泥鳅在不同水体中的食谱及对蚊幼虫摄食量的初步研究   总被引：5，自引：0，他引：5  

张世萍  朱庆红 《华中农业大学学报》1992,11(4):373-377

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武汉南湖摇蚊幼虫中国新记录   总被引：1，自引：0，他引：1  

郭先武 《华中农业大学学报》1994,13(6):615-620

本文记述了武汉南湖摇蚊幼虫中国新记录属、种。６个新记录种为美丽前突摇蚊Ｐｒｏｃｌａｄｉｕｓ （Ｐｓｉｌｏｔａｎｙｐｕｓ）ｂｅｌｌ－ｕｓ（Ｌｏｅｗ），毛突摇蚊Ｃｈａｅｔｏｃｌａｄｉｕｓ ｓｐ．，普隆蒂内曼摇蚊Ｔｈｉｅｎｅｍａｎｉｏｌａ ｐｌｏｅｎｅｎｓｉｓ Ｋｉｅｆｆｅｒ，伸足凯氏摇蚊Ｋｉｅｆｆｅｒｕｌｕｓ ｔｅｎｄｉｐｅｄｉｆｏｒｍｉｓ Ｇｏｅｔｇｈｅｂｕｅｒ，微小摇蚊Ｍｉｃｒｏｃｈｉｒｏｎｏｍｕ  相似文献   

Spawning success and early life history of longnose suckers in Great Lakes tributaries          下载免费PDF全文

Evan S. Childress  Rebecca Papke  Peter B. McIntyre 《Ecology of Freshwater Fish》2016,25(3):393-404

Fish eggs and larvae are often subject to very high mortality, and variation in early life survival can be important for population dynamics. Although longnose suckers (Catostomus catostomus) are widespread in northern North America, little is known about their early life history. We examined fecundity and early larval survivorship during sucker spawning events in three small Lake Michigan tributaries. Although egg deposition varied 25% among spawning events, estimated larval export to the lake varied over 25,000‐fold from around 1000 to 26 million. Based on variation in environmental conditions across years, it appears that spring flow and temperature may be important determinants of egg survival to larval outmigration. Larval age data suggest that most individuals that survived to outmigration hatched during a 2‐day period despite adult spawning across at least 10 days. Most larvae spent <2 weeks in the stream and emigrated around the time of transition from endogenous to exogenous feeding before substantial growth occurred. In two of three cases, larvae drifted exclusively at night; however, high drift rates occurred during both day and night in the case where larvae were very abundant, suggesting density‐dependent drift behaviour. Our results indicate that survival in tributary streams from egg deposition to larval export is highly variable in longnose suckers. These large differences in early life survival may translate into variability in recruitment, thereby influencing population structure and dynamics.  相似文献   

黑珍珠樱桃在黔北地区的生物学特性及栽培技术   总被引：2，自引：2，他引：0  

金方伦  向青云  敖学熙  韩成敏 《贵州农业科学》2010,38(3)

历经7年(2003-2009年)对黔北地区黑珍株樱桃进行了引种观察和栽培试验。结果表明:定植后第2年部分植株开花结果,第3年大部分植株开花结果,第4年植株普遍开花结果,第5～6年以后进入盛果期。植株抗病、抗虫性较强,同时抗低温、抗旱、抗裂果较强。在海拨800～1200m,平地、山地和坡地栽植生长结果均良好。并提出了采用高标准建园、配方施肥、合理修剪、保花保果、合理疏花疏果、有效防治病虫害和合理采收等配套的栽培措施。  相似文献   

“核桃黑”的防治技术     

张文虹 《陕西林业科技》2010,(3):47-49

核桃黑是由核桃举肢蛾（Atrijuglans hetaohei Yang）,黑斑病（Xanthomonas juglandis Dvwson）,桃蛀螟（Dichocrocis punctiferalis Guen＇ee）和核桃炭疽病（Colletotrichum gloeosporioides Penz）共同危害的结果。本文分析了发生危害的特点,提出了三项有效防治措施。  相似文献   

Effects of stocking density and algal concentration on the survival,growth and metamorphosis of Bobu Ivory shell,Babylonia formosae habei (Neogastropoda: Buccinidae) larvae     

Huaiping Zheng  Caihuan Ke  Zewen Sun  Shiqiang Zhou  Fuxue Li 《Aquaculture Research》2010,42(1):1-8

Independent and combined effects of stocking density and algal concentration on the survival, growth and metamorphosis of the Bobu Ivory shell Babylonia formosae habei larvae were assessed using a 5 × 5 factorial design with densities of 0.25, 0.5, 0.75, 1.00 and 1.50 larvae mL⁻¹ and algal concentrations of 5, 10, 15, 20 and 25 × 10⁴ cells mL⁻¹ in the laboratory. Larval growth, survival and metamorphosis were significantly affected by both the independent effects of stocking density and algal concentration and by their interaction. The highest per cent survival (72.5%) and metamorphosis (49.5%), fastest growth (41.57 μm day⁻¹) and shortest time to initial metamorphosis (10 days) all occurred at the lowest stocking density and the highest algal concentration. Both crowding and food limitation had independently negative impacts on the survival, growth and metamorphosis of larvae, and these negative impacts were further strengthened by the interaction of a higher stocking density and a lower algal concentration. Moreover, the results suggest that stocking density and algal concentration obviously played different roles in determining larval survival and growth. To maximize survival and growth, B. formosae habei larvae should be reared at a lower stoking density of 0.25 larvae mL⁻¹ and fed a higher algal concentration of 25 × 10⁴ cells mL⁻¹ in large-scale hatchery seed culture.  相似文献   

不同覆盖措施无公害清除五味子园杂草的试验     

刘士军 《防护林科技》2013,(12):39-40

通过对凤城市郊区北五味子园杂草种群分布情况的调查和实施不同覆盖措施清除杂草试验，结果表明：凤城市郊区五味子园杂草具有鲜明的季节特性和杂草分布不均匀特性，杂草滋生数量较大，对五味子植株生产影响较大；杂草主要通过草籽和串根繁殖；不同覆盖措施间控制杂草的效果差异极显著，以覆双层黑地膜取得的效果最好，杂草比对照减少99．80％。采取双层黑地膜覆盖技术是有效控制五味子园杂草滋生蔓延的最佳措施，能够达到彻底控制杂草的目的。  相似文献   

利用保健栽培技术防治烟草黑胫病的研究   总被引：3，自引：1，他引：2  

李勇  张定志 《现代农业科技》2011,(24):183+188

进行利用保健栽培防治烟草黑胫病的试验研究,结果表明:膜下小苗移栽的各项指标均优于其他处理,其防效达84.00%,烟叶鲜干比为7.00,上中等烟比例为90.76%,产量为2 382.00 kg/hm2。  相似文献   

温度对黑鲷无水保活工艺的影响          下载免费PDF全文

吴云辉  邱松林  蔡真珍  张媛  庞杰 《热带生物学报》2016,(3):314-317

比较了-2,0,2,4,6℃等5种不同无水保活温度下,黑鲷(Sparus macarocephlus)的成活率、O2消耗量、CO2排放量、血清皮质醇及肌糖原的变化趋势。结果表明:在0℃条件下,无水保活36 h后,黑鲷成活率为100%,0℃组在整个无水保活过程中耗氧量最少,CO2释放量上升最缓慢,其皮质醇含量始终接近正常值,因此,0℃为黑鲷最佳无水保活温度。  相似文献   

北部湾浮游幼虫群落结构及其环境适应性分析          下载免费PDF全文

王学锋  李纯厚  廖秀丽  贾晓平 《上海海洋大学学报》2010,(4):529-534

根据1998年2月至1999年5月在北部湾海域按季度进行的4个航次生态、环境综合调查资料,本文研究了北部湾海域浮游幼虫的主要类群及其季节变动。结果表明:北部湾海域浮游幼虫主要有15大类群;其中4类(长尾类幼虫、短尾类幼虫、口足类阿利玛幼虫、蛇尾类长腕幼虫)周年出现,其它为季节性出现。长尾类幼虫、口足类阿利玛幼虫、蛇尾类长腕幼虫、短尾类溞状幼虫、短尾类大眼幼虫及其它短尾类幼虫为优势类群。北部湾浮游幼虫的年丰度变化范围为0.02~7.65ind/m³,均值为0.50ind/m³,四季的丰度为夏季(0.86ind/m³)>春季(0.40ind/m³)>秋季(0.32ind/m³)>冬季(0.12ind/m³)。从春季到冬季整个浮游幼虫密集中心呈逆时针从湾的东北部向西北部海区移动,移至湾的中部后再返至西北部。K优势度曲线分析表明群落多样性由高到低依次为春季>冬季>夏季>秋季,总体上浮游幼虫群落多样性的季节差异不大。典范对应分析结果表明影响浮游幼虫栖息密度的主要因子是水温和pH,其次是盐度、溶解氧。  相似文献