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1.
Abstract— The microdistribution of ten numerically dominant species in a fish community at a rocky island in Lake Victoria was studied using invasive sampling. All were haplochromine cichlids. The community was characterized by high fish densities and by a dominance of Aufwuchs feeders . Species were non-randomly distributed, showing significant associations with water depth and other topographic parameters. Species occupied unique positions in a network of recurrent species groups. Niche partitioning through differential microdistribution was even more subtle than that reported for Lake Malawi's rock-dwelling cichlids. Species-specific microdistribution fitted qualitative predictions from ideal free distribution models with asymmetrical interference competition for food. No evidence was found for interspecific contest competition for space. Temporal niche shifts have been observed between periods of high and low water levels. Owing to a combination of reduced habitat availability with niche expansion in most species, niche overlap was larger during the lowwater period.  相似文献
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Abstract –  We studied the impact of two exotic salmonid species (brook trout, Salvelinus fontinalis and rainbow trout, Oncorhynchus mykiss ) on native brown trout ( Salmo trutta fario ) habitat, growth and survival. Habitat selection and vertical distribution between young-of-the-year of the three species were examined in a stream aquarium under different sympatric and allopatric combinations. In addition, similar species combinations were introduced in a Pyrenean mountain stream (southwest France) in order to extend laboratory results to growth and apparent survival. Both laboratory and field results indicated that rainbow trout significantly affected native brown trout habitat selection and apparent survival. On the contrary, brown trout habitat, growth and apparent survival were hardly affected by brook trout. These results support the idea that rainbow trout negatively influence native brown trout, and that competition could influence the outcome of fish biological invasions in freshwater ecosystems.  相似文献
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黄海中南部主要鱼种的生态位分析   总被引:4,自引:0,他引:4  
根据2006年黄海中南部4个季度月(1、4、8、10月)的渔业资源调查资料,运用定性、定量的方法分析了黄海中南部鱼类群落的种类组成、时空生态位宽度、时空生态位重叠以及优势种的季节变化,以期对该海域主要鱼种的生态位特征进行分析.结果表明,4个航次总共有鱼类57种,其中冬季39种,春季42种,夏季31种,秋季40种.4个航次共有相同鱼种22种,隶属于14科20属.时空生态位宽度值大于1的10个鱼种从大到小依次为黄鱼安鱼康Lophius litulon、小黄鱼Pseudosciaena polyactis、银鲳Pampus argenteus、七星底灯鱼Benthosema pterotum、小带鱼Trichiurus muticus、虻鲉Erisphex pottii、细纹狮子鱼Liparis tanakae、星康吉鳗Conger myriaster、白姑鱼Argyrosomus argentatus、带鱼Trichiurus haumela.这10种主要鱼类的生物量变动在黄海中南部受季节变化的影响是递增的.细纹狮子鱼与星康吉鳗的时空生态位重叠值最大,小带鱼与星康吉鳗的时空生态位重叠值最小.生态位宽度与相对重要性指数(IRI)相比,时空生态位宽度值最大的是黄鱼安鱼康,而IRI值最大的是鳀鱼,通过二者计算所得到主要鱼种在群落中的重要性排序不同.作者认为,生态位宽度与相对重要性指数(IRI)相比,能够更加全面的反映鱼类生物量在不同时间和空间尺度上的均匀度和变化情况.  相似文献
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鱼类生态形态学研究进展   总被引:2,自引:0,他引:2  
生态形态学(ecological morphology or ecomorphology)是一门比较的学科,是生物学和生态学的交叉领域.自从Karr和James[1]介绍"生态形态学"一词以来,对这个领域的研究兴趣稳步增长.在20世纪80年代以前,强调研究大量生态和形态变量之间的广泛联系,或者研究与Hutchinson生态位理论相一致的形态和生态格局.  相似文献
6.
博斯腾湖生态系统结构及其鱼载力分析   总被引:1,自引:0,他引:1       下载免费PDF全文
摘 要:新疆维吾尔自治区博斯腾湖生态系统结构较为简单。生态系统生产者由硅藻为主的浮游植物组成,构成博湖饵料生物的基础。淡水鱼类构成了生态系统消费者的主体。现有鱼群生态位分布较宽,鲢鱼、鳙鱼生态位重叠较多,池沼公鱼占有繁殖优势,鲈鱼和鲫鱼能够长期共存。根据不同深度水域的浮游植物生物量,运用ArcGIS软件计算博斯腾湖初级生产力为665091.07吨,理论鱼载力为4750.65吨。实际鱼载量远大于理论鱼载力,需要根据湖泊环境容纳量投放饵料。同时,建议考虑通过生态系统食物链的功能,适当地引进有制约小杂鱼习性的高位营养级的鱼类来维护水域生态系统的平衡,将湖泊内的小杂鱼转化成经济价值高的优质名特鱼类。  相似文献
7.
本文提出对大川河永生生物与虎嘉鱼生态位的初步研究结果:①大川河水生生物中藻类植物53属,浮游动物21属,水生昆虫14属,鱼类8属(9种)。②虎嘉鱼的生态位在大川河水生生物中处于能量的终极,食物链的顶端。  相似文献
8.
运用出现频率(F%)、尾数百分比(N%)、食物重叠指数(P)以及生境宽度(B)等指标分析了渤海日本和三疣梭子蟹的食性。结果表明,日本和三疣梭子蟹都属于底栖动物食性。主要饵料包括双壳类、底栖甲壳类、鱼类和头足类。日本碍食物生境宽度高于三疣梭子蟹。二者在各季节的食物重叠指数波动在0.39~0.53之间,属于中等重叠水平。摄食率都比较高,多在90%以上。  相似文献
9.
Two physical factors light or substrate (fibre glass, artificial vegetation, gravel and mud) were determined in a 24 m long artificial channel to have importance on the distribution of 33 tench 2+, mean size 11.8±0.9 cm S.L. For this purpose in five trials tench could select between the half of the channel occupied by their preferred light intensity (inferior to 10 lux) combined with the less preferred substrate (fibre glass) or the half with the combination of one of the substrates considered and higher light conditions (40 lux). Fish preferred, with a 100% frequency, the optimal light-less preferred substrate when compared with the combinations fibre glass, gravel and mud. When artificial vegetation was the substrate considered, tench selected the combination preferred substrate – non-optimal light intensity with a 98.26±2.68% frequency. This result changed when increasing light intensity up to 150 lux, avoiding the shading effect. We demonstrated that light has a bigger influence than substrate in juvenile tench habitat selection under controlled conditions.  相似文献
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