Laboratory studies on zooplankton‐cyanobacteria interactions     

Winfried Lampert 《新西兰海洋与淡水研究杂志》2013,47(3):483-490

Laboratory studies on cyanobacteria‐zooplankton interactions have largely focused on the inadequacy of cyanobacteria as a food source. Some features of cyanobacteria can be regarded as anti‐herbivore defences. Large colonies of Aphanizomenon, Anabaena and Microcystis cannot be handled by zooplankton, but do not interfere seriously with the filtering process. Small colonies and filaments, however, may cause severe inhibition of the feeding process by mechanical interference. This reduces zooplankton growth, reproduction, and survival. Copepods, rotifers, and Bosmina are less affected by mechanical disturbance than cladocerans. If ingested, some cyanobacteria may be poorly digested or may not provide essential nutrients. Some cyanobacteria are reported to be toxic to zooplankton. Several strains of Microcystis produce an endotoxin, but the amount of toxin produced differs among strains and with the condition of Microcystis. Zooplankton encountering toxic cells cease feeding. Some evidence of an extra‐cellular herbivore deterrent was found for Anabaena. Thus, cyanobacteria may either be individually protected or may create an environment that is unfavourable for efficient grazers (e.g., Daphnia).  相似文献   

Sequence polymorphism in a marine bivalve (Perna canaliculus) orphan G protein‐coupled receptor gene: Preliminary description and possible implications     

Andrew E. Fidler  Helgi B. Schiöth  Robert Fredriksson 《新西兰海洋与淡水研究杂志》2013,47(4):953-964

  相似文献   

红鳍东方鲀(Takifugu rubripes)选育家系构建与早期标准化培育   总被引：1，自引：0，他引：1  

李伟业  马爱军  王新安  孟雪松  刘忠强  刘圣聪  邹杰  岳亮  张涛  熊再峰 《海洋与湖沼》2013,44(4):944-952

采用巢式设计方法和人工受精技术, 对红鳍东方鲀(Takifugu rubripes)选育家系的构建与标准化培育技术进行研究。按照1雄配2雌的原则, 选取养殖、野生和日本3个群体的红鳍东方鲀进行定向交配, 并对红鳍东方鲀早期阶段苗种进行了环境标准化和一、二、三、四级数量标准化培育。结果表明, 红鳍东方鲀亲鱼产卵量大, 对构建父系半同胞家系十分有利; 从4次数量标准化看, 每次各家系内鱼苗数量都较为集中, 各阶段各家系的成活率也较高, 但存在部分家系间数量差异显著; 经过4次数量标准化, 成功构建22个父系半同胞家系, 48个母系全同胞家系。对早期阶段家系构建和培育存在的问题, 进行了探讨并提出拟解决方法, 为大规模建立红鳍东方鲀家系提供参照。  相似文献   

微型异养鞭毛虫摄食选择性的研究进展     

黄凌风  林施泉  熊源  陆家昌  吴林南 《海洋学报》2013,35(2):1-8

微型异养鞭毛虫(HNF)是海洋微微型浮游生物的重要摄食者,通过摄食作用对后者的种类(或类群)组成、粒径分布、数量结构和营养价值等属性具有重要的影响,而这与HNF的摄食选择性有直接关系。对HNF摄食选择性的研究有助于深入了解HNF在海洋微食物环乃至整个海洋生态系统中的作用。就国际上已开展的HNF摄食选择性相关研究进行了回顾,分析和总结了影响HNF选择性摄食的关键因素,如食物大小、游动性、营养价值及食物细胞表面的生化结构特征等,并重点介绍了HNF摄食选择性形成的主要机制以及HNF的选择性摄食在调节海洋微微型浮游生物群落结构中的作用。  相似文献   

放牧制度对荒漠草原可萌发土壤种子库的影响   总被引：1，自引：0，他引：1  

闫瑞瑞  卫智军  辛晓平  刘红梅  杨静  乌仁其其格 《中国沙漠》2011,30(3):703-709

 以内蒙古苏尼特右旗短花针茅荒漠草原为研究对象,通过划区轮牧与自由放牧的比较试验,研究可萌发土壤种子库对不同放牧制度的响应。结果表明:①可萌发种子库物种组成在划区轮牧草地为11种,自由放牧草地为8种,封育禁牧区为9种,划区轮牧较自由放牧和禁牧有利于提高草地群落可萌发土壤种子库的植物种数以及多年生优良牧草;可萌发土壤种子库密度在封育禁牧区为(19 533.33±10 552.83)粒·m-2,划区轮牧区为(3 233.33±524.21)粒·m-2,自由放牧区为(2 553.60±2 152.48)粒·m-2,可萌发土壤种子库密度封育禁牧区显著高于划区轮牧区与自由放牧区,两放牧处理间无显著差异。②不同处理可萌发土壤种子库垂直分布有共同趋势, 有75.06%~83.19%分布在0~5 cm土层内,14.16%~21.68%分布在5~10 cm土层内,2.65%~4.90%分布在10~15 cm土层内,且不同土层可萌发土壤种子库密度均为封育禁牧区显著高于划区轮牧区与自由放牧区,两放牧处理间无显著差异。③划区轮牧区可萌发土壤种子库的丰富度指数和多样性指数高于自由放牧区。划区轮牧区和封育禁牧区可萌发土壤种子库组成的相似性系数最大,为0.857。  相似文献   

四川祁家河铅锌硫多金属矿选矿试验研究   总被引：1，自引：0，他引：1       下载免费PDF全文

石磊  赵华伦  杜新  雷力  邱允武 《地质找矿论丛》2012,27(1):125-129

对四川祁家河铅锌硫多金属矿采用优先浮选流程,实现了铅、锌、硫的有效分离回收,获得了的铅品位和回收率分别为55.50％和75.45％的铅精矿,锌的品位和回收率分别为50.58％和92.87％的锌精矿,硫的品位和回收率分别为47.22％和71.76％的硫精矿.  相似文献   

选择性压盖技术在纸质海图生产中的应用     

王斌  崔洪生  顾锦华 《海洋测绘》2008,28(1):62-64

利用数字海图数据直接出版纸质海图是提高纸制图生产效率的重要手段，但由于数字海图与纸质海图在编制原则和表现规范上的差异造成由数字图生产纸质图时，需要大量的手工修编，从而增加了工作量，延长了成图周期。采用一种新的制图理念，利用ArcInfo的选择性压盖技术，制作纸质图符号库，选择正确符号化顺序，从而实现纸质海图生产与数字海图生产同步，减少重复劳动，缩短成图周期，提高了工作效率。  相似文献   

The trophic roles of microzooplankton in marine systems   总被引：4，自引：1，他引：3  

Calbet  Albert 《ICES Journal of Marine Science》2008,65(3):325-331

  相似文献   

Reconstruction of environmental histories to investigate patterns of larval radiated shanny (Ulvaria subbifurcata) growth and selective survival in a large bay of Newfoundland     

Baumann  Hannes; Pepin  Pierre; Davidson  Fraser J.M; Mowbray  Fran; Schnack  Dietrich; Dower  John F 《ICES Journal of Marine Science》2003,60(2):243-258

  相似文献   

Resource Competition and Selective Grazing of Plankton in a Multispecies Pelagic Food Web Model*     

Roel Riegman  Bouwe R. Kuipers 《Marine Ecology》1994,15(2):153-164

Abstract. An idealized mathematical, multispecies model of the pelagic foodweb was used to explore the impact of resource competition, selective grazing, and species composition within each trophic level on the structure and functioning of a foodweb at a variety of light irradiance and nutrient levels. This concept is based on the general assumption that poorly edible species are poor competitors. The concept demonstrates that with increasing eutrophication, specialists in competition will be replaced by generalists and subsequently by poorly edible primary producers. Controlling factors not only determine the growth rate of primary producers but also select predators according to their ability to utilize the energy fixation of the system. Plankton community structure seems to adapt in such a way that the energy fixation rate of the system is optimized at a given set of nutrients and light. Red tides, dense algal blooms in shallow lakes and the varying results of biomanipulation in shallow lakes, can be explained by the concept of selective grazing. If this assumption is correct, the same ecosystem concept may be applicable for terrestrial ecosystems.  相似文献