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排序方式: 共有123条查询结果,搜索用时 15 毫秒
1.
在宜黄开展对华南虎的野外调查,走访保护区范围内80%以上的村庄,大量华南虎在宜黄县境内的活动踪迹信息,表明宜黄境内有1~2个野生华南虎繁殖种群,数量5~8只.  相似文献   
2.
A 2 × 3 factorial feeding trial was conducted to determine effects of dietary Ca/P ratio and dietary microbial phytase on growth, mineral digestibility and vertebral mineralization in tiger puffer. The treatments consisted of three levels of Ca/P ratios (0.5, 1.0 and 1.5) combined either with phytase (2000 FTU kg?1 diet) or without supplementation, respectively. The Ca/P ratios were achieved by supplementing calcium at 0, 6 and 12 g kg?1 combined with the same level of inorganic P at 5 g kg?1. After a 50‐day feeding trial, puffer fish fed the diet at low Ca/P ratio (0.5) together with phytase had significantly higher growth rate and feed intake (FI) than other groups. Both dietary Ca/P ratio and phytase supplement were independent effects on plasma minerals and alkaline phosphatase. Interactive effect between both dietary treatments was observed on P and Zn contents in vertebrae and whole body. P and Zn digestibilities tended to increase with increased Ca/P ratio from 0.5 to 1.0, especially when phytase was supplemented. In conclusion, fish fed a diet with highest Ca/P ratio (1.5) showed the poorest growth performance and nutrients utilization. Dietary Ca/P ratio of 0.5 (without Ca supplement) with 2000 FTU phytase per kg would be the optimum combination in the diet of tiger puffer.  相似文献   
3.
傅文源 《野生动物》2009,30(5):231-233,244
在人工围栏的自然生境中,采用扫描取样法和焦点取样法对梅花山自然保护区"中国虎园"内13只华南虎(其中雌虎7只,雄虎6只)的采食行为进行了初步研究。结果表明,华南虎对采食时间、频率等受季节、生理状态、竞争等因素影响;采食行为在人工哺乳和自然哺乳成活的个体之间差异显著。  相似文献   
4.
Pond-breeding amphibians require aquatic and terrestrial habitats to complete their lifecycles, and preservation of both habitats is necessary for maintaining local populations. Current wetland regulations focus primarily on aquatic habitats, and criteria to define critical upland habitats and regulations to protect them are often ambiguous or lacking. We examined the association between the presence of seven pond-breeding amphibian species and the landscape composition surrounding 54 wetlands located within the Till Plains and the Glaciated Plateau ecoregions of Ohio, USA. We quantified landscape composition within 200 m of the wetland (“core terrestrial zone”) and the area extending from 200 m to 1 km from the wetland (“broader landscape context zone”). We constructed binary logistic regression models for each species, and evaluated them using Akaike Information Criterion. Presence of spotted salamanders (Ambystoma maculatum), Jefferson's salamander complex (A. jeffersonianum) and smallmouth salamanders (A. texanum) was positively associated with the amount of forest within the core zone. Presence of wood frogs (Rana sylvatica) was positively associated with the amount of forest within the core zone and the amount of forest within the broader landscape context zone. Presence of tiger salamanders (A. tigrinum tigrinum) was negatively associated with the cumulative length of paved roads within 1 km of the site, and presence of red-spotted newts (Notophthalmus v. viridescens) was negatively associated with the average linear distance to the five nearest wetlands. Overall salamander diversity was positively associated with the amount of forest within the core zone, and negatively associated with the presence of predatory fish and cumulative length of paved roads within 1 km of the site. Our results confirm the strong association between the structure of surrounding upland areas and amphibian diversity at breeding ponds, and stress the importance of preserving core terrestrial habitat around wetlands for maintaining amphibian diversity.  相似文献   
5.
Wild tigers are being annihilated. Tiger range countries and their partners met at the 1st Asian Ministerial Conference on Tiger Conservation in January 2010 to mandate the creation of the Global Tiger Recovery Program to double the number of tigers by 2022. Only 3200–3600 wild adult tigers remain, approximately half of the population estimated a decade ago. Tigers now live in only 13 countries, all of which are experiencing severe environmental challenges and degradation from the effects of human population growth, brisk economic expansion, rapid urbanization, massive infrastructure development and climate change. The overarching challenge of tiger conservation, and the conservation of biodiversity generally, is that there is insufficient demand for the survival of wild tigers living in natural landscapes. This allows the criminal activities of poaching wild tigers and their prey and trafficking in tiger derivatives to flourish and tiger landscapes to be diminished. The Global Tiger Recovery Program will support scaling up of practices already proven effective in one or more tiger range countries that need wider policy support, usually resources, and new transnational actions that enhance the effectiveness of individual country actions. The program is built on robust National Tiger Recovery Priorities that are grouped into themes: (i) strengthening policies that protect tigers; (ii) protecting tiger conservation landscapes; (iii) scientific management and monitoring; (iv) engaging communities; (v) cooperative management of international tiger landscapes; (vi) eliminating transnational illegal wildlife trade; (vii) persuading people to stop consuming tiger; (viii) enhancing professional capacity of policy-makers and practitioners; and (ix) developing sustainable, long-term financing mechanisms for tiger and biodiversity conservation.  相似文献   
6.
微卫星标记对红鳍东方鲀繁殖的指导应用及遗传分析   总被引:1,自引:0,他引:1  
利用已有设计的20个具有多态性的微卫星标记对16尾红鳍东方鲀亲鱼(10尾♂,6尾♀)的有效等位基因数、观望杂合度、期望杂合度、多态信息含量、遗传相似性系数、遗传距离等进行了检测.据此设计了10对亲鱼配组,获得10个子代家系.其中母本中16和8号的平均有效等位基因数和平均期望杂合度较其他亲本高,将其分别与3个父本配组,其他则参照遗传距离进行配组.于次年,对F110个家系的体质量、体长均值进行了比对,发现16♀与11♂配组得到的子代体质量、体长均值为最大.8♀和10♂配组得到的子代体质量、体长均值最小.结果表明,红鳍东方鲀子代杂种优势与亲本个体差异有关.  相似文献   
7.
半咸水人工湿地净化越冬养殖循环水的效果   总被引:4,自引:2,他引:2  
为拓展人工湿地在水产养殖上的应用,该文研究了半咸水人工湿地的循环水越冬系统中暗纹东方鲀越冬养殖效果和净化效能。结果表明,经过166d越冬养殖,暗纹东方鲀越冬成活率(76.94±13.87)%,饵料系数5.49±1.77。在无任何外源能源加温的情况下,系统水温保持在暗纹东方鲀幼鱼的生存最低温度以上。在半咸水环境下(7.6‰~9.9‰),人工湿地对养殖水有良好的净化效果:总氮去除率为30.5%、总氨氮为69.6%、亚硝酸盐为96.1%、硝酸盐为9.7%、总磷为18.4%、COD为38.8%、总悬浮物为79.7%,循环水经过人工湿地后水质符合国家渔业用水标准;越冬期间,越冬养殖池水质状况良好;除TN和NO3-N在越冬期间的去除率比在夏季的明显低外,其他主要污染物的去除率与夏季比较没有明显变化。在试验负载范围内,系统去除量随进水污染负载量的增加而增加;通过建立预测模型预测出湿地养殖面积比值0.36~0.97,与实际值1.26相比,养殖密度尚有提高的空间。因此,人工湿地能持续有效地去除暗纹东方鲀越冬循环水养殖系统中的主要污染物,说明该系统能在越冬养殖生产实际应用。  相似文献   
8.
9.
对两则《武松打虎》的译文从语言美学的角度进行比较与分析,认为两则译文虽然在文体的处理上、在表现人物特点的翻译手法上、在人物的塑造和体现原文折射出的文化意境上稍有差别,但均忠实地传达了原文的全部信息,原文的语言特点在译文中基本上都得到了再现。  相似文献   
10.
红鳍东方鲀仔鱼期摄食与生长的研究   总被引:8,自引:2,他引:8  
在水温 ( 1 6± 1 )℃条件下 ,红鳍东方 (Takifugurubripes)仔鱼孵出后 4d开始摄食 ,此时其卵黄囊体积由初孵时的 0 636mm3减少到 0 375mm3;1 2d时 ,卵黄完全耗尽。最高初次摄食率出现在卵黄耗尽时 ,可达 1 0 0 % ;仔鱼能维持 9d高达 90 %以上的初次摄食率。初次摄食强度最大值也出现在 1 2d。饥饿不可逆点 (PNR)出现在 1 5~ 1 6d。在内营养期日平均增长率为 0 2 1 7mm/d ;在PNR前的摄食期 ,饥饿仔鱼的日平均生长率为 0 0 1 7mm/d ;而摄食仔鱼的日平均生长率为 0 0 95mm/d ;PNR后至死亡前 ,饥饿仔鱼呈负增长 ,而摄食仔鱼的日平均生长率达 0 41 0mm/d。  相似文献   
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