若干生态因子对缢蛏稚贝生长和存活的影响     

许章程  韦信敏 《台湾海峡》1990,9(1):62-68

本文系在实验室条件下,研究用不同的饵料密度、稚贝密度、光照强度、底质以及这些因子相结合对缢蛏稚贝生长和存活的影响,从中找出缢蛏育苗的最佳培养条件,为人工或半人工育苗提供参考。  相似文献   

盐度对近江牡蛎幼虫生长及存活的影响     

薛凌展  阙华勇  张国范  杨笑波  方彰胜  高如承 《海洋科学》2007,31(9):73-77

采用室内培育手段,研究了盐度对近江牡蛎(Crassostrea rivularis)幼虫生长及存活的影响。将人工授精孵育的面盘幼虫分别置于盐度依次为16,25,30的砂滤海水中培育至眼点幼虫。每隔一天检测各盐度组幼虫的壳长、壳高和存活数量。结果表明,16盐度组的幼虫生长最快,25盐度组次之,30盐度组最慢。从受精后第14天开始,16盐度组幼虫的生长显著快于30盐度组(P<0.05)。在整个浮游幼虫阶段,高盐度组幼虫的存活率低于低盐度组,其中30盐度组的存活率最低。16和25盐度组在幼虫出现眼点之前均出现大量死亡现象,而30盐度组并没有出现大量死亡现象。上述结果说明,近江牡蛎幼虫经过高盐驯化,对高盐环境的抗性具有一定的提高。  相似文献   

BOOK REVIEWS     

《The Professional geographer》1986,38(2):195-222

Book Reviewed in this article: The Vanishing Farmland Crisis, Critical Views of the Movement to Preserve Agricultural Land . John Baden Protecting Farmlands . Frederick R. Steiner and John E. Theilacker Ecological Effects of Fire in South African Ecosystems . Peter de V. Booysen and Neil M. Tainton Geography in China . Wu Chuanjun , Wang Nailiang , Lin Chao and Zhao Songqiao Resource Inventory and Baseline Study Methods for Developing Countries . Francis Conant , Peter Rogers , Marion Baumgardner , Cyrus Mc Kell , Raymond Dasmann, and Priscilla Reining Principles of Remote Sensing . Paul J. Curran Famine As A Geographical Phenomenon . Bruce Currey and Graeme Hugo The Suburban Squeeze: Land Conversion and Regulation in the San Francisco Bay Area . David E. Dowall Senses of Place . John Eyles Uneven Development and the Geographical Transfer of Value . D. K. Forbes and P. J. Rimmer Issues in Wilderness Management . Michael Frome Land-use and Prehistory in South-east Spain , The London Research Series in Geography 8. Antonio Gilman and John B. Thornes with Stephen Wise Regions in Question, Space, Development Theory and Regional Policy . Charles Gore The Colorado River: Instability and Basin Management . William L. Graf Hazardous Waste Sites: The Credibility Gap . Michael R. Greenberg and Richard F. Anderson Peasants, Subsistence Ecology, and Development in the Highlands of Papua New Guinea . Lawrence S. Grossman Silver Cities: The Photography of American Urbanization, 1839-1915 Peter B. Hales Silicon Landscapes . Peter Hall and Ann Markusen Remaking Ibieca: Rural Life in Aragon under Franco . Susan F. Harding The European Energy Challenge: East and West . George W. Hoffman The Global Climate . John T. Houghton The Urban Jobless in Eastern Africa . Abel G. M. Ishumi . The Tourist: Travel in Twentieth-Century North America . John A. Jakle City and Society: An Outline for Urban Geography . R. J. Johnston Residential Segregation, The State and Constitutional Conflict in American Urban Areas . R. J. Johnston Accessibility and Utilization: Geographical Perspectives on Health Care Delivery . Alun E. Joseph and David R. Phillips To the Heart of Asia: The Life of Sven Hedin . George Kish North American Culture , Vol 1. Ary J. Lamme III Past and Present in the Americas: A Compendium of Recent Studies . John Lynch Ethnicity in Contemporary America: A Geographical Appraisal . Jesse O. Mc Kee The Shell Countryside Book . Richard Muir and Eric Duffey 1990 Planning Conference Series. Proceedings of the National Geographic Areas Conference . Proceedings of the Regional Geographic Areas Conferences Wood, Brick, and Stone: The North American Settlement Landscape . Vol. 2: Barns and Farm Structures . Allen G. Noble Bangladesh: Biography of a Muslim Nation . Charles Peter O'donnell  相似文献   

芒果嫁接成活气象条件及生产管理措施   总被引：3，自引：0，他引：3  

欧阳兆云  周冬梅  何德光 《气象科技》2010,38(1):133-135

利用芒果嫁接成活率多年分期物候观测以及同期的气象观测实况资料进行统计分析。结果表明,芒果嫁接成活率与嫁接后的接口愈合期气温成显著正相关,与光照、降水量、空气相对湿度相关不明显。建立了芒果嫁接成活率与嫁接后6天平均气温、最高气温回归方程,影响芒果嫁接成活的主要气象要素是日均温。个例分析表明芒果嫁接成活关键期即嫁接穗生理脆弱的接口愈合期,气温偏低或异常高温天气对芒果嫁接成活不利影响极大。讨论了依气象条件提高嫁接成活率注意事项,提出了相应的生产管理措施。  相似文献   

蓄水渗膜材料在造林中的应用研究     

谭敬  齐凯  张增志  李根柱 《干旱区地理》2005,28(3):357-361

从2001年始，以内蒙古干旱、半干旱区为试验区，研究蓄水渗膜材料水纤维和基体在不同土壤条件、不同栽培方案、不同时间、不同树种进行的造林试验。结果表明：经过3年的试验研究，提出了一套适应荒漠化地区应用的新材料在干旱区造林的工艺和技术方法。采用蓄水渗膜材料生态综合治理方案及植树方法，能够使原来的干旱区常规造林成活率由40％-70％提高到85％以上。  相似文献   

几种生态因子对尖刀蛏幼贝存活率和生长率的影响     

方军  李磊  陈琛  曾国权 《台湾海峡》2011,30(1):86-91

2008～2009年,在浙江省海洋水产养殖研究所永兴基地研究了底质、饵料、温度和盐度对平均壳长为32.28±3.98mm的尖刀蛏（Cultelles scalprum）幼贝存活率和生长率的影响.结果表明：尖刀蛏幼贝以软泥底质最佳,实验条件下存活率达到76.7%,其次为沙底质,存活率为71.7%,最差为硬泥底质,存活率仅为60.0%;几种易于大规模培养的微藻中,最适宜的饵料为牟氏角毛藻,实验条件下存活率达到90.0%,生长率达到25.9%,其次为球等鞭金藻和亚心形扁藻;尖刀蛏幼贝存活的适宜温度为10～30℃,最适生长温度为26～30℃;存活的适宜盐度为18～26,最适生长盐度为22.尖刀蛏与其他大多数沿岸贝类一样属于广温广盐性品种,其幼贝更适宜于在盐度较低的环境中生存.  相似文献   

四种单胞藻和海洋红酵母对刺参浮游幼虫生长与变态成活的影响     

张萍萍  李琪  孔令锋  于瑞海 《中国海洋大学学报(自然科学版)》2011,41(10):30-34

本实验研究4种单胞藻与海洋红酵母(Rhodomonas sp.)搭配以及单胞藻混合投喂对刺参浮游幼虫体长生长及变态存活率的影响。采用三角褐指藻(Phaeodactylum tricornutum)、小新月菱形藻(Nitzschia closteriumf.minutissima)、牟氏角毛藻(Chaetoceros muelleri)和等鞭金藻(Isochrysis galbana)与海洋红酵母分别以1∶0、0.8∶0.2、0.6∶0.4、0.4∶0.6、0.2∶0.8和0∶1的比例搭配投喂刺参浮游幼虫,观测浮游幼虫每天的体长变化以及变态成活率。结果表明,单胞藻与海洋红酵母以适当比例混合投喂能提高刺参幼虫的体长日增长率,单独投喂海洋红酵母的刺参变态成活率也显著高于单独投喂单胞藻组。采用2种单胞藻以0.5∶0.5的比例混合投喂浮游幼虫,结果表明牟氏角毛藻与小新月菱形藻混合投喂组刺参浮游幼虫的变态成活率高于牟氏角毛藻与等鞭金藻的混合组。  相似文献   

Gender,Work, and Household Survival in South Indian Fishing Communities: A Preliminary Analysis     

Holly M. Hapke 《The Professional geographer》2001,53(3):313-331

This article examines the interplay of gender, caste‐religion, and household survival strategy formation among Christian and Muslim fisher folk in the south Indian state of Kerala. The methodology consisted of surveys of forty‐one households in two villages in which data pertaining to male and female work patterns and other household level data were collected in the summer of 1999. My analysis demonstrates how particular ideologies of gender and work associated with different caste‐religion communities influence the strategies individual households adopt. I discuss intersections between gender and caste‐religion with other socioeconomic factors and illustrate the manner in which gender then gets reworked in particular ways in the course of economic transformation.  相似文献   

Artificial culture of amphioxus (Branchiostoma belcheri tsingtauense)     

Wu Xian-han  Zhang Bao-lu  Guo Zhen-yu  Qu Yan-mei 《中国海洋湖沼学报》2000,18(4):334-337

Mature amphioxus (Branchiostoma belcheri tsingtauense) collected by trawl in June, 1994 from Qingdao Shazikou sea area bottom sands, were cultured under controlled indoor conditions, where they spawned and their eggs were fertilized and hatched into larvae which gradually settled at the bottom and dug into the sands after 40-50 days culture in a water trough outdoors. The total survival rate of the larvae(LSR)was 5.5% before they went into the sands, 1.9% in 4 months, 0.7% in 10 months. The survival rate of the young fish which had dug into the sands (YSR) was 35.6% in 4 months, and 12.6% in 10 months. The amphioxus number tended to be constant from the 11th month on. In the first five months after incubation, the amphioxus body length increased by an average of about 1.5 mm a month, and about 0.4 mm a month from Dec. to May of next year. The maximum length after ten months was 24 mm; the average was about 11 mm. After two years culture in the water trough, the maximum length could reach 34-35 mm, when the amphioxus gonads began to develop.  相似文献   

Effects of larval density and salinity on the development of perch larvae (Perca fluviatilis L.)     

René Bein  Georg Ribi 《Aquatic Sciences - Research Across Boundaries》1994,56(2):97-105

We performed two experiments, one to test whether survival and initial swim bladder inflation of perchPerca fluviatilis are affected by population density (4 or 16 larvae 1^–1) or salinity (0, 0.6 and 1.2), and the second to test the salinity tolerance of larvae. In experiment 1, survival was higher at low larval densities and at salinities of 0.6 and 1.2 rather than in fresh water. Initial swim bladder inflation was not affected by salinity or density. Average survival of fry 24 days after hatching varied from 29.6% to 86.3%, but only an average of 19.2% of the hatched larvae had grown into viable fish with an inflated swim bladder. In experiment 2, survival varied from 19% to 49%, but was not significantly affected by salinities of up to 4.8. At a salinity of 9.6, only 2 out of 344 larvae survived.  相似文献