproductive response to high concentrations of food. They are patchily distributed and some appear to have behavioural traits that enable them to stay within localized patches of prey on which they may be dependent because of high metabolic costs. In the second category are crustacean predators and chaetognaths which have slower response times to the food environment but may have longer lifespans, lower daily maintenance needs and an ability to store lipids. They are less dependent on high densities of food organisms and can survive throughout winter, when gelatinous predators are rare. The effect of predation on abundance of copepods is estimated on the basis of both published and unpublished data. Should swarms of predators coincide with a critical gateway of zooplankton or larvae, then there may be total depletion. This applies especially to the nearshore zone of the West Coast and to semi-enclosed bays. The role of carnivorous zooplankton in the diets of commercially important fish species is stressed, but their importance in the regeneration of nutrients may be insignificant. 相似文献